| 51. |
- Kangas, Maarit, et al.
(författare)
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Comparison of low-complexity fall detection algorithms for body attached accelerometers
- 2008
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Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 28:3, s. 285-291
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Tidskriftsartikel (refereegranskat)abstract
- The elderly population is growing rapidly. Fall related injuries are a central problem for this population. Elderly people desire to live at home, and thus, new technologies, such as automated fall detectors, are needed to support their independence and security. The aim of this study was to evaluate different low-complexity fall detection algorithms, using triaxial accelerometers attached at the waist, wrist, and head. The fall data were obtained from standardized types of intentional falls (forward, backward, and lateral) in three middle-aged subjects. Data from activities of daily living were used as reference. Three different detection algorithms with increasing complexity were investigated using two or more of the following phases of a fall event: beginning of the fall, falling velocity, fall impact, and posture after the fall. The results indicated that fall detection using a triaxial accelerometer worn at the waist or head is efficient, even with quite simple threshold-based algorithms, with a sensitivity of 97-98% and specificity of 100%. The most sensitive acceleration parameters in these algorithms appeared to be the resultant signal with no high-pass filtering, and the calculated vertical acceleration. In this study, the wrist did not appear to be an applicable site for fall detection. Since a head worn device includes limitations concerning usability and acceptance, a waist worn accelerometer, using an algorithm that recognizes the impact and the posture after the fall, might be optimal for fall detection.
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| 52. |
- Kangas, M., et al.
(författare)
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Comparison of real-life accidental falls in older people with experimental falls in middle-aged test subjects
- 2012
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Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 35:3, s. 500-505
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Tidskriftsartikel (refereegranskat)abstract
- Falling is a common accident among older people. Automatic fall detectors are one method of improving security. However, in most cases, fall detectors are designed and tested with data from experimental falls in younger people. This study is one of the first to provide fall-related acceleration data obtained from real-life falls. Wireless sensors were used to collect acceleration data during a six-month test period in older people. Data from five events representing forward falls, a sideways fall, a backwards fall, and a fall out of bed were collected and compared with experimental falls performed by middle-aged test subjects. The signals from real-life falls had similar features to those from intentional falls. Real-life forward, sideways and backward falls all showed a pre impact phase and an impact phase that were in keeping with the model that was based on experimental falls. In addition, the fall out of bed had a similar acceleration profile as the experimental falls of the same type. However, there were differences in the parameters that were used for the detection of the fall phases. The beginning of the fall was detected in all of the real-life falls starting from a standing posture, whereas the high pre impact velocity was not. In some real-life falls, multiple impacts suggested protective actions. In conclusion, this study demonstrated similarities between real-life falls of older people and experimental falls of middle-aged subjects. However, some fall characteristics detected from experimental falls were not detectable in acceleration signals from corresponding heterogeneous real-life falls.
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| 53. |
- Kangas, Maarit, et al.
(författare)
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Sensitivity and specificity of fall detection in people aged 40 years and over
- 2009
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Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 29:4, s. 571-574
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Tidskriftsartikel (refereegranskat)abstract
- About one third of home-dwelling people over 65 years of age fall each year. Falling, and the fear of falling, is one of the major health risks that affects the quality of life among older people, threatening their independent living. In our pilot study, we found that fall detection with a waist-worn triaxial accelerometer is reliable with quite simple detection algorithms. The aim of this study was to validate the data collection of a new fall detector prototype and to define the sensitivity and specificity of different fall detection algorithms with simulated falls from 20 middle-aged (40-65 years old) test subjects. Activities of daily living (ADL) performed by the middle-aged subjects, and also by 21 older people (aged 58-98 years) from a residential care unit, were used as a reference. The results showed that the hardware platform and algorithms used can discriminate various types of falls from ADL with a sensitivity of 97.5% and a specificity of 100%. This suggests that the present concept provides an effective method for automatic fall detection.
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| 54. |
- Khandelwal, Siddhartha, 1987-, et al.
(författare)
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Evaluation of the performance of accelerometer-based gait event detection algorithms in different real-world scenarios using the MAREA gait database
- 2017
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Ingår i: Gait & Posture. - Amsterdam : Elsevier. - 0966-6362 .- 1879-2219. ; 51, s. 84-90
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Tidskriftsartikel (refereegranskat)abstract
- Numerous gait event detection (GED) algorithms have been developed using accelerometers as they allow the possibility of long-term gait analysis in everyday life. However, almost all such existing algorithms have been developed and assessed using data collected in controlled indoor experiments with pre-defined paths and walking speeds. On the contrary, human gait is quite dynamic in the real-world, often involving varying gait speeds, changing surfaces and varying surface inclinations. Though portable wearable systems can be used to conduct experiments directly in the real-world, there is a lack of publicly available gait datasets or studies evaluating the performance of existing GED algorithms in various real-world settings.This paper presents a new gait database called MAREA (n=20 healthy subjects) that consists of walking and running in indoor and outdoor environments with accelerometers positioned on waist, wrist and both ankles. The study also evaluates the performance of six state-of-the-art accelerometer-based GED algorithms in different real-world scenarios, using the MAREA gait database. The results reveal that the performance of these algorithms is inconsistent and varies with changing environments and gait speeds. All algorithms demonstrated good performance for the scenario of steady walking in a controlled indoor environment with a combined median F1score of 0.98 for Heel-Strikes and 0.94 for Toe-Offs. However, they exhibited significantly decreased performance when evaluated in other lesser controlled scenarios such as walking and running in an outdoor street, with a combined median F1score of 0.82 for Heel-Strikes and 0.53 for Toe-Offs. Moreover, all GED algorithms displayed better performance for detecting Heel-Strikes as compared to Toe-Offs, when evaluated in different scenarios. © 2016 Elsevier B.V.
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| 55. |
- Khandelwal, Siddhartha, 1987-, et al.
(författare)
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Novel methodology for estimating Initial Contact events from accelerometers positioned at different body locations
- 2018
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Ingår i: Gait & Posture. - Amsterdam : Elsevier. - 0966-6362 .- 1879-2219. ; 59, s. 278-285
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Tidskriftsartikel (refereegranskat)abstract
- Identifying Initial Contact events (ICE) is essential in gait analysis as they segment the walking pattern into gait cycles and facilitate the computation of other gait parameters. As such, numerous algorithms have been developed to identify ICE by placing the accelerometer at a specific body location. Simultaneously, many researchers have studied the effects of device positioning for participant or patient compliance, which is an important factor to consider especially for long-term studies in real-life settings. With the adoption of accelerometery for long-term gait analysis in daily living, current and future applications will require robust algorithms that can either autonomously adapt to changes in sensor positioning or can detect ICE from multiple sensors locations.This study presents a novel methodology that is capable of estimating ICE from accelerometers placed at different body locations. The proposed methodology, called DK-TiFA, is based on utilizing domain knowledge about the fundamental spectral relationships present between the movement of different body parts during gait to drive the time-frequency analysis of the acceleration signal. In order to assess the performance, DK-TiFA is benchmarked on four large publicly available gait databases, consisting of a total of 613 subjects and 7 unique body locations, namely, ankle, thigh, center waist, side waist, chest, upper arm and wrist. The DK-TiFA methodology is demonstrated to achieve high accuracy and robustness for estimating ICE from data consisting of different accelerometer specifications, varying gait speeds and different environments. © 2017 Elsevier B.V.
