Postural dynamics: clinical and empirical implications.

OBJECTIVE To provide a rationale for the examination of posture from a dynamic (behavioral) perspective and to relate the vertebral subluxation to postural instability and motion sickness via inefficiency. DATA COLLECTION A manual search of available reference texts and a computer search of literature from Index Medicus, PsycINFO, and ISI Science Citation Index Expanded were collected with an emphasis on postural dynamics, vertebral subluxation, and motion sickness. RESULTS Evidence linking behavioral and health research has emerged from the study of posture and postural dynamics. Studies examining the relation between postural control and motion sickness have shown that motion sickness is preceded and predicted by postural instability. Motion sickness is characterized by maladaptive response to unusual motion events. The symptoms are nonspecific and variable. Although the Postural Instability theory of motion sickness predicted that instability should precede sickness, it did not make any claims regarding the symptoms associated with it. Chiropractic literature has emphasized the effects of vertebral subluxation on neurologic dysfunction. Vertebral subluxation is a condition that is postulated to interfere with neurologic processes and may influence organ system function and general health. As in the case of motion sickness, symptoms are nonspecific and variable (and in some instances the person may have no symptoms). So what do these disorders have in common? In each instance the disruptions lead to inefficiency in the system. CONCLUSION Given this potential commonality, we propose that some of the methods used by behavioral researchers to study postural dynamics may also be of great utility to health care practitioners and psychologists alike. Furthermore we propose that this link will provide a framework that will allow scientists to address seemingly intractable problems such as motion sickness or subluxation.