Hallux Valgus And Walking Speed Influence Frontal Plane Net Joint Moments In Older Adults

Abstract

Hallux valgus (HV) is often comorbid with knee osteoarthritis (OA) in older adults. Both these conditions are known to adversely affect walking mechanics, but the biomechanical link between these conditions has not been established. Peak external knee adduction moment is a surrogate measure of knee OA severity and progression. However, this variable is sensitive to changes in walking speed. PURPOSE: To examine the effects of HV on peak external knee adduction moment while walking at controlled slow and fast speeds. METHODS: Nineteen older adults (65-80 years) with moderate-to-severe HV and 19 healthy older controls completed five walking trials at controlled slow (1.0 m·s-1) and fast (1.3 m·s-1) speeds. Three-dimensional lower extremity marker position and ground reaction force data were collected at 100 and 1000 Hz, respectively. External knee adduction moment was calculated using an inverse dynamics approach. Peak moments were identified for the more affected leg for the HV group and dominant leg for the control group for each trial. Two-way mixed model ANOVAs were used to examine the effects of group (HV vs. control) and speed (1.0 vs. 1.3 m·s-1) on peak external knee adduction moment. RESULTS: For peak knee adduction moment a group x speed interaction (p=0.035) was observed. With increase in walking speed external knee adduction moment increased (p<0.001), however, the HV group had twice as much of an increase in net peak knee adduction moment (16.6% greater; 0.53 ± 0.21 vs. 0.62 ± 0.25 Nm/kg) as compared to the control group (8.6% greater; 0.51 ± 0.13 vs. 0.56 ± 0.13 Nm/kg). CONCLUSIONS: Older adults with HV show altered knee joint mechanics at faster walking speeds. Knee adduction moment data suggest that older adults with HV may be at a greater risk for developing knee osteoarthritis.