A recent study examined whether the DEKA Arm, DEKA Research & Development, Manchester, New Hampshire, which features a compound, powered wrist and multiple grip configurations, improved the movement quality of upper-limb prosthesis users when compared to conventional prostheses. The researchers concluded that the effects of a month of training with the DEKA Arm on movement quality varied with participants’ skill and experience with conventional prostheses.
The study, led by researchers from the University of Michigan; Providence VA Medical Center, Rhode Island; and Brooke Army Medical Center, San Antonio, was published online before print on March 1 in the journal Prosthetics and Orthotics International.
The case series evaluated three people with transradial amputations as they completed tasks of daily life with their conventional prosthesis and with the DEKA Arm. Ten healthy controls completed the same tasks. The trajectory of the wrist joint center was analyzed to determine how different prostheses affected movement duration, speed, smoothness, and curvature compared to patients’ own intact limbs and controls.
The results indicate that movement quality decreased with the DEKA Arm for two participants, and increased for the third, according to the study’s authors. Prosthesis users made slower, less smooth, and more curved movements with the prosthetic limb compared to the intact limb and controls, particularly when grasping and manipulating objects. The researchers suggest that future studies should examine changes in movement quality after long-term use of advanced prostheses.