Shoulder-wearable soft robot for assisting older adults in scapular stretching.

We propose a wearable soft robot that assists with individualized scapula adduction and abduction for thoracic stretching in respiratory rehabilitation. Although thoracic stretching is known to be effective for respiratory rehabilitation, the range of motion of older adult patients narrows with age, and long-term external aid by physical therapists is required. The proposed robot consists of a soft and shoulder-wearable brace and cable-pulling mechanism to apply rotational torque on shoulders, resulting in stretching the thorax and scapulae. We designed the pulling mechanism by modeling the humeral head trajectory during stretching by a therapist and reproducing it with two linear actuators pulling the right and left shoulders simultaneously, based on position control aimed at achieving a target tension. The main results of validation experiments with older adults confirmed that the robot-assisted stretching was able to perform scapular stretching similar to that of a physical therapist.