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| 56. |
- Larsson, Johan, et al.
(författare)
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Increased double support variability in elderly female fallers with vestibular asymmetry.
- 2015
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Ingår i: Gait & Posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 41:3, s. 820-824
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Tidskriftsartikel (refereegranskat)abstract
- There is a broad consensus on the coupling of deteriorating gait and vestibular asymmetry, which has proved predictive of falls in the elderly. To date, research on this coupling remains inconclusive and has not focused specifically on fallers. In the present study, differences in gait variability were examined in a population of elderly females with fall-related wrist fractures, divided into samples with positive (N=28, 73±9 years) and negative head-shaking tests (N=6, 67±9 years). Swing, stance, and double support time variability were measured in preferred speed walking using GAITRite(®) and statistically evaluated in multivariate analysis of covariance with age as covariate. Results showed overall greater gait variability for the positive nystagmus group (p=0.03) despite non-significant adjustment of the covariate (p=0.18). In post-hoc analysis, the effect on variability in double support time emerged as a significant and large contributor to this difference (p=0.009, ηp(2)=0.20). Conversely, the ability of swing and stance time variability to discriminate between groups was both non-significant and small (p=0.25, ηp(2)=0.04 and p=0.34, ηp(2)=0.03 respectively). We believe that the increased variability might stem from a strategic use of double support to re-stabilize from balance perturbations during gait. To some extent, these results diverge from previous findings and need to be reassessed in future studies.
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| 57. |
- Larsson, Johan, et al.
(författare)
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Vestibular asymmetry increases double support time variability in a counter-balanced study on elderly fallers
- 2016
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Ingår i: Gait & Posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 45, s. 4-31
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Tidskriftsartikel (refereegranskat)abstract
- Vestibular asymmetry is a common cause of dizziness in the elderly, for whom it precipitates the risk of falling. Previous studies have shown that those with vestibular asymmetry displayed an altered variability in double support time (DST) compared to controls. However, swing time (SwT) variability findings are conflicting. In this study, we investigated if vestibular asymmetry might be causally connected to increased DST variability. We studied a group of eight elderly fallers with wrist fractures across three months, during which time four of them regained vestibular symmetry while four others developed an asymmetry. We evaluated the variability of DST and SwT, both when the participants suffered from vestibular asymmetry and when they did not. On average, variability in DST was significantly greater by 2.38 %CV (coefficient of variation) when participants scored positive for vestibular asymmetry compared to when not, t(5)=4.39, p=0.01, ξ=1.67. In contrast, SwT variability differed non-significantly by 0.44 %CV when participants had tested positive versus negative for vestibular asymmetry, t(5)=-0.87, p=0.39, ξ=-0.29. As a possible rationale for our results, we propose that increased DST variability may be the result of a re-stabilization strategy. Further research on DST variability and its correlation to the duration of vestibular asymmetry is recommended.
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| 58. |
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| 59. |
- Ledin, Torbjörn, 1962-, et al.
(författare)
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Effects of postural disturbances with fatigued triceps surae muscles or with 20% additional body weight
- 2004
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Ingår i: Gait & Posture. - 1879-2219 .- 0966-6362. ; 19:2, s. 184-193
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Tidskriftsartikel (refereegranskat)abstract
- One of the main issues for balance control is the ability to generate enough forces to execute motions and uphold stability. This study aimed to investigate whether induced fatigue of the triceps surae muscles and decreased muscle force due to temporary additional body weight affected the ability to withstand balance perturbations. Another aim was to examine whether postural control adaptation over time was able to compensate for the changes induced by fatigue and additional body weight. Eleven normal subjects were exposed to vibratory proprioceptive stimulation during three test conditions; a baseline test during normal condition; when the body weight was increased by 20%, by adding additional weight load; and when the triceps surae, muscles were fatigued. The tests were performed both with eyes open and closed. The body movements were evaluated by analyzing the anteroposterior and lateral torques induced towards the supporting surface measured with a force platform. Postural control was substantially affected both by the additional body weight, and by muscle fatigue in the triceps surae muscles. The anteroposterior and lateral body sway were larger both with added weight and fatigued muscles compared with the baseline test during quiet stance. However, the body sway induced by the vibratory stimulation was significantly larger with additional body weight compared with when the triceps surae muscles were fatigued. The differences between the test conditions were mostly pronounced during tests with eyes closed and in the high frequency body sway (>0.1 Hz). Postural control adaptation was able to reduce but not fully compensate for the changes induced by fatigue and additional body weight. Several hypotheses could account for these observations. (1) Fatigued muscles are less sensitive to muscle vibration, (2) muscle fatigue alters the muscle contractile efficiency and thus alters the ability to produce high-frequency, short-latency responses to balance perturbations. (C) 2003 Elsevier B.V. All rights reserved.
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| 60. |
- Leviäkangas, Aleksi, et al.
(författare)
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Associations of accelerometer-estimated free-living daily activity impact intensities with 10-year probability of osteoporotic fractures in adults.
- 2024
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Ingår i: Gait & Posture. - 1879-2219. ; 112, s. 22-32
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Tidskriftsartikel (refereegranskat)abstract
- Accelerometers are used to objectively measure physical activity; however, the relationship between accelerometer-based activity parameters and bone health is not well understood. This study examines the association between accelerometer-estimated daily activity impact intensities and future risk estimates of major osteoporotic fractures in a large population-based cohort.Participants were 3165 adults 46 years of age from the Northern Finland Birth Cohort 1966 who agreed to wear a hip-worn accelerometer during all waking hours for 14 consecutive days. Raw accelerometer data were converted to resultant acceleration. Impact magnitude peaks were extracted and divided into 32 intensity bands, and the osteogenic index (OI) was calculated to assess the osteogenic effectiveness of various activities. Additionally, the impact peaks were categorized into three separate impact intensity categories (low, medium, and high). The 10-year probabilities of hip and all major osteoporotic fractures were estimated with FRAX-tool using clinical and questionnaire data in combination with body mass index collected at the age of 46 years. The associations of daily activity impact intensities with 10-year fracture probabilities were examined using three statistical approaches: multiple linear regression, partial correlation, and partial least squares (PLS) regression.On average, participants' various levels of impact were 8331 (SD = 3478) low; 2032 (1248) medium; and 1295 (1468) high impacts per day. All three statistical approaches found a significant positive association between the daily number of low-intensity impacts and 10-year probability of hip and all major osteoporotic fractures. In contrast, increased number of moderate to very high daily activity impacts was associated with a lower probability of future osteoporotic fractures. A higher OI was also associated with a lower probability of future major osteoporotic fractures.Low-intensity impacts might not be sufficient for reducing fracture risk in middle-aged adults, while high-intensity impacts could be beneficial for preventing major osteoporotic fractures.
