Association between asymmetry and injury risk (n=848)
| Symmetry Index | Model 1 | Model 2 | Model 3 | Model 4 | |
| Soft | Hard | ||||
| Leg length | 1.14 (0.73 to 1.80) | 1.09 (0.69 to 1.72) | – | – | – |
| 0.566 | 0.703 | ||||
| Step length | 0.90 (0.77 to 1.05) | 0.90 (0.77 to 1.05) | – | – | – |
| 0.177 | 0.167 | ||||
| Contact time | 0.88 (0.76 to 1.02) | 0.87 (0.75 to 1.01) | – | – | – |
| 0.087 | 0.069 | ||||
| Flight time | 0.80 (0.64 to 1.00) | 0.79 (0.63 to 1.00) | 0.80 (0.64 to 0.99) | 0.67 (0.50 to 0.89) | – |
| 0.048 | 0.048 | 0.045 | 0.006 | ||
| Duty factor | 0.88 (0.76 to 1.02) | 0.87 (0.75 to 1.01) | – | – | – |
| 0.089 | 0.071 | ||||
| Vertical displacement of CoM | 0.95 (0.89 to 1.02) | 0.95 (0.88 to 1.02) | – | – | – |
| 0.147 | 0.127 | ||||
| Vertical stiffness | 0.95 (0.91 to 1.01) | 0.95 (0.90 to 1.00) | – | – | – |
| 0.082 | 0.053 | ||||
| Peak vertical force | 0.96 (0.88 to 1.06) | 0.96 (0.88 to 1.06) | – | – | – |
| 0.463 | 0.419 | ||||
| Peak breaking force | 0.96 (0.93 to 0.99) | 0.96 (0.93 to 0.98) | 0.96 (0.93 to 0.98) | 0.95 (0.91 to 0.99) | 0.97 (0.93 to 1.00) |
| 0.002 | 0.002 | 0.002 | 0.009 | 0.083 | |
| Peak propulsive force | 0.99 (0.95 to 1.03) | 0.99 (0.95 to 1.03) | – | – | – |
| 0.567 | 0.570 | ||||
| VIP | 1.00 (0.98 to 1.01) | 1.00 (0.98 to 1.01) | – | – | – |
| 0.467 | 0.635 | ||||
| Time to VIP | 0.97 (0.93 to 1.01) | 0.97 (0.94 to 1.01) | – | – | – |
| 0.198 | 0.212 | ||||
| Vertical instantaneous loading rate | 1.00 (0.99 to 1.01) | 1.00 (0.99 to 1.01) | – | – | – |
| 0.974 | 0.905 | ||||
| Vertical average loading rate | 0.99 (0.98 to 1.00) | 0.99 (0.98 to 1.00) | – | – | – |
| 0.111 | 0.137 | ||||
Running exposure: 22 178 hours. A total of 107 running-related overuse injuries were related to the lower limb. Values are subhazard rate ratio (95% CI). P values are presented in italics. P values<0.05 are presented in bold. Model 1 is the unadjusted model. Model 2=Model 1 adjusted for previous injury and running speed. Model 3=Model 2 mutually adjusted for all symmetry indices. Model 4=Model 3 stratified by shoe version (ie, soft and hard).
CoM, centre of mass; VIP, vertical impact peak.