The Ramp Power Test: A Power Assessment During a Functional Task for Older Individuals

Abstract

Power is critical to mobility and activities of daily living and is a key determinant of independence and falls prevention. Therefore, the quantification of power in older persons is critical. The power tests currently available are often expensive, potentially dangerous, and not reflective of everyday activities. We present a modification of an existing field test that uses ambulation up a standard access ramp to quantify functional power in older individuals. Three hundred sixty-three women and 157 men, aged 73.1 +/- 7.0 years, ambulated up a standard access ramp (1:12 rise/run ratio) as quickly as possible. Each person performed one practice and two timed trials. Comparisons with accepted power measures and reported patterns of change with aging supported the validity of the ramp power test. The test was found to be reliable across multiple trials and days. Pair-wise comparisons showed that for women the test was sensitive to differences in power output by half-decade, whereas for men it could distinguish between 9 of the 15 comparisons among age groups. Percentile scores are reported by half-decade for power in both genders. In > 1200 trials performed during this study, only one injury (a slightly strained hamstring) occurred. The ramp power test is valid and reliable and can safely distinguish power by half-decade in women and among the majority of age groups in men. Its safety, low cost, and ease of administration make it a feasible diagnostic tool to assess functional power levels in ambulatory older persons.