An exoskeleton is configured to reduce muscle forces in a user's back during forward lumbar flexion. The exoskeleton includes a frame coupled to the user's trunk, a first link coupled to a first thigh and rotatably connected to the frame, and a second link coupled to a second thigh and rotatably connected to the frame. An actuator coupled to the frame includes a first element and a second element that rotate or translate relative to each other to generate a force or torque transmitted through lines connected to the thigh links. A lockout mechanism selectively couples components of the exoskeleton to restrict rotation of the first link relative to the frame in at least one direction, providing controlled support during flexion while permitting free movement during other activities.

Presented are wearable sensor systems for monitoring user movement, methods for making/using such systems, exoskeletons employing such systems, and wireless-enabled wearable sensor devices for performing biometric measurements. A sensor system for monitoring movement of a user includes a wearable sensor device that is communicatively connectable to a sensor linking node. The sensor linking node wirelessly receives sensor data from the wearable sensor device and wirelessly communicates the received sensor data to a remote computing node. The wearable sensor device includes an expandable device body, such as an elastic compression sleeve or an adjustable strap, that is worn on an appendage of the user. The device body includes a mounting interface, such as mating hook-and-loop fastener pads, that removably mounts thereon a biometric sensor core (BSC) unit. The BSC unit contains a microcontroller assembly that is integral with a microcontroller device, a biometric sensor array, and a wireless communication device.