Question

which of the following is true concerning isotonic eccentric contraction?
multiple choice
the muscle shortens but tension remains constant.
the muscle lengthens but tension remains constant.
the muscle tenses and shortens.
the muscle tenses but length remains unchanged.
the muscle lengthens and tension declines.

Explanation:

In an isotonic eccentric contraction, the muscle contracts (tenses) while lengthening, and the tension remains relatively constant throughout the movement. Isotonic means there is movement (change in muscle length) with constant tension. Eccentric specifically refers to the muscle lengthening during the contraction.

• The first option ("The muscle shortens but tension remains constant") describes an isotonic concentric contraction.
• The third option ("The muscle tenses and shortens") is also a concentric contraction description.
• The fourth option ("The muscle tenses but length remains unchanged") is an isometric contraction (no change in length, only tension development).
• The fifth option ("The muscle lengthens and tension declines") is incorrect as tension is relatively constant in isotonic (both concentric and eccentric) contractions.

Answer:

The muscle lengthens but tension remains constant.