Topics: Sport materials. Abstract: Conception of rowing ergometer is constrained by many limits. One of them is that it must resist to forces applied on it, whatever is the frequency movement, and take few spaces in an apartment or a room. A good sport material must respect these two major constraints. In this study, we focus on resistance of material using forces quantification on each contact point on the rowing ergometer concept2® at different frequencies of practice. Our goal is to reveal where structure modifications could be effected in order to optimize conception. There are four contact points on this ergometer: “the handle, the seat and the two foot-stretchers”. On each point, forces are measured with a specific material. On the handle, a mono-directional sensor is used. Under the seat and the two foot-stretchers, 6 axis force plates were used. These measurements are realised with an expert rower who practice rowing on the concept2® ergometer more than twice in a week and is an international level rower on boat. One rowing cycle is selected for each produced stroke rate: 18 to 40 strokes per minute. First results show that forces are not really modified when stroke rate increases. Secondly, forces produced under the seat are not constant. An inertial parameter explains this inconstancy: the accelerated rower masses of his trunk and his upper limbs. Finally, on stret- cher,forces are different too because of inertial effect of whole body at the end of recovery. In resume, the structure of concept2® ergometer can be optimised, changed and probably costs less if we take into account this type measurements before design a rowing ergometer. Keywords: Rowing ergometer, applied forces, kinetics and performance. 1- Introduction The design of sport ergometers requires thorough knowledge of the studied sport. The design is characterized by the dilemma space and weight equipment versus resistance to the activity. Mechanically, it has to resist to the efforts developed by costumers. This resistance has to be sustainable over time. Moreover, the finished structure must allow a Forces Applied on Rowing Ergometer Concept2®: a Kinetic Approach for Development (P94) Nicolas Découfour 1 , Franck Barbier 1 , Philippe Pudlo 1 , Philippe Gorce 2 1. L.A.M.I.H. – UMR CNRS 8530, Université de Valenciennes, France - E-mail: nicolas.decoufour@univ-valenciennes.fr; philippe.pudlo@univ-valenciennes.fr; franck.barbier@univ-valenciennes.fr 2. HandiBio, Université du Sud Toulon-Var, France - E-mail: philippe.gorce@univ-tln.fr