Objective: The objective of the study was to determine the level and pattern of forces applied during simulated shoulder dystocia.
Study design: One hundred forty staff (95 midwives, 45 obstetricians) were randomized from 6 UK hospitals. Applied delivery force was measured during a standardized simulated shoulder dystocia. Maximum, average, total, and applied force gradients were calculated for each delivery.
Results: There was a wide range for all force variables: geometric mean maximum applied force 106 newtons (N) (range 6 to more than 250, n = 113), maximum force gradient 45 N/s (range 2-249, n = 113), total applied force 2954 N/s (range 33 to 14,197, n = 108), and average applied force 16 N (range 0-68, n = 108).
Conclusions: Despite participants managing the same scenario, there was great variation in the pattern and degree of traction used. High forces were applied during two thirds of simulations. Training must emphasize that maneuvers should be used to overcome shoulder dystocia while minimizing iatrogenic applied force.