Self-myofascial release will decrease the excitation of which of the following?

Self-myofascial release (SMR) is a flexibility technique that uses tools like foam rollers to apply gentle, sustained pressure to the myofascial tissues. According to NASM, this technique “stimulates the Golgi tendon organ (GTO), which in turn inhibits muscle spindle activity, decreasing excitation and allowing the muscle to relax.” Muscle spindles are sensory receptors sensitive to changes in muscle length and the rate of that change; they trigger reflexive contractions when they detect rapid stretch. Overactivity of muscle spindles can contribute to tightness and restricted range of motion. SMR works by initiating autogenic inhibition, allowing the targeted muscle to lengthen more effectively. The other options—Golgi tendon organs (inhibited by SMR stimulation), sarcomeres (the contractile units in muscle fibers), and myosin heads (part of the actin–myosin sliding filament mechanism)—are not directly the structures whose excitation is reduced by SMR. Therefore, the correct answer is that SMR decreases excitation of muscle spindles.