Cable-actuated, kinetically-balanced, parallel torque transfer exoskeleton joint actuator with or without strain sensing

A low-weight, high performance wearable assistive device for assisting motion of a joint of a wearer (e.g., an ankle) and/or resistance training of motion of the joint includes a lightweight upright member that may be attached to the wearer (e.g., fastened to the wearer's outside calf). Forces to assist or resist movement of the joint are coupled to a rotation bearing via cables. The bearing is disposed within the upright member such torsional deflection of the device under load is reduced, allowing the upright member to be lighter and/or less obtrusive to the wearer and less susceptible to failure.