Table 1.

Mean, standard deviation, and maximum of the measured forces and torques during palpation of the vertebra screw tract

	$F_{\mathit{xy}}$ (N)			$F_z$ (N)			$T_{\mathit{xy}}$ (Nm)			$T_z$ (Nm)
	$\mu$	$\sigma$	max	$\mu$	$\sigma$	max	$\mu$	$\sigma$	max	$\mu$	$\sigma$	max
Surgeon 1	0.28	0.24	1.12	0.31	0.47	7.78	0.037	0.029	0.134	0.002	< 0.001	0.005
Surgeon 2	0.19	0.15	0.89	0.23	0.36	5.14	0.028	0.020	0.113	0.001	< 0.001	0.002

Forces below 0.01 N and torques below 0.001 Nm have not been considered