Contact Patterns of Foot Roll-Over in Transtibial Amputees with Articulated Ankle Prostheses
摘要
This study aims to characterize and compare the initial and final foot contact patterns in unilateral transtibial amputees using non-articulated (NAA) and articulated ankle (AA) prosthetic feet. Twelve participants with unilateral transtibial amputation walked using both: a non-articulated ankle prosthesis (NAA) and an articulated ankle prosthesis (AA). Contact sequences of the intact (In) and prosthetic (Pr) foot were recorded using a Tekscan F-Scan® insole system and analyzed using custom Python routines. Contact patterns were classified into four types (A–D), based on the sequential engagement of heel, midfoot, forefoot, and toes. Type A (heel-to-toe sequence) dominated initial contact patterns across all limbs, with PrNAA showing the highest adherence (67.2%). In final contact, prosthetic limbs diverged: PrNAA retained Type A dominance, while PrAA favored Type C, where forefoot regions disengage prematurely. Intact limbs showed consistent initial contact strategies, but adapted their final contact pattern depending on the contralateral prosthesis. Articulated ankle prostheses allow more variable and adaptive take-off strategies, potentially enhancing propulsion and reducing asymmetry. This effect highlights the influence of ankle articulation on the dynamic control of gait termination and inter-limb coordination.