GAIT BIOMECHANICS AMONG FEMALE ENDURANCE RUNNERS: COMPARING DAYS WITH OR WITHOUT MENSTRUAL CYCLE-RELATED SYMPTOMS.

Objective: Determine differences in running biomechanics in female endurance runners between days when they did and did not report menstrual cycle-related symptoms.

Methods: Observational study. Subjects were provided RunScribe sensors to attach to their shoes to collect biomechanical data when running. Daily during the study period, subjects were sent a text message to complete a survey asking about their wellness, menstrual status, and training status. Descriptive measures (mean ± SD) were generated for whether runners reported being asymptomatic or symptomatic during runs and run workout details. Paired sample t-tests were executed to identify differences in impact Gs, braking Gs, pronation excursion, maximum pronation velocity, foot strike type, and gait speed between runs on days participants reported having menstrual-related symptoms (symptomatic) or not (asymptomatic). Participants needed to have recorded runs spanning the entire data collection window to be included for comparative analyses.

Results: Twenty-seven university club runners (age 20.5 ± 1.5) participated in the study. All runners (n = 27) experienced at least one menstrual cycle-related symptom during data collection. The average number of asymptomatic runs was 22.3 ± 17.1 and symptomatic runs was 9.1 ± 7.5. Daily mileage averaged 4.3 ± 1.9 miles and total mileage was 154.2 ± 115.4 miles. Fourteen runners had run data viable for pairwise sampling. There was no significant difference in biomechanical measures between symptomatic or asymptomatic days (p > .05).

Conclusion: This study prospectively monitored distance runners' activity while simultaneously recording symptoms related to the menstrual cycle. While runners reported fewer days running when symptomatic, we did not identify a difference in objective biomechanical measures between asymptomatic or symptomatic runs. Perceived symptom burden was present in this sport population and may warrant further exploration of perceived expectations of the menstrual cycle to athletic performance.