The Kinetic Chain

 

Many chronic or recurring spinal, pelvic, sacroiliac, and lower extremity complaints are associated with musculoskeletal disorders while walking.  How you walk tells the chiropractor a lot.  The main part of human walking happens when the foot is in weight-bearing contact with the ground or floor.  While the feet are supporting the rest of the body it is the first line of defense against gravitational and stress forces. This is when most of our musculoskeletal problems occur according to Dr. William M. Austin in his article called, “Walking:  The Effects on the Spine.”  Only when the foot is examined in its position of function (weight-bearing) can custom-made orthotics be created which provide the proper support for the individual’s unique postural problems.

 

When a foot goes forward and inward, there is a rotation of the entire leg and pelvis.  The increased rotational forces are transmitted into the pelvis, the sacroiliac joint and lumbar spine (lower back).  The pelvic area tilts to the front or to one side and many complications arise.  Until excessive pronation is corrected with custom-made Orthotics only short-term relief can be achieved with chiropractic adjustment.  Incorrect or excessive movements at any of these sub-phases send pounding bio-mechanical shocks to the knees, pelvis, and spine causing problems to develop.

 

According to an article called,” The Short Leg” by Dr. Terry R. Yochum human beings squander time and energy when walking on a short leg.  Leg Length Insufficiency or inequality (LLI) should concern the chiropractor because of the effect on the body’s functional integrity.  Every human body presents some degree of asymmetry.  Most clinical examinations cannot detect LLI less than 25 mm, and patients themselves may be unaware of the condition. LLI is the primary cause of low-back pain, unilateral hip arthrosis, and lower extremity stress.

 

LLI can be categorized as structural or functional.  Both types evoke similar responses in the musculoskeletal system when present for sustained periods.  First, the lumbar spine usually compensates by forming a curve to the side of the short leg.  The pelvis and sacral base incline likewise, toward the deficient side.  Second, the lumbar vertebral segments normally rotate the spinous process to the concavity of the curve and the bodies rotate to the convexity.  Third, this coupled lateral bending and rotation creates stress to the intervertebral discs.  The center of gravity is shifted to the unlevel side.  Increased stress and energy expenditure result from walking or running.  According to Dr. Yochum clinical research confirms the correlation of pain and LLI in 79 to 89% of patients’ studies.

 

Leg length insufficiency can occur due to unequal growth rates, fractures, deformities, or altered joint architecture.  Functional leg length insufficiency refers to leg length differences not caused by anatomical deficiency.  This type of short leg results from excessive foot pronation, muscle contractures, or pelvic and sacral subluxations.

 

The structural misalignment with prolonged cases of LLI affects muscular pull and the amount of weight borne by the joints.  The body can tolerate such abnormalities for short periods, but when weight and pull fall abnormally on the musculoskeletal system, serious and often subtle consequences can occur.  The body’s adaptation resources become exhausted, and routine movements require greater muscular effort.  Endurance is reduced and strain on the body increases.  Stress can be transmitted to the ligaments, creating a vicious cycle of misalignment, muscle fatigue, and ligament stress.  These problems of LLI are troubling with activities that require fine balance or equal leg strength and control.  Patients who spend a great deal of time on their feet, athlete, and other active individuals are most like to exhibit clinical systems related to LLI.

 

A disturbance in one area of the body can cause immediate adaptation and functional change in another area.  Some studies have identified various signs and symptoms that accompany LLI:  One sign is that the ankle on the side of LLI is commonly excessively pronated as the foot is planted on the ground.  This forces the foot outward and causes excessive tibial torsion.  A second sign is that LLI has a negative effect on oxygen usage.  Dr. Yochum verified by a subsequent study that shoe lifts could improve oxygen consumption.

 

Both visual and radiographic procedures can be used to detect the presence of leg length insufficiency.  Dr. Daniel L. Moore can determine the clinical management for LLI if you are experiencing any of these conditions.

By Janice Rudeen

 

 

 

 

 

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