Table 4.

Association between HAV exposure to rock drills and impact wrenches as separate variables and VPTs on dominant second finger: elevated VPT (dB) per 10-fold increase in days exposed to daily vibration in m/s²(A8)

Frequency	Rock drill exposure: 5.4 m/s2(A8) Dominant second finger (n=104)	Impact wrench exposure: 1.2 m/s2(A8) Dominant second finger (n=104)
Hz	Unstandardised coefficient B (95% CI)	Unstandardised coefficient B (95% CI)
8	2.08 (0.96 to 3.20)*	0.91 (−0.05 to 1.87)
16	1.96 (0.99 to 2.94)*	1.03 (0.20 to 1.87)*
32	1.86 (0.91 to 2.81)*	0.88 (0.07 to 1.69)*
64	2.23 (0.88 to 3.58)*	1.01 (−0.15 to 2.17)
125	2.65 (1.28 to 2.83)*	1.27 (0.10 to 2.44)*
250	3.40 (1.74 to 5.06)*	1.70 (0.28 to 3.12)*
500	3.36 (1.50 to 5.21)*	0.74 (−0.85 to 2.33)

Models included age (using categories of age <60 and ages 60–69 years), rock drill exposure and impact wrench exposure.

*P≤0.05.

HAV, hand–arm vibration; VPT, vibration perception threshold.