A-56 Free Communication/Poster - Running Wednesday, May 31, 2017, 7:30 AM - 12:30 PM Room: Hall F
High vertical load rates have been linked to common running injuries. Interventions to reduce load rates have developed to reduce impact related injuries. Two popular approaches are increasing cadence (CAD) and using a forefoot strike (FFS) pattern. However, the effects of these interventions have not been compared in the same study.
PURPOSE: To compare the effects of increasing CAD and transitioning to a FFS pattern to reduce impact loading in healthy recreational runners.
METHODS: 35 habitual rearfoot strike runners, ages 19-42 yrs, running 5-15 mi/wk, with a CAD of < 170 steps/min were randomized to a FFS group (n=16, 5M) or increased CAD group (n=19, 5M). All subjects performed 4 wks of strengthening exercises. This was followed by 8 sessions of gait retraining (GR) over 3 wks using auditory feedback specific to each group. Run time was increased from 10-30 min over the 8 sessions, and feedback time was faded over the last 4 sessions. An instrumented treadmill assessment was done at baseline, at 1wk post GR, and at 1 mo follow-up. Variables of interest were vertical average and instantaneous load rates (VALR, VILR) measured in bodyweights (BW)/s.
RESULTS: Groups were similar in all variables at baseline (Figure 1). FFS group reduced VALR by 58% and VILR by 44%. CAD group reduced VALR by 26% and VILR by 24%. At 1 mo, load rates for both groups were significantly lower than baseline, but FFS maintained reductions to a greater extent. A 5.6% increase in cadence occurred in both groups following GR. At 1 mo follow-up cadence remained higher in both groups, but to a greater extent in FFS group.
CONCLUSION: These data suggest that transitioning to a FFS results in greater reduction of vertical load rates and greater persistence of these changes over time.