Question

Which of the following statement(s) is/are CORRECT about isotonic and isometric tests?

• A. In an isotonic test, muscle is subjected to a constant tension and its length is recorded.
• B. In an isotonic test, muscle is held at constant length, and the contractile force generated by the muscle is recorded.
• C. In an isometric test, muscle is held at constant length, and the contractile force generated by the muscle is recorded.
• D. In an isometric test, muscle is subjected to a constant tension and its length is recorded.

Hint:

In an isometric test, the muscle remains at constant length while the force it generates is measured. In an isotonic test, the muscle changes length under a constant load.

Answer 1

The Correct Option is A, C

Let’s examine each statement: 
Step 1: Isotonic test. 
In an isotonic test, the muscle is subjected to a constant tension, and its length is recorded as the muscle contracts. This means the tension remains constant while the muscle shortens.
Option (A) is correct as it accurately describes the isotonic test, where the muscle contracts under constant tension, and the length changes.
Option (B) is incorrect because in an isotonic test, the muscle’s length changes, not held constant.
Step 2: Isometric test. 
In an isometric test, the muscle is held at a constant length, and the contractile force generated by the muscle is recorded. There is no change in the length of the muscle during the contraction.
Option (C) is correct as it accurately describes the isometric test.
Option (D) is incorrect because in an isometric test, the muscle is not subjected to constant tension but held at a fixed length. Thus, the correct answers are (A) and (C).