- orthopedic limitations that would prohibit from performing plantar-flexion or knee-extension exercise - contraindication to mri (pacemaker, metal implants, or certain types of heart valves), or be at medical risk from undergoing an mri examination - enrolled in a rehabilitation program - bmi <40 kg/m2 and weigh <400lbs - prior history of pulmonary embolism or deep vein thrombosis

- orthopedic limitations that would prohibit from performing plantar-flexion or knee-extension exercise - contraindication to mri (pacemaker, metal implants, or certain types of heart valves), or be at medical risk from undergoing an mri examination - enrolled in a rehabilitation program - bmi <40 kg/m2 and weigh <400lbs - prior history of pulmonary embolism or deep vein thrombosis