Test-retest reliability and the utility of manual muscle testing with a hand-held myometer in men with spinal cord injury

Aim. The aim of this paper was to determine the test-retest reliability of hand-held dynamometry (HHD) in men with SCI. The utility of HHD to determine strength changes associated with a testosterone replacement therapy (TRT) intervention in hypogonadal men with SCI was also performed. Methods. Nine men with SCI completed the test-retest portion of the study; three subjects completed the TRT sub-study. Make and break tests on 2 separate visits were employed to determine peak strength and torque (i.e., normalizing for point of force application) for shoulder adduction, abduction, flexion and extension of the dominant and non-dominant sides. For TRT, a dual energy x-ray absorptiometry (DXA) measurement of lean tissue mass (LTM) and break test during shoulder flexion of the non-dominant side was performed prior to and a following treatment. The intra-class correlation coefficient (ICC) was determined within and between visits for all tests. For exploratory purposes, simple regression analyses were performed to describe linearity between the respective percent change of arm LTM and torque. Results. Reproducibility was excellent for strength and torque (ICC>0.8) in all tests except for that of inter-visit non-dominant abduction test (ICC=0.73). ICC was consistently higher on the dominant side during the flexion and extension break tests compared to make tests, but inconsistent for abduction and adduction. After TRT, a trend toward a significant positive correlation between the percent change of LTM and toque was observed (P=0.08). Conclusion. HHD is reliable and provides reproducible measures in assessing strength, and potentially changes in strength after intervention, in individuals with SCI.