Measuring Plantar Flexor Voluntary Activation and Maximal Voluntary Contraction in a Portable, Seated Method: A Validity and Reliability Study

. 2026 Mar 10;11(1):116. doi: 10.3390/jfmk11010116

	Voluntary ^a
Predictors	Estimates	95% CI	p
(Intercept)	87.11	75.29–98.94	<0.001 *
Laboratory method ^a	1.39	−2.60–5.37	0.495
Ankle pain (/10)	−0.32	−1.12–0.48	0.435
Maximal voluntary contraction (N)	0.02	0.01–0.03	<0.001 *
Age (years)	−0.52	−1.01–−0.02	0.041 *
^a In comparison to the portable protocol; * indicates statistical significance; Akaike Information Criterion: 265.2356. Voluntary activation model including body mass.