Abstract
With the increasing use of isokinetic devices, a need exists to establish the inter and intra machine reliability of devices reputedly measuring the same outcome measure. The maximum peak torque values generated while 15 subjects performed internal and external shoulder rotation at the velocities of 60, 120 and 160°/s were recorded on three separate isokinetic machines: Kin-Com, Cybex II, and Lido. Statistical analyses in the form of analysis of variance and intraclass correlation coefficients were performed. The ANOY A revealed significant differences (P> 0.001), across subjects as planned, but also across machines apart from when measuring internal shoulder rotation at 60°/s (P > 0.001). ICCs were all high and significant (P > 0.001), but at anyone time apart from the recording at 60°/s for internal rotation, only two of the three machines were in agreement. For internal rotation, the Kin-Com gave consistently lower values than the other two machines, while for external rotation the Lido gave consistently lower values.