Posture

By Peter Rouse, Director Optimum Performance

The production of movement depends on the structural integrity and alignment of the Kinetic Chain, this structural alignment is known as posture.

Definition of Posture by the Academy of Orthopaedic Surgeons, 1947: Posture is usually defined as the relative arrangement of the parts of the body. Good posture is that state of muscular and skeletal balance which protects the supporting structures of the body against injury or progressive deformity irrespective of the attitude (erect, lying, squatting, and stooping) in which these structures are working or resting.

Posture is the independent and interdependent alignment (Static Posture) and function (Transitional and Dynamic Posture) of all components of the kinetic chain at any given moment and is under the control of the central nervous system.

Static postural alignment is best described in terms of the positions of the various joints and body segments, however it should be noted that it has been demonstrated by Hellebrandt (1940) that even the static standing posture is not in fact completely static but rather “movement upon a stationary base”. It was revealed that the centre of gravity did not remain motionless above the base of support no matter how still the Client attempted to stand.

Transitional posture refers to maintaining posture through transitional movements. An example of this is when sitting down into a chair. Dynamic posture refers to maintaining posture more through dynamic movement as can be seen in many sports.

The musculoskeletal system is designed to work in a mechanically and physiological efficient manner to use the least possible amount of energy. Feldenkrais showed that the poorer the posture, the more energy it takes to move the body.

Ideal functional posture maintains the structural integrity and optimum alignment of each component of the Kinetic Chain. This promotes optimum length-tension relationships, force-couple relationships and joint kinematics.

A client with poor posture is more likely to have greater stress in the stabilizer muscles and joints because movements begins and ends in poor posture, and because alignment is poor. Also, the increased stress on the joint and stabilizer musculature will increase the likelihood of injury.

The Kinetic Chain consists of the myofascial system, articular system and the neural system. The central nervous system, through a process called sensorimotor integration, sorts the cumulative information from these three systems and allows for neuromuscular control.

Component movements of the kinetic chain are predictable based on anatomical, biomechanical, and structural concepts. The summation of individual motion segments creates predictable patterns of motion, which are all controlled by the central nervous system. If one component in the kinetic chain is out of alignment, it will create predictable pattern of tissue overload and dysfunction, leading to decreased neuromuscular control and initiation of the cumulative injury cycle. The cumulative injury cycle causes decreased performance and eventually injury.

Davis’ Law states that soft tissue models along the lines of stress. If soft tissue has an inelastic collagen matrix that forms in a random fashion, the result can be alterations in normal tissue extensibility. Appropriate flexibility training must be utilized to restore the normal extensibility of the entire soft tissue complex.

These predictable patterns of dysfunction are referred to as Serial Distortion Patterns. Serial Distortion Patterns refer to the state in which the structural integrity of the kinetic chain is compromised because components of that kinetic chain are out of alignment.

This places abnormal distorting forces on the structures of the kinetic chain that are above and below the dysfunctional segment. For example, if one segment in the kinetic chain is out of alignment, (cervical spine in an upper cross syndrome), then other movement segments have to compensate in attempts to balance the weight distribution of the dysfunctional segment. The kinetic chain seeks structural and functional efficiency.

Most people do not consider the effects of posture until pain or discomfort is felt. Pain related to postural deviations is a common clinical occurrence. Poor posture contributes to more that just an aesthetic problem but could be the cause of many elements that your client may be showing this making it the first place to start.

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