Clinical biomechanics
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Clinical biomechanics · Dec 1999
Lumbar coupling during lateral translations of the thoracic cage relative to a fixed pelvis.
To determine lumbar coupling during lateral postural translations (lumbosacral list) of the thoracic cage relative to a fixed pelvis. ⋯ The clinically common posture of lateral translation of the thoracic cage (lumbosacral list) is often associated with disc herniation. Yet normal lumbar coupling patterns and total range of motion of this movement have not been established in the literature. Normal values for lumbar segmental coupling on anterior-posterior lumbo-pelvic radiographs during trunk list might be important for an analysis of segmental instability since segmental translations were determined to be 1 mm or less.
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Clinical biomechanics · Feb 1999
Comparative Study Clinical TrialEffects of abdominal belts on intra-abdominal pressure, intra-muscular pressure in the erector spinae muscles and myoelectrical activities of trunk muscles.
To evaluate the effects of abdominal belts on lifting performance, muscle activation, intra-abdominal pressure and intra-muscular pressure of the erector spinae muscles. ⋯ Wearing abdominal belts raises intra-muscular pressure of the erector spinae muscles and appears to stiffen the trunk. Assuming that increased intra-muscular pressure of the erector spinae muscles stabilizes the lumbar spine, wearing abdominal belts may contribute to the stabilization during lifting exertions.
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Clinical biomechanics · Jan 1999
The in vivo dynamic response of the spine to perturbations causing rapid flexion: effects of pre-load and step input magnitude.
To evaluate the impact of muscle pre-activation levels and load magnitude on the response of the trunk to loading conditions causing rapid flexion. ⋯ The results of this study provide insight into several mechanisms involved in the dynamic stability of the spine. Injuries can be caused by unexpected and rapid loading of the spine. A study of the mechanisms available to respond to such perturbations is important to an understanding of spine mechanics and the etiology of low back injury.
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To determine whether quadriceps (Q) angles were bilaterally symmetric in individuals asymptomatic vs symptomatic for anterior knee pain. ⋯ Future investigations of the Q angle must ensure that measures are derived bilaterally and analysed appropriately. Data from unilateral vs bilateral symptomatic subjects should be evaluated separately, and the shortcomings of standard ANOVA structural models must be recognized.
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Clinical biomechanics · Jun 1998
The effects of external mechanical stimulation on the healing of diaphyseal osteotomies fixed by flexible external fixation.
The purpose of this study was to investigate the effect of an externally applied mechanical stimulus on fracture healing under flexible fixation. DESIGN: Stimulation of fracture healing under various conditions of interfragmentary movement in an in vivo fracture model on 41 sheep. ⋯ These results suggest that the optimal interfragmentary movement for acceleration of delayed fracture healing is in the range of 0.5 mm. However, the enhancement of the healing of flexibly-fixed fractures by external application of interfragmentary movement is limited. RELEVANCE: In this model the external application of a mechanical stimulus in addition to the stimulation caused by normal loading and the flexibility of the fixation did not enhance the healing process significantly. It appears that the external application of interfragmentary motion is promising perhaps only for patients unable to stimulate their fracture healing by weight-bearing.