Table 2.

Descriptive characteristics of the physical exposures.

Variable	Categories	Upper extremity pain		Healthy references		p value
		N	%	N	%
Contact cooling	Never	336	65.4	2,142	73.6	<0.001
	One tenth of time	100	19.5	495	17.0
	One quarter of time	32	6.2	132	4.5
	Half the time	17	3.3	66	2.3
	Three quarters of time	17	3.3	45	1.5
	Almost always	12	2.3	31	1.1
Ambient cooling	Never	291	56.8	1,799	61.6	0.005
	One tenth of time	101	19.7	618	21.2
	One quarter of time	59	11.5	256	8.8
	Half the time	28	5.5	143	4.9
	Three quarters of time	20	3.9	52	1.8
	Almost always	13	2.5	51	1.7
Severe ambient cooling	Never	311	61.0	2,019	69.3	<0.001
	One tenth of time	102	20.0	585	20.1
	One quarter of time	45	8.8	149	5.1
	Half the time	26	5.1	88	3.0
	Three quarters of time	15	2.9	41	1.4
	Almost always	11	2.2	31	1.1
Heavy manual handling	Never	301	59.0	2,016	69.3	<0.001
	A few days per month	69	13.5	322	11.1
	One day per week	22	4.3	132	4.5
	A couple of days per week	47	9.2	208	7.2
	Every day	71	13.9	229	7.9
Work with vibrating tools	Never	391	76.2	2,408	82.7	0.013
	One tenth of time	67	13.1	282	9.7
	One quarter of time	26	5.1	99	3.4
	Half the time	11	2.1	60	2.1
	Three quarters of time	10	1.9	31	1.1
	Almost always	8	1.6	30	1.0