Background/Purpose: Individuals with hip osteoarthritis (OA) commonly walk with less hip extension compared to individuals without hip OA. This alteration is often attributed to walking speed, structural limitation, and/or hip pain. It is unclear if individuals with pre-arthritic hip disease (PAHD), such as dysplasia, femoroacetabular impingement syndrome, and acetabular labral tears, also walk with altered movement patterns. Thus, the objective of this study was to 1) determine if individuals with PAHD walk with less hip extension compared to individuals without pain, and 2) investigate potential reasons for this motion alteration.

Methods: Adolescent and adult individuals with PAHD and healthy controls without pain were recruited. Provocative hip tests (FABER, FADIR, and resisted straight leg raise) were used to confirm presence (PAHD group) or absence (Control group) of hip pain. Kinematic data were collected while walking on a treadmill at three speeds: preferred, fast (25% faster than preferred), and prescribed (1.25 m/s). Peak hip extension, peak hip flexion, and hip excursion were calculated at each walking speed. Linear regression analyses with GEE were used to examine the effects of group, sex, task, side, and their interactions.

Results: Hip angle data from 137 individuals with PAHD and 60 individuals without pain were included in the study (Table 1). The PAHD group was older than the Control group (p=.003). Individuals with PAHD had 2.9° less peak hip extension compared to individuals in the Control group (95% Confidence Interval (CI): 0.6, 5.1; p=.014) when walking at their preferred speed. At the prescribed speed, the PAHD group walked with 2.7° less hip extension than the Control group (95% CI: 0.4, 5.0; p=.022). Given the persistence of the finding despite walking at the same speed, the observed reduction in hip extension was not due to speed alone. When compared to the preferred speed, both groups increased their hip extension, hip flexion, and hip excursion by similar amounts at the fast speed, and no group-by-task interaction was noted (p=.206). This finding suggests that the PAHD group had the ability to walk with more hip extension at the preferred speed, and thus, the difference was not due to structural limitation. Within the PAHD group, individuals that reported pain during the walking task did not use different hip angles or excursion compared to individuals reporting no pain (p≥.185); thus, pain during walking was not the primary reason for reduced hip extension.

Conclusion: The results of this study indicate that the kinematic alteration common in individuals with hip OA exists early in the continuum of hip disease and was present in individuals with PAHD. The reduced hip extension during walking was not explained by preferred walking speed, structural limitation, or current pain; therefore, intervening on these factors alone is unlikely to address the habitual motion alteration.

Table 1. Mean (standard deviation or range) demographic data for individuals with pre-arthritic hip disease (PAHD) and individuals without pain (Control).

« Back to ACR Convergence 2021

ACR Meeting Abstracts - https://acrabstracts.org/abstract/individuals-with-pre-arthritic-hip-pain-walk-with-hip-motion-alteration-common-in-individuals-with-hip-oa/