Exploring relevant parameters and investigating their reproducibility of task-oriented unimanual strength measurement in children with unilateral cerebral palsy

Purpose: To explore relevant parameters and investigate their test-retest reliability within the scope of the push button task of the Task-oriented Arm-hAnd Capacity (TAAC) measured in children with unilateral Cerebral Palsy (CP). Methods: 118 children diagnosed with unilateral CP, aged between 6 and 18 years, participated in this study. Thetest–retest reliability of the force generated during the push button task of the TAAC was investigated using an intraclass correlation (ICC) two-way random model with absolute agreement. The ICCs were calculated across the whole age group and for two separate age subgroups (6–12 and 13–18 years). Results: Test-retest reliability of the parameters “mean peak force of all attempts”, “overshoot of force”, “number of successful attempts” and “time to complete four successful attempts” were moderate to good (ICC range 0.667–0.865; 0.721–0.908; 0.733–0.817, respectively). Conclusions: The results showed moderate to good test-retest reliability for all parameters. The parameters “mean peak force” and “number of successful attempts” are the most relevant parameters, as these parameters are task-specific and the most functional for clinical practice.Implications for Rehabilitation Clinical relevant information about the use of task-oriented strength during the performance of daily activity has been added to strength measurements in children with Cerebral Palsy. The Task-oriented Arm-hAnd Capacity instrument is a reliable, objective and simple instrument to measure task-oriented strength during daily activity and is ready for use in a clinical setting. The Task-oriented Arm-hAnd Capacity instrument is both a capacity and performance-based test. The measurement with the push button task showed moderate to good test-retest reliability.