Stability of muscle fibers on the descending limb of the force-length relation. A theoretical consideration

Abstract

For the past 40 years it has generally been accepted that the descending limb of the force-length (F-L) relation of muscle fibers is unstable; strong sarcomeres are thought to shorten onto the ascending limb of the F-L relation at the expense of weak sarcomeres which are stretched beyond the thin-thick myofilament overlap. This unstable behavior has not been demonstrated by direct observation but has been inferred indirectly, based on the negative slope of the F-L relation. Intuitively, the idea that the sarco…