Assessment for upper limb motor function in stroke survivors using a virtual box and block test(VBBT) system: A feasibility and age-related study

Upper limb (UL) motor function declines with age in healthy individuals, yet many technology-based assessment tools for stroke survivors lack specific age-related normative ranges and robust clinimetric validation. The present study is to investigate the cliniparameter properties of a virtual box and block test (VBBT) system for assessing UL motor function in stroke survivors, with a focus on test-retest reliability, validity and age-related range of each kinematic and kinetic parameters. A total of 113 healthy adults and 16 stroke survivors were enrolled. Four VBBT-derived parameters, including mean velocity (MV), time to peak velocity (TPV), spectral arc length of grip force (SPARC-PF), and location time (LT) were analyzed. Results showed that all VBBT parameters demonstrated good to excellent test–retest reliability (ICC = 0.68–0.75), and moderate to strong correlations to conventional clinical assessments, supporting concurrent validity. As all parameters were effected by age (r = 0.632–0.746), the normative ranges corresponding to specific ages can be calculated using a quadratic polynomial with age as the independent variable. Results indicated that the VBBT is a reliable, valid, and age-sensitive tool for assessing UL motor function after stroke. It addressed key limitations of traditional assessments and holds promise for precision rehabilitation and outcome monitoring.