Assessing climbing-specific strength: The impact of body position and elbow flexion on reliability and predictive validity

Finger strength is a key determinant of climbing performance, yet the optimal method for reliable assessment remains unsettled. This study evaluated the reliability and validity of finger strength assessments across four positions: seated and standing with bent and straight arms. Twenty-six intermediate-to-elite climbers completed a climbing-specific isometric pull-down test on two occasions, 48-96 hours apart. Average and peak force outputs from the mean of three attempts and the best single attempt were analyzed. Tests performed with bent arms showed slightly higher between-sessions reliability (intraclass correlation coefficient [ICC] = 0.983-0.991) compared to straight arms (ICC = 0.978-0.989). Seated positions yielded better within-session reliability (CV = 1.81-2.99%; ICC = 0.985-0.990) than standing (CV = 2.33-3.11%; ICC = 0.951-0.979). Between-sessions coefficient of variation (CV) ranged from 2.04% to 3.37%. Relative finger strength correlated more strongly with climbing performance (r = 0.425-0.767) than absolute strength (r = 0.422-0.741), with seated positions showing the strongest associations (r = 0.709-0.767). Absolute values demonstrated slightly higher test-retest reliability, but relative values were more predictive of climbing ability, particularly in sport climbing. All tested positions proved viable for assessing maximal finger strength, although seated with bent arms appears slightly more reliable and valid. Finally, averaging three attempts or using the best single attempt provided comparable reliability.