Journal of biomechanics
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Journal of biomechanics · Sep 2009
Non-invasive model-based estimation of aortic pulse pressure using suprasystolic brachial pressure waveforms.
Elevated central arterial (aortic) blood pressure is related to increased risk of cardiovascular disease. Methods of non-invasively estimating this pressure would therefore be helpful in clinical practice. To achieve this goal, a physics-based model is derived to correlate the arterial pressure under a suprasystolic upper-arm cuff to the aortic pressure. ⋯ Correlation between estimated and actual central waveforms was greater than 90%. Individualization of model parameters did not significantly improve systolic and diastolic pressure agreement, but increased waveform correlation. Further research is necessary to confirm that more accurate brachial pressure measurement improves central pressure estimation.
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Journal of biomechanics · Sep 2009
Fixation compliance in a mouse osteotomy model induces two different processes of bone healing but does not lead to delayed union.
Delayed unions are a problematic complication of fracture healing whose pathophysiology is not well understood. Advanced molecular biology methods available with mice would be advantageous for investigation. In humans, decreased fixation rigidity and poor reduction are generally associated with delayed unions. ⋯ The less flexible bridging plate induced only intramembranous ossification whereas the more flexible bridging plate induced a mixture of endochondral and intramembranous ossification. However, the different plates led to a delay in healing of only 3-5 days in the period between 14 and 21 post-operative days. In mice, considerable fixation flexibility is necessary to induce secondary bone healing similar to that which occurs in humans, but this was not sufficient to induce a substantial delay in bone healing as would be expected in humans.
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Journal of biomechanics · Aug 2009
Finite-element simulation of flexor digitorum longus or flexor digitorum brevis tendon transfer for the treatment of claw toe deformity.
Claw toe deformity sometimes leads to dorsiflexion of the metatarsophalangeal joint (MPJ) and plantar flexion of the proximal (PIPJ) and distal interphalangeal (DIPJ) joints. Flexor digitorum longus tendon transfer (FDL) is currently the gold standard for the correction of this problem. Transfer of the flexor digitorum brevis (FDB) has been recently proposed as an alternative method to treat such deformity. ⋯ FDB transfer resulted in a more uniform distribution of stress along the entire toe, although differences were small in all cases. These results confirm that both the tendon-transfer techniques are effective in the treatment of claw toe deformity. Therefore, the choice of technique is at the discretion of the surgeon.
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Journal of biomechanics · Aug 2009
Comment LetterComment on "Contributions of the individual ankle plantar flexors to support, forward progression and swing initiation during walking" ((Neptune et al., 2001) and "Muscle mechanical work requirements during normal walking: the energetic cost of raising the body's center-of-mass is significant" (Neptune et al., 2004).
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Journal of biomechanics · Aug 2009
Author's Response to Comment on "Contributions of the individual ankle plantar flexors to support, forward progression and swing initiation during walking" (Neptune et al., 2001) and "Muscle mechanical work requirements during normal walking: The energetic cost of raising the body's center-of-mass is significant" ().