Age-Related Differences in Postural and Goal-Directed Movements During Medial-Lateral Rhythmic Stepping.

Lateral stability and weight transfer are important for successful stepping and are associated with falls in older adults (OAs). This study assessed the influence of step pacing frequency during medial-lateral stepping in place on body center of mass and lower limb movement in young adults, middle-aged adults, and OAs. Medial-lateral center of mass and stepping limb motion and lower limb loading data were collected. Center of mass motion decreased with increasing pacing frequency and increased to a lesser extent with decreasing pacing frequency. Step length was relatively resistant to changes in pacing frequency. OAs exhibited reductions in whole body and stepping motion compared with younger adults. OAs exhibited greater support limb loading. OAs adapt both postural and stepping strategies to successfully step under time-critical conditions.