Self reported driving habits in subjects with persistent whiplash associated disorder: relationship to sensorimotor and psychologic features
From: Archives of Physical Medicine and Rehabilitation. 2008 Jun;89(6):1097-102
Self reported driving habits after whiplash injury and to determine any relation among self reported driving habits, selected sensorimotor impairments, and psychologic features. Subjects (n=30) with chronic whiplash and 30 asymptomatic controls. The Driving Habits Questionnaire (composite driving tasks score), Neck Disability Index, 28-item General Health Questionnaire, Impact of Events Scale-Revised, Tampa Scale for Kinesiophobia, neck range of motion, neck joint position error, and smooth pursuit neck torsion test.
Subjects in the whiplash group had equal driving exposure and driving spaces (distances, locations) compared with control subjects but reported significantly more driving difficulty with most driving tasks. There were no significant correlations between the composite driving tasks score and any of the sensorimotor impairments, but there were significant and moderate correlations between the composite driving task score and both pain and disability (Neck Disability Index score, .518) and anxiety (General Health Questionnaire score -28, .518; Impact of Events Scale-Revised score, .524). Persons with chronic whiplash have greater self reported driving difficulty than controls, which appears to relate more to reported levels of pain and disability and psychologic stress than laboratory measures of features of neck sensorimotor control.
Biomechanical model study of pelvic belt influence on muscle and ligament forces
From: Journal of Biomechanics. 2008 May 21; [Epub ahead of print]
Many patients with low back and/or pelvic girdle pain feel relief after application of a pelvic belt. External compression might unload painful ligaments and joints, but the exact mechanical effect on pelvic structures, especially in (active) upright position, is still unknown. In the present study, a static three-dimensional (3-D) pelvic model was used to simulate compression at the level of anterior superior iliac spine and the greater trochanter. The model optimised forces in 100 muscles, 8 ligaments and 8 joints in upright trunk, pelvis and upper legs using a criterion of minimising maximum muscle stress. Initially, abdominal muscles, sacrotuberal ligaments and vertical sacroiliac joints shear forces mainly balanced a trunk weight of 500N in upright position. Application of 50N medial compression force at the anterior superior iliac spine (equivalent to 25N belt tension force) deactivated some dorsal hip muscles and reduced the maximum muscle stress by 37%. Increasing the compression up to 100N reduced the vertical SIJ shear force by 10% and increased sacroiliac joint compression force with 52%. Shifting the medial compression force of 100N in steps of 10N to the greater trochanter did not change the muscle activation pattern but further increased sacroiliac joint compression force by 40% compared to coxal compression. Moreover, the passive ligament forces were distributed over the sacrotuberal, the sacrospinal and the posterior ligaments. The findings support the cause-related designing of new pelvic belts to unload painful pelvic ligaments or muscles in upright posture.
Individual and work related risk factors for neck pain among office workers
From: European Spine Journal. 2007 May; 16(5): 679–686.
Work related neck disorders are common problems in office workers, especially among those who are intensive computer users. It is generally agreed that the etiology of work related neck disorders is multidimensional which is associated with, and influenced by, a complex array of individual, physical and psychosocial factors.
The results of this study indicate that physical and psychosocial work factors, as well as individual variables, are associated with the frequency of neck pain. These association patterns suggest also opportunities for intervention strategies in order to stimulate an ergonomic work place setting and increase a positive psychosocial work environment.
Work related neck disorders are common problems in office workers, especially among those who are intensive computer users The worldwide trend is for people to use computers for longer periods daily, due to increased computer-based tasks at work as well as during leisure activities. Introduction of the computer into the workplace has meant changes in work organization, and a different use of worker physical and mental potential. It is generally agreed that the etiology of work related neck disorders is multidimensional which is associated with, and influenced by, a complex array of individual, physical and psychosocial factors. Among these various risk factors, work-related psychosocial factors appear to play a major role. Work-related psychosocial variables may include aspects of the work content, organization, and interpersonal relationships at work, finances and economics. Individual factors are considered as confounding factors that influence the relation between psychosocial demands and the occurrence of neck pain. Furthermore, psychosocial demands may be highly correlated with physical demands, which also indicate a confounding effect of physical factors on the relation between work-related psychosocial variables and the occurrence of neck pain.
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Decreased isometric neck strength in women with chronic neck pain and the repeatability of neck strength measurements
From: Archives of Physical Medicine and Rehabilitation. 2004 Aug;85(8):1303-8
To evaluate neck flexion, extension, and, especially, rotation strength in women with chronic neck pain compared with healthy controls and to evaluate the repeatability of peak isometric neck strength measurements in patients with neck pain. Twenty-one women with chronic neck pain and healthy controls matched for sex, age, anthropometric measures, and occupation. Peak isometric strength of the cervical muscles was tested in rotation, flexion, and extension.
Significantly lower flexion (29%), extension (29%), and rotation forces (23%) were produced by the chronic neck pain group compared with controls. When the repeated test results were compared pairwise against their mean, considerable variation was observed in the measures on the individual level. Intratester repeatability of the neck muscle strength measurements was good in all the 4 directions tested in the chronic neck pain group. The coefficient of repeatability was 15N, both in flexion and extension, and 1.8 Nm in rotation. On the group level, improvement up to 10% due to repeated testing was observed.
The group with neck pain had lower neck muscle strength in all the directions tested than the control group. This factor should be considered when planning rehabilitation programs. Strength tests may be useful in monitoring training progress in clinical settings, but training programs should be planned so that the improvement in results is well above biologic variation, measurement error, and learning effect because of repeated testing.
Predicting persistent pregnancy related low back pain
From: Spine. 2008 May 20;33(12):E386-93
A cohort study to examine the course of subtypes of low back pain experienced [no low back pain, pelvic girdle pain, lumbar pain, and combined pelvic girdle pain and lumbar pain (combined pain)] during gestational weeks 12 to 18 and 3 months postpartum, and to explore potential predictors for persistent pelvic girdle pain or pelvic girdle pain and lumbar pain postpartum.
Low back pain is more prevalent in pregnant women (25%) than in the general population (6.3%). Persistent low back pain postpartum (16%) is usually studied as a single entity. However, only one subgroup of low back pain, pelvic girdle pain, is associated with pregnancy. Several studies have suggested an association between muscular dysfunction and pregnancy-related low back pain, however, muscle dysfunction has not been evaluated as potential predictor of persistent low back pain postpartum. Possible subgroup differences in the course and predictors of persistent low back pain are unknown.
Pregnant women (n = 308) were classified into low back pain subgroups by mechanical assessment of the lumbar spine, pelvic pain provocation tests, standard history, and pain drawings. Trunk muscle endurance, hip muscle strength (dynamometer) and gait speed were evaluated. Multiple logistic regression was used to identify predictors from self-reports and clinical examination. RESULTS: Women with combined pain recovered to a lower degree 33% (17 of 51) than those with pelvic girdle pain 66% (56 of 85) or lumbar pain 72% (21 of 29). Predictors for having persistent pelvic girdle pain or combined pain after delivery were low endurance of back flexors, older age, combined pain in early pregnancy and work dissatisfaction (explained variance 30%).
Women with pelvic girdle pain and lumbar pain were identified to be a target group since they had the most unfavorable course and since the classification of pelvic girdle pain and lumbar pain pain was found to be a predictor for persistent pain postpartum. Identification of women at risk for persistent pain postpartum seems possible in early pregnancy and requires physical examination and self-reports. Pregnancy had low impact on the course of lumbar pain.
