Vibrotactile perception thresholds, dB (SD) relative to 10−6 m/s2, by frequency and finger
| Test finger | Frequency (Hz) | Vibration perception thresholds, dB (SD) | ||
| Exposed to: rock drills n=33 | Impact wrenches n=52 | No exposure to RD/IW n=19 | ||
| Dominant hand | ||||
| Second finger | 8 | 104.0 (6.8) | 101.4 (6.1) | 98.1 (4.7) |
| 16 | 109.3 (6.0) | 106.8 (5.3) | 103.6 (4.1) | |
| 32 | 113.2 (6.7) | 110.9 (4.1) | 108.7 (4.7) | |
| 64 | 111.2 (8.8) | 108.4 (6.4) | 104.9 (6.5) | |
| 125 | 110.1 (8.4) | 106.4 (6.4) | 103.3 (8.5) | |
| 250 | 119.3 (9.8) | 114.7 (8.1) | 109.7 (9.8) | |
| 500 | 132.9 (12.5) | 126.4 (8.6) | 123.1 (7.8) | |
| Fifth finger* | 8 | 104.0 (7.7) | 100.6 (5.0) | 97.9 (5.2) |
| 16 | 109.8 (7.0) | 106.3 (4.9) | 103.8 (5.9) | |
| 32 | 113.2 (7.4) | 110.9 (5.5) | 108.4 (6.0) | |
| 64 | 112.5 (9.3) | 110.6 (6.9) | 106.2 (5.9) | |
| 125 | 112.6 (13.1) | 108.3 (8.9) | 103.5 (7.2) | |
| 250 | 120.8 (15.8) | 115.3 (11.8) | 111.4 (9.9) | |
| 500 | 132.4 (14.1) | 128.5 (11.9) | 122.6 (10.3) | |
| Non-dominant hand | ||||
| Second finger† | 8 | 102.2 (6.4) | 99.2 (5.3) | 98.5 (6.0) |
| 16 | 107.9 (6.7) | 104.9 (6.1) | 103.5 (5.6) | |
| 32 | 111.3 (6.9) | 109.6 (5.9) | 106.9 (4.4) | |
| 64 | 109.3 (8.1) | 106.2 (7.6) | 104.1 (7.0) | |
| 125 | 109.3 (10.1) | 105.6 (8.5) | 102.7 (8.5) | |
| 250 | 116.7 (12.3) | 113.0 (10.1) | 109.1 (10.0) | |
| 500 | 128.6 (14.1) | 124.5 (12.0) | 119.7 (9.9) | |
| Fifth finger‡ | 8 | 103.2 (7.3) | 99.2 (5.4) | 98.1 (3.6) |
| 16 | 108.2 (7.2) | 105.3 (6.0) | 103.7 (3.8) | |
| 64 | 111.7 (10.2) | 109.0 (7.4) | 107.7 (6.3) | |
| 125 | 111.5 (13.8) | 107.4 (9.2) | 105.6 (7.6) | |
| 250 | 119.1 (14.8) | 113.2 (10.9) | 109.7 (9.2) | |
| 500 | 130.5 (13.8) | 126.5 (11.6) | 121.9 (9.9) | |
*n=51 for impact wrench operators, n=18 for no exposure.
†n=50 for impact wrench operators.
‡n=51 for impact wrench operators.
IW, impact wrench; RD, rock drill.