Researchers at the Methodist Rehabilitation Center, Jackson, Mississippi, evaluated changes in temporal-spatial gait characteristics between walking with a non-microprocessor prosthetic knee (NMPK) and a microprocessor prosthetic knee (MPK). They found that most of the tested subjects improved temporal-spatial gait while using the microprocessor prosthetic knee; in one subject, none of the ten gait parameters were in favor of the MPK.
Using a single-subject ABA/BAB study design, seven NMPK users (all men, age 50-84 years, 3-40 years post-amputation) were transitioned through the ABA or BAB phases (A-NMPK, B-MPK, five weeks each). Four weekly gait evaluations were performed at three self-selected speeds with an electronic walkway. The NMPK-MPK differences in stride length-cadence relationship, prosthetic weight acceptance, single-limb support, and step width were evaluated for each subject.
In the BAB group, longer use of the MPK was associated with shorter prosthetic weight acceptance and longer single-limb support times across three speeds. Step width either improved with the MPK or remained unchanged in most subjects.
The researchers concluded that the evidence of individual subject improvements in gait coordination, greater reliance on the prosthetic side, and better stability with the MPK than NMPK over a range of walking speeds demonstrates the practical utility of the single-subject method in clinical decision-making. The method was feasible and reliable for documenting changes in gait at the individual level, which is relevant for clinical practice.
The study was published in Prosthetics and Orthotics International.