Effect of running cadence on tibial acceleration: implications for runners experiencing stress injuries

I. Purpose The purpose of this study was to determine the influence of cadence modification on tibial acceleration (TA) in the interest of exploring potential methods to reduce the incidence of stress-related running injuries. II. Methods Eleven injury-free distance runners were recruited to run at 6 different cadences with acoustic pacing. An inertial measurement unit (IMU) containing an onboard triaxial accelerometer was mounted on the right medial distal tibia to record acceleration at each of these paces. A repeated-measures ANOVA was conducted to determine differences in tibial acceleration over varying cadences. Effect sizes (╖2 and Cohen’s d) were examined to determine meaningfulness of the results. Secondary analyses were conducted to determine potential covarying effects. III. Results The repeated measures ANOVA indicated that cadence significantly affected peak axial tibial acceleration (F=7.59, p<0.001, ╖2=0.43). Post-hoc tests showed that peak axial TA was significantly lower at the fastest cadence compared to the slowest cadence (p<0.001, Cohen’s d=0.813, mean difference=1.085 g). At lower cadences, females have exceptionally higher TA (p=0.01), and the difference in TA among females from their slowest to fastest cadence was significant (p<0.001). The difference in TA among males from slowest to fastest cadence did not change significantly (p=0.78). IV. Conclusion The hypothesis was fully supported: TA decreases as cadence increases. Upon further examination, these differences were driven primarily by females. A decrease in TA is indicative of decreased external force being applied to the tibia. Results of this study suggest that increasing cadence while maintaining the same speed could result in potentially lowered risk of injury, and is especially important for females.