Clinical biomechanics
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Clinical biomechanics · Mar 2013
Comparative StudyBiomechanical comparison of an angular stable plate with augmented and non-augmented screws in a newly developed shoulder test bench.
The proximal humeral fracture is one of the most common fractures. Although there are a number of treatment options available, the clinical outcomes in geriatric patients are still unsatisfactory. Therefore, the aim of this study was to investigate the biomechanical behaviour of an angular stable plate with either augmented or non-augmented screws using two different fracture models in a shoulder test bench with active muscle forces. ⋯ In an unstable fracture model under dynamic testing conditions, augmentation leads to a decreased per cycle motion and varus impaction of the humeral head.
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Clinical biomechanics · Mar 2013
Controlled Clinical TrialFactors contributing to lumbar region passive tissue characteristics in people with and people without low back pain.
Previously, we demonstrated that people in the Rotation with Extension low back pain subgroup display greater asymmetry of passive tissue characteristics during trunk lateral bending than people without low back pain. The purpose of this secondary analysis is to examine factors that explain the group differences. ⋯ Anthropometrics explained passive measures with trunk lateral bending to both sides, in both groups. For people in the Rotation with Extension subgroup, there was a direct relationship between trunk muscle performance and passive measures to the right. Muscle is an important contributing factor to asymmetry in this subgroup and should be considered in treatment.
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Clinical biomechanics · Mar 2013
Effects of cervical orthoses on neck biomechanical responses during transitioning from supine to upright.
Our objectives were to use a hybrid cadaveric/surrogate model to evaluate the effects of the cervicothoracic orthosis and collar on head and neck biomechanical responses during transitioning from supine to upright. ⋯ The simple maneuver of supine-to-upright transitioning, commonly performed clinically, produced complex neck loads and motions including head protrusion which caused cervical spine snaking. Neck motions consisted of extension at the upper cervical spine and flexion at the subaxial cervical spinal levels. Of the devices tested, the cervicothoracic orthosis, with anterior strut locked, provided the greatest cervical spine immobilization thereby reducing the risk of potential secondary neck injuries.
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Clinical biomechanics · Mar 2013
Simulated transversus abdominis muscle force does not increase stiffness of the pubic symphysis and innominate bone: an in vitro study.
The transversus abdominis muscle is thought to exert a stiffening effect on the sacroiliac joints. However, it is unknown whether this muscle is capable of increasing pubic symphysis and innominate bone stiffness during load exerted on the pelvis. The objective of this study is to investigate whether in vitro simulated force of transversely oriented fibres of the transversus abdominis increases stiffness of the pubic symphysis and innominate bone. ⋯ Simulation of the force of a single muscle - transversus abdominis - does not increase stiffness of the pubic symphysis and innominate bone. The hypothesized stiffening influence of the transversus abdominis on the pelvic ring was not confirmed in vitro.
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Clinical biomechanics · Mar 2013
Increasing posterior tibial slope does not raise anterior cruciate ligament strain but decreases tibial rotation ability.
It was investigated whether the strain of the anterior cruciate ligament and tibial kinematics are affected by increasing posterior tibial slope. ⋯ The hypothesis that increasing posterior tibial slope results in higher anterior cruciate ligament strain was not confirmed. However, knee kinematics were affected in terms of a reduced tibial rotation. From a biomechanical point of view the data do not support the efficacy of sagittal osteotomies as performed to stabilize anterior cruciate ligament deficient knees.