Isotonic Exercise is defined by which feature?

Isotonic Exercise is defined by which feature?

• A. Shortens and lengthens the muscle through a complete ROM
• B. Shortens and lengthens the muscle with no ROM
• C. Rigid contraction without movement
• D. Constant velocity resistance with accommodating resistance

Answer: (A)

Isotonic exercise involves the muscle changing length as the joint moves through a full range of motion under a constant external load. This means the muscle shortens during concentric actions and lengthens during eccentric actions while the limb travels through the entire range. An example is a dumbbell bicep curl, where the arm moves through the ROM and the muscle length changes. This distinguishes isotonic work from isometric contractions (no joint movement and no change in muscle length) and from isokinetic work (movement occurs at a constant speed with accommodating resistance).

Isotonic exercise involves the muscle changing length as the joint moves through a full range of motion under a constant external load. This means the muscle shortens during concentric actions and lengthens during eccentric actions while the limb travels through the entire range. An example is a dumbbell bicep curl, where the arm moves through the ROM and the muscle length changes. This distinguishes isotonic work from isometric contractions (no joint movement and no change in muscle length) and from isokinetic work (movement occurs at a constant speed with accommodating resistance).