Table 2. Descriptive Statistics of Lifting Variables at Baseline and Their Correlation With Self-Reported Low-Back Pain (LBP) at One-Year Follow-Up (N = 78).
| All Subjects, M (SD) (n = 78) | Non-LBP, M (SD) (n = 53) | LBP, M (SD) (n = 25) | R (n = 78) | p Value (n = 78) | |
|---|---|---|---|---|---|
| Number of lifts per shifta | 103.6 (135.7) | 94.8 (137) | 122.4 (134.7) | .10 | .4 |
| Lift time per shift (min)a | 192.2 (248.3) | 178.8 (254.8) | 220.7 (236.5) | .08 | .5 |
| Mean lifting frequency (per min) | 7.2 (3.2) | 7.0 (3.1) | 7.8 (3.5) | .12 | .3 |
| Mean load (kg) | 6.3 (2.5) | 6.2 (2.8) | 6.3 (2.0) | .005 | .97 |
| Mean CLI | 1.5 (1.0) | 1.4 (1.1) | 1.7 (0.7) | .12 | .29 |
| Maximum lifting frequency (per min) | 8.4 (4.1) | 8.1 (4.1) | 9 (4.1) | .11 | .36 |
| Maximum load (kg) | 9.0 (6.8) | 9.2 (7.5) | 8.5 (5.0) | –.05 | .67 |
| Maximum CLI | 2.0 (1.6) | 2.0 (1.8) | 2.2 (1.0) | .08 | .5 |
Note: CLI = composite lifting index; r = biserial correlation coefficient.
a
Derived variable based on analyzed lifts and job rotation pattern during an 8-hr shift.