The body sensor network (BSN) system allows communication among sensor nodes attached to different parts of human body to monitor body motion and vital parameters. BSN system using wired network is more secure in terms of data transmission and consume less power than wireless network. Stretchable conductive wires that can withstand large strains without change in resistance are highly desired. In this work, a meter-scale stretchable conductive wire composed of serpentine enameled wire embedded in stretchable elastomer is developed using a large area compatible process. The wires are used to connect the wearable pressure and strain sensors and circuit boards at different locations on the human body to construct a BSN system for motion detection. The wires show high conductivity and electrical stability under bending, twisting and prolonged stretching, with negligible impact on the analog and digital signal transmission when connecting the wearable sensors to the circuit boards. Due to the stable performance of the stretchable conductive wires and the wearable pressure and strain sensors, the designed BSN system can detect human motion in real time and can recognize motion posture.