Table 3.

Descriptive Statistics of Twenty-Seven Risk Factor Variables in JEM. Kruskal Wallis Test for Each Exposure (R-Squared) Reported for 27 Risk Factor Variables to Determine Amount of Variance Explained by PCS Job Code.

										Minutes/Day
Exposure Variable	Scale	N	Mean	SD	P05	P25	Med	P75	P95	Mean	SD	R2
Physical intensity	6––20	26821	9.80	3.20	6	7	9	12	15	-------	------	0.39
Stand	1––4	29597	2.59	1.12	1	2	2	4	4	168	143	0.55
Repetition	1––4	26424	1.75	1.09	1	1	1	2	4	90	130	0.18
Change tasks	1––4	26581	2.94	1.11	1	2	3	4	4	204	142	0.10
Rest eyes	1––4	31848	3.10	1.13	1	2	4	4	4	232	145	0.19
Kneel or squat	1––4	29574	1.58	0.91	1	1	1	2	4	62	101	0.39
Bend trunk	1––4	30853	1.66	0.97	1	1	1	2	4	70	107	0.35
Drive machinery	1––4	29385	1.10	0.46	1	1	1	1	2	15	51	0.27
Drive car or truck	1––4	29357	1.41	0.88	1	1	1	1	4	46	99	0.29
Handle objects 1–4 kg	0––4	31116	1.03	1.46	0	0	0	2	4	69	119	0.36
Handle objects >4 kg	0––4	28306	0.80	1.24	0	0	0	2	4	48	100	0.38
Carry loads <10 kg	0––4	28240	0.72	1.15	0	0	0	1	3	39	89	0.36
Carry loads 10–25 kg	0––4	28297	0.58	0.94	0	0	0	1	3	24	69	0.37
Carry loads > 25 kg	0––4	28271	0.51	0.83	0	0	0	1	2	17	57	0.36
Use vibrating tools	1––4	28437	1.11	0.47	1	1	1	1	2	17	55	0.30
Use computer screen	1––4	31017	3.15	1.12	1	2	4	4	4	240	146	0.55
Use keyboard or scanner	1––4	28437	3.11	1.15	1	2	4	4	4	231	149	0.52
Bend neck	1––4	32048	2.45	1.11	1	1	3	3	4	149	133	0.08
Arms above shoulder	1––4	32712	1.39	0.73	1	1	1	2	3	38	74	0.23
Reach behind	1––4	29482	1.27	0.57	1	1	1	1	2	26	53	0.05
Arms abducted	1––4	32634	1.39	0.79	1	1	1	1	3	41	85	0.21
Bend elbow	1––4	33722	1.42	0.85	1	1	1	1	4	45	91	0.23
Rotate forearm	1––4	32647	1.22	0.62	1	1	1	1	3	25	66	0.30
Bend wrist	1––4	32599	1.36	0.79	1	1	1	1	3	40	87	0.22
Press base of hand	1––4	33127	1.14	0.49	1	1	1	1	2	17	51	0.23
Finger pinch	1––4	33128	1.45	0.88	1	1	1	1	4	48	97	0.13
Work outdoors	1––4	35187	1.38	0.78	1	1	1	1	3	38	81	0.31