Intramuscular Force Transmission
The architectural form of skeletal muscle, the pattern of activity/usage between neighbouring fibres, and the pathways for lateral and lengthwise tension delivery are all of interest in understanding muscle function and dysfunction. We have attempted to contribute to understanding of intramuscular force transmission by investigating the functional relationships between coactive motor units, and by examining the detailed molecular and morphological features at sites of tension transfer. We found that tension delivery is modulated by interaction between active and inactive fibres, that many muscle fibre terminations feature structural coupling between fibres, and that sites of tension delivery feature a variety of proteins including acetylcholinesterase, NCAM, dystrophin and two splice variants of the a7 integrins. We conclude that structural and molecular pathways exist to deliver force within, along, and between muscle fibres, and that the quality/quantity of tension delivered from any single fibre is at least partly a consequence of whether its neighbouring fibres are synchronously coactive.
KeywordsMotor Unit Mammalian Skeletal Muscle Myotendinous Junction Lateral Transmission Neighbouring Fibre
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- Sheard, P.W., McHannigan, P., and Duxson, M.J., 1999, Single and paired motor unit performance in skeletal muscles: Comparison between simple and series-fibred muscles from the rat and the guinea pigBasic and Applied Myology9, 79–87.Google Scholar