IV. MUSCLE ASSOCIATIONS

A. IPSILATERAL ASSOCIATION

This section of this chapter and Chapter V are perhaps the most important as far as the localization, evaluation, and treatment of organ and cardiovascular pathologies are concerned (with the exception of injuries to the cerebral hemispheres as cerebrovascular accidents and other forms of brain damage). The term pathology refers to any abnormal deviation from the normal or healthy condition of an organ, nervous pathway, or blood vessel. Pathology to an organ, the colon for instance, could be self-limited in cases of diverticulosis, diverticulitis or small polyps or it could involve many other organs as in the presence of adenocarcinoma.

A differential diagnosis of the gravity of a condition can be established by a global evaluation of the organic, nervous, and vascular systems. Our clinical experience has systematically confirmed the close relationship between muscles and their related cutaneous sensory nerve endings and specific organs. The stimulation of afferent nerve endings produces a response in the associated organs, in all probability through the channels of the reticular formation, even if the initial stimuli to the sensory nerve endings are first picked up by the dorsal column system, the spinothalamic system, or the spinocerebellar tract (see Chapter V).

In the chapter on neurology, we have seen that the reticular formation is concerned with autonomic functions and primitive motor control and that it reaches every organ and muscle of the body through its multi-synaptic ramifications. Another important feature of the reticular formation is that most of the ascending and descending fibers are uncrossed fibers.

The descending reticular formation is mostly an ipsilateral system of double innervating to the organs and muscles: the lateral reticulo spinal tract reaches the preganglionic autonomic fibers and the medial reticulo spinal tract reaches the lower motor neurons (see Figure 1-7).

We have found that a pathology to an organ, joint, or bone will reveal itself by a dual imbalance of the proximal and distal agonistic and antagonistic muscles, tendons, or joint structures associated with it. Cystitis, for instance, will reveal a double imbalance of the flexors and extensors of the foot, the hand, the neck, and locally of the lower abdominals and the last lumbars.

We will therefore classify the ipsilaterally associated muscles according to their ipsilateral counterparts. Muscles on the left or on the right side of the centerline, or gravity line, have identical associated muscles. Therefore, in the following classification, there is no need to specify if muscles are on the left or right hand of the body.

The following tables show clinically deduced associations (see Figures 4-1 to 4-11):

We will now turn our attention to the muscles that act as stabilizers of the hip and shoulder joints. As we mentioned earlier, the infraspinatus is the ipsilateral complement or counterpart of the gluteus medius. The teres minor is the complement of the gluteus minimus, and the supraspinatus is the ipsilateral complement of the tensor of the fascia lata (see Figures 4-10).

Let us now briefly describe the aforementioned muscles:

The gluteus medius is located on the outer surface of the ilium. Its origin is situated between the superior and middle curved lines, and its insertion point is on the great trochanter.

The gluteus minimus is located beneath the gluteus medius and also arises from the outer surface of the ilium between the middle and inferior curved lines. Its insertion is on the anterior border of the great trochanter.

The tensor of the fascia lata arises from the outer lip of the crest of the ilium and the anterior superior iliac spine, and it follows the outer side of the thigh to become the ilio-tibial band that inserts on the external tuberosity of the tibia.

The main activity of these three muscles is to stabilize the hip joint in the standing position and to support the body when standing on one limb. These muscles also protect and prevent a dislocation of the hip when a person jumps down on the ground from a higher elevation. The tensor of the fascia lata is an internal rotator, flexor, and abductor of the lower limb. The gluteus medius is an abductor of the thigh. It is also an internal rotator and extensor when contracting the anterior muscle fibers and is an external rotator and extensor when contracting the posterior muscle segment. The gluteus minimus is an external rotator and a weak abductor.

The infraspinatus arises from the internal two-thirds of the infraspinous fossa. The fibers of the muscle converge to a tendon that inserts into the middle facet of the great tuberosity of the humerus.

The teres minor arises from the upper two-thirds of the external border of the scapula. Its fibers terminate in a tendon that inserts into the inferior facet of the great tuberosity of the humerus.

The supraspinatus finds its origin in the supraspinous fossa. Muscle fibers converge to a tendon that inserts on the superior facet of the great tuberosity of the humerus.

The main activity of the latter three muscles is to protect the shoulder joint. The supraspinatus prevents the displacement of the head of the humerus upwards when a stress is applied vertically and upward on the axis of the humerus as, for example, when an individual supports his body with the help of the upper limbs only. The infraspinatus and the teres minor prevent the backward dislocation of the shoulder joint if a blow or a very strong pressure is applied to the head of the humerus from the front to the back. The supraspinatus also assists the deltoid in raising the arm during abduction. The infraspinatus and teres minor are both external rotators of the arm.