A research team analyzed the influence of prosthetic ankle power generation on the sound side knee load of participants with transfemoral amputations during level walking. The team concluded that the biomechanical sound side loading parameters were reduced with the powered foot at optimal power in comparison to SACH and energy-storing and -returning feet, resulting in relief of the sound side.
Data was collected from six male participants (age: 47 [34-58] years) with unilateral transfemoral amputations while level walking. They were evaluated while using a microprocessor knee joint and a SACH foot, an energy-storing and -returning foot, and a powered foot (Ottobock’s C-Leg microprocessor knee joint, and the 1D10, Triton, and Empower feet, respectively). The order of testing the different foot scenarios was randomized.
Each powered foot was adapted in three configurations: without power, low power, and optimal power. An optoelectronic camera system with 12 cameras and two force plates were used in all conditions.
During the gait analyses, the subjects were instructed to walk on the level walkway, first with self-selected comfortable velocity and afterward with fast velocity. Nine valid trials were measured for each condition. The subjects had at least one hour for acclimatization.
According to the study, ankle power on the prosthetic side showed significant differences about foot types and different settings of the powered foot. The knee adduction moment, the knee flexion moment, and the vertical ground reaction forces on the sound side were significantly reduced with the powered foot and optimal power and energy storing and returning in comparison to the SACH. When analyzing the parameters for the different powered foot configurations, only some showed significant results at normal velocity.
Apart from the varied ankle power on the prosthetic side, the researchers concluded that the construction of the foot section seems to be important for the load on the sound side knee.
The open-access study, “How does ankle power on the prosthetic side influence loading parameters on the sound side during level walking of persons with transfemoral amputation?,” was published in Prosthetics and Orthotics International.