Isotonic contractions involve tension development during which changes in muscle length?

Isotonic contractions involve tension development during which changes in muscle length?

• A. Tension develops only during shortening
• B. Tension develops during shortening or lengthening
• C. Tension develops only during lengthening
• D. No length change

Answer: (B)

Isotonic contractions are about producing enough tension to move a load, so the muscle changes length as it works. This happens in two ways: it can shorten (concentric) to lift or accelerate the load, or lengthen (eccentric) to control the descent or resist the load. In both cases, tension is developed during the actual change in length. This differs from isometric contractions, where tension is produced but the muscle length stays the same.

Isotonic contractions are about producing enough tension to move a load, so the muscle changes length as it works. This happens in two ways: it can shorten (concentric) to lift or accelerate the load, or lengthen (eccentric) to control the descent or resist the load. In both cases, tension is developed during the actual change in length. This differs from isometric contractions, where tension is produced but the muscle length stays the same.