What functional pathologies are typically associated with pain? Depending on one's individual approach any or all of the following may be pursued: joint dysfunction, trigger points, or muscle imbalances. Different functional pathologies are screened for in the hope that a "key link" will be found. Such a key link gives the clinician a foothold in the management of pain syndromes related to dysfunction. The chiropractor believes that there is a pivotal dysfunction which if found and treated will help alleviate pain.
Such an approach is important for treating pain because dysfunction is the primary cause of pain in the motor system.1 Even with structural pathology the critical difference between symptomatic and asymptomatic structural pathology is most likely due to dysfunction.2 A patient's recovery is contingent on restoring function in the motor system.
Assessment of structural pathology or disease is important for ruling out "red flags" for urgent or emergency referral. But the vast majority of patients do not have clinically significant structural pathology (90 percent). In these patients it is the assessment of function/dysfunction of the motor system which is paramount. Since functional pathologies are present in everyone we must identify "chains" of functional pathology which are related to a patient's symptoms or decompensation.3 Most importantly, our assessment should identify the key link in a patient's dysfunctional chain which either reflexly or biomechanically has the most significant effect on the the motor system. Such a key link is the starting point for efficient, efficacious treatment. This is the intrinsic dysfunction which is the beginning point for manipulative therapy or chiropractic.
Chain reactions involving pathokinesiology and abnormal arthrokinematics occur commonly. Gait is the classic example of an activity occurring as part of a kinetic chain. Faulty gait often results from forefoot instability (i.e., hyperpronation) during mid-stance to toe off. This can travel up the chain and lead to knee, hip and low back problems. Another example of a kinetic chain involves the muscles, joints and motor program for reaching, grasping, carrying, or prehension. A dysfunction of the sternoclavicular or glenohumeral joints or muscle imbalance of the scapulothoracic muscles will result in a loss of the normal scapulohumeral rhythm. In the end the patient may develop wrist/elbow repetitive strain syndromes or myofascial syndromes of the head and neck. One should think of the craniomandibular system as being part of a kinetic chain responsible for mastication. Masticatory muscle dysfunction may affect the temperomandibular and cervicocranial joints resulting in jaw, facial, head or neck pain. Interface between muscles and joints is the rule rather than the exception in the motor system.
Chain reactions linking various dysfunctional tissues involved in a task occur as a normal consequence of soft tissue overload. Muscles being the active component of the motor system adapt and may eventually fatigue. Panjabi says, "the muscles and tendons ... are the means through which the spinal system generates forces and provides the required stability to the spine."4 Bogduk and Twomey say, "such processes may underlie what might otherwise be called 'fatigue' in a ligament or capsule. After prolonged strain, ligaments, capsules, and intervertebral discs of the lumbar spine may creep, and they may be liable to injury if sudden forces are unexpectedly applied during their vulnerable, recovery phase."5
The key link is what every chiropractor searches for. The best DCs are the ones who find a key link and then with a single adjustment "magically" achieve a dramatic, far reaching effect on the locomotor system. Chain reactions in the motor system provide the most reliable "map" of this terrain. Of course, the question of how long will the positive effect last is the great weakness of this approach! If extrinsic stressors (i.e., faulty ergonomics, repetitive overload) are present as perpetuating factors then short term results will be the rule rather than the exception. Unless the chiropractor and patient are content to repeat their magic act on a regular basis recurrences are likely. It is considered more cost effective to pursue active rehabilitation rather than becoming dependent on passive interventions.6 The goal of rehabilitation is to achieve a level of functional restoration so that the patient can safely manage the "demands" of their occupation or lifestyle.
All too often the chiropractic approach suffers because it does not adequately rehabilitate the motor system. According to Janda there are four stages to rehabilitation.7
- Normalize Joint Function
- Relax and/or Stretch Hypertonic Muscles
- Facilitate and/or Strengthen Inhibited Muscles
- Reprogram Coordinated Movement Subcortically
Successful manipulation to a key link will have a distant effect throughout the kinetic chain. It has the potential to not only reduce a local fixation, but to have a reflex effect on hypertonic and inhibited muscles related segmentally or functionally. But if there is cerebellar involvement, peripheral treatment with manipulation is unlikely to reach deep enough into the central nervous system to reprogram subcortical movement patterns. According to Panjabi, the central nervous system controls motor responses, "the neural subsystem receives information from the various transducers, determines specific requirements for spinal stability, and causes the active subsystem to achieve the stability goal."4 Janda proposes propriosensory treatments such as balance training as the mainstay of subcortical training.8 Sensory motor stimulation from the soles of the feet (rocker/wobble boards or balance shoes) or pelvis (gymnastic balls) can increase the speed of activation of inhibited muscles and decrease the irritability threshold of hypertonic muscles on a subcortical or semi-automatic basis.9,10
Chiropractors who realize the limitations of the adjustment model can avoid the disappointment of achieving only short-term results. Manipulation and rehabilitation must be joined together to achieve lasting results. Mastering the evaluation of functional chains (gait, prehension, mastication, etc.) and finding a key link amenable to manipulation is the first step. Then, it is necessary to search for extrinsic factors which can be addressed through education and ergonomics to reduce exposure to harmful stress and strain. Finally, specific rehabilitation goals must be established such as relaxing overactive muscles, facilitating weak muscles, and improving the quality of basic movement patterns (i.e., gait, lifting, carrying, etc.). Manipulation has proven it can accelerate both pain relief and return to work. But can we improve our track record with respect to high recurrence rates? Education and exercise are the keys to preventing reinjury and recurrence.
- Lewit K. Manipulative Therapy in Rehabilitation of the Motor System. 2nd edition. London: Butterworths, 1991.
- Lewit K. The functional approach. J Orth Med 1994;16;73-74.
- Lewit K. Manipulation and rehabilitation. In Rehabilitation of the Spine: A Practitioner's Manual, Liebenson C (ed). Williams and Wilkins, Baltimore, 1995.
- Panjabi MM. The stabilizing system of the spine. Part 1. Function, dysfunction, adaptation, and enhancement. J Spinal Disorders 1992;5:383-389.
- Bogduk N, Twomey LT. Clinical Anatomy of the Lumbar Spine. 2nd edition. Churchill Livingstone, Melbourne, 1991.
- Clinical Standards Advisory Group: Back Pain, London 1994, HMSO
- Jull G, Janda V. Muscles and motor control in low back pain. In Twomney LT, Taylor JR eds. Physical Therapy for the Low Back, Clinics in Physical Therapy, Churchill Livingstone, New York, 1987.
- Janda V, Vavrova M. Propriosensory training. In Rehabilitation of the Spine: A Practitioner's Manual , Liebenson C (ed). Williams and Wilkins, Baltimore, 1995.
- Bullock-Saxton JE, Janda V, Bullock MI. Reflex activation of gluteal muscles in walking. Spine 18:6;704-708, 1993.
- Konradsen L, Ravn JB. Ankle instability caused by prolonged peroneal reaction time. Acta Orthopaedica Scan 1990;61:388-390.
Craig Liebenson, DC
Los Angeles, California
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