From my previous few articles, in which I reviewed the various fascial planes and slings, it should be obvious that postural changes, asymmetries and compensations are detrimental to human performance. For posture to be possible, normal postural reflexes must be in operation, maintaining perfect balance between opposing muscle groups (see the works of Janda with respect to tonic versus phasic muscle groups).
Since there are numerous causes of poor or compensatory/adaptive posture, only a few will be mentioned in this article. Joints are the location of many of the alterations of an adaptive frame. Joint dysfunction complex as a result of trauma, either macro or micro in nature, is frequently accompanied by disturbances in other systems; balance and autonomic concomitants are but two examples. The maintenance of balance involves many feedback systems and is far too complex to develop in this short column. Suffice it to say that until the dysfunction is corrected, postural defects will occur and joint compensations throughout the musculoskeletal system will be activated.
Diseases of bones and joints accompanied by productive or destructive changes are evident when compensatory or asymmetrical gait results from postural alterations. With joint dysfunction or disease, time brings disease of the muscular system. This is a result of changes in joint tension and position, a proprioceptive feedback mechanism. Partial or complete loss of action/activity by one group of muscles permits the antagonist to act without opposition, i.e. with anterior head carriage and time, there is a weakening of the hip flexors resulting in the deep erector spinae and the multifidus to act in an unopposed manner.
Clearly, one can visualize the gait changes and secondary postural adaptations that will occur from this dysfunctional state. From a joint articulation point of view, aberrant or decreased motion results in a barrage of nociceptive afferent input. Dysafferentation of the peripheral and central nervous system results, producing alterations in muscle action, joint stability (a reason for postural rehabilitation - see Dr. Craig Leibenson's text Rehabilitation of the Spine: A practitioner's Manual for a detailed explanation) and body balance. Superimpose upon this scenario a nutritional deficit. The result is impaired trophic function, fatigue and general weakness, which so frequently accompany convalescence or inactive lifestyles and are responsible for a large number of postural changes a nd compensations in our patients. Abnormal gait patterns usually point to postural compensations, and visualization of the patient prior to examination is of great clinical significance.
Habit and occupation are both associated with the position of various portions of our bodies that over time cause postural compensation, creep, hysteresis and set, and result in postural attitude alterations. These changes in position and function cause serious biomechanical changes and joint complex dysfunction. The normal segmental weightbearing of the body is widely distributed, and the function is often transferred to a joint or joints that are not intended for it, i.e., asymmetrical overload syndromes or right and/or left frontal plane asymmetries are the result of such shifts in the functional symmetry of joint surfaces.
The importance of the above should not be underestimated. Symmetries often become effective early in life when the developing framework of the child is subjected to prolonged postural positions, as in sitting or as a result of a sedentary lifestyle. Instances in which poor posture has been assumed for a relief of pain are well-known and well-documented. For expample the strong tendency of the body to keep the eyes on a horizontal plane accounts for the scoliosis that so characteristically accompanies torticollis from whatever cause.
As I explained in my previous series of articles, the various systems of the body are interconnected and interrelated in so many ways that in considering changes in one, the others must also be noted if our evaluations and subsequent treatments are to be correct. To be correct, the maintenance of posture depends upon a neuromusculoskeletal system held in correct relation, controlled by muscles acting under the direct influence of the nervous system. For a very quick review of the neurology of the subluxation and the neurology of the chiropractic adjustment, see Chiropractic and Pain Control by David Seaman,DC,DABCN.
Normal metabolic processes are essential, for the proper nutrition of these systems. When poor posture exists, unfavorable changes take place, altering the structure of parts, disturbing their normal relations; normal muscular balance is lost. Oxygenation of tissues can be reduced by postural and gait abnormalities. According to Dr. Tom Dorman, such abnormalities may be responsible for the chronic fatigue in the elderly when attempting to do their normal duties. The majority of marked postural deformities develop slowly and are often detectable in the very young as visual postural closed kinetic chain activities are observed. The postural deformities and compensations are the result of a series of changes on a time continuum. From the onset, there is some disturbance of vertebral mechanics since the weight bearing is shifted, producing various degrees of joint stress and eventually strain, followed by creep, hysteresis and set.
Posture and postural changes in the form of pelvic or spinal compensation can and do result from improper foot and ankle mechanics. This (and the fascial continuities of the posterior compartment complex and first ray complex) will be the topic of my next column.
