Inter-examiner and intra-examiner agreement for assessing simulated leg length inequality using palpation and observation during a standing assessment

Abstract

Osteopaths commonly assess leg length. Inequalities in leg length are associated with an increased incidence of low back pain, adaptive muscle shortening, ligamentous and capsular hypomobility and degenerative joint disease. Accurate detection of leg length inequality could allow early preventative intervention. Several clinical methods of assessing leg length are documented, yet few show convincing reliability. The aim of this study was to determine the inter-examiner and intra-examiner reliability of the standing assessment of leg length inequality using heel inserts to simulate leg length discrepancy. Twenty-seven subjects (mean age=23) were examined by eight examiners. Assessment of leg length was performed by palpation of iliac crests, posterior superior iliac spines, greater trochanters and gluteal folds with the subjects standing. Examiners indicated whether leg length was equal or if there was a longer leg on the left or right. Subjects were assessed with no heel insert and heel inserts of 0.5cm and 1 cm in their shoes. Each insert intervention was examined twice on each subject by each examiner. Zero, 0.5cm and 1cm interventions demonstrated inter-examiner percentage agreement of 52.5% ( K=0.27), 53.9% ( K=0.28) and 63.4% ( K=0.19) respectively. Zero, 0.5cm and 1cm interventions demonstrated intra-examiner percentage agreement of 58.4% ( K=0.35), 60.7% ( K=0.34) and 63.5% ( K=0.14) respectively. The results of this study indicate that examiners are unable to reliably detect simulated leg length discrepancies of 1cm or less by standing assessment.