Table 2.

Average discharge rate and coefficient of variation (CV) for interspike interval (ISI) for the two groups of motor units during the two tasks

	Discharge rate (pps)		CV for ISI (%)
	Tonic	Intermittent	Tonic	Intermittent
Ramp contraction	11.9 ± 2.7	13.4 ± 2.7	28.0 ± 9.2	27.4 ± 10.4
Sustained contraction	13.7 ± 3.3*	11.0 ± 3.3*†	21.2 ± 9.4*	34.6 ± 12.3†

Mean ±s.d. for the first five ISIs at recruitment during the ramp contraction and during the sustained contraction.

^*P < 0.05 compared with the ramp contraction (recruitment threshold task).

^†P < 0.05 compared with the tonic motor units.