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- Elert, Jessica, 1954-, et al.
(author)
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Lack of gender differences in the ability to relax between repetitive maximum isokinetic shoulder forward flexions : A population-based study among northern Swedes
- 2000
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In: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 83:4-5, s. 246-256
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Journal article (peer-reviewed)abstract
- The aim of the present study was to analyse the effects of gender and age in a population-based sample of clinically healthy subjects on: (1) strength, endurance and perception of fatigue, (2) mean frequency (MNF) of the electromyogram (EMG), and (3) the ability to relax between active contractions (signal amplitude ratio, SAR) of the surface EMG of an isokinetic shoulder forward flexion test. With this aim we have analysed aspects of the validity of MNF as an indicator of fatigue, using peak torque as a criterion variable. The subjects were 27 men and 28 women (age range: 20-60 years), who were obtained by random sample from the official census lists (participation rate: 66%). The peak torque and surface EMG of two portions of the trapezius, deltoid and infraspinatus muscles were recorded throughout 100 repetitive maximal isokinetic shoulder forward flexions. No significant differences in the perception of fatigue and relative endurance levels of peak torque and work were found between males and females. Males were significantly stronger than females and, on average, females produced approximately 60% of the output of the males, 76% after normalisation for body mass. The men had significantly lower MNF endurance levels for three of the investigated muscles. When controlled for age and body mass, the men had a significantly higher MNF of the deltoid muscle than did the females. These differences were only found for the deltoid muscle. Significant correlations existed between the MNF of the four muscles and biomechanical output, indicating criterion validity for the MNF variable with respect to fatigue. There were no significant effects of gender or age on the ability to relax between repetitive contractions (SAR). The higher prevalence of musculoskeletal complaints of the neck-shoulder region in females cannot be explained by a higher intrinsic muscle tension. Age, gender, body mass index and biomechanical output can have significant effects upon MNF. These effects are important considerations in the interpretation of MNF, for instance in ergonomic situations.
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- Grip, Helena, et al.
(author)
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Classification of Neck Movement Patterns Related to Whiplash-Associated Disorders Using Neural Networks
- 2003
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In: IEEE transactions on information technology in biomedicine. - : IEEE. - 1089-7771 .- 1558-0032. ; 7:4, s. 412-418
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Journal article (peer-reviewed)abstract
- This paper presents a new method for classification of neck movement patterns related to Whiplash-associated disorders (WAD) using a resilient backpropagation neural network (BPNN). WAD are a common diagnosis after neck trauma, typically caused by rear-end car accidents. Since physical injuries seldom are found with present imaging techniques, the diagnosis can be difficult to make. The active range of the neck is often visually inspected in patients with neck pain, but this is a subjective measure, and a more objective decision support system, that gives a reliable and more detailed analysis of neck movement pattern, is needed. The objective of this study was to evaluate the predictive ability of a BPNN, using neck movement variables as input. Three-dimensional (3-D) neck movement data from 59 subjects with WAD and 56 control subjects were collected with a ProReflex system. Rotation angle and angle velocity were calculated using the instantaneous helical axis method and motion variables were extracted. A principal component analysis was performed in order to reduce data and improve the BPNN performance. BPNNs with six hidden nodes had a predictivity of 0.89, a sensitivity of 0.90 and a specificity of 0.88, which are very promising results. This shows that neck movement analysis combined with a neural network could build the basis of a decision support system for classifying suspected WAD, even though further evaluation of the method is needed.
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- Sterner, Ylva, et al.
(author)
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Acute and chronic whiplash disorders - A review
- 2004
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In: Journal of Rehabilitation Medicine. - : Medical Journals Sweden AB. - 1650-1977 .- 1651-2081. ; 36:5, s. 193-210
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Journal article (peer-reviewed)abstract
- Objective: This review examines acute and chronic whiplash-associated disorders to facilitate assessment, treatment and rehabilitation for further research and evidence-based practises. Design: A review of the literature. Results and conclusion: Whiplash-associated disorders account for a large proportion of the overall impairment and disability caused by traffic injuries. Rarely can a definite injury be determined in the acute (or chronic) phase. Crash-related factors have been identified, and several trauma mechanisms possibly causing different injuries have been described. Most whiplash trauma will not cause injury, and the majority of patients (92-95%) will return to work. Litigation is not a major factor. Cognitive impairments are not the same as brain injury. Variables such as pain intensity, restricted motion, neurological symptoms and signs, together with central nervous system symptoms can be used to predict a situation with risk of remaining complaints. Influences of other factors - the same as for other chronic pain conditions - also exist. Persistent/chronic pain is not merely acute pain that persists over time, changes occur at different levels of the pain transmission system. Chronic whiplash-associated disorders are associated with problems concerning social functioning, daily anxieties and satisfaction with different aspects of life. Adequate information, advice and pain medication together with active interventions might be more active in the acute stage. Early multidisciplinary rehabilitation focusing on cognitive-behavioural changes might be of value. To develop specific treatment and rehabilitation, it is important to identify homogenous subgroups.
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6. |
- Sterner, Ylva, et al.
