The relationship between pelvic torsion and anatomical leg length inequality: a review of the literature

ObjectiveAlthough it is common to find assertions relating functional leg length inequality (LLI) to pelvic torsion and other states of subluxation, comments and/or data concerning anatomical LLI in this same context are uncommon. This review of the literature synthesizes the evidence on pelvic torsion in relation to anatomical LLI.MethodsThe literature was searched using the PubMed; Manual, Alternative, and Natural Therapy Index System; Allied and Complementary Medicine Database; Cumulative Index to Nursing and Allied Health Literature; and Index to Chiropractic Literature databases for primary studies that related LLI, either artificially created or naturally occurring, to pelvic torsion. Extracted data included natural vs artificial LLI, method of creating or detecting LLI, subject selection, methodology for measuring pelvic torsion, and results.ResultsNine English-language studies were retrieved published 1936-2004. Seven determined the impact of artificial, transient LLI on pelvic torsion, whereas 2 studied the effect of naturally occurring LLI.ConclusionAcross varying methodologies for measuring LLI and pelvic torsion, a consistent, dose-related pattern was identified in which the innominate rotates anteriorly on the side of a shorter leg and posteriorly on the side of the longer leg. This finding was contrary to the common assertion that the ilium rotates posteriorly on the side of a short leg and vice versa. Practitioners of manual medicine who derive vectors for intervention based on leg checking procedures should consider the possibility that the direction of pelvic torsion may be variable depending on whether the LLI is of anatomical or functional origin.