Treating A Runner With Proximal Plantar Fasciitis, Hip Pain And A Limb Length Discrepancy

Author(s): 
Joseph C. D’Amico, DPM

   We resolved the left hip pain with appropriate implementation of a 1/4-inch lift on the right side in athletic footwear as well as improvements in hip internal ranges of motion. After the first ESWT treatment, the patient's comfort level was 90 percent and he hadsignificant reduction of heel pain upon arising from bed.

Pertinent Insights On Addressing Limb LengthDiscrepancy

The structural status of most individuals is not completely symmetrical and is usually characterized by one leg being longer than the other. This limb length discrepancy increases with age until ages 16 to 18. At this point, the limb length discrepancy is approximately 1.1 cm and patients usually easily compensate. When there are greater discrepancies than this, a host of debilitating problems may ensue. Most experts agree that limb length discrepancies of 2 cm or greater are enough to cause significant symptomatology. However, even minor discrepancies may result in major problems when the musculoskeletal system is subject to increased system demands such as those that occur during sports participation.

   One can assess limb length discrepancy directly with supine or standing measurements. In my experience, standing radiographs are the most accurate as clinicians may assess either relative or absolute length of the limb. For indirect assessment of limb length, place lifts under the shorter limb until the patient achieves pelvic symmetry.

   The problem is that neither of these methods assesses the pathomechanical impact of the discrepancy during ambulation. What’s more, both a level pelvis and equal limb length do not ensure symmetrical function. Some individuals with an imbalanced pelvis have symmetrical feet and limb function as do some individuals with uneven limb lengths. The underlying issue is the objective assessment of symmetry during function.

   In my early years in practice, I would equalize limb length based on clinical and radiographic measurements as well as sacral leveling. The use of computer assisted gait analysis taught me that leveling the pelvis or equalizing limb length may in fact create pedal and limb imbalances that manifest by asymmetrical plantar pressures as well as temporal parameter gait disturbances. We cannot predict functional symmetry or asymmetry following the use of prescription foot orthoses. Therefore, one should not address this until several weeks after dispensing the orthotic.

   Note whether asymmetry is present. See if the patient has an extended midstance phase, increased single support, increased stance, increased calcaneal duration and increased medial calcaneal pressure all with the longer limb. Also note the presence of an increased propulsive phase, decreased midstance, decreased calcaneal duration, and relative supinatory center of force all on the shorter limb. If all of the aforementioned signs are present, then equalization with lift therapy in 1/8-inch increments is indicated. In essence, the longer functioning limb pronates and the shorter limb supinates in an attempt by the patient to extend the length of the extremity.

   In this case, the heel pain was being perpetuated by the continued need for further collapse of the left foot to shorten the longer limb. This was not a symptom producer for everyday walking but because of the increased demands placed on the foot during running — the theory that during running, forces on the foot are increased by three times that of body weight and are three times that for everyday walking — the limb length discrepancy recurrently precipitated the calcaneal symptomatology.

   Dr. D’Amico is a Professor in the Division of Orthopedic Sciences at the New York College ofPodiatric Medicine. He is a Diplomate of the American Board of Podiatric Orthopedics. He is a Fellow of the American College of Foot and Ankle Orthopedics and the American Academy of Podiatric Sports Medicine. Dr. D’Amico is in private practice in New York City.

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