G-40 Free Communication/Poster - Running Mechanics Saturday, June 4, 2016, 7: 30 AM - 11: 00 AM Room: Exhibit Hall A/B
PURPOSE: Non-rearfoot strike landing patterns (NRFS) have been associated with reduced injury risk in runners. The purpose of this ongoing study was: 1) assess foot strike patterns between two groups of rearfoot strike (RFS) runners attempting to transition to a NRFS pattern with and without the use of biofeedback technology, and 2) to prospectively compare injury incidence rates at 6 and 12 months between RFS and NRFS runners.
METHODS: 108 habitual RFS runners (mean age= 27.1 ± 9.4, 75% male) participated in a 2 hour training session to transition to a NRFS pattern. Participants were then randomized into a Biofeedback Group (BFG, n= 52), which wore an ankle-based sensor providing feedback on their strike pattern, and a control group (CON, n=56), which received no feedback. Both groups were instructed in a foot and lower leg strengthening program in preparation for the transition. Foot strike pattern and cadence were assessed pre and post-training, and at 6 months. Injury and mileage data were collected through weekly email surveys over 6 months. Chi square analyses were used to assess differences between groups and between times.
RESULTS: Eighty-one percent of runners demonstrated a NRFS pattern following the 2 hour training session (87/108, p < 0.001). The percentage of NRFS runners remaining at the six month follow-up decreased in both groups, but this was not significant (CON = 68%, p = 0.20; BFG = 75%, p = 0.34). There was no statistical difference in the number of participants that transitioned from RFS to NRFS pattern between groups at the six month follow-up (p = 0.41). Compliance in the BFG was only 14% due to technical limitations of the sensor. Injury rates were similar between RFS runners (29% injured) and NRFS runners (22% injured) after six months (p = 0.47). The relative risk for knee injury in RFS runners, regardless of group, was 9.93 (95% CI: 1.15, 85.4; p-value= 0.04).
CONCLUSION: A large percentage of runners were able to transition to a NRFS pattern with small, group based training without the use of a biofeedback device. Greater changes in the BFG may have been seen had compliance been better. There was no definitive difference in injury rates between RFS and NRFS runners at the 6 month follow-up. Injury rates and mechanics will be reassessed at 12 months.