Table 5.
Multivariate linear regression models of selected subjective ratings of exposure and corresponding direct-measured exposures, stratified on presence/absence of wrist/hand symptoms at the time of measurement.
| Self-reported exposure (Y) | Direct-measured exposure (X1) | Intercept (β0) | Slope (β1): no symptoms (X2 = 0) | Slope (β1 + β2): symptoms (X2 = 1) | R2 |
|---|---|---|---|---|---|
| Wrist/hand positions | Flexion–extension acceleration | 4.75 | −0.00128 | 0.00607* | 0.13 |
| Manual effort | Grip force (%MVC) | 5.16 | −9.91 | 9.24** | 0.45 |
| Pace | Flexion–extension acceleration |
2.98 | 0.00490 | 0.00946* | 0.21 |
MVC = maximum voluntary contraction.
Note: Slopes are determined from a single regression model with a term for interaction of the direct-measured exposures and a dummy variable for presence/absence of symptoms.
Y = β0 + β1 × X1 + β2 × X1 × X2 , where X2 = 0 or 1.
*
p < 0.05.
**
p < 0.01.