Neuromechanical coupling in the regulation of muscle tone and joint stiffness

The ability of the nervous system to accommodate changes to joint mechanics is crucial in the maintenance of joint stability and the prevention of injury. This neuromechanical coupling is achieved through several mechanisms such as the central and peripheral regulation of muscle tone and subsequent alterations to joint stiffness. Following joint injury, such as a ligamentous sprains, some patients develop functional instability or require surgery to stabilize the joint, while others are able to cope and display limited impairments. Several researchers have attempted to explain these divergent outcomes, although research using proprioceptive tasks and quantifying reaction times has led to equivocal results. Recent innovations have allowed for the simultaneous measurement of mechanical and nervous system function among these subsets. The intent of this review was to explore the relationships between joint stiffness and nervous system function, and how it changes following injury. By better understanding these mechanisms, researchers and clinicians may better develop and implement rehabilitation protocols to target individual deficits among injured populations.