Posture is the state of balance and coordination of musculoskeletal and visceral systems. Skeletal asymmetry is a major source of muscle strain inasmuch as compensatory muscular control is necessary to maintain a working posture and to keep the eyes level. For example, a length discrepancy between the lower limbs causes a chain reaction of muscular overloads of the entire musculoskeletal system. The tilted pelvis requires contraction of the quadra-tus lumborum muscle to curve the lumbar spine in order to bring the rest of the body over the pelvis. Consequently, the spine above is tilted to the other side. This tilt requires further compensation of neck muscles such as the sternocleidomastoid and upper trapezius. This sustained contraction and overload facilitates the development of trigger points inside the postural muscles, from gastrocnemius through soleus, adductors, iliotibial band, gluteus muscles, piriformis, iliopsoas, quadratus lumborum, muscles of the shoulder girdle, trapezius, and neck muscles.
Any of the muscles in this series can be the cause of a similar chain reaction if they are fatigued, rigid, shortened, or injured. This chain reaction degrades the coordination and function of the musculosk-eletal system and creates musculoskeletal pain. It has been shown that trigger points in one muscle may reflexively inhibit the activity of a functionally related muscle in the same region.5
Postural pain has both muscular and ligamen-tous origins. The critical role of muscle overload and muscle strain in posturally induced musculosk-eletal pain merits more clinical attention. A triggerpoint structure develops within muscles that have been affected by acute episodic overload, by sustained contraction (as in asymmetric posture), by excessive repetition of the same movement, or by being left in a shortened position for a period of time. In addition to the pain caused by muscles, electromyographic data demonstrate that sustained tension on the joint capsule and ligaments can also cause pain.6 Thus endogenous contracture, as well as a trigger-point structure, develops in joint capsules and ligaments. Knowledge of this physiologic process helps clinicians understand why athletes, and even nonathletic healthy people, need regular integrative systemic dry needling (ISDN) to restore and maintain normal physiology of the soft tissues.
Was this article helpful?
This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.