This article presents ongoing developments in our team to establish coordination between upper and lower limbs in FES-assisted posture and gait. The approach is described from a theoretical and technical aspect and preliminary experimental results are presented. The proposed solution is based on a Body Area Network embedding sensor and actuator (electrical stimulators) nodes. We illustrate preliminary results in two main applications: gait assistance in post-stroke hemiplegia and sit-to-stand transfer in complete paraplegia.