Question

When there is no change in muscle length during contraction, it is called as

• A. Isometric
• B. Isotonic
• C. Isostasis
• D. Refractory period

Answer 1

The correct option is A Isometric

In contrast to isotonic contractions, isometric contractions generate force without changing the length of the muscle. This is typical of muscles found in the hands and forearm, the muscles do not change length, and joints are not moved, so a force for grip is sufficient. An example is when the muscles of the hand and forearm grip an object; the joints of the hand do not move, but muscles generate sufficient force to prevent the object from being dropped.
Whereas a tetanic contraction is a sustained muscular contraction (as in tetanus), when a muscle's motor unit is stimulated by multiple impulses at a sufficiently high frequency. Each stimulus causes a twitch.