Precision and Patient Outcomes in PAL: A Comparison of Manual versus ZIT Measurements

Purpose: Perceived Activity Level (PAL) assessments play an essential role in evaluating functional capacity, monitoring patient progress, and guiding rehabilitation planning.Traditionally, PAL has been measured manually by clinicians; however, the introduction of digital tools such as the ZIT (Zone-Indexed Tracking) system offers the potential for enhanced precision and objectivity.This study aims to compare the accuracy, consistency, and impact on patient outcomes between manual PAL measurements and ZIT-based digital assessments in musculoskeletal rehabilitation patients.Methods: A comparative observational study was conducted from January to July 2025, enrolling 60 patients undergoing rehabilitation for lower-limb musculoskeletal conditions.Participants were evaluated using both manual PAL scoring and ZIT digital measurement during their initial assessment and at 6-week follow-up.Reliability was assessed through inter-rater agreement (ICC), while measurement precision was evaluated using mean absolute error (MAE) between repeated scores.Functional outcomes were assessed using the Lower Extremity Functional Scale (LEFS) and patientreported satisfaction scores.Paired t-tests and Bland-Altman plots were used for statistical comparison. Results:ZIT measurements demonstrated significantly higher precision with lower MAE values compared to manual assessments (p < 0.01).Interrater reliability for ZIT was excellent (ICC = 0.93), while manual scoring showed moderate agreement (ICC = 0.71).Patients assessed and monitored with ZIT data showed greater improvement in LEFS scores (average +12.6 points) compared to those monitored manually (+8.4 points).Patient satisfaction was also higher in the ZIT group, with 82% reporting clearer understanding of their progress versus 59% in the manual group.Conclusion: Digital ZIT-based measurements provide superior precision, reliability, and clinical usefulness compared to traditional manual PAL scoring.Integration of ZIT tools into routine rehabilitation practice may enhance clinical decision-making, improve patient engagement, and lead to more favorable functional outcomes.Further randomized clinical trials are recommended to establish longterm benefits and cost-effectiveness.