Senior Health

Removing the Underlying Cause of Joint Damage

Mark Charrette, DC

It's my belief that when it comes to treating patients, every case is distinct, requiring a unique treatment plan. But what if you could effectively enhance responses to your chiropractic care in 80 percent of your adult patients? Wouldn't that be a boon to your practice? There is a coordinated interplay between movements of the lower extremity and stability of the pelvis and spine. In fact, because proper vertebral function is intimately related with a coordinated gait,1 foot problems such as excessive or asymmetrical pronation may be the underlying cause of the subluxations you are treating.

It is noteworthy that both low back pain and foot problems affect roughly the same percentages of adults – four of five or 80 percent.2 However, most patients with foot problems experience little or no pain in their feet. The feet are designed to be both flexible adapters to various ground conditions and rigid foundational platforms for the entire body. Because of this adaptability, the actual site of pain predominantly manifests farther up the body's kinetic chain. Rather than experiencing foot pain, patients present with pain in the knees, hips, pelvis and neck.

Unfortunately, too often a patient's need for stabilizing orthotics may be considered only after an inadequate response to chiropractic care. Let's explore the major non-foot indicators that highlight the need for orthotics. Patients with an obvious need should be scanned (or casted) and fitted early in their treatment plan. Consistent use with your adult patients will facilitate a positive response to your adjustments and prevent frustration both for the patient and you, the doctor.

Kinetic-Chain Relationships

It is important to appreciate the prevalence of pedal instabilities and understand the kinetic-chain relationships that exist throughout the body. According to Magee, "at least 80 percent of the general population has foot problems that can often be corrected by proper assessment, treatment, and, above all, care of the feet. Lesions of the ankle and foot can alter the mechanics of gait and, as a result, cause stress on other lower limb joints; this in turn may lead to pathology in these joints."3 Dananberg has clearly established certain gait patterns as an etiology of chronic postural pain.4 Furthermore, not only does this affect joints, but also "any change in foot position affects the posture of the entire body above it. The somatovisceral changes, and vice versa, can wreak havoc on the entire body."5

The most common structural misalignment of the lower extremity is excessive pronation, affecting primarily the medial arch. Inferior and medial displacement of the talus pulls the tibia into excessive internal rotation. To a lesser degree, the femur also rotates internally, despite resistance from the piriformis. Because of its origin on the sacrum, piriformis contractures create an anterior-inferior sacrum and stimulate the antagonist to this misalignment, the gluteus maximus. The gluteus maximus irritation promotes a posterior-inferior innominate rotation and hypertonic hamstrings.

This typical lower extremity and pelvic distortion pattern continues its devastation into the spine. According to Lovett's Law, the lowest freely moving lumbar body will rotate to the side of the inferior sacrum, creating a functional lateral lumbar curvature. Furthermore, according to Free, the trapezius on the side of the hypertonic hamstrings may create an occiput inferiority and an atlas laterality, "with cervical pain on the side of the tight hamstring."6

Just as we educate our patients, it's important not to confuse asymptomatic, or pain free, with non-subluxated or non-involved. When you observe findings in any of the following areas, consider the condition of your patient's feet.

The Knees

As the biomechanical link between the ankle and pelvis, this hinge-like joint bears the brunt of excessive rotational torquing during hyperpronation. If this conversion of torque occurs beyond normal limits, the tibia can subluxate in internal rotation. It is an excess of these rotational forces that results in repetitive microtraumas. Designed primarily for flexion and extension, it is no surprise why the knee is the most common extraspinal site of degenerative arthritis.7

The most common cause of degenerative joint disease is the presence of abnormal biomechanical forces on a normal or healthy joint. Excessive pronation causes internal tibial fixation and stretches the knee's supportive ligaments. Treatment that ignores involvement of the feet will never remove the underlying cause of this joint destruction.

Leg-Length Inequality and Pelvic Misalignments

Leg-length inequality (LLI) is categorized as either structural or functional. Both types result in similar adaptations throughout the musculoskeletal system and are difficult to distinguish without extensive evaluation. Obvious clinical findings include rotations in the pelvis and lumbar spine, with associated lumbosacral and paraspinal strains. Because of adaptation, patients may be unaware of their LLI, and the first indication is often found on a routine, weight-bearing, A-P lumbopelvic radiograph.

Excessive pronation or pelvic unleveling can each create a functional LLI that produces lateral spinal curvatures. The resulting muscular tension manifests in the paraspinals and quadratus lumborum, and LLI has been reported as a significant contributing factor in lumbosacral strains.8 Depending on whether the inequality is structural or functional, a combination of stabilizing orthotics and lift support help eliminate the biomechanical stress of LLI. The next time your A-P lumbopelvic film reveals misalignments or unleveling, evaluate the feet.

The Cervical Spine

Lack of stability in the feet involves all three arches. With hyperpronation, the anterior metatarsal arch collapses and shifts the body's center of gravity forward. The resulting pelvic anterior translation produces increased lumbar lordosis and thoracic kyphosis and extension. Attempting to maintain the head over the new center of gravity, patients will decrease their cervical lordosis while translating the head anterior.

The result is that the delicate cervical muscles designed for fine motor control are recruited for postural stability – a task for which they are inefficient and one that predisposes the patient to tension headaches. Repeatedly adjusting the same spinal segments suggests poor structural support for that region.

As you improve posture and support the feet, you stabilize the interplay between the lower extremity and the pelvis and spine. Realizing that 80 percent of adults have foot and back problems (the percentage is probably higher in the average chiropractic office), it is essential to augment your care of the spine by supporting the feet. Evaluating your patients for individually designed stabilizing orthotics early in their care gives you an effective tool to break up the consistent and destructive patterns of misalignment that result from excessive pronation.

References

  1. Yekutiel MP. The role of vertebral movement in gait: implications for manual therapy. J Man Manip Ther, 1994;2:22-27.
  2. Schafer RC. Chiropractic Management of Sports and Recreational Injuries. Baltimore: Williams & Wilkins, 1982:443, 517.
  3. Magee DJ. Orthopedic Physical Assessment. St. Louis: W.B. Saunders, 1987:448.
  4. Dananberg HJ. Gait style as an etiology to chronic postural pain, parts I and II. J Am Podiatr Med Assoc, 1993; 83(8):433-441 and 83(11):615-624.
  5. Valmassy R, Subotnick SI. Orthoses. In: Subotnick SI, Strauss M, eds.: Sports Medicine of the Lower Extremity. St. Louis: W.B. Saunders, 1999:466.
  6. Free RV. Some common denominators in spinal misalignments, part 2. Digest Chiro Econ, 1988;30(6):128-129.
  7. Barron MC, Rubin BR. Managing osteoarthritic knee pain. J Am Osteopath Assoc, 2007; Nov;107(10 Suppl 6):ES21-27.
  8. Winterstein J. Lower Extremity Inequality: Short Leg Syndrome. In: Lawrence D, ed.: Fundamentals of Chiropractic Diagnosis and Management. Baltimore: Williams & Wilkins, 1990.
July 2012
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