How might the relationship between force and length of muscl

How might the relationship between force and length of muscle , the relationship between force and angular velocity of muscle be used in determining the optimum tiser height( distance between stairs) in home for elderly?( include diagram)

Solution

Ans.) The relationship between force and length of muscle can be explained with the help of isometric length-tension curve which represents the force of a muscle that is capable of holding at a series of distinct lengths. Basically, the length-tension relationship states that isometric tension generation in skeletal muscle is a measure of the magnitude of overlap between actin and myosin filaments.

The relationship between muscle size and force of contraction is complicated due to the muscle’s architecture. In muscle, an anatomical cross-sectional area is found where the muscle has widest point and it is perpendicular to the length of the muscle. In a parallel fiber muscle, this cross-sectional area cuts the entire fibers of the muscle. Though, in few muscles like a pennate muscle the anatomical cross-sectional area cuts across only a portion of the fibers composing the muscle not the whole fibre. Thus, the anatomical cross-sectional area interprets the number of fibers present in a pennate muscle and hence its force production capabilities.

In a same way, a muscle that appears to be intended for force production due to a large physiological cross sectional area (PCSA), when is placed with a very small moment arm, in fact produces high joint excursions or angular velocities. Keeping in mind this fact, one can decide the distance between the stairs. As muscle design may or may not be a reflection of its actual use in the physiologic torque-generating system.