Noting that proprioception and kinesthesia are crucial senses for human limb control, but are currently lacking in modern prosthetic limbs, a research team developed an artificial sensory feedback system to improve the sense of joint speed information and how it may impact the performance and adaptation of prosthetic control. They tested the system’s effectiveness in improving control and adaptation to novel conditions and said the improved reaching strategy suggested that joint speed feedback may help prosthesis users’ reach performance following sudden changes to prosthesis control.
Sixteen right hand-dominant, non-amputee subjects participated in two experimental sessions: one session with no audio feedback, and one session with frequency-modulated joint speed audio feedback. The participants sat in front of a computer monitor and placed their right arms in a wrist brace. The wrist brace was supported by a ball bearing cart on a table adjusted so the subject’s shoulder was abducted to 90 degrees. The ball bearing cart allowed the brace to move freely across the surface of the table.
The reaching tasks required simultaneous control of positional- and myoelectric-controlled joints, similar to myoelectric prosthesis control. The researchers concluded that their results confirmed that simulated reaches were possible, despite initial subject difficulty.
The open-access study, “Artificial Joint Speed Feedback for Myoelectric Prosthesis Controls,” was published in bioRxiv.