What is the difference between isotonic and isometric muscle contractions?
A.
Isotonic contractions produce no movement while isometric contractions produce movement.
B.
Isotonic contractions produce movement while isometric contractions produce no movement.
C.
Isotonic contractions generate tension in the muscle while isometric contractions involve shortening of the muscle fibers.
D.
Isotonic contractions involve contraction of individual muscle fibers while isometric contractions involve the entire muscle.
The correct answer is:
B. Isotonic contractions produce movement while isometric contractions produce no movement.
Explanation:
- Isotonic Contractions: These involve muscle shortening or lengthening, which produces movement. During an isotonic contraction, the muscle changes length while the tension remains constant. For example, lifting a weight involves isotonic contractions as the muscle shortens to lift the weight.
- Isometric Contractions: These occur when the muscle generates tension without changing length, meaning there is no movement. The muscle remains the same length while producing force, such as when holding a weight in a stationary position.
So, isotonic contractions produce movement, while isometric contractions do not.