Student: Caroline N. Bertram*
Mentor: Matthew F. Moran
Major: Exercise Science
Purpose: Gait retraining is effective at altering running mechanics to help reduce injury risk (4, 5). Many gait retraining programs, require subjects to modify their form based on external cues (e.g. auditory, visual). The purpose of this study was to determine how well runners were able to adjust their running cadence (i.e. stride rate) to match an auditory cue (metronome) during a submaximal run, and if running experience had an impact on how well the stimuli was matched.
Methods: Fourteen participants (5M, 9F; 21.7 ± 4.2 yo) were recruited and classified as experienced (E) or inexperienced (I) runners based on days and kilometers run per week. Day one of testing consisted of a VO2 peak test. On the second day of testing, participants ran on a treadmill for 19 mins at 65-70% of their VO2 peak, attempting to modify stride rates to a metronome beat. The metronome was set to correspond with ± 6, 12, and 18% of the self-selected stride rate. The conditions were randomized, and each lasted 3 min. High speed video (240 Hz) was collected to determine the actual stride rate for each trial. Results: Participants in each group had similar self-selected cadences (E: 70.2±6.5 strides*min-1, I: 72.7±8.2 strides*min-1). On average, E runners displayed a greater average absolute value deviation (2.9±2.2%) from the metronome cue than I runners (1.8±1.2%). Imposed cues of -18% resulted in the greatest deviations across both groups (5.4±5.3%). Although treadmill velocity was held consistent, both groups displayed significantly higher oxygen consumption at the completion of the 19 min run (p<0.05).
Conclusion: Overall, inexperienced runners display better adherence to an imposed stride frequency than experienced runners. This implies that they may adhere to a metronome-based gait retraining program better than their more experienced counterparts. Experienced runners maintain a preferred cadence, while inexperienced runners are more variable in their running patterns and alter their cadence with greater ease. The overall increase in oxygen consumption implies that the program was fatiguing. This should be considered in the development of gait retraining protocols.
Key Words: stride frequency, metronome, running mechanics