The purpose of this study was to examine intratester, intertester, and inte
rdevice reliability of range of motion measurements of the elbow and forear
m. Elbow flexion and extension and Forearm pronation and supination were me
asured on 38 subjects with elbow, forearm, or wrist disease by 5 testers. S
tandardized test methods and a randomized order of testing were used to tes
t groups of patients with universal standard goniometers, a computerized go
niometer, and a mechanical rotation measuring device. Intratester reliabili
ty was high for all 3 measuring devices. Meaningful changes in intratester
range of motion measurements taken with a universal goniometer occur with 9
5% confidence if they are greater than 6 degrees for flexion, 7 degrees for
extension, 8 degrees for pronation, and 8 degrees for supination. Intertes
ter reliability was high for flexion and extension measurements with the co
mputerized goniometer and moderate for flexion and extension measurements w
ith the universal goniometer. Meaningful change in interobserver range of m
otion measurements was expected if the change was greater than 4 degrees fo
r flexion and 6 degrees For extension with the computerized goniometer comp
ared with 10 degrees and 10 degrees respectively, if the universal goniomet
er was used. Intertester reliability was high For pronation and supination
with all 3 devices. Meaningful change in forearm rotation is characterized
by a minimum of 10 degrees for pronation and 11 degrees for supination with
the universal goniometer Reliable measurements of elbow and Forearm arm mo
vement are obtainable regardless of the level of experience when standardiz
ed methods are used. Measurement error was least For repeated measurements
taken by the same tester with the same instrument and most when different i
nstruments were used.