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| 61. |
- Lim, Yi Huey, et al.
(författare)
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Postural control adaptation to optic flow in children and adults with autism spectrum disorder
- 2019
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Ingår i: Gait & Posture. - : Elsevier. - 0966-6362 .- 1879-2219. ; 72, s. 175-181
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Tidskriftsartikel (refereegranskat)abstract
- Background: Sensory reweighting is important for humans to flexibly up-weigh and down-weigh sensory information in dynamic environments. There is an element of time involved in the sensory reweighting process. A longer time spent on sensory reweighting may increase the destabilizing effect of postural control. Individuals with autism spectrum disorder (ASD) are reported to have poor postural control. It is uncertain if a different sensory reweighting process underlies the postural control deficit in children and adults with ASD.Research question: To explore the sensory reweighting capability in ASD, the present study examined whether the temporal domains of postural control differed in children and adults, with and without ASD under various optic flow conditions.Methods: Thirty-three children (8–12 years old) and 33 adults (18–50 years old) with and without ASD underwent quiet standing in six radial optic flow conditions. Each condition lasted for 60 s and was shown twice to all participants. For each optic flow condition, changes in postural response within-trial and between-trials were measured.Results: Under various optic flow illusions, both children with and without ASD took a longer time to restore their posture compared with adults with and without ASD. Nonetheless, all groups demonstrated comparable abilities to adjust their posture to one that is close to the baseline position after one exposure to the optic flow stimulation.Significance: The present study showed that the temporal domains of postural control under different optic flow conditions were similar between individuals with and without ASD from the same age group. The ability to down-weigh visual information efficiently comes with the developmental progression of the sensory reweighting system. These findings suggest that the sensory reweighting process does not elucidate the postural control deficits in individuals with ASD and thus alternative explanations to determine the underlying mechanism for postural instability are needed.
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| 62. |
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| 63. |
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| 64. |
- Maiwald, Christian, et al.
(författare)
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The effect of intracortical bone pin application on kinetics and tibiocalcaneal kinematics of walking gait
- 2017
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Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 52, s. 129-134
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Tidskriftsartikel (refereegranskat)abstract
- Gait analysis using bone anchored markers requires local anaesthesia, which may affect subjects gait patterns.Kinetic and kinematic variables were collected using two protocols (skin vs. bone anchored markers).No systematic differences were found between the two protocols.We conclude that the validity of the recorded variables is not affected by local anaesthesia.Bone anchored markers using intracortical bone pins are one of the few available methods for analyzing skeletal motion during human gait in-vivo without errors induced by soft tissue artifacts. However, bone anchored markers require local anesthesia and may alter the motor control and motor output during gait. The purpose of this study was to examine the effect of local anesthesia and the use of bone anchored markers on typical gait analysis variables. Five subjects were analyzed in two different gait analysis sessions. In the first session, a protocol with skin markers was used. In the second session, bone anchored markers were added after local anesthesia was applied. For both sessions, three dimensional infrared kinematics of the calcaneus and tibia segments, ground reaction forces, and plantar pressure data were collected. 95% confidence intervals and boxplots were used to compare protocols and assess the data distribution and data variability for each subject. Although considerable variation was found between subjects, within-subject comparison of the two protocols revealed non-systematic effects on the target variables. Two of the five subjects walked at reduced gait speed during the bone pin session, which explained the between-session differences found in kinetic and kinematic variables. The remaining three subjects did not systematically alter their gait pattern between the two sessions. Results support the hypothesis that local anesthesia and the presence of bone pins still allow a valid gait pattern to be analyzed.
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| 65. |
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| 66. |
- Modig, Fredrik, et al.
(författare)
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Study I: Effects of 0.06% and 0.10% blood alcohol concentration on human postural control.
- 2012
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Ingår i: Gait & Posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 35:3, s. 410-418
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Tidskriftsartikel (refereegranskat)abstract
- Alcohol intoxication causes many accidental falls presented at emergency departments, with the injury severity often related to level of blood alcohol concentration (BAC). One way to evaluate the decline in postural control and the fall risk is to assess standing stability when challenged. The study objective was to comprehensively investigate alcohol-related impairments on postural control and adaptive motor learning at specific BAC levels. Effects of alcohol intoxication at 0.06% and 0.10% BAC were examined with posturography when unperturbed or perturbed by calf vibration. Twenty-five participants (mean age 25.1years) were investigated standing with either eyes open or closed. Our results revealed several significant findings: (1) stability declined much faster from alcohol intoxication between 0.06% and 0.10% BAC (60-140%) compared with between 0.0% and 0.06% BAC (30%); (2) sustained exposure to repeated balance perturbations augmented the alcohol-related destabilization; (3) there were stronger effects of alcohol intoxication on stability in lateral direction than in anteroposterior direction; and (4) there was a gradual degradation of postural control particularly in lateral direction when the balance perturbations were repeated at 0.06% and 0.10% BAC, indicating adaptation deficits when intoxicated. To summarize, alcohol has profound deteriorating effects on human postural control, which are dose dependent, time dependent and direction specific. The maximal effects of alcohol intoxication on physiological performance might not be evident initially, but may be revealed first when under sustained sensory-motor challenges.
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| 67. |
- Modig, Fredrik, et al.
(författare)
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Study II: Mechanoreceptive sensation is of increased importance for human postural control under alcohol intoxication.
- 2012
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Ingår i: Gait & Posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 35:3, s. 419-427
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Tidskriftsartikel (refereegranskat)abstract
- Standing postural stability relies on input from visual, vestibular, proprioceptive and mechanoreceptive sensors. When the information from any of these sensors is unavailable or disrupted, the central nervous system maintains postural stability by relying more on the contribution from the reliable sensors, termed sensory re-weighting. Alcohol intoxication is known to affect the integrity of the vestibular and visual systems. The aim was to assess how mechanoreceptive sensory information contributed to postural stability at 0.00% (i.e. sober), 0.06% and 0.10% blood alcohol concentration (BAC) in 25 healthy subjects (mean age 25.1 years). The subjects were assessed with eyes closed and eyes open under quiet standing and while standing was perturbed by repeated, random-length, vibratory stimulation of the calf muscles. Plantar cutaneous mechanoreceptive sensation was assessed for both receptor types: slowly adapting (tactile sensitivity) and rapidly adapting (vibration perception). The correlation between recorded torque variance and the sensation from both mechanoreceptor types was calculated. The recorded stability during alcohol intoxication was significantly influenced by both the tactile sensation and vibration perception of the subjects. Moreover, the study revealed a fluctuating association between the subjects' vibration perception and torque variance during balance perturbations, which was significantly influenced by the level of alcohol intoxication, vision and adaptation. Hence, one's ability to handle balance perturbations under the influence of alcohol is strongly dependent on accurate mechanoreceptive sensation and efficient sensory re-weighting.
