RT journal article
T1 Agreement-Based Validation of ISOMETRO for Upper-Limb Isometric Tension Measurements
A1 González Montesinos, José Luis
A1 Fernández Santos, Jorge del Rosario
A1 Jiménez Pavón, David
A1 Sánchez Delgado, Alejandro
A1 Aragón Martín, Rubén
A1 Escudier-Vázquez, Juan Manuel
A1 España Romero, Vanesa
A2 Didáctica de la Educación FísicaPlástica y Musical
K1 isometric force
K1 isometric strength
K1 agreement analysis
K1 criterion agreement
K1 force plate
K1 load cell
K1 measurement chain
K1 muscular strength
K1 exercise testing
K1 biomechanics
K1 biomedical sensors
AB Muscular fitness is a key component of health and athletic performance, and isometric strength is a widely used indicator. This study reports an agreement-based validation of the Isometric Strength Measurement Device (ISOMETRO) for upper-limb isometric tension measurements under controlled laboratory conditions. Twenty-one healthy young amateur rock climbers (11 men and 10 women) performed four upper-limb tensile tests (shoulder adduction at 90°, shoulder adduction at 60°, shoulder extension at 90°, and elbow extension at 90°). Agreement with an independent criterion device was evaluated using a force plate, while a series-connected load cell was used as an internal consistency check of the measurement chain. Linear mixed-effects models showed that ISOMETRO strongly predicted force plate values (β = 0.999, SE = 0.002, p < 0.001), with a marginal R2 > 0.99. Bland–Altman analysis indicated negligible bias (−0.08 N) and narrow limits of agreement (−4.97 to 4.81 N), and concordance was excellent (CCC ≥ 0.996). The series-connected load cell comparison also showed near-unity agreement (β = 0.998, SE = 0.003, p < 0.001), supporting internal measurement chain integrity. These findings support excellent agreement between ISOMETRO and force plate measurements for upper-limb tensile isometric testing along the vertical axis in young amateur rock climbers under controlled laboratory conditions. However, given the specific sample characteristics and the strictly vertical laboratory configuration, these results should not be generalized to other populations, joint angles, force directions, or non-laboratory environments without further validation. Further studies are needed to confirm performance in more diverse contexts and to establish reliability for repeated-measurement applications.
PB MDPI
SN 1424-8220
YR 2026
FD 2026-02-27
LK http://hdl.handle.net/10498/39008
UL http://hdl.handle.net/10498/39008
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 09-may-2026