INTRODUCTION AND HYPOTHESIS: The prevalence of female stress urinary 
incontinence is high, and young adults are also affected, including athletes, 
especially those involved in "high-impact" sports. To date there have been 
almost no studies testing pelvic floor muscle (PFM) activity during dynamic 
functional whole body movements. The aim of this study was the description and 
reliability test of PFM activity and time variables during running.
METHODS: A prospective cross-sectional study including ten healthy female 
subjects was designed with the focus on the intra-session test-retest 
reliability of PFM activity and time variables during running derived from 
electromyography (EMG) and accelerometry.
RESULTS: Thirteen variables were identified based on ten steps of each subject: 
Six EMG variables showed good reliability (ICC 0.906-0.942) and seven time 
variables did not show good reliability (ICC 0.113-0.731). Time variables (e.g. 
time difference between heel strike and maximal acceleration of vaginal 
accelerator) showed low reliability. However, relevant PFM EMG variables during 
running (e.g., pre-activation, minimal and maximal activity) could be identified 
and showed good reliability.
CONCLUSION: Further adaptations regarding measurement methods should be tested 
to gain better control of the kinetics and kinematics of the EMG probe and 
accelerometers. To our knowledge this is the first study to test the reliability 
of PFM activity and time variables during dynamic functional whole body 
movements. More knowledge of PFM activity and time variables may help to provide 
a deeper insight into physical strain with high force impacts and important 
functional reflexive contraction patterns of PFM to maintain or to restore 
continence.