Source: DGNews  |  Posted 8 years ago

By Roberta Friedman, PhD

BALTIMORE, MD -- May 16, 2003 -- The ability of an elderly person to perform activities of daily living can be determined reliably by measuring how long it takes them to move a gallon jug of water from a low to a high shelf, according to findings reported here today at the 2003 Annual Scientific Meeting of the American Geriatrics Society.

The gallon jug test reveals significant differences among elderly people. Investigators also found that the test has an average error of 6.8% in two consecutive tests, with a re-test correlation of 0.92 (P<0.001).

Moving moderately heavy objects can allow providers to "see if people are in their right age group, or not" in terms of their motor function, said Bernard Roos, MD, chair of research in gerontology and professor of medicine and neurology, University of Miami, Florida. The jug test will help design exercise programs for strength training in elders, Dr. Roos said.

Dr. Roos and researchers at the Stein Gerontological Institute and University of Miami studied 563 people over age 60. The investigators measured the time it took each participant to move gallon jugs of water from a knee-high shelf to one at shoulder height. Five jugs, weighing 8.4 pounds, had to be moved as quickly as possible. Study subjects were not allowed to change hands.

The investigators compared pairs of people divided into 5-year age groups. Significant differences appeared among the half-decade groupings, more so for women -- due to a higher number of older women than men in the study. The researchers generated percentile scores for each half decade of age.

Tested subjects were asked to work as quickly as possible, with one practice trial and two test trials while a trained observer timed the task with a stopwatch.

Tests are already available that ask about ability to perform the light motor skills of dressing, food preparation and paperwork. The jug test showed inverse correlation with the person's self-rated ability to function in activities of daily living, the researchers found in a smaller study of 14 subjects. The correlation coefficient of 0.72 was statistically significant (P<0.01).

No correlation appeared for available, objective tests of function and self rating by the elderly of their abilities. The gallon jug test "is not a real world test" because of the speed request, said co-investigator Damian Stanziano, a doctoral candidate in the department of exercise physiology at the University of Miami, "but it is closer" than the existing function tests.

These existing tests of observed functioning -- such as chair sit stand and functional reach -- do correlate to physical strength and endurance, said Wesley Smith, also a doctoral candidate in the department of exercise physiology, also involved in the study.

Smith said the group plans larger studies, and also hopes to develop additional task-specific tests or better self rating scales. Both are needed, Smith said, "if we want to get a handle on how well these people are functioning at home."

[Study title: The Gallon-Jug Shelf Test: A New Method of Assessing Age-Dependent Changes in the Ability to Manipulate Moderately Heavy Objects. Abstract P418]