in relation to contraction of muscle passive force is defined as tension, which opposes lengthening.
in relation to contraction of muscle passive force is defined as?
tension , which opposes lengthening
length-tension relationship relates the strength of an isometric contraction to the length of the muscle at which the contraction occurs. muscles operate with greatest active tension when close to an ideal length (often their resting length). when stretched or shortened beyond this (whether due to the action of the muscle itself or by an outside force), the maximum active tension generated decreases. this decrease is minimal for small deviations, but the tension drops off rapidly as the length deviates further from the ideal. due to the presence of elastic proteins within a muscle cell (such as titin) and extracellular matrix, as the muscle is stretched beyond a given length, there is an entirely passive tension, which opposes lengthening. combined together, there is a strong resistance to lengthening an active muscle far beyond the peak of active tension.
muscle contraction
the three-element hill muscle model is a representation of the muscle mechanical response. the model is constituted by a contractile element (ce) and two non-linear spring elements, one in series (se) and another in parallel (pe). the active force of the contractile element comes from the force generated by the actin and myosin cross-bridges at the sarcomere level. it is fully extensible when inactive but capable of shortening when activated. the connective tissues (fascia, epimysium, perimysium and endomysium) that surround the contractile element influences the muscle's force-length curve. the parallel element represents the passive force of these connective tissues and has a soft tissue mechanical behavior. the parallel element is responsible for the muscle passive behavior when it is stretched, even when the contractile element is not activated. the series element represents the tendon and the intrinsic elasticity of the myofilaments. it also has a soft tissue response and provides energy storing mechanism.
hill's muscle model