| Blasted needle | Drilled needle | Control needle |
FP 1st peak (mean [SD]) (N) | 0.42 (0.02) | 0.44 (0.05) | 0.42 (0.02) |
FP 2nd peak (mean [SD]) (N) | 0.82 (0.04) ** | 0.69 (0.02) | 0.73 (0.03) |