Prevalence of frontal plane pelvic postural asymmetry--part 1.

Despite 80 years of study, questions of how leg length difference relates to recurrent pain and somatic dysfunction remain controversial. The authors hypothesize that a correlation exists between leg length inequality and back pain. They further hypothesize that if common compensatory patterns described in classic osteopathic medical literature exist, these patterns should interact with the pelvic postural asymmetry patterns of Lloyd and Eimerbrink in a predictable, most probable, and congruent fashion. This article reviews the osteopathic medical, as well as the allopathic medical and chiropractic literature for studies that meet criteria for evidence-based comparison. Using lumbar radiographic studies produced with subjects standing, the authors examined the prevalence of six types of pelvic postural asymmetry in a consecutive case series of 421 patients with low back pain. Establishing the frequency of pelvic postural asymmetry patterns is a necessary first step in creating an evidence-based foundation to further clarify postural compensatory patterns. Various correlations between and within these patterns are identified.