ROLE OF MOBILIZATION

ROLE OF MOBILIZATION

The mobilization techniques are supposed to induce several beneficial effects. The neurophysiological effect is based on the stimulation of peripheral mechanoreceptors and the inhibition of nociceptors. The biomechanical effect is the result of forces directed at the joint resistance within the limits of the patient's tolerance. The main functions of joint mobilization are to restore joint mobility and facilitate correct biomechanics of the structures involved. The neurophysiological effect is based on the stimulation of peripheral mechanoreceptors and the inhibition of nociceptors (pain fibers). Nociceptors are unmyelinated nerve fibers, which have a higher stimulation threshold than mechanoreceptors.

Evidence indicates that stimulation of peripheral mechanoreceptors blocks pain transmission to the central nervous system. Wyke hypothesized that this phenomenon is the result of a direct release of inhibitory transmitters within the basal spinal nucleus that inhibits the forward flow of incoming nociceptive afferent activity. Joint mobilization is a method of improving the rate of discharge of mechanoreceptors, thereby reducing the intensity of many types of pain. The biomechanical effect of joint mobilization focuses on direct tension of the periarticular tissue to prevent complications resulting from immobilization and trauma. Lack of stress on the connective tissue causes changes in normal joint mobility. The periarticular tissue and the muscles surrounding the joint show significant changes after periods of immobilization. Frank et al and Akeson et al reported a decrease in water and glycosaminoglycans (GAG, the lubricant of fibrous tissue), an increase in fatty fibrous infiltrates (which can form adhesions as they mature and become scars), an increase in the cross of abnormally positioned collagen - links (which can contribute to the inhibition of slippage of collagen fibers) and loss of orientation of the fibers within the ligaments (a loss that significantly reduces their strength). Passive movement or tension in the tissue can help prevent these changes by maintaining tissue homeostasis. The exact prevention mechanisms are uncertain.

Contraindications

We can understand contraindications to joint mobilization by becoming aware of the common abuses of passive movement. The abuses of passive movement can be broken down into two categories: creating an excessive trauma to the tissue and causing undesirable or abnormal mobility. Improper

techniques, such as extreme force, poor direction of stress, and excessive velocity, may result in serious secondary injury. In addition, mobilization to joints that are moving normally or that are hypermobile can create or increase joint instability. Ultimately, selection of a specific technique determines the contraindications. For example, the very gentle grade I oscillations, as described by Maitland, rarely have contraindications. These techniques are mainly used to block pain. They are of small amplitude and controlled velocity. In contrast, manipulative techniques have many contraindications. Haldeman

described the following conditions as major contraindications to thrust techniques: arthritides, dislocation, hypermobility, recent trauma, bone weakness and destructive disease, circulatory disturbances, neurologic dysfunction, and infectious disease.

Principles of Joint Mobilization Techniques:

Specificity of Manual Techniques

Manual therapy techniques are designed to restore intimate joint mechanics. Several general principles should be remembered during application of the techniques. Hand Position The mobilization hand should be placed as close as possible to the joint surface, and the forces applied should be tangent to the joint and directed at the restricted periarticular tissue. The stabilization hand counteracts the movement of the mobilizing hand by applying an equal but opposite force, or by supporting or preventing movement at surrounding joints. Excessive tension in the therapist’s hands during joint mobilization can cause the patient to guard against the mobilization.

Direction of Movement

The direction of movement of mobilization should take into account the mechanics of the joint mobilized, the arthrokinematic and osteokinematic impairments of the dysfunction, and the current reactivity of the involved tissue. However, the major consideration should be moving the humeral head into the restriction or into the barrier. A study that investigated the presence of the cytocontractile protein vimentin in

the connective tissue of patients with adhesive capsulitis demonstrated that contracture resulted from selective involvement of the anterior capsule. The rotator cuff interval, the coracohumeral ligament, and the axillary fold were noted to be the specific areas in the anterior capsule that demonstrated the greatest amount of vimentin. The study showed that fibroplasia, heavy production of type III collagen fibers, involved the entire joint capsule.  The clinical implication of this study is that manual therapy for patients with adhesive capsulitis must focus on the coracohumeral ligament, rotator cuff interval, and axillary fold areas of the anterior capsule. Noevidence of contracture of the posterior capsule was reported.

Specificity of the direction of imposed demand may result in more successful outcomes of manual therapy.

Post a Comment

0 Comments