. Author manuscript; available in PMC: 2019 Oct 2.

Published in final edited form as: Hum Factors. 2008 Apr;50(2):227–236. doi: 10.1518/001872008X250692

Table 2.

Maximum axial push force, grip force, normal force, torque about the long axis of the handle, FDP EMG and FDS EMG for all push methods and handle materials by gender (mean ± 1 SD) (Push methods include preferred push, straight push, and push with an inward/outward torque at a comfortable level, or at 30%, 50%, and 80% of the maximum torque level. Handle diameter = 57.8 and 51.2 mm for the rubber and aluminum handle, respectively)

Male (n = 6) Handle material: Aluminum (handle diameter = 51.2 mm)
Method		Push Force (N)	Grip force¹ (N)	Normal force² (N)	Torque (Nm)	FDP (%)	FDS (%)
Preferred		113 ± 19	142 ± 82	328 ± 110	2.1 ± 2.0	63 ± 17	56 ± 14
Straight		107 ± 20	109 ± 51	266 ± 99	0.7 ± 0.5	63 ± 11	58 ± 12
Inward torque	comf	99 ± 28	156 ± 73	380 ± 216	3.0 ± 1.5	65 ± 19	62 ± 22
	30%	92 ± 29	118 ± 75	298 ± 141	2.3 ± 0.5	58 ± 12	63 ± 10
	50%	95 ± 34	151 ± 70	350 ± 200	3.2 ± 0.8	57 ± 13	69 ± 18
	80%	78 ± 33	181 ± 54	404 ± 194	4.2 ± 1.3	68 ± 15	70 ± 20
Outward torque	comf	84 ± 31	147 ± 42	395 ± 190	−2.5 ± 1.0	72 ± 10	54 ± 11
	30%	88 ± 23	124 ± 57	345 ± 112	−1.7 ± 1.2	69 ± 14	48 ± 9
	50%	74 ± 27	138 ± 61	364 ± 106	−2.2 ± 0.8	76 ± 17	49 ± 9
	80%	83 ± 31	167 ± 65	443 ± 154	−3.0 ± 1.1	82 ± 20	53 ± 12

Handle material: Rubber (handle diameter = 57.8 mm)
Method		Push force (N)	Grip force¹ (N)	Normal force² (N)	Torque (Nm)	FDP (%)	FDS (%)
Preferred		136 ± 25	137 ± 65	259 ± 68	1.5 ± 2.3	64 ± 20	56 ± 18
Straight		112 ± 27	115 ± 50	199 ± 69	0.3 ± 0.6	51 ± 11	51 ± 11
Inward torque	comf	110 ± 27	160 ± 56	323 ± 157	3.7 ± 2.5	61 ± 15	68 ± 14
	30%	94 ± 27	107 ± 22	209 ± 71	2.5 ± 0.7	53 ± 14	59 ± 13
	50%	96 ± 35	144 ± 37	267 ± 115	4.1 ± 1.3	60 ± 15	68 ± 17
	80%	97 ± 27	220 ± 55	400 ± 177	6.0 ± 2.0	70 ± 17	75 ± 16
Outward torque	comf	92 ± 24	180 ± 46	239 ± 73	−3.5 ± 1.6	71 ± 9	48 ± 6
	30%	95 ± 22	125 ± 44	176 ± 48	−2.1 ± 0.7	62 ± 13	48 ± 8
	50%	91 ± 32	155 ± 59	216 ± 55	−2.9 ± 1.2	69 ± 12	49 ± 7
	80%	74 ± 28	229 ± 78	270 ± 58	−4.4 ± 1.6	79 ± 18	53 ± 5

Female (n=6) Handle material: Aluminum (handle diameter = 51.2 mm)
Method		Push force (N)	Grip force¹ (N)	Normal force² (N)	Torque (Nm)	FDP (%)	FDS (%)
Preferred		62 ± 22	55 ± 21	142 ± 84	0.5 ± 0.4	60 ± 13	70 ± 12
Straight		57 ± 25	51 ± 19	138 ± 85	0.2 ± 0.2	70 ± 13	70 ± 6
Inward torque	comf	53 ± 24	67 ± 29	157 ± 94	1.3 ± 0.7	67 ± 14	71 ± 12
	30%	49 ± 27	54 ± 25	137 ± 81	0.9 ± 0.6	59 ± 8	70 ± 9
	50%	51 ± 27	66 ± 31	151 ± 93	1.3 ± 0.8	59 ± 9	71 ± 13
	80%	50 ± 28	81 ± 29	165 ± 107	1.6 ± 1.0	65 ± 10	77 ± 10
Outward torque	comf	44 ± 20	51 ± 16	146 ± 74	−1.1 ± 0.6	71 ± 13	66 ± 8
	30%	44 ± 27	35 ± 14	107 ± 70	−0.6 ± 0.4	65 ± 17	63 ± 9
	50%	46 ± 27	41 ± 19	137 ± 80	−1.0 ± 0.6	74 ± 17	63 ± 12
	80%	43 ± 20	60 ± 29	178 ± 117	−1.4 ± 0.9	84 ± 12	67 ± 11

Handle material: Rubber (handle diameter = 57.8 mm)
Method		Push force (N)	Grip force¹ (N)	Normal force² (N)	Torque (Nm)	FDP (%)	FDS (%)
Preferred		65 ± 29	42 ± 18	93 ± 64	0.5 ± 1.1	63 ± 18	64 ± 22
Straight		61 ± 32	38 ± 32	100 ± 121	0.1 ± 0.1	65 ± 13	70 ± 19
Inward torque	comf	59 ± 27	53 ± 42	114 ± 120	1.5 ± 1.0	64 ± 16	75 ± 19
	30%	61 ± 32	36 ± 16	87 ± 68	1.1 ± 0.7	60 ± 13	72 ± 20
	50%	59 ± 28	51 ± 28	112 ± 111	1.6 ± 0.9	63 ± 15	74 ± 18
	80%	57 ± 29	64 ± 30	122 ± 120	2.2 ± 1.2	67 ± 17	75 ± 17
Outward torque	comf	50 ± 24	67 ± 40	97 ± 82	−1.6 ± 0.9	79 ± 15	68 ± 16
	30%	48 ± 26	45 ± 26	62 ± 50	−0.9 ± 0.7	57 ± 11	63 ± 18
	50%	47 ± 24	57 ± 39	72 ± 47	−1.4 ± 0.6	66 ± 15	65 ± 18
	80%	43 ± 21	68 ± 49	93 ± 79	−1.9 ± 1.1	74 ± 14	67 ± 17

Grip force was measured with a split cylinder with the force gauge’s major axis aligned to the forearm (see Figure 1a).

Normal force is the total normal contact force between the hand and the cylindrical handle. Normal force was measured with a pressure sensitive pad wrapped around the cylindrical handle (see Figure 1a).