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| 68. |
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| 69. |
- Murans, Girts, et al.
(författare)
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Kinematic and kinetic analysis of static sitting of patients with neuropathic spine deformity
- 2011
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Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 34:4, s. 533-538
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Tidskriftsartikel (refereegranskat)abstract
- Wheelchair dependent children with neuropathic and neuromuscular diseases have up to 90% risk for progressive spine deformities. An unbalanced sitting can induce progression of spinal and pelvic deformities. Many current clinical assessment methods of sitting of such patients are semi-quantitative, or questionnaire-based. A 3D movement analysis offers quantitative and objective biomechanical analysis of sitting. The aim was to validate a method to describe quiet sitting and differences between patients and controls as well as to apply the methodology for pre- and post-operative comparison. The analysis was performed on 14 patients and 10 controls. Four patients were retested after spine surgery. Seat load asymmetry was up to 30% in the patient group comparing to maximum 7% in the control group. The asymmetric position of Ground Reaction Force vector between left and right sides was significant. Plumb line of cervical 7th vertebra over sacral 1st was different only in rotation. The location of Common Center of Pressure relative to inter-trochanteric midpoint was more anterior in controls than in patients. Pelvic inclination in patients was smaller, the obliquity and rotation was similar. There were no significant differences between patients and controls of the thorax position. Results with more changes in the seat-loading domain in comparison with posture indicate good postural control compensation of spinal deformity induced disequilibrium despite neuromuscular disease in the background. The comparison of the pelvic obliquity data from kinematics and X-ray showed good correlation. The four patients tested postoperatively improved after surgery.
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| 70. |
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| 71. |
- Naili, J. E., et al.
(författare)
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The centre of mass trajectory is a sensitive and responsive measure of functional compensations in individuals with knee osteoarthritis performing the five times sit-to-stand test
- 2018
-
Ingår i: Gait & Posture. - : Elsevier. - 0966-6362 .- 1879-2219. ; 62, s. 140-145
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to evaluate whether the trajectory of the body's Centre of Mass (CoM) is a sensitive and responsive measure of functional compensations in individuals with knee osteoarthritis (OA) performing the Five Times Sit-to-Stand test (5STS). This prospective study included 21 individuals with OA and 21 age- and gender-matched controls. Motion analysis data was collected while participants performed the 5STS, one month prior and one year after total knee arthroplasty (TKA). Pain was evaluated using a visual analogue scale. Repeated measures ANOVAs were used to evaluate (1) differences in the area under the curve (AUC) of CoM trajectories, and (2) the effect of number of sit-to-stand cycles on the AUC. Preoperatively, individuals with OA displayed a larger contralateral shift (p = 0.009) and forward displacement of the CoM (p < 0.004) than controls. Postoperatively, CoM trajectories of OA individuals were not statistically different from controls. However, upon comparison of specific cycles, OA individuals displayed a larger forward displacement during the final cycle. Pain was significantly reduced postoperatively (p = 0.001). The CoM trajectory appears to be a sensitive and responsive measure of functional compensations. The increased contralateral shift of the CoM represents a strategy to reduce pain by unloading the affected knee. Postoperatively, when pain was substantially reduced, OA individuals were comparable to controls. The increased forward CoM displacement characterises a strategy to reduce muscular effort by reducing the required knee extension moment. Postoperatively, OA individuals were comparable to controls in all cycles but the last, possibly suggesting residual muscle weakness.
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| 72. |
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| 73. |
- Nedergård, Heidi, et al.
(författare)
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Inclination angles of the ankle and head relative to the centre of mass identify gait deviations post-stroke
- 2020
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Ingår i: Gait & Posture. - : ELSEVIER IRELAND LTD. - 0966-6362 .- 1879-2219. ; 82, s. 181-188
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Tidskriftsartikel (refereegranskat)abstract
- Background: Whole-body movement adjustments during gait are common post-stroke, but comprehensive ways of quantifying and evaluating gait from a whole-body perspective are lacking.Research question: Can novel kinematic variables related to Center of Mass (CoM) position discriminate side asymmetries as well as coordination between the upper and lower body during gait within persons post-stroke and compared to non-disabled controls?Methods: Thirty-one persons post-stroke and 41 age-matched non-disabled controls walking at their self-selected speed were recorded by 3D motion capture. The Ankle-CoM Inclination Angle (A-CoMIA) and the Head-CoM Inclination Angle (H-CoMIA) defined the angle between the CoM and the ankle and the head, respectively, in the frontal plane. These angles and their angular velocities were compared between groups, and with regard to motor impairment severity during all phases of the gait cycle (GC) using a functional interval-wise testing analysis suitable for curve data. Upper and lower body coordination was assessed using crosscorrelation.Results: The A-CoMIA was symmetrical between body sides in persons post-stroke but larger compared to controls. The angular velocity of A-CoMIA also differed when compared to controls. The H-CoMIA was consistently asymmetrical in persons post-stroke and larger than in controls throughout the stance phase. There were only minor group differences in the angular velocity of H-CoMIA, with some side asymmetry in persons post-stroke. The A-CoMIA of the non-affected side, and the HCoMIA, discriminated between persons with more severe impairments compared to those with milder impairments post-stroke. The variables showed strong cross correlations in both groups.Significance: The A-CoMIA and Head-CoMIA discriminated post-stroke gait from non-disabled, as well as motor impairment severity. These variables with the advantageous curve analysis during the entire GC add valuable whole-body information to existing parameters of post-stroke gait analysis through assessment of symmetry and upper and lower body coordination.
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| 74. |
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| 75. |
- Nilsson, Kjell-Åke, 1956-
(författare)
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Detecting post-operative change in gait function using principal component analysis in subjects with cerebral palsy
- 2006
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Ingår i: Gait & Posture. - : Elsevier. - 0966-6362 .- 1879-2219. ; 24, s. 152-153
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Principal components analysis is a multivariate statistical method that has been used in gait analysis. One example of use of the method is the production of The Gillette Gait Index. This index, indicating normality in gait function, has been presented and validated by previous authors. According to suggestions made by these authors, the index could potentially be used to evaluate change in gait function after surgical intervention in subjects with cerebral palsy. The Gillette Gait Index was calculated using principal components analysis for nineteen individuals with cerebral palsy (5 hemiplegics, 13 diplegics and 1 quadriplegic; mean age 16 years, range 10-31 years) in a retrospective study. The change in index value per individual from the pre- to the postoperative situations was compared to the evaluation of change made by an experienced clinician. Agreement was evaluated using Cohen´s kappa ( k ), resulting in a value of k=0.406, which is usually considered to be a fair to moderate level of agreement.
