A pilot study was conducted to test and compare efficiency and functional capabilities of a 3D-printed prosthetic arm and a commercially available manufactured myoelectric hand to determine if 3D-printed upper-limb prostheses could provide a cost-effective alternative. The results and observations made by the researchers suggested the myoelectric prosthesis was more practical and efficient than the 3D-printed device. The study was published in the July 2017 issue of the Journal of Prosthetics & Orthotics (JPO).
A Box and Blocks Test was used to assess the efficiency of a myoelectric i-limb (Touch Bionics, Livingston, Scotland) and a 3D-printed Limbitless Arm (Limbitless Solutions, Orlando, Florida). The research team designed a quasi-experimental, static group comparison trial with 24 able-bodied participants, 14 men and ten women who were healthy, were right hand–dominant, and had a mean age of 26.1 years (± 4.2 years). Two custom devices, to which the two prostheses attached distally, were created to accommodate the participants. The prostheses were tested by the participants over two visits with a two-week crossover period.
The mean number of blocks moved with the 3D-printed device was significantly lower than with the myoelectric prosthesis. For trial 1, the mean was 8.4 ± 3.6 blocks with the 3D-printed device versus 12.9 ± 3.3 with the i-limb. For trial 2, the mean was 8.3 ± 3.6 blocks with the 3D-printed device versus 13.8 ± 4.1 with the i-limb. Furthermore, the researchers found that the mean number of blocks moved improved when using the myoelectric prosthesis versus the 3D-printed hand by 53.6 percent in trial 1 and 66.3 percent in trial 2.
The researchers obtained similar findings after completing separate analyses by gender. For men, in trial 1 the mean was 9.1 ± 3.3 blocks with the 3D-printed device versus 12.9 ± 3.7 with the myoelectric prosthesis; in trial 2, the mean was 9.6 ± 3.2 blocks with the 3D-printed device versus 14.1 ± 4.7 with the myoelectric prosthesis. For women, in trial 1 the mean was 7.5 ± 3.9 blocks with the 3D-printed device versus 12.8 ± 2.9 with the myoelectric prosthesis; in trial 2, the mean was 6.3 ± 3.4 blocks with the 3D-printed device versus 13.4 ± 3.2 with the myoelectric prosthesis.