Author(s): NEDOVIC, N.1, JOVANOVIC, S.1, KOVACIC, I.2, GAPIC, V.3, PECOVNIK TOMAŽIC, E.4, KOZINC, Ž.4, Institution: UNIVERSITY OF BELGRADE, Country: SERBIA, Abstract-ID: 974

INTRODUCTION:
The Enhanced Paper Grip Test (EPGT) is a clinically simple, low-cost tool for assessing toe flexor strength, which is one of a key component of postural control and mobility. Establishing its psychometric properties across diverse populations and conditions is crucial for its adoption in research and clinical practice.
METHODS:
Three studies evaluated the EPGT's reliability and validity. Study 1 (n=20 adults) tested its biomechanical robustness by measuring force output on surfaces with different friction coefficients (paper, linoleum, cardboard). Study 2 (n=21 adults) assessed its test-retest reliability over 10-14 days and convergent validity against handgrip dynamometry. Study 3 (n=100 children) examined its intra- and inter-rater reliability in a pediatric sample and its relationship with static balance.
RESULTS:
Across all studies, the EPGT demonstrated consistently high relative reliability (Intraclass Correlation Coefficients [ICCs] ranging from 0.76 to 0.98), indicating excellent consistency for ranking individuals within a group. This was maintained across different testing surfaces (Study 1) and across raters in children (Study 3). However, absolute reliability was more variable, with coefficients of variation (CVs) ranging from 7% in controlled adult studies to 24% for inter-rater measurements in children, suggesting less precision for tracking within-individual change over time. The test showed moderate correlations with handgrip strength (r ~0.47-0.56) and static balance (r=0.40), supporting its construct validity.
CONCLUSION:
The EPGT is a biomechanically robust and feasible tool for assessing toe flexor strength. Its high relative reliability supports its use for screening and group comparisons. However, variable absolute reliability, especially in pediatric contexts, calls for a better standardization of protocols and rater training for tracking individual changes. Further research should refine methodological standardization and clarify responsiveness to change to facilitate its implementation in clinical and experimental settings.