Question

1. Define isometric contraction and describe an example Isometric contraction occurs when the muscle is activated but held at a fixed length. An example would be the muscles of the leg when holding oneself in a squat position.
2. When the current reached the following stages, what proportion of fibers in the muscle were contracting?

a) at threshold
b) at the maximal stimulus
c) above the maximal stimulus

Answer 1

Answer:

1. Isometric contraction is best defined as a contraction that is not associated with any movement.  It can be used by the therapist to increase strength and elasticity.

An example of an isometric contraction is carrying an object in front of you. The weight of the object would be pulling downward, but your hands and arms would be opposing the motion with equal force going upwards. Since your arms are neither raising or lowering, your biceps will be isometrically contracting.

2.

a. At threshold just a few muscle fibers are being recruited.

b. At the maximal stimulus is 100% of recruitable fibers are contracting.

c. Above maximal stimulus, the number of contracting fibers cannot increase.

Explanation: