Comparison of four different categories of prosthetic feet during ramp ambulation in unilateral transtibial amputees.

BACKGROUND: Comparative effectiveness of prosthetic feet during ramp ambulation in unilateral transtibial amputees, who function at different Medicare Functional Classification Levels, has not been published. OBJECTIVE: To determine differences in symmetry in external work between four categories of prosthetic feet in K-Level-2 and K-Level-3 unilateral transtibial amputees during ramp ascent and descent. STUDY DESIGN: Randomized repeated-measures trial. METHODS: Ten subjects completed six testing sessions during which symmetry in external work was calculated using F-scan in-sole sensors. Between testing sessions 1 and 2, subjects received standardized functional prosthetic training. In Sessions 3-6, subjects tested four feet--solid ankle cushion heel, stationary attachment flexible endoskeleton, Talux (categories K1, K2, and K3, respectively), and Proprio-Foot (microprocessor ankle)--using a study socket and had a 10- to 14-day accommodation period with each foot. RESULTS: During ramp descent, K-Level-2 subjects demonstrated higher symmetry in external work values with Talux and Proprio-Foot compared to the solid ankle cushion heel foot. K-Level-3 subjects also had higher symmetry in external work values with the Talux foot than the solid ankle cushion heel foot. Ramp ascent symmetry in external work values were not significantly different between feet. CONCLUSIONS: Prosthetic foot category appears to influence symmetry in external work more during decline walking than incline walking. K-Level-2 unilateral transtibial amputees achieve greater symmetry from K3 dynamic response prosthetic feet with J-shaped ankle and microprocessor ankles while descending ramps. CLINICAL RELEVANCE: The findings suggest that K-Level-2 unilateral transtibial amputees benefit from K3 dynamic response prosthetic feet with J-shaped ankle. These results support the prescription of K3 feet for K-Level-2 amputees who frequently negotiate ramps.

Comparison between microprocessor-controlled ankle/foot and conventional prosthetic feet during stair negotiation in people with unilateral transtibial amputation.

Contrary to stance-phase dorsiflexion of conventional prosthetic feet, the microprocessor-controlled Proprio foot permits swing-phase dorsiflexion on stairs. The purpose of this study was to compare Symmetry in External Work (SEW) between a microprocessor-controlled foot and conventional prosthetic feet in two groups with unilateral transtibial amputation (Medicare Functional Classification Levels K-Level-2 and K-Level-3) during stair ascent and descent. Ten subjects were evaluated while wearing three conventional prosthetic feet- solid ankle cushion heel (SACH), stationary attachment flexible endoskeleton (SAFE), and Talux-and the Proprio foot using a study socket and were given a 10- to 14-day accommodation period with each foot. Ground reaction forces were collected using F-scan sensors during stair ascent and descent. The SEW between the intact and amputated limbs was calculated for each foot. During stair ascent, the Proprio foot resulted in a higher interlimb symmetry than conventional prosthetic feet, with significant differences between the Pro prio and SACH/SAFE feet. The swing-phase dorsiflexion appeared to promote greater interlimb symmetry because it facilitated forward motion of the body, resulting in a heel-to-toe center of pressure trajectory. During stair descent, all feet had low symmetry without significant differences between feet. The movement strategy used when descending stairs, which is to roll over the edge of a step, had a greater influence on symmetry than the dorsiflexion features of prosthetic feet.

Influence of gait training and prosthetic foot category on external work symmetry during unilateral transtibial amputee gait.

BACKGROUND: Prosthetic foot prescription guidelines lack scientific evidence and are concurrent with an amputee's concurrent with an amputee's Medicare Functional Classification Level (K-Level) and categorization of prosthetic feet. OBJECTIVE: To evaluate the influence of gait training and four categories of prosthetic feet (K1, K2, K3, and microprocessor ankle/foot) on Symmetry in External Work for K-Level-2 and K-Level-3 unilateral transtibial amputees. DESIGN: Randomized repeated-measures trial. METHODS: Five K-Level-2 and five K-Level-3 subjects were tested in their existing prosthesis during Session 1 and again in Session 2, following 2 weeks of standardized gait training. In Sessions 3-6, subjects were tested using a study socket and one of four randomized test feet. There was an accommodation period of 10-14 days with each foot. Symmetry in External Work for positive and negative work was calculated at each session to determine symmetry of gait dynamics between limbs at self-selected walking speeds. RESULTS: K-Level-2 subjects had significantly higher negative work symmetry with the K3 foot, compared to K1/K2 feet. For both subject groups, gait training had a greater impact on positive work symmetry than test feet. CONCLUSION: Higher work symmetry is possible for K-Level-2 amputees who are trained to take advantage of K3 prosthetic feet designs. There exists a need for an objective determinant for categorizing and prescribing prosthetic feet.

Application of self-report and performance-based outcome measures to determine functional differences between four categories of prosthetic feet.

We examined the application of outcome measures to determine changes in function caused by standardized functional prosthetic gait training and the use of four different prosthetic feet in people with unilateral transtibial limb loss. Two self-report measures (Prosthetic Evaluation Questionnaire-Mobility Scale [PEQ-13] and Locomotor Capabilities Index [LCI]), and three performance-based measures (Amputee Mobility Predictor with a prosthesis [AMPPRO], 6-minute walk test [6MWT] and step activity monitor [SAM]) were used. Ten people with unilateral transtibial limb loss, five with peripheral vascular disease (PVD) and five without PVD, completed testing. Subjects were tested at baseline and after receiving training with their existing prosthesis and with the study socket and four prosthetic feet, i.e., SACH (solid ankle cushion heel), SAFE (stationary attachment flexible endoskeletal), Talux, and Proprio feet, over 8 to 10 weeks. Training was administered between testing sessions. No differences were detected by the PEQ-13, LCI, 6MWT, or SAM following training and after fitting with test feet. The AMPPRO demonstrated differences following training with the existing prosthesis in the PVD group and between selected feet from baseline testing ( p