Grant: Discovery Grants Program - Individual

Foot orthoses are among the most commonly used external supports with the objective to modify lower limbs biomechanics (movements, joint moments, plantar pressure and muscle activity) and normalize altered or suboptimal body functions. They change lower limbs biomechanics through the production of reaction forces acting on the feet and thus, the stiffness of their shell is crucial. Many extrinsic additions are commonly used in research to stiffen the foot orthoses' shell and consequently change lower limbs biomechanics during functional tasks (e.g., level and stair gait). However, these features remain an emerging rather than a proven concept because their effects on lower limbs biomechanics have not yet been adequately characterized. Also, only preliminary results showed that extrinsic additions to foot orthoses change their stiffness. Thus, there is an important need to study how foot orthoses' materials and extrinsic additions change their ability to produce reaction forces (via changes in stiffness) and determine how these translate into biomechanical changes to the lower limbs during functional tasks. Also, one of the biggest challenges when selecting the foot orthoses' designs in research is our insufficient knowledge on how to predict their biomechanical effects for specific populations. The effects of foot orthoses on lower limbs biomechanics could be dependent on the individuals wearing them but the current state of knowledge does not allow to adequately predict how one will respond to current orthotic practices. The long-term goal of this research program is to better understand the underlying mechanisms of action of foot orthoses and how to predict their effects during functional tasks as well as inform the development of new types of foot orthoses fabrication processes and innovations. The specific objectives will be to (1) Determine how foot orthoses' design (e.g., material, extrinsic additions) influences their ability to generate reaction forces to the foot; (2) Identify how novel and conventional methods in foot orthoses manufacture, in terms of material and extrinsic additions, can modify lower limbs biomechanics; (3) Identify biomechanical, morphostatic and foot orthoses-related predictors of foot orthoses' ability to modify lower limbs biomechanics during functional tasks. This research program will contribute to increasing the body of knowledge on how foot orthoses' structural factors and extrinsic additions modify their stiffness and induce changes to lower limbs biomechanics. More specifically, it will help to better understand how they work and most importantly how to predict their effects during functional tasks. Results will fill an important gap in the knowledge base in Natural Sciences and Engineering by informing the development of future studies with the objectives to better understand foot orthoses' mechanism of action and the development of new manufacturing methods for foot orthoses.