The Torque Referenced to a Perceived Exertion Level Is Affected by the Type of Movement in Men With Spinal Cord Injury

Objectives To compare a standardized submaximal intensity (based on the rate of perceived exertion [RPE]) with the percentage of the average and peak torque during a familiarization session in individuals with different spinal cord injury (SCI) levels in gravity-resisted and gravity-assisted movements. Methods This was a cross-sectional study at a rehabilitation hospital. Thirty-six individuals stratified in tetraplegia (TP), high paraplegia (HP), and low paraplegia (LP) groups and 12 matched control participants (CG) were enrolled in the study. Participants performed a maximum strength test using isokinetic dynamometry. The familiarization consisted of 10 submaximal repetitions with a level 2 (i.e., 20% of the maximum score) in the Resistance Exercise Scale (OMNI-RES). Fisher's exact test compared the percentages of the average torque (%ATFam) and peak torque (%PTFam) of the familiarization (based on the peak torque during the maximum strength tests) to the %ATFam and %PTFam attained with 20% of RPE. The coefficient of variation (CV) was calculated to assess the torque dispersion during each familiarization set. Results The %ATFam was lower for gravity-assisted compared to gravity-resisted movements for HP, LP, and CG (p ≤ .05). The CV was significantly lower in gravity-resisted movements during familiarization for TP, LP, and CG. Conclusion Different RPE levels should be adopted for gravity-resisted or gravity-assisted upper limb exercises to maintain the same relative intensity during a familiarization session.