Athletic Training Practice Exam

What type of exercise involves a muscle contraction with a changing length at a constant velocity?

1. Isokinetic

2. Isotonic

3. Isometric

4. PNF

The correct answer is: Isokinetic

Isokinetic exercise is characterized by a muscle contraction that occurs at a constant velocity, while the length of the muscle changes. This type of exercise typically requires specialized equipment that facilitates the movement at a predetermined speed, ensuring that the force exerted by the muscle is maximized throughout the entire range of motion. In isokinetic exercises, the resistance provided by the machine adjusts to match the force exerted by the muscle. This allows for a comprehensive strength training regimen that can enhance muscle performance while also reducing injury risk due to the controlled environment in which the movement occurs. The other exercise types, such as isotonic, involve varying speed and resistance, where the muscle shortens or lengthens against a consistent load, and isometric exercises maintain the same muscle length without movement. PNF, or proprioceptive neuromuscular facilitation, is a stretching technique that combines contraction and relaxation of muscles but does not focus on isokinetic movement at a constant velocity. Therefore, the defining feature of isokinetic exercise makes it the correct choice in this context.