The effects of hallux valgus and walking speed on dynamic balance in older adults.

BACKGROUND: Hallux valgus (HV) contributes to deficits in static balance and increased fall risk in older adults. Very limited research has examined dynamic balance deficits in walking in this population. These individuals generally walk slowly, as balance challenge is lesser at slow speeds. RESEARCH QUESTION: How does the dynamic balance of older adults with HV differ from healthy controls at controlled slow and fast walking speeds? METHODS: Nineteen older adults with HV and 13 healthy controls completed 5 continuous walking trials at 1.0 and 1.3 m·s-1 as whole body marker position and ground reaction force data were captured. Dynamic balance was evaluated using whole body center of mass (COM) and center of pressure (COP) inclination angles (IA) and duration of double support. RESULTS: There were no differences in measures of dynamic balance between older adults with and without HV at slow and fast speeds. At the faster speed, the peak sagittal plane COM-COP IA increased and the double support duration decreased, while the peak frontal plane COM-COP IA were not affected. SIGNIFICANCE: Older adults with HV do not exhibit deficits in dynamic balance during continuous walking at comfortable speeds when compared to healthy older adults.

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.