A prosthetic leg prototype for improved mediolateral balance control: Design of a case–control study

Background: Missing active ankle control limits prosthetic walkers in their ability to control mediolateral balance. Mediolateral balance control may be improved by increasing hip strategy effectiveness. To this purpose, a new, patented prosthetic device has been developed. This paper presents the design of a study focused on validating the prototype on improvements of mediolateral balance control by comparing it to a classic prosthetic set-up. Methods: Ten adult unilateral transfemoral amputees and ten age- and weight-matched (± 10%) able-bodied individuals will walk on the Gait Real-time Analysis Interactive Lab. Subjects will perform three walking tasks: (1) Unperturbed walking at 80%, 100%, and 120% of comfortable velocity, (2) walking while being mediolaterally perturbed, and (3) walking while stepping on projected light beams. Full-body kinematic and kinetic data will be recorded. Various walking and balance parameters will be analysed. Discussion: It is expected that by increasing hip ab-/adduction effectiveness, the prototype will improve mediolateral balance control in prosthetic walking. Also, it is expected that the prototype will reduce asymmetric lateral trunk bending. Finally, this study will provide valuable new insights into mediolateral balance control during prosthetic walking