This video was shot following a selection in the competition for doctoral students and young doctors of the international conference TISLR14. I introduce in a concise and informative way a study which concerns the movement, constitutive parameter of the signs of all Sign Languages. The movement is not studied according to its trajectory, but through the biomechanical deployment of the upper limbs. Considering the forearm and the arm in addition to the hand makes it possible to propose new linguistic associations of forms and functions, and more broadly to question the construction of meaning by the body form.