Arm Prosthesis Research for Rowing Adaptation

Arielle Torres developed a transradial rowing prosthesis as part of her final project for her master’s in Mechanical Engineering at Nottingham University. Once she had developed a prototype, she approached Marlow RC’s BEA PR3-PD Kirsty Mason to provide user feedback and functionality testing. Kirsty had employed a number of adapted prosthetics for other adaptive sports she participated in especially weight training.

The biggest challenge to a rowing-optimised prosthetic was (a) repetition, and (b) degrees of freedom:

• REPETITION: The device had to stay secure in place for a relatively long period of time (eg. 10 minutes of a race) without any adjustment. By contrast, a weight lifting prosthetic could be adjusted after every training set if need be. Even on an erg, one could stop momentarily for minor adjustments relatively easily.
• DEGREES OF FREEDOM: Rowing (sweep) involved quite a variety of angle movements of the grip relative to the arm and the vector of torque. For simple land training on a rowing machine, the motion is very straight with little change in angle. Actually, Kirsty had been able to use her weight-lifting prosthetic quite effectively on the erg. But that same device rowing on the water caused all manner of discomfort (eg. back stress, uneven pressure on the arm, inability to complete the full stroke motion, grip issues).

Arielle’s research represents a major piece of work to document the challenges and considerations as well as a number of solutions attempted. In the end, the pandemic lockdown last year meant that Kirsty could no longer go on the water so further testing, feedback and refinement of the device was not feasible. Nonetheless, Arielle has kindly shared her work with Adaptive Rowing UK here so others investigating possibilities in their area can benefit from it.

Arielle summarised her work:

• · “This design report was completed in March 2019 in fulfilment of an integrated Masters in Mechanical Engineering at The University of Nottingham. The report includes a review of existing sports-specific prostheses followed by a breakdown of the design process taken to develop a customisable, 3D printed rowing prosthesis prototype.”
  
  “Following the submission of this report, efforts were made to further develop and improve the rowing prosthesis design. However, progression was restricted as the designer lacked an intrinsic understanding of the challenges encountered by users of upper limb prostheses. As such, a search was conducted for an individual who had both rowing experience and a transradial amputation.”

  “Eventually, such an individual was found and in June 2019 a meeting was arranged with Kirsty Mason, a talented and ambitious British pararower. Kirsty shared her personal experiences with protheses, including the challenges she faced both on and off the water, which highlighted to the designer some of the limitations of existing prosthetic solutions. Common issues included a limited or inadequate range of movement and impractical grips or attachments.”
  
  “Often a prosthesis is used in a way not originally intended by the designer for the user to accomplish a task or action. This is caused by a communication gap between the designer and user of the prosthesis. After the meeting with Kirsty, the importance of communicating with amputees during the iterative design process and finally obtaining feedback for the final design, is critical to ensure future prostheses are optimally designed with the user fully in mind.”

Here is a copy of the report “Design_of_an_Active_Transradial_-_Design_Report_12_April_2019” (and here is its Appendix) for reference.