TABLE 2.

Measurement of force from bull sperm flagella during an isometric stall

	Isometric stalls (n)	Frames of stall (n)	Force (×10−10 N)	Lever arm (μm)	Torque (×10−15 N × m)
1.0 mM ATP*	48	40 ± 66	2.52 ± 0.68	15.3 ± 3.8	3.89 ± 1.58
0.1 mM ATP	16	129 ± 223†	2.08 ± 0.79†	16.8 ± 4.1	3.56 ± 1.83
0.1 mM ATP and 1.0 mM ADP	14	71 ± 56	1.94 ± 0.35‡	21.5 ± 2.6§	4.11 ± 0.53

Data are mean + SD.

^*Previously published data (20).

^†p < 0.05.

^‡p < 0.005.

^§p < 0.0001.