The awareness of the position and movement of one’s own body. One can think of proprioception as a feedback mechanism: Sensory nerve receptors called proprioceptors, located in the muscles and joints, send the brain information about where the body is and how it is moving. The brain in turn uses the information to make adjustments in position and movement. Proprioception is essential for normal body movement and balance.
The body keeps its balance and regulates its movement using three interdependent systems:
- The system of proprioception described above
- The vestibular system, located in the inner ear, which helps provide the body’s sense of balance, in part by allowing the body to adjust to the changing position of the head
- Vision, which helps orient people to their surroundings
When one of these systems is not working, it is more difficult to stay balanced, and the other systems have to compensate. So, for example, when a person’s eyes are closed, he or she must rely on proprioception and the vestibular system to stay balanced. When prioprioception is affected, the other systems must pick up the slack.
A number of conditions can impair proprioception, including fatigue, alcohol intoxication, and disorders of the inner ear. Studies have also found that osteoarthritis (OA) of the knee is associated with impaired proprioception. People with knee OA may thus be less aware of their knee’s position and movement and be at greater risk of injuring it or of suffering a fall. It is unclear whether, as some researchers speculate, impaired proprioception helps cause OA of the knee (presumably by interfering with proper movement and weight-bearing) or whether OA of the knee somehow damages the joint’s receptors.
In many cases, proprioception can be improved through balance exercises, including such practices as yoga and tai chi. People with poor proprioception can benefit from working with a physical therapist.