Abstract
The purposes of this study were to compare isokinetic dynamometer (IKD) and hand-held dynamometer (HHD) based protocols for determining isometric shoulder rotation strength and to quantify the variation that could be expected when interchanging scores. Shoulder external rotation (ER) and internal rotation (IR) torques (Nm) of 20 healthy males and 20 healthy females (mean age 58 ± 9 years) were determined with the subject seated and the glenohumeral joint positioned in the scapular plane, on two separate occasions. RCs were excellent for IKD and HHD protocols, and for parallel reliability between the protocols (Res > 0.86). No significant differences were observed between test occasions or protocols (P > 0.05). Protocol difference scores (IKD – HHD score) demonstrated good reliability on one occasion (Res > 0.62) and excellent reliability over two occasions (Res > 0.75). No significant differences were observed between protocol difference scores on the two test occasions, or when averaged over occasions (P > 0.05). When interchanging scores, IR torques determined using the IKD and the HHD protocols tended to be similar (0.0 ± 3.2 Nm), whereas during ER, torques determined using the HHD protocol tended to be about 0.8 ± 2.0 Nm higher than those determined using the IKD protocol. Although scores determined using IKD and HHD test protocols were not characterized by precise interchangeability, the range of scores describing interchangeability was relatively small.