Operative vaginal delivery is the main risk factor for pelvic floor trauma occurrence and especially for obstetric anal sphincter injuries. These complications are strongly and negatively impact women's health: fecal incontinence, perineal pain, sexual dysfunction.

The risk appears higher in case of operative vaginal delivery assisted by forceps compared to a vacuum delivery. This considered it is likely that optimizing the performance of the operator that perform the operative vaginal delivery will reduce the morbidity associated with this intervention. There are data bout how to optimize the placement of the forceps on the fetal head before performing the delivery but there are no data about the movement of the obstetrician during this intervention.

The objective is to analyse the posture and the movement of the obstetrician during a simulated forceps operative vaginal delivery using a 3D cinematic analysis. Secondary objectives are to analyse the traction force applied on the forceps during the delivery, to describe the different postures in terms of stability and last to compare the self-declared practice to the objectively observed.

This is a prospective study including 40 volunteers (medical doctors and registrars).

Each volunteer will perform a simulated operative vaginal delivery using a Suzor's Forceps on a high fidelity mannequin. Postures and movement will be assessed using optometric analysis. The force of traction will be assessed during the operative delivery thank to a force sensor on the forceps. The self declared practice collected thanks to individual questionnaires will be compared to the observed practice during the simulation.

The prospects are to identify the best posture and movement for performing an operative vaginal delivery and to promote tools for simulation of medical students.

Inclusion Criteria:

• Medical doctor or registrar that have an experience of operative vaginal delivery using forceps in their clinical activity

Exclusion Criteria:

• No practice of the forceps at all

The population will be constituted of 40 volunteers that are medical doctor obstetricians or registrar in obstetrics with an experience of the operative vaginal delivery using Suzor's Forceps.

All the participants will be aged of 18 or more and will give their informed and written free consent before any investigation.

There is no patient in this study which is a simulation study performed on MD and registrar.