Effect of lower-extremity muscle power training on muscle strength, balance function and walking ability in older adults with heart failure: a randomized controlled trial

Purpose: This study investigated the combined effect of lower-extremity muscle power training and regular cardiac rehabilitation on muscle strength, balance function, and walking ability of older adults with heart failure. Methods: Thirty-one patients, comprising 17 males and 14 females, aged between 66 and 89 years and diagnosed with non-severe heart failure, were randomly assigned to either the intervention group (n = 15) or control group (n = 16). Both groups participated in a 12-week regular rehabilitation program, with the intervention group receiving additional lower-extremity muscle power training. Various outcome measures, including muscle strength (the five-times-sit-to-stand test and knee extensor peak torque), balance function (Berg balance scale and functional reach test), and walking ability (4-m walk and Timed Up-and-Go tests) were assessed at baseline and 12 weeks after the intervention. Results: Of the 31 participants, 27 completed the study protocol. The intervention group demonstrated significantly greater improvement in the five-times-sit-to-stand test time, indicating enhanced lower-extremity muscle power compared to the control group. Both groups showed significant differences in the Berg balance scale, functional reach test, 4-m walk test, and Timed Up-and-Go test between baseline and 12 weeks. However, the effect sizes for the changes during the study period were larger in the intervention group (d = 0.74–1.19) than the control group (d = 0.57–0.96). Conclusion: Combining lower-extremity muscle power training with regular cardiac rehabilitation may lead to additional improvements in muscle function for older adults with heart failure, resulting in enhanced dynamic balance and walking ability. Trial registration number/date of registration: UMIN000032087/April 4, 2018.