Impairment of muscle strength and muscle power in the lower extremities, balance/postural control, and walking ability have been recognized as important risk factors for falls.1 However, muscle strength should be distinguished from muscle power: muscle strength is defined as the maximal force that a muscle can produce against a given resistance, while muscle power (force × velocity) is defined as the product of force and speed;1,2 the former is related to bone strength whereas the latter is related to falling.1–4 Thus, improvement of muscle power, rather than muscle strength, is likely to be important for preventing falls. Proximal leg muscle power can be evaluated by measuring the chair-rising time.