Swing phase mechanics of healthy young and elderly men Peter M. Mills * , Rod S. Barrett Biomechanics-Dynamics Group, School of Physiotherapy and Exercise Science, Grith University, Gold Coast, Qld, Australia Abstract This study examined the eect of ageing on the swing phase mechanics of young and elderly gait. Sagittal plane marker trajectories and force plate data were collected while 10 young 24:9 0:9 years) and eight elderly 68:9 0:4 years) subjects walked at their preferred walking speeds. Comparison between young and elderly gait was made for a range of spatial± temporal, kinematic and kinetic variables with emphasis given to identifying possible dier- ences at toe-o, minimum metatarsal±phalangeal joint clearance and heel contact. In order to control for the confounding eect of gait velocity on the dependent variables, a multivariate analysis of covariance was used to identify dierences between the young and elderly subjects due to age. In contrast to studies that have reported lower preferred walking speeds in the elderly compared to the young [J.O. Judge, R.B. Davis III, S. Ounpuu, Step length reductions in advanced age: the role of ankle and hip kinetics, Journal of Gerontology: Medical Sciences 51 1996) M303±312; D.C. Kerrigan, M.K. Todd, U. Della Croce, L.A. Lipsitz, J.J. Collins, Biomechanical gait alterations independent of speed in the healthy elderly: evidence for spe- ci®c limiting impairments, Archives of Physical and Medical Rehabilitation 79 1998) 317± 322], no dierences in walking speed nor in the spatial±temporal variables that determine walking speed were detected. The elderly were however, found to have a greater hip extension moment at the time of minimum metatarsal±phalangeal joint clearance, and a signi®cantly higher anterior±posterior velocity heel contact velocity that was linked to a signi®cantly higher shank and foot angular velocity at heel contact. Since many gait variables are highly correlated with walking speed [C. Kirtley, M.W. Whittle, R.J. Jeerson, In¯uence of walking speed on www.elsevier.com/locate/humov Human Movement Science 20 2001) 427±446 * Corresponding author. Tel.: +61-7-5552-8357; fax: +61-7-5552-8674. E-mail address: p.mills@mailbox.gu.edu.au P.M. Mills). 0167-9457/01/$ - see front matter Ó 2001 Elsevier Science B.V. All rights reserved. PII:S0167-945701)00061-6