Objective: The purpose of the study was to further develop the psychometric rigor of the Grasp and Release Test (GRT), a hand function assessment designed to measure tendon transfer and functional electrical stimulation (FES) outcomes on functional limitation of individuals with tetraplegia.
Methods: Nineteen participants (21 hands) between 7 and 20 years of age with cervical-level spinal cord injuries (SCIs) participated in this study. Three participants (5 hands) had strong C6 or C7 function and underwent bilateral surgical tendon transfers to restore volitional thumb and finger flexion. The remaining 16 participants (16 hands) had C5- or weak C6-level SCI and underwent unilateral surgical implantation of the Freehand System for stimulated grasp and release. Preliminary evaluation of test-retest reliability, predictive validity, and sensitivity to change of the GRT was conducted. Reproducibility of test scores was evaluated by intraclass correlation coefficients (ICCs).
Results: Three objects-which included a fork, paperweight, and videotape-had perfect correlation. For the 3 remaining GRT objects, ICC values were significant (block = 0.87, peg = 0.93, can = 0.99; P < 0.01). For predictive validity, the relationships between 12-month Functional Independence Measure (FIM) scores and the peg, block, paperweight, and total number of GRT objects were nonsignificant. Correlation was significant between 12-month FIM scores and the fork (rho = 0.624, P < 0.01), can (rho = 0.700, P < 0.01), and videotape (rho = 0.503, P < 0.05). Sensitivity to change was evident by a significant difference between baseline and postrehabilitation GRT scores for the fork (z = 3.05, P < 0.01), paperweight (z = 2.83, P < 0.01), and can (z = 2.66, P < 0.01), and between the total number of GRT objects that were manipulated following surgery as compared with the number prior to surgery (z = 3.40, P < 0.05).
Conclusion: Based on this study, the GRT has good test-retest reliability as evidenced by coefficients between 0.87 and 1.00, and is able to detect changes in hand function following tendon transfers and FES.