Systematic reviews, randomized clinical trials, and clinical practice guidelines recommend exercise for a variety of conditions affecting aging and older adults. However, the optimal mode of exercise for this population remains unknown. Power training is one mode of exercise that has gained popularity in recent years and involves exercises designed for improving not only strength but also speed. As rehabilitation professionals, how often do we assess muscle power in older adults? Similarly, how often do we use power training for the rehabilitation of older adults? Finally, what is the evidence for power training in aging and older adults, and is it safe? This issue examines the effects of power training on select conditions that frequently impact aging individuals. What follows is a summary of what each narrative review adds to this issue in Topics in Geriatric Rehabilitation.
* Hood and Klima examined power production poststroke and its effects on arm function, balance, gait, transfers, and functional ability. Examples of objective measures to assess muscle power in this population are provided. Their synthesis of studies suggests that exercise protocols should combine strength and velocity strategies, along with specificity of training and intensity, to maximize power. Furthermore, improvements in muscle power are associated with improvements in function poststroke.
* Chen and Yoshida summarized current evidence about the effects of muscle power and power training on physical function, balance, and fall prevention in older adults. Results indicate that muscle power can be a stronger predictor of function than muscle strength. In addition, power training can be more effective than strength training in improving function and is a feasible and safe intervention for older adults living with frailty. Power training can also improve balance, but more studies are needed to determine its effectiveness in preventing falls in older adults.
* Malin reviewed the literature on power training in individuals with Parkinson's disease. In this population, there is limited but compelling evidence to support an association between lower extremity power and balance and mobility. In addition, trends toward reduced falls after power training have been reported. The benefits of other types of interventions (eg, Nordic Walking and Power Yoga) on power and symmetry have also been discussed.
* Corkery et al summarized studies that used power training for older adults with knee osteoarthritis. Across the studies cited, power training seemed to have a positive impact on power, strength, and function. In addition, studies reported high adherence and tolerance, and no serious adverse events associated with power training. This review suggests that power training may be a useful addition to an exercise program for older adults with knee osteoarthritis.
* A narrative review by Shultz and MacLennan highlighted the importance of assessing and rehabilitating muscle power after total knee arthroplasty. Literature was summarized on the changes in lower extremity power after arthroplasty and rehabilitation strategies (eg, high-velocity training, eccentric training, and aquatic therapy) to improve power after arthroplasty. Evidence also supported the association between muscle power and function in this population.
* The review by Chui et al examined the effects of power training in older adults with hip osteoarthritis and total hip arthroplasty. For both populations, studies frequently examined exercise but there were few studies that specifically used power training or provided sufficient information about intervention parameters. Across the different types of studies examined, there was insufficient evidence to suggest that power training was more effective than other forms of training for those with hip osteoarthritis. Improvements were noted for those with total hip arthroplasty, but the majority of these findings could not be attributed to power training alone.
We hope that this issue will provide some useful information for the rehabilitation of aging and older individuals with a variety of diagnoses and impairments including stroke, impaired balance, Parkinson's disease, knee osteoarthritis, total knee arthroplasty, hip osteoarthritis, and total hip arthroplasty. There is a growing body of evidence to support the assessment of muscle power, the use of power training, and the association between improvements in power and function. Furthermore, these studies support power training as a well-tolerated and safe form of exercise that may improve rehabilitation outcomes.
-Kevin Chui, PT, DPT, PhD, GCS, OCS, CEEAA, FAAOMPT
-Kimberly Malin, PT, MS, DHSc, NCS
-Sheng-Che Yen, PT, PhD
Issue Editors