| 1. |
- Ledin, Torbjörn, 1962-, et al.
(author)
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Effects of postural disturbances with fatigued triceps surae muscles or with 20% additional body weight
- 2004
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In: Gait & Posture. - 1879-2219 .- 0966-6362. ; 19:2, s. 184-193
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Journal article (peer-reviewed)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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| 2. |
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| 3. |
- Gutierrez-Farewik, Elena M., et al.
(author)
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Centre of mass motion during gait in persons with myelomeningocele
- 2003
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In: Gait & Posture. - 0966-6362 .- 1879-2219. ; 18:2, s. 37-46
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Journal article (peer-reviewed)abstract
- The movement of the centre of mass in the vertical and lateral directions during gait in children with myelomeningocele was analyzed. The children were classified into five groups depending on the successive paresis of lower limb muscle groups and compared to a control group. In the groups with. dorsi- and plantarflexor weakness, the excursions increased and an anterior trend in the centre of mass was observed. In the groups with additional abductor paresis, the lateral excursion was highest and the vertical excursion low due to increased transverse and frontal motion and reduced sagittal motion. With further paresis of the hip extensors, the centre of mass was more posteriorly positioned due to compensatory trunk extension. Improved understanding of individual children's solutions to their muscle paresis can be obtained by visualizing the centre of mass relative to the pelvis. Centre of mass analyses in myelomeningocele offer an important complement to standard gait analysis.
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| 4. |
- Gutierrez-Farewik, Elena M., et al.
(author)
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Characteristic gait kinematics in persons with lumbosacral myelomeningocele
- 2003
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In: Gait & Posture. - 0966-6362 .- 1879-2219. ; 18:3, s. 170-177
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Journal article (peer-reviewed)abstract
- Thirty self-ambulatory children with mid-lumbar to low-sacral myelomeningocele who walked without aids and 21 control children were evaluated by three-dimensional gait analysis. Characteristic kinematic patterns and parameters in the trunk, pelvis, hip, knee and ankle were analyzed with respect to groups with successive weakness of the ankle plantarflexor, ankle dorsiflexor, hip abductor, hip extensor and knee flexor muscles. Extensive weakness of the plantarflexors resulted in kinematic alterations in the trunk, pelvis, hip and knee and in all three planes seen as knee flexion, anterior pelvic tilt and trunk and pelvic rotation. Additional extensive weakness of the dorsiflexors made little difference in the walking strategy. Large kinematic alterations in all planes were observed where there was a large extent of additional weakness of the hip abductor but strength remaining in the hip extensors. In this group, gait was characterized by large lateral sway of the trunk, rotation of the trunk and pelvis, pelvic hike and increased extension of the knees. In the group with total poresis hip extensors but yet some knee flexion, gait was similar to the previous group but there was less sagittal plane movement greates and posterior trunk tilt. Gait analysis provides an understanding of the compensatory strategies employed in these patients. Clinical management can be directed towards stabilizing the lower extremities and accommodating large upper body motion to preserve this method of self-ambulation even in children who have considerable hip extensor and abductor weakness.
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| 5. |
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| 6. |
- Harringe, M L, et al.
(author)
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Postural control measured as the center of pressure excursion in young female gymnasts with low back pain or lower extremity injury.
- 2008
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In: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 28:1, s. 38-45
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Journal article (peer-reviewed)abstract
- Gymnasts are known to practice and compete although suffering from injuries and pain. Pain may change strategies for postural control. The primary aim of the present study was to investigate how center of pressure (COP) measurements are influenced by low back pain and lower extremity injury in top-level female gymnasts. A secondary aim was to study the reliability of these measurements using a test-retest design, and how this depends on the duration of the test. Fifty-seven top-level gymnasts were included in four groups: non-injured (NI, n=18), low back pain (LBP, n=11), lower extremity injury (LEI, n=17) and a multiple injury group (MI, n=11). COP excursion during quiet stance was measured on a force platform, during 120s: (1) hard surface/eyes open, (2) hard surface/eyes closed, (3) foam surface/eyes open and (4) foam surface/eyes closed. The COP excursion increased, for all groups, during the foam surface/eyes closed measurement compared to the other three tests. Furthermore, the LBP group showed a 49% (p=0.01) larger COP area compared to the LEI group in the foam surface/eyes closed condition. Measurements on foam surface were in general more reliable than tests on hard surface and tests with eyes closed were more reliable than tests with eyes open. Tests during 120s were in most cases more reliable than tests during 60s. In conclusion the COP excursion is influenced by injury location. Quiet stance measurements on foam surface with eyes closed seems to be reliable and sensitive in young female gymnasts.
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| 7. |
- Agustsson, A., et al.
