Effects of back extensor strengthening exercises on postural alignment, physical function and performance, self-efficacy, and quality of life in Japanese community-dwelling older adults: A controlled clinical trial

Abstract

ABSTRACT. Objective: To examine the changes in postural alignment and kyphosis-correlated factors after 6 months of back extensor strengthening exercise in a group of community-dwelling older adults aged ≥65 years. Methods: We quasi-randomized 29 subjects into an intervention group treated with a back extensor strengthening program and a control group treated with a full-body exercise program. These groups com- pleted 20-30 minutes of exercise directed by a physical therapist one or more times per week and were in- structed to exercise at home as well. The participants were assessed prior to and after the intervention using the following criteria: postural alignment of “usual” and “best” posture, physical function, physical per- formance, self-efficacy, and quality of life. The differences between two factors (group and period) were compared for each of the measurement variables. Results: Subjects who adequately completed the exercises were analyzed. A reduced knee flexion angle was noted in the “best” posture of both groups, as were im- proved physical function and performance with the exception of one-leg standing time. Verifying the effect size in the post-hoc analysis, the body parts that showed changes to postural alignment after the intervention differed between groups. Conclusions: Back extensor strengthening exercises improved physical function and performance, but did not improve spinal alignment. The changes due to these interventions were not significantly different from changes observed in the full-body exercise group. However, post-hoc analysis re- vealed that the effect size of posture change was different, possible indicating that the two groups experi- enced different changes in the postural alignment.