People with unilateral transfemoral amputations often experience an asymmetrical and less stable gait pattern and a greater cognitive demand of walking. A team of researchers studied whether this is affected by the prosthetic suspension. They evaluated spatiotemporal and stability-related gait parameters, as well as cortical activity during walking between highly active (K3-K4) and able-bodied people, and between people with a bone-anchored prosthesis and those with a socket-suspended prosthesis.
The study concluded that while anticipated differences in gait parameters in people with transfemoral amputations were confirmed, no significant effect of the fixed suspension of a bone-anchored prosthesis was found.
Eighteen able-bodied people and 20 people with unilateral transfemoral amputations (ten bone-anchored prosthesis users and ten socket-suspended prosthesis users) walked on a treadmill at their preferred speed.
Spatiotemporal and margin of stability parameters were extracted from 3D movement recordings. In addition, 126-channel electroencephalogram (EEG) was recorded. Brain-related activity from several cortical areas was isolated and source-level data was divided into gait cycles and subjected to time–frequency analysis to determine gait-cycle dependent modulations of cortical activity.
The researchers concluded that the participants with transfemoral amputations walked with smaller and wider steps and with greater variability in mediolateral foot placement than the able-bodied subjects; no significant differences were found between bone-anchored prosthesis and socket-suspended prosthesis users.
The EEG analysis yielded four cortical clusters in frontal, central (both hemispheres), and parietal areas. No statistically significant between-group differences were found in the mean power over the entire gait cycle.
The event-related spectral perturbation maps revealed differences in power modulations between the transfemoral amputations and able-bodied groups, and between bone-anchored prosthesis and socket-suspended prosthesis users, with the largest differences observed around heel strike of either leg.
The open-access study, “The influence of prosthetic suspension on gait and cortical modulations is persons with a transfemoral amputation: socket-suspended versus bone-anchored prosthesis,” was published in the Journal of NeuroEngineering and Rehabilitation.
