Over the past few years, in France, the use of child restraint systems increases continuously. But, the accidentologic data highlight that improvements are still necessary to decrease the frequency and the severity of the cervical and abdominal injuries. In order to extend the knowledge about the lesional mechanisms of these two body segments, numerous studies are undertaken to design transducers.Relating to the abdomen, with the current device (block of plasticine) recommended for the dynamic tests, we have only a posteriori evaluation. Consequently, this method does not allow to obtain data relative to the time. It is an important lack for the development of new child safety devices.This paper presents an intra-abdominal pressure transducer, designed and developed at the Laboratory of impacts and Biomechanics of INRETS. In a first step, this transducer is implanted into the TN03 dummy.The first pan presents the results of quasi-static tests carried out to evaluate the transducer sensitivity with respect to the disturbing effects produced by the lumbar spine flexion. Then, we examine the results of the first dynamic tests in different configurations.This transducer allows to study thoroughly the child kinematics. But, the elaboration of an abdominal protection criterion developed from the transducer signal is not easy. The mean reason is linked to the specific behavior of the TNO dummy. The improvment of the child dummies biofidelity is an acute and urgent necessity.