A highly debated postural issue begging for a reasonable explanation is the "short right-leg syndrome" (Fig. 1). Although an inferred awareness of right-sided limb-length shortness has existed for centuries, along with decades of published research, no one has provided a universally acceptable answer to two very important questions:
1. Why the unusual regularity of short right legs seen in clinic?
2. How does this common postural pattern trigger compensatory hip, back and pelvic pain?
Let's start by reviewing notable research regarding functional and structural short right legs and then discuss theories, assessments and corrections that help deal with this troublesome disorder. As Sir William Osler once stated, "In order to treat something, we must first be able to recognize it." Any endeavor to tackle limb-length discrepancy and associated compensations, armed with inadequate evaluation tools, surely will lead to failure and frustration. In the absence of radiographic measurements, massage therapists must develop keen palpatory and visual skills for detecting osseous and soft-tissue dysfunction. Aberrant patterns are best known and classified using the acronym
ART: Asymmetry, Restriction of motion, and Tissue-texture irregularity. Although many tests and treatment modalities have proven successful in treating short legs and associated compensations, we'll focus on only a few fundamental myoskeletal techniques that add to your toolbox of touch.
Fig. 1. Anatomic (structural) short right leg
Fig. 2. Short right leg producing contralateral pelvic rotation.
Fig. 3. Low right-femoral head and sacral base with compensatory lumbar scoliosis (sidebent left, rotated right).
Leg Length and Back Pain
In two deftly designed studies (1962 and 1983), Denslow and Chase measured leg-length discrepancy in 361 and 294 subjects presenting with low back pain.1 Using the most sophisticated radiographic technology currently available, their papers (published in the American Academy of Osteopathy) reported the following findings concerning limb-length discrepancy:
Significant incidence of short right legs (66 percent);
Lumbar convexity to the short leg side (sidebent left - rotated right); and
A high correlation illustrating contralateral (left) pelvic rotation. (Fig. 2)
By comparing sagittal-plane femoral-head height and sacral base angulation (Fig. 3), the authors concluded that innominate bones rotate around the sacrum (iliosacral tilt). Transverse plane images revealed that the pelvis also can rotate as a block around the vertical lumbar spine. Denslow and Chase's pioneering work helped biomedical researchers understand how shortened limbs torsion the pelvis, creating painful lumbar compensations. Their data not only confirmed leg-length findings conducted by previous researchers but also prompted new, more sophisticated imaging studies. In 2004, John H. Juhl, DO, testified that 68 percent of 421 low back pain patients presented radiographically with short right legs.
Functional Leg-Length Assessments
Through the years, manual therapists have made available many creative ways to differentiate functional (fixable) from structural (true) limb-length differences. Screening exams taught in educational programs often place too much emphasis on supine leg-length assessment in determining pelvic disorders. Frequently, one leg will appear shorter during visual observation of the supine client's medial malleoli (Fig. 4) when, in fact, the leg lengths actually are equal or just the opposite of how they appear radiographically when standing. For example, in the presence of a true (structural) short right leg, standing ASIS measurements should show an inferior slope on the short side. However, when the client lies supine (removed from vertical gravitational compression), the left leg may unexpectedly test shorter than the right. While a lot of factors may contribute to this finding, one of the most common culprits is length/strength imbalance in deep intrinsic postural muscles such as the quadratus lumborum (QL). When unilaterally short and tight, the QL can 'hip hike' the left ilium as the client begins to have an off-weighted supine posture. Awkwardness mounts as the left leg now appears shorter than the right.
Figure 5 presents an helpful contract/relax/assist maneuver to lengthen the hypercontracted left QL.
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