Improve Patient Care and Grow Your Practice: Address the Short Leg
By Michelle Paris, DC
What if you could genuinely help improve existing and new patient outcomes while dramatically increasing compliance; yet add no extra hard costs to your practice and only 10 additional minutes to a typical treatment plan? In our practice, 35-40 percent of cases present with a short leg. The corrective results, functionally and structurally, are often astonishing. Correcting even as little as a 5 mm LLD in very fit patients creates a significant positive effect.
A Refresher: What Is a Short Leg?
Leg-length inequality or leg-length discrepancy (LLD) is well-documented in the literature, but grossly under-evaluated. There are two types of discrepancies: functional LLD and structural (true) LLD. A functional LLD occurs as a result of muscle imbalances, pelvic torsion or other mechanical reasons. The adjustments you already make positively address this.
An anatomical short leg is due to several orthopedic or medical conditions. Often, one growth plate closes before the other. Still unknown why this occurs, various studies report that between 25-50 percent of the population demonstrates a true LLD. Other causes include trauma, broken bones, surgical repair, joint replacement, radiation exposure, tumors or LCP [Legg-Calve-Perthes] disease.
The effects of a short leg depend upon the individual and the extent of discrepancy. The most common manifestation is a lateral deviation of the lumbar spine toward the short side, vertebral body rotation, and compensatory curves that can extend to the neck and even impact the TMJ. Studies have shown that A-P curve abnormalities can result, too. More significant are the biomechanic and kinematic changes that occur in patients, leading to chronic back and sacroiliac joint pain. Altered gait is particularly significant for athletes and runners who do not correct the LLD.1-2
Idiopathic scoliosis accounts for less than 4 percent of the population. A recent study reported that 94.4 percent of idiopathic scoliosis patients demonstrated improves curves when appropriate measures were taken to correct LLD.3 This means that the majority of scoliosis cases are not really idiopathic!
Clues: Clinical Presentation
Patients may experience few or no symptoms prior to the age of 25-35. The most common symptom is chronic LBP, but frequent mid- and upper-back pain, and neck, hip or knee discomforts, are common subjectives. Same-sided and repeated injury, or pain to the hip, knee and/or ankle, is a hallmark of a long-standing untreated LLD. Many patients explain that chiropractic helps, but adjustments don't hold.
Marketing Flash: Use Social Media, the Web and Literature to Encourage Home Screening
It's easy for patients to evaluate whether they may have a short leg:
Evaluation of LLD with a patient supine, using tape measurements from the ASIS to the malleoli, results in inter-examiner reliability only to 5 mm.4 Valid evaluation requires a weight-bearing A-P X-ray with the CR through the femur heads, and is as reliable as other more expensive and radiation intensive testing such as bone scans and 3-D imaging.5
Gait and foot analysis is critical with associated foot and ankle pain, as some conditions will significantly impact leg length. Excessive pronation can lower the pelvis and hip on that side and contribute to the appearance of a short leg, yet relying on orthotics to correct an LLD is seldom appropriate. Nike conducted an excellent study years ago to determine the best running shoe. The results were published, but not used as marketing material. The best shoe includes the least amount of padding.6 The incidence of ankle sprains is increased exponentially with the support of a "good" running shoe and the same is true for orthotics.7
If you don't perceive a stick underfoot, your foot and body don't make necessary accommodations, and you sprain your ankle. That said, running barefoot or in Keds might be great on crushed granite, dirt or grass, but the compromise made for modern running requires some padding to protect the foot from increased loading on hard asphalt.