(author)
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Validity and reliability of an iPad with a three-dimensional camera for posture imaging
- 2019
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In: Gait and Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 68, s. 357-362
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Journal article (peer-reviewed)abstract
- Background: It is important to quantify a static posture to evaluate the need for and effectiveness of interventions such as physical management, physiotherapy, spinal orthosis or surgical treatment on the alignment of body segments. Motion analysis systems can be used for this purpose, but they are expensive, require a high degree of technical experience and are not easily accessible. A simpler method is needed to quantify static posture. Research objective: Assess validity and inter and intra rater reliability using an iPad with a 3-D camera to evaluate posture and postural deformity. Method: A 3-D model of a lying posture, created using an iPad with a 3-D camera, was compared to a Qualisys motion analysis system of the same lying posture, the latter used as the gold standard. Markers on the trunk and the leg were captured by both systems, and results from distance and angle measurements were compared. Results: All intra-class correlation coefficient values were above 0.98, the highest systematic error was 4.3 mm for length measurements and 0.2° for angle measurements. Significance: A 3-D model of a person, with markers on anatomical landmarks, created with an iPad with a 3-D camera, is a valid and reliable method of quantifying static posture. Conclusion: An iPad with a 3-D camera is a relatively inexpensive, valid and reliable method to quantify static posture in a clinical environment.
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| 8. |
- Bartonek, Asa, et al.
(author)
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A new carbon fibre spring orthosis for children with plantarflexor weakness
- 2007
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In: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 25:4, s. 652-656
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Journal article (peer-reviewed)abstract
- We tested a new orthosis with a carbon fiber spring constructed to enable energy storing during increasing dorsiflexion in mid-stance, and to use the energy at the end of stance phase to aid push-off. The orthosis was tested on children with plantarflexor weakness due to motor disorders. All subjects were tested with 3D gait analysis with both the new orthosis and with their regularly used orthosis. In this technical note, the results of three individuals are reported. The preliminary findings show increased dorsiflexion, altered knee kinematics and improved kinetic and temporo-spatial parameters. Although the carbon spring orthosis influenced the subjects' gait in different ways, we conclude that the tested subjects with plantarflexion weakness benefit from the carbon fiber spring orthoses during walking. The parents' and children's subjective impressions as acquired from a questionnaire were also positive.
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| 9. |
- Bartonek, Asa, et al.
(author)
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Influence of heel lifts during standing in children with motor disorders
- 2011
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In: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 34:3, s. 426-431
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Journal article (peer-reviewed)abstract
- Heel wedges may influence standing posture but how and to what extent are unknown. Thirty-two children with motor disorders - 16 with arthrogryposis multiplex congenita (AMC) and 16 with cerebral palsy (CP) - and 19 control children underwent a three-dimensional motion analysis. Unassisted standing during 20s with shoes only and with heel lifts of 10,20 and 30 mm heights was recorded in a randomized order. The more weight-bearing limb or the right limb was chosen for analysis. In both the AMC and CP groups, significant changes were seen between various heel lifts in ankle, knee and pelvis, and in the control group in the ankle only. Between orthosis and non-orthosis users significant differences were seen between different heel lift conditions in ankle, knee and trunk in the AMC group and in the ankle in the CP group. Pelvis position changed toward less anterior tilt with increasing heel height, but led to increasing knee flexion in most of the children, except for the AMC Non-Ort group. Children with AMC and CP represent different motor disorders, but the heel wedges had a similar influence on pelvis, hip and knee positions in all children with CP and in the AMC orthosis users. A challenge is to apply heel heights adequate to each individual's orthopaedic and neurologic conditions to improve biomechanical alignment with respect to all body segments.
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| 10. |
- Bartonek, A., et al.
(author)
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The influence of spasticity in the lower limb muscles on gait pattern in children with sacral to mid-lumbar myelomeningocele : a gait analysis study
- 2005
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In: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 22:1, s. 10-25
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Journal article (peer-reviewed)abstract
- Gait analysis and recording of standing position were performed in 38 ambulatory children with myelomeningocele. Thirty-four were independent ambulators and four required a walking aid. All subjects were assigned one of four muscle function groups based on muscle strength. They were also divided into subgroups based on the distinction between flaccid and spastic paresis in the lower limb joints. A comparison was made between the gait pattern of the children with spasticity and that of the children with flaccid paresis in each muscle function group. Spasticity in only the ankle joint muscles influenced the subject's gait and standing position compared to the subgroups with a flaccid paresis. Even larger deviations in gait and standing position were observed when spasticity occurred in muscles at the knee and hip joints. When setting ambulatory goals the presence of additional neurological symptoms such as spasticity and inadequate balance should be taken into consideration.
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