LEG LENGTH DISCREPANCY AND PELVIC OBLIQUITY
Pelvic obliquity (PO) is a highly complex concept, which is as yet poorly understood by the majority of health professionals, because it brings into play many joints, muscles, tendons and ligaments between the feet and spinal column. It is often associated with various compensatory issues affecting gait and eventually leads to degenerative arthritis (osteoarthritis) of the hip, knee, foot and of the lower lumbar spine.
The pelvis moves along all three spatial planes in a figure eight configuration which twists along the central axis when walking. It is comprised of three joints (two sacroiliac and one pubic symphysis) that join it to the femoral heads, which are rounded and allow for a wide range of movement, as well as to the spine at intervertebral disc L5-S1. The surrounding musculature actions powerful muscle vectors, transmitting body weight to the lower limbs and allowing the body to stand on two feet, in both a stationary and dynamic stance.
This makes it quite difficult to assess whether the pelvic inclination is due to an actual difference in leg length or to a postural problem or an intrinsic pelvic deformation. Only an experienced physician accustomed to the study of this type of phenomena and having specialized x-rays in hand can correctly diagnose the situation.
Traditionally, a scanography has been used to evaluate inequality of the lower limbs and usually involves scanning the legs with the patient lying down. This procedure has significant drawbacks in that the position of the patient during the scan is not reflective of their actual posture in action. Certain labs have improved upon this by scanning the patient standing up, but the results still do not give the observer insight on complex pelvic mechanics and how the pelvis interacts with the spinal column to compensate for the alleged limb inequality.
The method advocated by Clinique OrthoChiropratique chiropractors combines clinical (patient physical examination and muscular testing) and radiological assessments. First, we perform a visual appraisal of the patient’s overall posture including the pelvic area, then we observe their gait to identify any functional problems. Since an x-ray is only a 2D image of a 3D patient, it must always be interpreted with caution, which is why we save it for last and use it only to validate clinical observations.
Our method of radiological assessment of the pelvis is adapted from the Ferguson method, which according to our experience is much more clinically useful than a CT scan of the lower limbs. The 30° incline of the x-ray tube over a patient in frontal view allows for the simultaneous assessment of:
- hip height (femoral heads)
- pelvic bone (iliac) alignment
- disc inclination at the base of the sacrum—cornerstone that supports the spinal column and the entire weight of a person’s torso within their pelvis, transmitting it to the lower limbs. Because the sacroiliac joint barely moves at all (2° on each side), measurement in the coronal plane of disc L5-S1 inclination is therefore very representative of the mechanical constraints applied on the lower lumbar spinal column, provided, of course, that the x-ray be properly centred.
- lower lumbar spine alignment (L3-L4-L5) and potential compensations—it is crucial to take these into consideration so as not to undermine the patient should a shoe lift be considered.
TREATMENT OF PELVIC OBLIQUITY OR INEQUALITY OF THE LOWER LIMBS
If PO is diagnosed, the first thing to do is to determine whether it is functionally or structurally related. A functionally related condition designates the appearance of inequality attributable to posture or even muscle contracture, while a structurally related condition designates actual skeletal asymmetry (structural or anatomical inequality).
In the first case, appropriate chiropractic postural Remodeling care will usually produce a better alignment of the pelvis and thus decrease, or even eliminate, the symptoms associated with the functional impairment.
In the second case involving actual pelvic structural asymmetry or an anatomical difference in the height of the lower limbs, it is customary to insert a shoe lift to compensate, thereby limiting the negative impact on the patient’s posture and joints, as depending their severity, such conditions can lead to health issues in the more or less long term. In the case of growing children, the shoe lift may be only temporarily required, while in the case of adults having attained skeletal maturity, it is more than likely that the lift be permanently required as their skeletal anomaly is irreversible.
At the Clinique OrthoChiropratique, we have over fifteen years of experience in assessing and treating this type of condition and we work in close collaboration with several teams of podiatrists and orthotists.