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| 76. |
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| 77. |
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| 78. |
- Nordin, Ellinor, et al.
(författare)
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Changes in step-width during dual-task walking predicts falls
- 2010
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Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 32:1, s. 92-97
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to evaluate whether gait pattern changes between single- and dual-task conditions were associated with risk of falling in older people. Dual-task cost (DTC) of 230 community living, physically independent people, 75 years or older, was determined with an electronic walkway. Participants were followed up each month for 1 year to record falls. Mean and variability measures of gait characteristics for 5 dual-task conditions were compared to single-task walking for each participant. Almost half (48%) of the participants fell at least once during follow-up. Risk of falling increased in individuals where DTC for performing a subtraction task demonstrated change in mean step-width compared to single-task walking. Risk of falling decreased in individuals where DTC for carrying a cup and saucer demonstrated change compared to single-task walking in mean step-width, mean step-time, and step-length variability. Degree of change in gait characteristics related to a change in risk of falling differed between measures. Prognostic guidance for fall risk was found for the above DTCs in mean step-width with a negative likelihood ratio of 0.5 and a positive likelihood ratio of 2.3, respectively. Findings suggest that changes in step-width, step-time, and step-length with dual tasking may be related to future risk of falling. Depending on the nature of the second task, DTC may indicate either an increased risk of falling, or a protective strategy to avoid falling.
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| 79. |
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| 80. |
- Patel, Mitesh, et al.
(författare)
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The effect of foam surface properties on postural stability assessment while standing.
- 2008
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Ingår i: Gait & Posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 28, s. 649-656
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Tidskriftsartikel (refereegranskat)abstract
- A common assessment of postural control often involves subjects standing on a compliant surface, such as a foam block, to make balance tests more challenging. However, the physical properties of the foam block used by different researchers can vary considerably. The objective of this study was to provide an initial approach for investigating whether two of the foam properties, i.e. density and elastic modulus, influenced recorded anteroposterior and lateral torque variance with eyes open and eyes closed. Thirty healthy adults (mean age 22.5 years) were assessed with posturography using three different types of foam block placed on a force platform. These blocks were categorised: firm foam, medium foam and soft foam by their elastic modulus. To investigate the spectral characteristics of recorded body movements, variance values were calculated for total movements, movements <0.1Hz and movements >0.1Hz. Results showed that anteroposterior and lateral torque variances >0.1Hz were larger when standing on the firm foam compared with medium and soft foam and in turn were larger on the medium foam compared with the soft foam with eyes closed. Moreover, GLM and correlation analysis demonstrated that the properties of the foam blocks affected anteroposterior torque variance >0.1Hz and lateral torque variance in all frequency ranges. In addition, the stabilising effect of vision in the anteroposterior direction had a greater influence when the subjects' stability was increasingly challenged by the support surface, as illustrated by the higher torque variance values. In conclusion, caution should be taken when analysing balance deficits with foam test setups, because the foam properties may influence the recorded body movements.
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| 81. |
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| 82. |
- Raaben, Marco, et al.
(författare)
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Real-time visual biofeedback during weight bearing improves therapy compliance in patients following lower extremity fractures
- 2018
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Ingår i: Gait & Posture. - : ELSEVIER IRELAND LTD. - 0966-6362 .- 1879-2219. ; 59, s. 206-210
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Tidskriftsartikel (refereegranskat)abstract
- Background: Individuals with lower extremity fractures are often instructed on how much weight to bear on the affected extremity. Previous studies have shown limited therapy compliance in weight bearing during rehabilitation. In this study we investigated the effect of real-time visual biofeedback on weight bearing in individuals with lower extremity fractures in two conditions: full weight bearing and touch-down weight bearing. Methods: 11 participants with full weight bearing and 12 participants with touch-down weight bearing after lower extremity fractures have been measured with an ambulatory biofeedback system. The participants first walked 15 m and the biofeedback system was only used to register the weight bearing. The same protocol was then repeated with real-time visual feedback during weight bearing. The participants could thereby adapt their loading to the desired level and improve therapy compliance. Results: In participants with full weight bearing, real-time visual biofeedback resulted in a significant increase in loading from 50.9 +/- 7.51% bodyweight (BW) without feedback to 63.2 +/- 6.74% BW with feedback (P=0.0016). In participants with touch-down weight bearing, the exerted lower extremity load decreased from 16.7 +/- 9.77 kg without feedback to 10.27 +/- 4.56 kg with feedback (P=0.0718). More important, the variance between individual steps significantly decreased after feedback (P=0.018). Conclusions: Ambulatory monitoring weight bearing after lower extremity fractures showed that therapy compliance is low, both in full and touch-down weight bearing. Real-time visual biofeedback resulted in significantly higher peak loads in full weight bearing and increased accuracy of individual steps in touch-down weight bearing. Real-time visual biofeedback therefore results in improved therapy compliance after lower extremity fractures.
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| 83. |
- Rennie, Linda, et al.
(författare)
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The reliability of gait variability measures for individuals with Parkinson's disease and healthy older adults - The effect of gait speed.
- 2018
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Ingår i: Gait & posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 62, s. 505-509
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Tidskriftsartikel (refereegranskat)abstract
- Step-to-step variability is a marker of reduced motor control and a frequently studied outcome measure in neurodegenerative disorders such as Parkinson's disease (PD) as compared to healthy older adults (HOA). To challenge motor control of gait, walking should be tested at different gait speeds. Good reliability is essential, and gait variability estimates show good reproducibility when sampled at normal gait speed. The aim was therefore to investigate if gait variability could be reliably sampled at slow and fast speeds for individuals with PD and HOA by evaluating test-retest reliability.29 (14 males) subjects with idiopathic PD, Hoehn &Yahr 2 (n=18) and 3,≥60years, and 25 age matched HOAwere included. Spatiotemporal gait data was collected (GAITRite) during slow, normal, and fast walking on two occasions.Measurement error was lowest for gait variability estimates based on 40 steps in both groups. This was true across all speeds in HOA, but only for normal and fast gait speeds in the PD cohort. Due to increased homogeneity in the variability estimates intraclass correlation coefficients (ICC) were low for HOA, except for step width variability. In the PD cohort ICCs were good to excellent for temporal- and step width gait variability across speeds.HOA demonstrated reliable gait variability estimates across all speeds, whereas Individuals with PD were reliable at normal and fast gait speeds only Estimates should be based on at least 40 steps. Step width variability was overall the most reliable variable across groups and speed conditions.
