Main author: Anna Lára Ármannsdóttir
Institution or Company: Háskóli Íslands
Co-Authors, Institution or Company:
Christophe Lecomte, Háskóli Íslands, Össur. Sigurður Brynjólfsson, Háskóli Íslands. Kristín Briem, Háskóli Íslands.
Introduction: A change in terrains and walking speed alters the demands on the musculoskeletal system compared to level walking at a self-selected speed. A typically prescribed prosthetic foot for individuals with lower-limb amputation has fixed components such as the stiffness category. Limited capabilities at the ankle joint level to respond to more demanding terrains may induce undesirable compensations in the gait pattern among amputees. A novel foot, the Variable Stiffness Ankle (VSA), has been designed to allow for a stiffness variation by the users themselves, and was analyzed in this study. A special interest was for the option to use a softer foot during the more demanding gait tasks of fast and sloped gait conditions.
Methods: Five individuals with a trans-tibial amputation participated in the study. Three stiffness settings of the novel VSA foot were contrasted during three different gait speeds for level walking as well as for 7,5° incline and decline walking.
Results: Statistically significant interactions reflected task-dependent demands for greater range of motion. In terms of subject-specific reports on preferences and evaluation of stiffness settings, results varied.
Conclusion: Varying stiffness did have an effect on prosthetic foot dynamics. When considering the need for increased ankle range of motion in more demanding gait tasks, a foot that allows the users themselves to adjust stiffness according to the gait task performed may be of benefit for active individuals, possibly affecting the user´s satisfaction and comfort during various daily activities.
