Effects of restricted ankle range of motion on human walking : an application to transtibial amputee gait patterns

Graduation date: 2012Alterations in gait patterns are commonly observed in individuals with transtibial amputation (TTA) who use a prosthesis. Current commercially available ankle-foot prostheses (AFP) offer very little range of motion (ROM) at the ankle joint. Previous researchers have hypothesized that lack of ankle ROM significantly contributes to alterations in TTA gait patterns. However, different patterns have been observed among TTA using the same AFP. Therefore it is unclear how restricted ankle ROM in current commercially available ankle-foot prostheses (AFP) contributes to observed changes in gait. Alterations in gait patterns have been shown to increase the incidence of low back pain and other musculoskeletal injuries. TTA have a greater incidence of low back pain and osteoarthritis of the knee and hip. Therefore it is important for researchers to understand the influence of different prosthetic components on gait in order to optimize gait patterns and minimize complications due to alterations in gait. The purpose of this study was to determine what compensatory alterations in gait patterns may occur as a result of imposed restricted ankle range of motion. Kinematic data was collected from 19 participants (9 men, 10 women) age 18-32 with no previous history of lower extremity injury or deformity in two conditions: level-ground walking with no restriction and level ground walking with the ankle restricted at 0 degrees plantarflexion by plaster casting. Results indicated that restricted ankle ROM contributes to decreased velocity and cadence and decrease in gait symmetry. A compensatory pattern was observed for pelvic obliquity, hip and knee flexion at toe-off and foot progression angle. Observed patterns did not resemble those observed in TTA. Results suggest that restricted ankle ROM contributes to some components of alterations in gait patterns observed in TTA. However a combination of other components, including loss of proprioception and power generation at the metatarsophalangeal (toe) joints may have a more significant contribution to TTA gait patterns than restricted ankle ROM alone