Impact of Exercise to Improve Gait Efficiency on Activity and Participation in Older Adults With Mobility Limitations: A Randomized Controlled Trial

Background. Definitive evidence that exercise interventions that improve gait also reduce disability is lacking. A task-oriented, motor sequence learning exercise intervention has been shown to reduce the energy cost of walking and improve gait speed, but whether the intervention also improves activity and participation has not been demonstrated. Objective. The objective of this study was to compare the impact of a task-oriented, motor sequence learning exercise (TO) intervention and the impact of an impairment-oriented, multicomponent exercise (IO) intervention on activity and participation outcomes in older adults with mobility limitations. The mediating effects of a change in the energy cost of walking on changes in activity and participation also were determined. Design. This study was a single-blind, randomized controlled trial. Setting. The study was conducted in an ambulatory clinical research training center. Participants. The study participants were 47 older adults (mean age = 77.2 years, SD = 5.5) with slow and variable gait. Intervention. The intervention was a 12-week, physical therapist-guided program of TO or IO. Measurements. Measures of activity (gait speed over an instrumented walkway; daily physical activity measured with an accelerometer; confidence in walking determined with the Gait Efficacy Scale; and physical function determined with the total, basic lower-extremity, and advanced lower-extremity components of the Late-Life Function and Disability Instrument [Late-Life FDI]) and participation (disability limitation dimension and instrumental role [home and community task performance] domain components of the Late-Life FDI) were recorded before and after the intervention. The energy cost of walking was determined from the rate of oxygen consumption during self-paced treadmill walking at the physiological steady state standardized by walking speed. An adjusted comparison of activity and participation outcomes in the treatment arms was made by use of an analysis of covariance model, with baseline and change in energy cost of walking added to the model to test for mediation. Tests were used to determine the significance of the mediating effects. Results. Activity improved in TO but not in IO for confidence in walking (Gait Efficacy Scale; mean adjusted difference = 9.8 [SD = 3.5]) and physical function (Late-Life FDI basic lower-extremity component; mean adjusted difference = 3.5 [SD = 1.7]). Improvements in TO were marginally greater than those in IO for gait speed, physical activity, and total physical function. Participation improved marginally more in TO than in IO for disability limitations and instrumental role. Limitations. The older adults were randomized to the intervention group, but differences in baseline measures had to be accounted for in the analyses. Conclusions. A TO intervention that improved gait also led to improvements in some activity and participation outcomes in older adults with mobility limitations.