The gallon-jug shelf-transfer test: an instrument to evaluate deteriorating function in older adults.

This study examined the validity, reliability, and discriminatory capacity of the gallon-jug shelf-transfer (GJST) test. Six hundred fifty-three independent-living older adults (463 women age 72.9 +/- 7.0 years, 190 men age 74.3 +/- 6.7 years) participated. Participants moved five 1-gallon jugs (approximately 3.9 kg) from a knee-high to a shoulder-high shelf as quickly as possible. The GJST showed an exponential performance decline with age, and there were significant correlations between the GJST and common functional tests (p<.001). High within-day and between-days reliability was detected. The test also detected differences resulting from training status (p<.01) and training protocols (p<.05). The GJST is a valid, reliable, inexpensive, safe, and easily administered clinical test for identifying physically vulnerable elders who could benefit from interventions such as exercise to improve their physical capacities and maintain independence.