title: The influence of ankle-foot orthoses on gait and energy expenditure in spina bifida.
abstract: We examined the effect of ankle-foot orthoses (AFOs) on gait and energy expenditure in children with spina bifida. Nine boys and three girls, 6 to 16 years of age, took part in the study. There were four children each with L4, L5, and sacral level lesions. Each child underwent gait analysis and energy consumption studies with and without AFOs. Walking speed was faster with AFOs (mean, 58 m/min) than without (mean, 50 m/min, p < 0.01). Stride length improved significantly (p < 0.001) from 0.89 m barefoot to 1.08 m with AFOs. Double support time was decreased from 0.32 seconds barefoot to 0.28 seconds with AFOs (p < 0.05). The oxygen cost of walking was significantly better with (0.33 mL/kg/m) than without AFOs (0.41 mL/kg/m, p < 0.001). Hip flexion at initial contact was increased. Ankle kinematics were unchanged, but ankle power generation showed a significant improvement; from 0.5 W/kg barefoot to 1.3 W/kg with AFOs. Increased ankle power generation results in improved hip flexion and stride length, which contributes to increased walking speed and reduced oxygen cost. The stability conferred by the AFOs is reflected in the reduced time spent in double support.
authors.affiliation: Gait Analysis Laboratory, Musgrave Park Hospital, Belfast, Northern Ireland. duffyc@cryptic.rch.unimelb.edu.au
authors.forename: C M
authors.initials: CM
authors.lastname: Duffy
authors.forename: H K
authors.initials: HK
authors.lastname: Graham
authors.forename: A P
authors.initials: AP
authors.lastname: Cosgrove
mesh_terms: D000293:Adolescent; D002648:Child; D004734:Energy Metabolism; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D009989:Orthotic Devices; D010101:Oxygen Consumption; D016135:Spinal Dysraphism / Q000503:physiopathology*; D016138:Walking / Q000502:physiology