Maintaining posture represents the end result of many complex interactions within the body. The ideal neutral erect posture is assumed when the earlobe, tip of the shoulder, hip joint and the malleoli (bump on the side of the ankle) all line up on a plumb line.

Regulation and Control of Posture and Balance

The musculoskeletal tissues of the body including the spine have specialized nerve endings which respond to physical stimuli such as pressure, compression, vibration and stretch. These specialized receptors facilitate the propagation of nerve signals which travel to the central nervous system including the spinal cord. The nerve signals stimulate reflex reactions including changes in the degree of muscle contraction and relaxation. The maintenance of an upright posture involves the integration of various postural reflexes.

The postural reflexes are influenced by numerous factors including sensory (afferent) information from the eyes, the middle ear vestibular apparatus, and the neurological input from specilialized receptors of the musculoskeletal tissues including ligaments, tendons and muscles.

Some patients lose balance and postural control secondary to muscle weakness, a condition which occurs more common in the elderly.  As an individual becomes more sedentary their muscles get smaller in size, a process referred to as muscle atrophy. Loss of muscle size and function leads to less effective postural reflexes and abnormal posture.