Question

What are disadvantages associated with muscles that cross more than one join

Answer 1

Two-joint muscle is defined as a muscle that can produce moments about two joints. These joints are designed for efficiency of movement and less energy is required to move two joints with the same muscle than engage two different muscles. For this reason, most of the two muscle joint are used for power movements like walking, running, jumping, climbing, etc. In addition, the Muscle gets put on a stretch before it contracts - giving it maximum power for an explosive movement.

But the main disadvantage of two joint muscle ( BIARTICULAR MUSCLES ) that it rears uglt head quitely often. Active insufficiency is where the biarticular muscle cannot shorten enough to do all the move of the joints that it crosses. Remember that a muscle can only shorten by 40% of its resting length. Passive insufficiency is where the muscle cannot stretch out enough for both of the joints to move through their full range. This occurs in the movement where the movement of both joints is stretching the muscle,