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| 84. |
- Rennie, Linda, et al.
(författare)
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The validity of the Gait Variability Index for individuals with mild to moderate Parkinson's disease.
- 2017
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Ingår i: Gait & posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 54, s. 311-317
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Tidskriftsartikel (refereegranskat)abstract
- Increased step-to-step variability is a feature of gait in individuals with Parkinson's disease (PD) and is associated with increased disease severity and reductions in balance and mobility. The Gait Variability Index (GVI) quantifies gait variability in spatiotemporal variables where a score ≥100 indicates a similar level of gait variability as the control group, and lower scores denote increased gait variability. The study aim was to explore mean GVI score and investigate construct validity of the index for individuals with mild to moderate PD. 100 (57 males) subjects with idiopathic PD, Hoehn & Yahr 2 (n=44) and 3, and ≥60 years were included. Data on disease severity, dynamic balance, mobility and spatiotemporal gait parameters at self-selected speed (GAITRite) was collected. The results showed a mean overall GVI: 97.5 (SD 11.7) and mean GVI for the most affected side: 94.5 (SD 10.6). The associations between the GVI and Mini- BESTest and TUG were low (r=0.33 and 0.42) and the GVI could not distinguish between Hoehn & Yahr 2 and 3 (AUC=0.529, SE=0.058, p=0.622). The mean GVI was similar to previously reported values for older adults, contrary to consistent reports of increased gait variability in PD compared to healthy peers. Therefore, the validity of the GVI could not be confirmed for individuals with mild to moderate PD in its current form due to low associations with validated tests for functional balance and mobility and poor discriminatory ability. Future work should aim to establish which spatiotemporal variables are most informative regarding gait variability in individuals with PD.
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| 85. |
- Riad, Jacques, et al.
(författare)
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Anatomical and dynamic rotational alignment in spastic unilateral cerebral palsy
- 2020
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Ingår i: Gait and Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 81, s. 153-158
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Tidskriftsartikel (refereegranskat)abstract
- Background: Even in mild unilateral cerebral palsy increased internal hip rotation can be noted on physical- and gait examination. The influence of spasticity on femoral growth in the transverse plane is not clear. These deviations and asymmetry in movement pattern may negatively affect efficiency of gait and cause psychological concerns about appearance. Research question: Is increased internal hip rotation on the involved side in mild unilateral CP common and is there compensatory external pelvic rotation to keep foot progression symmetrical? Methods: This prospective study included 45 individuals with unilateral cerebral palsy, mean age 17.7 (13.0−24.0) years. All were Gross Motor Function Classification Level I. Physical examination, three-dimensional gait analysis and magnetic resonance imaging for assessment of rotational alignment was performed. Results: On physical examination internal hip rotation was mean 50.6 (SD 10.4) degrees on the involved side and 44.3 (SD 10.3) on the non-involved side, p = 0.001. In gait analysis calculating the whole gait cycle, internal hip rotation was mean 2.3 (6.2) degrees on the involved side, and on the non-involved side external 1.8 (7.6) degrees, p = 0.004. Increased external pelvic rotation was noted on the involved side, mean 2.0 (4.3) degrees with corresponding internal rotation on the non-involved side, mean 3.6 (4.4), p = 0.001. There was no difference in foot progression, p = 0.067, with mean 5.1 (8.6) and 3.9 (6.4) external respectively. Magnetic resonance imaging revealed femoral torsion on the involved side mean 17.3 (11.3) degrees compared to 11.4 (10.8) on the non-involved side, p = 0.001. Significance: Transverse plane asymmetry in the femur was noted in mild unilateral cerebral palsy. Increased anatomical and dynamic internal rotation was compensated for by external pelvic rotation. Rotational malalignment may contribute to gait deviations in this mild group and should be part of the overall assessment. © 2020 Elsevier B.V.
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| 86. |
- Riad, Jacques, et al.
(författare)
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Arm posture score and arm movement during walking : A comprehensive assessment in spastic hemiplegic cerebral palsy
- 2011
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Ingår i: Gait & Posture. - : Elsevier B.V.. - 0966-6362 .- 1879-2219. ; 33:1, s. 48-53
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Tidskriftsartikel (refereegranskat)abstract
- Patients with hemiplegic cerebral palsy often have noticeably deviant arm posture and decreased arm movement. Here we develop a comprehensive assessment method for the upper extremity during walking.Arm posture score (APS), deviation of shoulder flexion/extension, shoulder abduction/adduction, elbow flexion/extension and wrist flexion/extension were calculated from three-dimensional gait analysis. The APS is the root mean square deviation from normal, similar to Baker's Gait Profile Score (GPS)[1].The total range of motion (ROM) was defined as the difference between the maximum and minimum position in the gait cycle for each variable. The arm symmetry, arm posture index (API) was calculated by dividing the APS on the hemiplegic side by that on the non-involved side, and the range of motion index (ROMI) by dividing the ROM on the hemiplegic side by that on the non-involved side.Using the APS, two groups were defined. Group 1 had minor deviations, with an APS under 9.0 and a mean of 6.0 (95% CI 5.0–7.0). Group 2 had more pronounced deviations, with an APS over 9.0 and a mean of 13.1 (CI 10.8–15.5) (p=0.000). Total ROM was 60.6 in group 1 and 46.2 in group 2 (p=0.031). API was 0.89 in group 1 and 1.70 in group 2 (p<0.001). ROMI was 1.15 in group 1 and 0.69 in group 2 (p=0.003).APS describes the amount of deviation, ROM provides additional information on movement pattern and the indices the symmetry. These comprehensive objective and dynamic measurements of upper extremity abnormality can be useful in following natural progression, evaluating treatment and making prognoses in several categories of patients.
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| 87. |
- Rusaw, David, 1978-, et al.
(författare)
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Development of a limits of stability protocol for use in transtibial prosthesis users : Learning effects and reliability of outcome variables
- 2017
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Ingår i: Gait & Posture. - : Elsevier. - 0966-6362 .- 1879-2219. ; 58, s. 539-545
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Tidskriftsartikel (refereegranskat)abstract
- The aims of this study were to empirically quantify reliability and learning effects of a Limits of Stability protocol for transtibial prosthesis users. Outcome variables from center of pressure and center of mass were tested on: 1) multiple test repetitions within a single test occasion; and 2) between multiple test occasions. Trantibial prosthesis users (n=7) and matched controls (n=7) executed five trials of the Limits of Stability protocol on two occasions per day, on two consecutive days. Inter-trial learning effects and reliability of outcomes extracted via center of mass and center of pressure were evaluated utilizing standard biomechanics laboratory equipment. Reliability was good to excellent except the reaction time variable which was poor (Pooled 95%CI of ICC=0.248-0.484). An inter-trial learning effect was present in directional control for prosthesis users when the first trial was included in analysis (center of mass: 95%CI of r=0.065-0.239; center of pressure: 95%CI of r=0.076-0.249). The use of standard biomechanics lab equipment can produce reliable results for the Limits of Stability protocol. Researchers should be aware of low reliability of reaction time variable in the protocol assessed and should execute at least one practice trial prior to that which is used in subsequent analysis.
