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Updated: Feb 7, 2026

Isolating Myofibrils from Skeletal Muscle Biopsies and Determining Contractile Function with a Nano-Newton Resolution Force Transducer
Published on: May 7, 2020
Force-length relation of skeletal muscles: from sarcomeres to myofibril
1School of Engineering and Computer Science, University of Hull, Hull, HU6 7RX, UK. m.hou@hull.ac.uk.
Abstract:
Sarcomeres are building blocks of skeletal muscles. Given force-length relations of sarcomeres serially connected in a myofibril, the myofibril force-length relation can be uniquely determined. Necessary and sufficient conditions are derived for capability of fully lengthening or completely shortening a myofibril under isometric, eccentric or concentric contraction, and for the myofibril force-length relation to be a continuous single-valued function. Intriguing phenomena such as sarcomere force-length hysteresis and myofibril regularity are investigated and their important roles in determining myofibril force-length relations are explored. The theoretical analysis leads to experimentally verifiable predictions on myofibril force-length relations. For illustration, simulated force-length relations of a myofibril portion consisting of a sarcomere pair are presented.
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