Because lower-limb prosthetic alignment can be subjective and a misalignment induces gait deviations and long-term joint diseases, a research team set out to identify the effect of the transfemoral alignment prosthesis on ground reaction forces and thermal images of the residual limb. They found that poor prosthetic alignment produced an irregular heat distribution on the residual limb, which can provide prosthetists with a better understanding of the alignment procedure and improve the user’s compliance.
The effect of misalignment and nominal alignment was evaluated in 16 individuals with transfemoral amputations. The nominal alignment was considered as the optimal alignment for each subject. Misalignment included random variations in the anterior-posterior and medial-lateral translation of the prosthetic foot and the angle of flexion-extension, abduction-adduction, and internal-external rotation of the socket and prosthetic foot. Fifteen people with no amputations made up the control group. The ground reaction force parameters and temperature of the residual limb were analyzed for each alignment condition.
According to the study, the prosthesis did not produce statistically significant changes in the average temperature of residual limbs. However, the temperature distribution on the skin was different, therefore thermal images can support the prosthetist during the alignment procedure. The misalignment produced an irregular heat diffusion on the anterior, posterior, and lateral sides of the residual-limb contour compared to the nominal alignment. The sound limb did not show differences between nominal alignments and misalignments for most ground reaction force parameters. For almost all ground reaction force parameters, significant differences were observed for the prosthetic limb between misalignment and nominal alignment, the study’s authors wrote.
The study, “The effect of prosthetic alignment on the stump temperature and ground reaction forces during gait in transfemoral amputees,” was published in Gait & Posture.