Group Exercise Instructor Free Test Prep

Answer: A - Muscle spindles play a major role in the sensory-motor feedback loop by signaling changes in muscle length. The spindles are positioned in parallel with skeletal muscle fibers; this unique position allows them to play the role of mechanoreceptor, rapidly responding to changes in the muscle. They can serve a protective function, by activating the stretch reflex when a muscle is rapidly over-stretched, and a proprioceptive function, by telling the brain where the body is positioned in space.