Clinical biomechanics
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Clinical biomechanics · Jul 2008
Stature loss and recovery following a period of loading: effect of time of day and presence or absence of low back pain.
Stature reductions in asymptomatic individuals, caused by a set load, are lower later in the day when stature is in the trough of diurnal variation; hence most stature reduction investigations are conducted in the morning. Recent evidence suggests that it is not the reductions in stature, but the recovery of stature, that is of greatest importance. The aim of this investigation was to establish whether stature recovery is also affected by time of day and to determine if any differences exist between a chronic low back pain and asymptomatic group. ⋯ Further investigations of stature recovery should be restricted to the morning when comparing individuals with and without chronic low back pain, as time of day appeared to have effect on stature recovery, particularly in the asymptomatic group. Time dependent differences in stature change between these two populations warrants further investigation.
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Clinical biomechanics · Jun 2008
Do flexion/extension postures affect the in vivo passive lumbar spine response to applied axial twist moments?
The injury potential and mechanical effects of combining axial rotation with non-neutral flexion/extension postures in vivo remains poorly understood, despite being identified as a risk factor in epidemiological and in vitro studies. The purpose of this experiment was to quantify the passive axial twist motion of the lumbar spine in various postures, and to assess whether non-neutral flexion/extension postures cause a detectable change in the range of twist motion and/or spine rotational stiffness. ⋯ The lumbar spine stiffness and rotational range were modified by flexed-extended postures. The postural mechanism observed may be due to a change in the initial distance separating the facets prior to rotation. This information will be useful in determining spine rotational injury mechanisms through comparison with in vitro literature and for patient positioning during diagnostic tests.
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Clinical biomechanics · Jun 2008
Gluteus medius muscle activation patterns as a predictor of low back pain during standing.
Low back pain is a primary source of disability and economic costs. Altered trunk muscle activation in people with low back pain, specifically agonist/antagonist co-activation, has been previously demonstrated. Prevailing theory considers this muscle activation pattern to be adaptive to low back pain. Muscle activation patterns prior to, and during, the development of low back pain in asymptomatic individuals, have not been well studied. ⋯ Agonist-antagonist co-activation may not be entirely adaptive, and may in fact predispose some individuals to develop low back pain. Muscle activation patterns at the hip may be a useful addition for screening individuals to identify those at risk of developing low back pain during standing.
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Clinical biomechanics · Jun 2008
Middle and ring fingers are more exposed to pulley rupture than index and little during sport-climbing: a biomechanical explanation.
Finger pulley injury is a common incident observed during sport-climbing. The total rupture of one or several pulleys is highly debilitating and requires surgical reconstruction and/or rehabilitation programs. Literature reports show that fingers are not equally exposed to this injury. The ring and middle fingers are usually injured while the index and little fingers are less exposed. The objective of this study was to determine the biomechanical factors leading to the enhanced exposure of ring and middle finger pulleys. ⋯ These results are relevant and could help clinicians to understand finger pulley pathologies and adapt the surgical interventions to reconstruct the fingers pulleys.
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Clinical biomechanics · May 2008
Controlled Clinical TrialA new approach to detecting asymmetries in gait.
Traditional parameters used to assess gait asymmetries, e.g., joint range of motion or symmetry indices, fail to provide insight regarding timing and magnitude of movement deviations among lower limb joints during the gait cycle. This study evaluated the efficacy of a new approach for quantifying aspects of gait asymmetry. ⋯ Region of deviation analysis effectively identified the timing and magnitude of deviations throughout the gait cycle, and provided information about the impact of a joint-mobility perturbation on neighboring joints. This new methodology will be useful in clinical settings to identify, characterize, and monitor recovery from asymmetric behaviors associated with injuries or pathologies.