Modified Concept 2 Rowing Machine with Manual Fes Controller for Total Body Exercise in Paraplegia

Concept 2 indoor rowing machine (Concept 2 Inc., USA), an exercise and training machine for able-bodied population, was modified for total body exercise in paraplegia. A new seating system provides trunk stability and constrains the leg motion to the sagittal plane. A 4-channel electrical stimulator activates the quadriceps and hamstrings in drive and recovery phases of rowing cycle. Force sensing resistors (FSR) on the handle measure the thumb press as the command signal to the electrical stimulator. Optical encoders measure the position of the seat and handle during rowing. To synchronize the movement of the upper and lower body, a manual control system uses the voluntary thumb presses to determine the timing of the stimulation to the leg muscles. The manual control system was intuitive and easy to learn and resulted in well-coordinated rowing. Evaluation of the modified rower by paraplegic volunteers showed that it is effective, safe, and an affordable exercise alternative for paraplegics.