Differences of Relative and Absolute Strength of Individuals With Spinal Cord Injury From Able-Bodied Subjects: A Discriminant Analysis

Abstract

Strength training is one of the most common interventions employed to increase functional independence during rehabilitation of individuals with spinal cord injury (SCI). However, in the literature, different results have been reported in terms of strength modifications after a SCI compared with a control group (CG). This study aimed to verify whether discriminant analysis using relative and absolute strength is able to discriminate individuals with different levels of SCI from a CG and to compare strength values of men with different levels of SCI with a CG. Cross-sectional study. Rehabilitation hospital setting. A total of 36 individuals with SCI stratified in tetraplegia (TP; C6-C8), high paraplegia (HP; T1-T6), and low paraplegia (LP; T7-L2), and 12 matched control subjects were enrolled in the study. The subjects performed a maximum strength test of elbow extension/flexion and also shoulder abduction/adduction and flexion/extension in an isokinetic dynamometer. Discriminant analysis was carried out to identify which strength variables would be able to discriminate the TP, HP, or LP groups from the CG. A 1-way analysis of variance was performed to compare peak torque and agonist/antagonist ratio means. Shoulder adduction, followed by elbow extension peak torque, was the best variable for discriminating the TP group from the CG (function coefficients: -0.056 and 0.051, respectively, Wilks Λ = 0.41, P ≤ .05). There were no significant differences between the HP group, LP group, and CG. The strength similarity of the paraplegic groups and the CG should not be extrapolated for activities of daily living or sports. The TP group demonstrated lower peak torque for all movements than the CG.