Table 4.

Validity of isometric methods shown by correlation between back extensor strength values from three hand-held dynamometer isometric methods and isokinetic dynamometer-derived torque.

Test position	Session 1		Session 2
	R	95% CI	r	95% CI
Standing	0.50**	0.28, 0.67	0.60**	0.42, 0.73
Prone	0.54**	0.31, 0.74	0.54**	0.31, 0.74
Sitting	0.32*	0.07, 0.52	0.32*	0.04, 0.57

r, Pearson’s correlation coefficient; CI, confidence interval.

*P <0.05; **P <0.01.