B-40 Free Communication/Poster - Sport Biomechanics: JUNE 1, 2011 1:00 PM - 6:00 PM: ROOM: Hall B
Tibial stress fractures (TSF) in runners have been linked to elevated tibial shock (TS) and vertical instantaneous and average load rates (VILR and VALR). We previously found that gait retraining with real-time visual feedback (FB) reduced high load rates on the trained leg during treadmill running. In most subjects, these variables were also reduced on the untrained, contralateral leg. However, it is unknown if these results transfer to overground running, where most runners log their mileage.
PURPOSE: To determine if subjects decrease vertical loading on both legs following a gait retraining intervention.
METHODS: 6 subjects (30.0 ± 5.2 yr), running > 10 mpw have participated in this ongoing study. They exhibited high vertical loading at baseline, TS > 8g. Each subject completed 8 running sessions with no feedback (CTRL) followed by 8 sessions with FB aimed to decrease vertical loading on the trained limb. We measured VILR, VALR and vertical impact peak (VIP) at baseline, post CTRL and post FB during overground running on both legs. Due to the small sample size, the data were analyzed descriptively.
RESULTS: At baseline, 5/6 subjects had elevated vertical loading on their untrained, contralateral leg, but it was not as excessive as their trained leg. On average, loads changed < 4% following CTRL. Following FB, loading decreased to within normal limits on both limbs. Load rates decreased 37% on each leg, and VIP decreased 30% on each leg (Figure 1).
CONCLUSION: Loading appeared to reduce on both legs following gait retraining but not following a control period. Based upon these results, training effects gained from treadmill gait retraining transfer to overground running.
Support: DOD W911NF-05-1-0097 & W81XWH-07-1-0395 & NIH 1 S10 RR022396.