participants from the inter-tester reliability study were
also measured to determine intra-tester reliability. Fifteen
additional participants were recruited to establish intratester
reliability. Therefore for the intra-tester reliability
study, 37 unimpaired volunteers ranging from 19–45
years (mean 31 years) participated. There were 23 women
and 14 men with 19 left knees and 18 right knees tested.
To be included, participants needed to be healthy adults
who had a full range of motion of the knee joint and no
history of knee injury. A blocked random numbers table
was computer generated. The leg being tested was
assigned from this random numbers table. Written consent
was obtained from all participants. This study was
approved by the Faculty of Health Sciences Ethics Committee,
La Trobe University, Australia (FHEC 05/35).
A sample size of at least 35 participants was used, based
on Cohen' s formula [22] with alpha set at 0.05 and 80%
power. For two assessors at least 35 participants were
required to yield 80% power for alpha at 0.8 [23].
Testers
Two testers (PP and PF) who had 1–3 months experience
using the electrogoniometer participated in the intertester
reliability study. One tester (PP) participated in the
intra-tester reliability study. Both testers were physiotherapists
with more than three years clinical experience
involving the use of standard goniometers.
Procedure
Participants were asked to wear shorts for ease of attachment
of the electrogoniometer to the lateral side of the
knee joint. Shoes and socks were removed during testing
to accurately locate the lateral malleolus. The tested knee
was wrapped with thin foam to minimise any visible skin
markings made by the electrogoniometer which may have
influenced the testers.
For the measurements in standing, each tester attached
the electrogoniometer to the knee joint in the neutral knee
position, in accordance with manufacturer's guidelines