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| 88. |
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| 89. |
- Schellenbach, Michael, et al.
(författare)
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Adult age differences in familiarization to treadmill walking within virtual environments
- 2010
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Ingår i: Gait & Posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 31:3, s. 295-299
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Tidskriftsartikel (refereegranskat)abstract
- We assessed age-related differences in adults in familiarization to treadmill walking within virtual environments (VE), and examined whether treadmill walking after familiarization resembles overground walking. Seventeen younger and 17 older adults walked at preferred speed on an overground walkway and afterwards walked at the same speed for 20 min on a treadmill coupled to a VE. A motion capture system was used to measure spatio-temporal gait parameters. On the treadmill, both younger and older adults initially displayed decreased step length and increased step width, cadence, and time in double support relative to overground walking. Except for time in double support, step characteristics approached overground walking-behavior with a negatively accelerated trend. After 15 min of treadmill walking, changes became minor corresponding to less than 1% deviations to individuals' overground walking. At the end of familiarization, average differences in step length, cadence, and double support relative to overground walking were reduced to less than 5 percent in both age groups. For step width, younger adults approximated overground walking after 20 min more closely than older adults, probably reflecting larger initial differences between treadmill and overground walking among older adults. We conclude (a) that 20 min of familiarization to treadmill walking in a VE are sufficient to reach stable walking patterns resembling those observed in overground walking, but that some differences between the two settings remain, especially in older adults; (b) that sufficient familiarization to the treadmill is needed to ascertain the validity and generalizability of comparisons between younger and older adults. (C) 2009 Elsevier B.V. All rights reserved.
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| 90. |
- Seidel, David, et al.
(författare)
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Measurement of stressful postures during daily activities : An observational study with older people
- 2011
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Ingår i: Gait & Posture. - : Elsevier. - 0966-6362 .- 1879-2219. ; 34:3, s. 397-401
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Tidskriftsartikel (refereegranskat)abstract
- This study measured the postures of older people during cooking and laundry. A sample of men and women aged 75+ years (n=27) was recruited and observed in a home-like environment. Postures were recorded with a measurement system in an objective and detailed manner. The participants were videotaped to be able to see where 'critical' postures occurred, as defined by a trunk inclination of ≥60°. Analysis of data was facilitated by specially developed software. Critical postures accounted for 3% of cooking and 10% of laundry, occurring primarily during retrieving from and putting in lower cabinets, the refrigerator, laundry basket or washing machine as well as disposing into the waste bin. These tasks involve a great variation in postural changes and pose a particular risk to older people. The results suggest that the use of stressful postures may decrease efficiency and increase fatigue, eventually leading to difficulties with daily activities. The specific tasks identified during which critical postures occurred should be targeted by designers in order to improve the activities. A few examples are given of how better design can reduce or eliminate some of the postural constraints.
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| 91. |
- Stensdotter, Ann-Katrin, et al.
(författare)
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Altered postural control strategies in quiet standing more than 20 years after rupture of the anterior cruciate ligament
- 2016
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Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 46, s. 98-103
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To explore long-term consequences of anterior cruciate ligament (ACL) rupture on postural sway and control strategies during bilateral quiet standing, in subjects treated with or without reconstructive surgery compared to uninjured controls. Method: 70 individuals who had unilateral ACL rupture 23 +/- 2.4 years ago (33 received ACL reconstructive surgery, ACL(R), and 37 had physiotherapy only, ACL(PT)) and 33 uninjured matched controls (CTRL) (mean age 46 +/- 5.3) stood quietly with eyes closed for 3 min on a firm and on a compliant surface, respectively. Center of pressure (CoP) was registered with a force plate and postural sway was calculated from center of mass (CoM) derived from 3D kinematics. Sway density (SD) analyses of CoP assessed distance and duration of stable phases. The torque controlling postural sway was estimated from CoP-CoM. Results: Comparisons across conditions to CTRL revealed larger CoP-CoM-area in ACLR (p = 0.017, Cl: 10.95, 143.10), but not in ACL(PT). Mean distance between SD-peaks was greater for ACLR (p < 0.001, Cl: 1.73, 5.31) than for ACLRT (p = 0.006, Cl: 0.56, 4.12) relative to CTRL. Duration of SD -peaks was smaller for both ACLR and ACLRT (p < 0.001, Cl: 4.04, 1.23 and 3.82, 1.03, respectively) compared to CTRL. CoM-area in the ACL-groups did not differ from CTRL. Conclusions: ACL-injured subjects demonstrated greater postural control efforts than CTRL but without significant differences in postural sway. Control efforts were thus not directly associated with sway and further research should be focused on variance in postural control strategies.
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| 92. |
- Stensdotter, Ann-Katrin, et al.
(författare)
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Postural control in quiet standing in patients with psychotic disorders
- 2013
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Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 38:4, s. 918-922
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Tidskriftsartikel (refereegranskat)abstract
- There is evidence that patients with psychotic conditions display greater center of pressure (CoP) displacement during quite standing than healthy subjects, but the underlying impairments in the control mechanisms are uncertain. The aim of this study was to identify the nature of possible impairments in the control of posture by modulation of visual and kinesthetic information during quiet standing. Center of pressure (CoP) data and whole-body kinematics of the center of mass (CoM) were recorded during quite standing on a firm surface with eyes open and with eyes closed, and standing with eyes open on a yielding surface. During all three conditions, patients displayed greater migration of CoM and CoP-CoM, a measure related to ankle joint torque, whereas CoP-frequency (MPF) was similar in patients and healthy subjects. Our results suggested that greater postural sway in patients may depend on disproportionally large ankle joint torque without corresponding increase in frequency. Furthermore, interactions between groups and conditions suggested that the patients made less use of visual information for postural control than the healthy subjects.
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| 93. |
- Stensdotter, Ann-Katrin, et al.
