Assessment of isokinetic and hand-held dynamometer measures of shoulder rotator strength among individuals with spinal cord injury

Objective: To determine the intrarater reliability of the hand-held dynamometer (HHD) for the measurement of shoulder rotation and to examine the relationship between the peak force values of the HHD and the isokinetic dynamometer. Participants: Twenty-five spinal cord injured individuals, 12 persons with paraplegia and 13 persons with tetraplegia between the ages of 18 and 42 years, were recruited from the community. Setting: Private practice clinic. Procedures: All participants were tested with the HHD by one examiner to determine reliability. On the same day, these participants underwent isokinetic testing to determine the relationship of the HHD and Cybex dynamometer measurements. Results: The intraclass correlation coefficients for the intrarater reliability ranged from .89 to .96. The Pearson product moment correlation was used to analyze the relationship between the two devices. All coefficients (.52 to .88) were statistically significant (p < .01); however, Separate analyses for the persons with paraplegia and tetraplegia differed considerably. There was substantial variability of the isokinetic strength values at the lower levels of isometric strength. Conclusions: The HHD can be used reliably to measure shoulder rotation in paraplegic and tetraplegic spinal cord injured individuals. Although it appears that the relationship between HHD and isokinetic measurement is poor for the participants with tetraplegia, the variability of the isokinetic scores indicates that this observation may be a function of the method of isokinetic measurements. Further study with a modified isokinetic testing protocol is needed to clarify the results of the participants with tetraplegia. (C) 1997 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.