Systematic review and meta-analysis of gait mechanics in young and older adults

Background Age-related gait changes may play a critical role in functional limitations of older adults. Despite sizable interest in determining how age alters walking mechanics, small sample sizes and varied outcome measures have precluded a comprehensive understanding of the impact of age on lower extremity joint kinematics and kinetics. Objective The aim of this study was to perform a systematic review and meta-analysis of the aging gait mechanics literature. Methods The overall standardized effect of age on walking mechanics was computed for 29 studies (200 standardized effects). To account for variation in reported outcome variables, analyses were carried out for comparisons between young and older adult results using all discrete kinematic or kinetic variables reported for the ankle, knee, or hip. Different variables reported for a given joint were then analyzed as separate categorical moderators. Results The overall standardized effect of age was large for ground reaction forces, moderate for ankle and small for knee and hip kinematics and ankle and hip kinetics. When the analysis was restricted to studies with similar or matched walking speed, the standardized effects of age remained similar except for hip power generation and knee kinematic variables. Conclusions The results of this meta-analysis provide evidence to support moderate standardized effects, with and without consideration of walking speeds, for changes in lower extremity kinematics, joint moments and powers at the ankle, and ground reaction forces. The standardized effects of age for knee mechanics are less conclusive and would benefit from further research.