(författare)
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Postural sway in single-limb and bilateral quiet standing after unilateral total knee arthroplasty
- 2015
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Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 41:3, s. 769-773
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To investigate whether total knee arthroplasty (TKA) was associated with stability in single-limb stance and whether reduced stability in single-limb stance was associated with increased postural sway in bilateral quiet standing.Methods: 3D kinematics for center of mass was used to assess postural sway in 23 subjects with TKA and 23 controls. Tests included bilateral quiet standing with and without vision and on a compliant surface, and single-limb stance.Results: 30% of the subjects in the TKA group were unable to maintain single-limb stance for 20 s on any leg. Of the 70% in the TKA group able to stand on one leg, mean sway velocity in the medio-lateral direction was marginally higher for the prosthetic side (p = .02), but no differences were found between the TKA and the control group in single-limb stance. Performance in bilateral quiet standing was similar in TKA-subjects, able as well as unable to stand on one leg, and controls. Reduced quadriceps strength in the contralateral leg, higher BMI, and older age predicted failure to maintain single-limb stance.Conclusion: In subjects able to stand on one leg, performance was considered comparable between the prosthetic and contralateral side and between groups. Inability to stand on one leg did not affect postural sway in bilateral quiet standing. The results suggest that inability to maintain single-limb stance is explained by reduced physical capacity rather than the knee condition in itself. The present study emphasizes the importance of physical activity to improve strength and functional capacity.
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| 94. |
- Stokes, V P, et al.
(författare)
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From stride period to stride frequency.
- 1998
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Ingår i: Gait & posture. - 1879-2219. ; 7:1, s. 35-38
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Tidskriftsartikel (refereegranskat)abstract
- The stride-cycle frequency of gait data is often estimated by taking the inverse of the average stride-cycle time (stride period) over several stride-cycles. We derive the density function of the stride-cycle frequency frequency (stride frequency) and describe some of its properties. We also show the conditions under which the inverse of the mean stride period is a 'good' estimate of the mean stride frequency. Copyright 1998 Elsevier Science B.V.
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| 95. |
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| 96. |
- Tjernström, Fredrik, et al.
(författare)
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Adaptation of postural control to perturbations-a process that initiates long-term motor memory.
- 2002
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Ingår i: Gait & Posture. - 1879-2219. ; 15:1, s. 75-82
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Tidskriftsartikel (refereegranskat)abstract
- The objective was to investigate postural control adaptation during daily repeated posturography with vibratory calf stimulation. The posturography was performed with eyes open and closed daily for 5 days and after 90 days on 12 healthy subjects. The postural control adaptation could be described as two separate processes, a rapid adaptation during the test progress and a long-term habituation between consecutive test days. The adaptive improvements gained during the 5 days consecutive testing, largely remained 90 days later but seemed restricted to the same test situation. The findings suggest that balance rehabilitation should include a variety of repeated exercises, which are sufficiently long to induce habituation.
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| 97. |
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| 98. |
- Tjernström, Fredrik, et al.
(författare)
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Romberg ratio in quiet stance posturography-Test to retest reliability.
- 2015
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Ingår i: Gait & Posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 42:1, s. 27-31
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Tidskriftsartikel (refereegranskat)abstract
- We investigated test to retest reliability and intraindividual variability of Romberg ratios in quiet stance posturography. Thirty-six healthy young adults (17 males, 19 females aged 15-38 years) were divided into 3 groups with different time-intervals between consecutive trials (20min, 3h and 24h respectively). Each group performed 5 posturography recordings in a randomized order of eyes open (EO) or closed (EC)+once after 3 months. We measured the torque variance in posturography and calculated Romberg ratios. Total postural sway as well as sway above and below 0.1Hz was analyzed.
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| 99. |
- Toots, Annika, et al.
(författare)
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Backward relative to forward walking speed and falls in older adults with dementia
- 2022
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Ingår i: Gait & Posture. - : Elsevier. - 0966-6362 .- 1879-2219. ; 96, s. 60-66
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Tidskriftsartikel (refereegranskat)abstract
- Background: Adults with dementia have a high risk of falls and fall-related injuries. A greater slowing of backward walking speed (BWS) relative to forward (FWS) has been indicated with older age, and slower BWS has been related to an increased risk of falls. Similarly, slow BWS relative to FWS has been observed in people with dementia.Research question: Is slower BWS, and slower BWS relative to FWS associated with increased risk of prospective falls in older adults with dementia?Methods: In total, 52 women and 12 men with dementia living in nursing homes, mean age 86 years, and mean Mini-Mental State Examination score of 14.2 points were included. BWS and FWS was measured over 2.4 m, and the directional difference (DD) calculated (100*((FWS-BWS)/FWS)). Falls were followed for 6 months by review of fall incident reports in electronic medical records at nursing homes and the regional healthcare provider.Results: Altogether, 95 falls occurred with mean incidence rate 3.1 falls per person-years. Of included participants, 15 (23%) fell once, and 17 (27%) fell twice or more. In negative binomial regression analyses, greater DD was associated with lower prospective incidence fall rate ratio, IRR (IRR= 0.96, p < .001), while BWS was not (IRR= 0.04, p = .126).Significance: In this study of adults with dementia, slower BWS was not associated with prospective falls. However, slower BWS relative to forward (greater DD) was associated with fewer falls, and possibly a protective response. This is novel research, yet results are promising and indicate that assessing walking speed in multiple directions may inform fall risk in adults with dementia.
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| 100. |
- Toots, Annika, et al.
(författare)
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Exercise effects on backward walking speed in people with dementia : a randomized controlled trial
- 2021
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Ingår i: Gait & Posture. - : Elsevier. - 0966-6362 .- 1879-2219. ; 85, s. 65-70
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Tidskriftsartikel (refereegranskat)abstract
- Background: Multidirectional walking, including backward walking, is integral to daily activities, and seems particularly challenging in older age, and in people with pathology affecting postural control such as dementia.Research Question: Does exercise influence backward walking speed in people with dementia, when tested using habitual walking aids and without, and do effects differ according to walking aid use?Methods: This study included 141 women and 45 men (mean age 85 years) with dementia from the Umeå Dementia and Exercise (UMDEX), a cluster-randomized controlled trial study set in 16 nursing homes in Umeå, Sweden. Participants were randomized to a High-Intensity Functional Exercise (HIFE) program targeting lower limb strength-, balance and mobility exercise or to a seated attention control activity. Blinded assessors measured 2.4-meter usual backward walking speed, at baseline, 4 - (intervention completion) and 7-month follow-up; tested 1) with habitual walking aids allowed, and 2) without walking aids.Results: Linear mixed models showed no between-group effect in either backward walking speed test at 4 or 7 months; test 1) 0.005 m/s, P = .788 and –0.006 m/s, P = .754 and test 2) 0.030 m/s, P = .231 and 0.015 m/s, P = .569, respectively. In interaction analyses, exercise effects differed significantly between participants who habitually walked unaided compared with those that used a walking aid at 7 months (0.094 m/s, P = .027).Significance: In this study of older people with dementia living in nursing homes, the effects of exercise had no overall effects on backwards walking speed. Nevertheless, some benefit was indicated in participants who habitually walked unaided, which is promising and merits further investigation in future studies.
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