(author)
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The incidence of whiplash trauma and the effects of different factors on recovery
- 2003
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In: Journal of Spinal Disorders & Techniques. - : Lippincott Williams & Wilkins. - 1536-0652 .- 1539-2465. ; 16:2, s. 195-199
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Journal article (peer-reviewed)abstract
- We performed a prospective study of patients with a whiplash trauma to the cervical spine to describe the incidence of these injuries and to evaluate prognostic factors for disability and recovery. A total of 356 patients were enrolled in the study. All the patients received a comprehensive questionnaire after the injury, and 296 cases responded to the follow-up protocol more than 1 year after the accident. Disability related to the whiplash trauma was used as the outcome variable for the assessment of prognostic factors. The annual incidence of acute whiplash trauma in the catchment area was 4.2 per 1,000 inhabitants and 3.2 per 1,000 for whiplash-associated disorder grades 1-3. Thirty-two percent reported persisting disability at follow-up. The following factors were significantly associated with a poor prognosis: pretraumatic neck pain, low educational level, female gender, and whiplash-associated disorder grades 2-3.
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7. |
- Sterner, Ylva, 1948-
(author)
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Whiplash associated disorders : acute and chronic consequences with some implications for rehabilitation
- 2001
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Doctoral thesis (other academic/artistic)abstract
- Background: Whiplash associated disorders (WAD) account for a large proportion of the overall impairment and disability from traffic injuries and causes substantial bio psychosocial consequences for some individuals.Aims: To increase the knowledge about factors described in terms of either function /impairment, activity/disability and life satisfaction in acute and chronic WAD as well as possible implications for rehabilitation. Within this aim the incidence and recovery rate of whiplash injury and prognostic factors of interest for early rehabilitation have been studied.Subjects and Methods: Fifty-five healthy controls and 34 WAD subjects were analysed within and between groups concerning a) biomechanical out put, endurance, fatigue and muscle tension (EMG activity of trapezius, infraspinatus and deltoideus) during repetitive shoulder forward flexion b) impairments and activity/disability and life satisfaction.356 subjects seeking medical attention due to whiplash trauma, 296 were available at follow up, mean 16 months post injury. Incidence and odds ratio of accident and other background factors on disability were determined. Thirty-four out of 43 patients with whiplash injury were investigated through quantitative sensory tests at six weeks and 71 months after injury. 62 WAD participated in an interdisciplinary rehabilitation program (a pilot study) designed to evaluate such rehabilitation program for patients with chronic (in relatively early stage) WAD. Program evaluation of impairment, disability and life satisfaction (prospective and retrospective) was carried out before and after program and at 6 months.Results: No significant effects of sex or age on the ability to relax between repetitive r muscle contractions (SAR) were found in healthy subjects (study I). Significantly higher inability to relax between contractions was found for the two portions of trapezius and infraspinatus in the WAD group compared to the healthy group (study II). Significantly lower levels of activity preferences were noted for three out of five indices in females with WAD The WAD group had significantly higher prevalence of neropsychological and emotional symptoms. Both pain related symptoms and neropsychological symptoms were of significant importance for aspects of disability and life satisfaction in this group (study IV). Sensory disturbances over the trigeminal skin area persisted over the years. At follow-up a significant correlation was found between the sensory disturbances and the symptoms related to the central nervous system while no significant relationship was found with the musculoskeletal symptoms (study HI) .The annual incidence according to the grading of the Quebec Task Force on Whiplash-Associated Disorders (WAD 1-3) was 3.2/1000 and 4.2/1000 when WAD 0 was included. Sixty-eight percent of the patients recovered during the follow-up Pre-traumatic neck pain, low educational level, female gender and WAD grade E-Ill were significantly associated with a poor prognosis (study IV). . Participants in the rehabilitation program reported increased coping ability. Stress reactions seemed rather frequent (32 %). Pain intensity in the neck and upper back were significantly decreased at 6 months follow-up. However, for most of the functional and psychological markers, no significant changes were found (study V).Conclusion: The higher prevalence of musculoskeletal complaints of the neck shoulder region in females cannot be explained by higher muscle tension and clinical assumption of increased muscle tension seems correct in whiplash patients Results indicate heterogeneity among WAD subjects. Females are at risk after a whiplash trauma but the severity of initial symptoms and signs also affect outcome as well as low education. High levels of neuropsychological symptoms and pain, signs of posttraumatic stress, fear and avoidance, loss of control, anxiety, bio-mechanical and psychosocial factors at work (studies) and social support are potential factors to be aware of. Extensive and costly investigations are in most cases not necessary. However most persons will recover a whiplash injury. Multidisciplinary/interdisciplinary assessment should be considered at three months if substantial negative effect on the person’s ability to function and health situation exists.
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8. |
- Öhberg, Fredrik, et al.
(author)
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Chronic Whiplash Associated Disorders and Neck Movement Measurements : An Instantaneous Helical Axis Approach
- 2003
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In: IEEE transactions on information technology in biomedicine. - : IEEE. - 1089-7771 .- 1558-0032. ; 7:4, s. 274-282
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Journal article (peer-reviewed)abstract
- This paper presents an assessment tool for objective neck movement analysis of subjects suffering from chronic whiplash-associated disorders (WAD). Three-dimensional (3-D) motion data is collected by a commercially available motion analysis system. Head rotation, defined in this paper as the rotation angle around the instantaneous helical axis (IHA), is used for extracting a number of variables (e.g., angular velocity and range, symmetry of motion). Statistically significant differences were found between controls and subjects with chronic WAD in a number of variables.
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