During interaction, speakers tend to adjust the amount of coarticulatory cues to increase or decrease perceptual distances between competing speech units. Anticipatory coarticulation has also been observed in the visual-gestural modality. Despite this, little is known about the use of coarticulatory strategies in sign language. We built the first study that investigates coarticulation in French Sign Language (LSF) using 3D Electromagnetic Articulography (EMA) to provide precise kinematic measurements in sign production. In this novel approach, a deaf native signer was recorded (EMA/video) producing phonological pairs of signs composed of ‘1’- and/or ‘3’-handshape. Our findings demonstrate that kinematic data allows for the detection of coarticulation in various discourse contexts. Temporally, we observe the anticipation of the ‘3’-handshape before the end of its immediately preceding ‘1’-handshape sign (and vice versa). Spatially, the (repetitive movement of) the sign is affected by reduction/truncation if followed by another sign. Within a dynamical approach (Articulatory Phonology), we analyze the kinematics of our sign data as a result of systematic patterns of overlapping organization triggered by the phonological system. Based on this view, we attempt to take a step forward towards an integration of gradient and categorical processes such as coarticulation and assimilation.