Local muscle pressure stimulates the principal receptors for proprioception
Muscle spindles are considered the principal receptors for proprioception, sensing stretch and signaling limb position and velocity. Here, we show that local muscle pressure is an adequate stimulus for human spindles in isometric conditions, and that pressure enhances spindle responses during stretch, as hypothesized due to compression of the spindle capsule. Our findings redefine basic muscle feedback and urge reassessment of proprioception's role in sensorimotor function and various neuromuscular conditions.