Development of a graded pelvic loading pathway using external pelvic acceleration variables to aid return to running postpartum

Objectives: To assess the basis for developing a graded loading pathway that is specific to the pelvis, to aid return to running postpartum. Participants: Seventeen runners (28.4 ± 7.0 years, 63.7 ± 9.2 kg, 1.63 ± 0.06 m) completed five treadmill running conditions and eight overground activities. Main outcome measures: Repeated measures ANOVA/Friedman tests assessed differences in pelvic acceleration variables between treadmill running conditions. Correlations assessed relationships between pelvic acceleration, kinetic variables and ratings of perceived pelvic impact. Activities were ranked according to pelvic acceleration variables. Means±SDs and medians (IQR) were calculated as appropriate. Results: Grounded running had lower peak pelvic acceleration (2.8 ± 0.5 g), average (18.5(14.2–26.5) gs⁻¹) and instantaneous (32.2(25.3–44.5) gs⁻¹) jerk and area under acceleration curve (0.58(0.56–0.62 gs) compared to habitual running per step. However, per kilometre, grounded running was not always lower. Relationships between variables differed across activities. A graded pelvic loading pathway was presented, spanning from walking to double leg high hopping. Conclusions: A graded pelvic loading pathway was developed that could be further refined to aid postpartum return to running. Grounded running demonstrated lower pelvic acceleration loading than habitual running and may provide a suitable transition prior to returning to running. Localised variables may be needed to adequately inform pelvic activity progressions.