The purpose of this study was to analyze kinetic and kinematic data of individuals with unilateral transtibial limb loss and the effect different alignments have on the individual’s gait while they walk over uneven terrain. Individuals with lower limb loss are currently having their prostheses dynamically aligned to ensure a satisfactory walking gait on level ground with smooth surfaces, usually in the clinician's office or hallway. This study was looking to determine whether or not current prosthesis alignment procedures are adequate for determining a satisfactory walking gait on non-level and non-smooth terrains as well level smooth surfaces. An effective and efficient walking pattern is necessary to prevent degenerative conditions within the bones, muscles or other tissues of the body, due to compensations of the gait pattern. Sometimes, individuals are able to mask any compensations if their safety is unaffected by their surroundings and they are able to maintain a gait that appears normal or optimal. However, if terrains used on a daily basis present a sense of insecurity, gait compensations could be more problematic to the individual and they need to be addressed and corrected as best they can. This study determined that while there were some changes in gait on the uneven surface, due to the number of subjects it is unclear whether the changes are significant. The individuals showed a decrease in walking speed and step length and an increase in step width. There were also changes in the peak axial force.

Persons suffering central nervous system damage, such as a stroke, coma patients, or individuals that have suffered damage to the spinal cord, brainstem, cerebellum, and motor cortex, sometimes develop an asymmetric walking pattern where one leg does not fully swing backward. This uneven gait hinders these individuals in properly and efficiently moving through everyday life. Previous research in humans and various animals has introduced a split belt treadmill to analyze possible rehabilitation, which can recreate a correct gait pattern by altering the speed of each track. Gait adaptation was achieved by having the split belt treadmill move each leg at a different velocity relative to the ground and thus forcing a symmetric gait. Test subjects‟ gait would adapt to the speeds and a normal gait pattern could be conditioned while on the split belt treadmill. However, after short trials, individuals were unable to neurologically store these feed-forward walking patterns once walking over ground. Also, test subjects would have difficulty adapting their learned walking gait over different walking environments. The gait enhancing mobile shoe (GEMS) makes it possible to adjust an asymmetric walking gait so that both legs move at a relatively symmetric speed over ground. It alters the wearers walking gait by forcing each foot backwards during the stance phase, operating solely by mechanical motion, transferring the wearer‟s downward force into a horizontal backwards motion. Recreating the split belt treadmill effect over ground by using the GEMS will potentially enable me to test the long term effects of a corrected gait, which is impossible using a split belt treadmill. A previous prototype of the GEMS [1] successfully generated a split belt treadmill walking pattern, but had various drawbacks, such as variable motion from step to step. My new design of this rehabilitation shoe promises to alter the user‟s gait as a split belt treadmill does, and to be mechanically stable operating without any external power sources. I designed and constructed a new motion controlled gait enhancing mobile shoe that improves the previous version‟s drawbacks. While mimicking the asymmetric gait motion experienced on a split-belt treadmill, this version of the GEMS has motion that is continuous, smooth, and regulated with on-board electronics. An interesting aspect of this new design is the Archimedean spiral wheel shape that redirects the wearer‟s downward force into a horizontal backward motion. The design is passive and does not utilize any motors and actuators. Its motion is only regulated by a small magnetic pthesis brake. Initial tests show the shoe operates as desired, but further experimentation is needed to evaluate the long-term after-effects.