Beasley, in 1956, clearly established the need for muscle
strength testing methods that are more precise and objective
than manual muscle testing.1 Using a manual force gauge, he
demonstrated that differences in strength of 20% to 25% are
not distinguished by manual muscle tests and that manual
muscle tests sometimes fail to identify weakness in knee
extensor muscles with a 50% loss in strength. Since Beasley's
important work, numerous reports have been published describing
the use of both isokinetic and hand-held
dynamometers in strength testing. Although a number of
reports have described the reliability of testing with isokinetic
dynamometers and fixed force gauges little information
is available regarding the reliability of testing with hand-held
dynamometers. The only statement of which I am aware that
addresses the reliability of hand-held dynamometry is that of
Hosking and associates who reported that "the variation in
repeated strength measurements in 18 children did not often
exceed ±15 percent of the initial values
If the practicing clinician is to have confidence in handheld
dynamometry, evidence that the procedure is reliable is
needed. On the basis of previous test results, I expected to
prove that hand-held dynamometry is a highly reliable assessment
technique. The purpose of this paper is to describe the
reliability of three consecutive isometric strength measurements
obtained during the testing of 18 different muscle
groups.