Clinical biomechanics
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Clinical biomechanics · Dec 2004
Clinical TrialKinematic analysis of functional lower body perturbations.
Sudden changes in direction on a single weight-bearing-limb are commonly associated with injury to the lower extremity. The purposes of this study were to assess the between day reliability of hip, knee, and ankle kinematic displacements achieved with internal and external femur-on-weight-bearing-tibia rotation perturbations and to determine the effect of these perturbations on three dimensional hip, knee and ankle kinematics. ⋯ The lower extremity perturbation device provides a consistent external and internal perturbation of the femur on the weight-bearing-tibia. The observed transverse and frontal plane kinematics are similar to motions observed during cross-over and side-stepping tasks.
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Clinical biomechanics · Nov 2004
Clinical TrialCervical muscle response to posterolateral impacts--effect of head rotation.
Rear impacts may be offset, and may also occur with the head rotated at impact. The purpose of this study was to determine the response of the cervical muscles to increasing low-velocity rear impacts offset by 45 degrees to the subject's right, but also with the head rotated either right or left. ⋯ Head rotation in a right posterolateral impact modifies the cervical response mainly by generating an asymmetry in the paired sternocleidomastoid electromyograms. This may asymmetrically affect the risk of injury to the sternocleidomastoids. An understanding of the muscular response to rear-impacts of different types and the effect of head rotation at the time of impact is relevant to understanding the mechanism of acute whiplash injury and may be helpful to develop targeted treatments and preventative measures.
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Clinical biomechanics · Oct 2004
Comparative StudyA biomechanical model of the effect of subtalar arthroereisis on the adult flexible flat foot.
The hypothesis tested was that the increased load on the medial arch in the adult flat foot can be reduced through a 6 mm subtalar arthroereisis. ⋯ Our analysis indicates that a 6 mm subtalar arthroereisis in an adult flat foot model decreases the load on the medial arch.
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Clinical biomechanics · Oct 2004
The effect of sagittal alignment on adjacent joint mobility after lumbar instrumentation--a biomechanical study of lumbar vertebrae in a porcine model.
The mechanisms and changes in range of motion of neighboring mobile segment (adjacent level) after the instrumented posterior stabilization are not completely understood. This study aims to investigate the effect of sagittal alignment on the adjacent joint mobility after lumbar instrumentation. ⋯ The iatrogenically produced kyphotic lumbar spine by posterior instrumentation might cause larger adjacent joint mobility on the superior adjacent joint as compared to the instrumented lordotic lumbar spine. This study implies that an instrumented spine in lordosis is less likely to develop adjacent instability than a kyphotic spine.
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Clinical biomechanics · Aug 2004
Multidirectional neck strength and electromyographic activity for normal controls.
To assess the multidirectional force and indwelling electromyographic activity during maximal effort isometric actions of the neck. ⋯ The greater precision revealed novel information about the isometric strength of the neck and its musculature.