Somatosensation, similar to kinesthesia (Sherrington, 1916), and often times referred to as just proprioception is the sense of one’s own body position and body motion in space. There has been some debate as to the functional necessity of certain somatosensory receptors for the construction and monitoring of kinematic and kinetic parameters associated with changes in body position (for review see Proske ; Gandevia, 2012). Nonetheless, the prominent discourse in the present literature is that somatosensory information emerges from a combination of inputs from numerous sensory organs including: skin receptors, joint receptors, muscle spindles, and Golgi tendon organs.
It has been demonstrated that skin afferent receptors play a substantial role in one’s sense of body position (Edin & Abbs, 1991; Edin, 2004). For example, both the slow-acting and fast-acting mechanoreceptors in non-glabrous skin have been shown to respond to voluntary finger and hand movements. Fast-acting receptors produce rapid graded responses depending on the extent of movement-induced skin stretch at proximal joints. Slow-acting receptors respond directionally by increasing discharge during proximal-joint flexion and decreasing discharge during proximal-joint extension. Furthermore, it has been demonstrated that the activity of neurons responsive to skin stretch in the primary somatosensory cortex is correlated with their activity levels when encoding kinematic information about joint positions (Cohen, Prud’homme, ; Kalaska, 1994). These results suggest that skin receptors could contribute to limb localization both during static postures and limb movement.