From Force Plates to AI: Establishing Validity and Reliability of a 2D AI-Camera System for Quantifying Sit-to-Stand Power Measurement

BACKGROUND: ) using body mass, stature, chair height, and performance time via a validated equation. The criterion method computed power from average peak vertical ground-reaction forces and IMU-derived vertical displacement. Concurrent validity between AI and criterion power was assessed using Pearson's correlation coefficient (r) with 95% confidence intervals (CI) and Bland-Altman analysis. Test-retest reliability for AI and criterion measures was evaluated using a two-way mixed-effects intraclass correlation coefficient (ICC(3,1)) with 95% CI, and measurement error was quantified via the standard error of measurement (SEM) and minimal detectable change at 95% confidence (MDC₉₅). RESULTS: (31.6%). CONCLUSION: The findings of this study support the use of a 2D AI-camera system as a valid and highly reliable tool for quantifying muscle power during the 30-second Sit to Stand Power Test. The 2D AI-camera system offers a promising solution for scalable, objective performance testing in clinical and remote settings.