ACSM Personal Trainer Certification Practice Exam

What is the nature of an isokinetic contraction?

1. Consistent muscle length with no movement

2. Variable force with accommodating speed

3. Constant tension with a specified range

4. Static hold without any movement

The correct answer is: Variable force with accommodating speed

An isokinetic contraction is characterized by variable force with accommodating speed. This type of contraction occurs when a muscle contracts at a constant speed throughout the entire range of motion, typically facilitated by specialized equipment that adjusts resistance based on the force the muscle generates. This means that as the individual exerts more force, the machine accommodates by providing more resistance, allowing for maximum effort at any point in the movement while maintaining a consistent speed. This is particularly beneficial in rehabilitation settings, where controlling the speed of contraction can help prevent injury while still promoting muscle strengthening. The uniqueness of isokinetic contractions lies in this ability to adapt resistance, making it effective for enhancing muscular strength and endurance through controlled speeds, which differs from other types of contractions such as isometric or isotonic.