Redistribution of joint moments and work in older women with and without hallux valgus at two walking speeds

Background: Hallux valgus (HV) is a highly prevalent foot deformity in older women. Differences in lower extremity joint function of older women with and without HV during walking at slower and faster speeds are unknown. Research question: Does walking speed affect lower extremity joint range of motion (ROM) and net extensor joint moment and associated work in older women with and without HV? Methods: Thirteen older women with HV and 13 controls completed five walking trials at 1.1 and 1.3 m.s(-1) as kinematic marker position and ground reaction force data were collected. Net ankle, knee, and hip joint moments were computed using inverse dynamics during the stance phase. Positive joint work was calculated by integrating hip power in early stance, knee power in mid stance, and ankle power in late stance. Results: Average ankle ROM and plantarflexor moment did not increase with walking speed in the HV group, while in the control group these variables were greater for the faster compared to the slower speed (p < 0.05). The magnitude of increase in ankle joint work with speed was 12 % lesser in the HV compared to the control group (p = 0.008). The hip ROM, extensor moment, and associated work was greater in the HV compared to the control group (p<0.05). Knee and hip joint ROM, extensor moments, and work increased with walking speed in both groups (p<0.05). Significance: Older women with HV compared to older women without HV demonstrate a distal-to-proximal redistribution by increasing hip motion and effort to compensate for reduced ankle contribution during walking.