TMS and Postural Muscle Imbalances

As chiropractic physicians we often see our patients presenting with "poor posture" and posture-related problems, such as headaches and low back pain. Our chiropractic education emphasized observance of the patient's posture, noting anterior head held position, increased or decreased lordosis, and the presence or absence of a scoliotic curve.

Posture, much like the weather, is discussed, but very little is done about it. We make our patients aware of their posture and tell them to stand straighter, and to possibly exercise muscles that appear to be weaker than they should be.

Granted, there are many situations in which posture is governed by a structural abnormality. Examples include: scoliotic curves due to a hemivertebra or anatomical short leg; hypertrophy of the posterior articular pillars in the cervical spine resulting in a straightened cervical spine; Klippel-Feil syndrome, which is fusion of two or more pairs of cervical segments, in conjunction with undescended scapula; or even traumatic causes such as an anterior vertebral body compression fracture which causes a gibbus presentation of the thoracic spine.

In our usual patient population, poor posture is a result of muscular imbalance from environmental and functional conditions. Environmental conditions include types of furniture sat on during relaxation or work. Functional conditions include positions in which patients perform work, as well as the asymetric or repetitive nature of tasks performed at work or a poorly structured exercise program.

Often in these cases there are muscle groups that appear to be weak; we may recommend exercises to strengthen these muscles to help correct posture. In some cases this may have some beneficial effect. However, most doctors find that changing the patient's posture is not that easy, nor are the results of a strengthening program readily obvious or effective.

Exercise programs typically do not work efficiently to change the patient's posture. One reason, is a neurologic inhibitory response that has not been addressed when describing the exercise program. For example, in a rounded shoulder posture, there is weakened lower scapula stabilizers (rhomboids and middle/lower trapezius muscles). Most doctors recognize this and would prescribe the use of equipment to strengthen these muscle groups. But strength training alone is not effective because there is a reciprocal inhibition of these muscles from over-active upper trapezius and pectoralis major/minor muscles. These muscles which are hyperactive, or facilitated, tend to inhibit their antagonists, allowing for a more rounded shoulder posture.

The upper trapezius inhibits the lower trapezius such that the scapula is lifted higher and rotated outward, while the pectoralis major/minor pulling on the scapula indirectly, as well as directly, inhibit the rhomboids and middle trapezius, which allows the scapula and the glenohumeral joint to roll more forward.

Resultant problems with the rounded shoulder position are further complicated by the increased kyphotic curve which typically results in an increased cervical lordosis which is maintained by the increased facilitation or activation of the sternocleidomastoid muscle, as well as the suboccipital muscles. (Along with that, you will also typically find an inhibition of the deep neck flexors.)

Because of this master-slave relationship between these muscle groups, the agonist and antagonist, treating for the weakened antagonist is usually less effective because of the neurologic inhibition placed on these muscles. Therefore, before the patient trains these muscles, there should be an adequate and biomechanically safe stretching of the hyperactive musculature.

I would like to emphasize the stretching involved should be biomechanically sound in its approach. Stretching fads as well as jazzercise and aerobic activity sometimes produce high stresses with long levers over many joints and this can result in more problems than the original muscular imbalance.

Many examples of poor stretching techniques are seen in popular exercise videotapes or exercise manuals. These stretches fail to take into account the possibility of increased or decreased lordotic curves or cervical spine problems, a situation that as chiropractic physicians we should be aware of when advising patients to stretch.

Therapeutic muscle stretching (TMS) is a form of safe stretching which maximizes the efficiency of the stretch while minimizing the possible damage which might result from an improper stretch. TMS uses basic neurologic reflexes. After a maximal isometric contraction there is a proportional relaxation; agonist and antagonist have a reciprocal inhibition phenomenon when one or the other is contracted.

In performing TMS on patients, the doctor takes into full account the soft tissue and osseous structures that are being possibly compromised and makes every effort to keep the stretch only within the area of the muscle tissue.

In observing people stretching before a running event, you will see many examples of people stretching more of their anterior hip capsule and less of their quadriceps; more their low back and less of their hamstrings.

Using TMS, the doctor guides the patient through the proper contract-relax sequence to achieve a maximum stretch to the muscular tissue. Once these muscle tissues have been stretched, it is more likely that the weaker tissues, the antagonist, will receive less of an inhibitory influence and thus be facilitated and further strengthened by an exercise program.

Clearly all of our patients' postural problems cannot be addressed by muscle stretching. However, a very large percentage of our patients' problems are the result of musculature imbalance, and through the proper application of therapeutic muscle stretching the imbalance can be resolved and the patients' posture has a greater likelihood of becoming a permanent change instead of a temporal phenomenon.

Joseph A. Cimino, D.C.
Portland, Oregon