The effects of oar-shaft stiffness and length on rowing biomechanics

This work investigates the effects of oar-shaft stiffness and length on rowing biomechanics. The mechanical properties of the oar-shafts were examined using an end-loaded cantilever system, and theoretical relations were proposed between the mechanics of the oar-shafts and rowing performance. On-water experiments were subsequently conducted and rowing biomechanics measured via the PowerLine Rowing Instrumentation System. The PowerLine system measures force and oar angle on the oarlock, as well as proper boat acceleration. The convergent validity and test-retest reliability of the PowerLine force measurements were determined prior to the on-water experiments. Thereafter, rowers were tested over a set distance using oar-shafts of different stiffness and length. There were slight differences in the biomechanics between rowing with the different oar configurations. However, the measured differences in the biomechanical parameters were on the same order of magnitude as the rower’s inter-stroke inconsistencies

Biomechanical Modelling of Paralympic Wheelchair Curling

This research represents the first documented investigation into the biomechanics and neural motor control of Paralympic wheelchair curling. A multibody biomechanical model of the wheelchair curling delivery was developed in reference to a Team Canada Paralympic athlete with a spinal cord injury. Subject-specific body segment parameters were quantified via dual-energy x-ray absorptiometry. The angular joint kinematics throughout the wheelchair curling delivery were experimentally measured using an inertial measurement unit system; the translational kinematics of the curling stone were additionally evaluated with optical motion capture. The experimental kinematics were optimized to satisfy the kinematic constraints of the multibody biomechanical model. The optimized kinematics were subsequently used to compute the resultant joint moments through inverse dynamics analysis. The neural motor control of the Paralympic athlete was modeled using forward dynamic optimization. The predicted kinematics from different optimization objective functions were compared with those experimentally measured throughout the wheelchair curling delivery. Of the optimization objective functions under consideration, minimizing angular joint accelerations resulted in the most accurate predictions of the kinematic trajectories and the shortest optimization computation time. The implications of these findings are discussed in relation to musculoskeletal modeling and optimal equipment design through predictive simulation

Inverse Dynamics Modelling of Paralympic Wheelchair Curling

Accepted author manuscript version reprinted, by permission, from Journal of Applied Biomechanics, 2017 (ahead of print) 1-19, http://dx.doi.org/10.1123/jab.2016-0143. © Human Kinetics, Inc.Paralympic wheelchair curling is an adapted version of Olympic curling played by individuals with spinal cord injuries, cerebral palsy, multiple sclerosis, and lower extremity amputations. To the best of the authors’ knowledge, there has been no experimental or computational research published regarding the biomechanics of wheelchair curling. Accordingly, the objective of this research was to quantify the angular joint kinematics and dynamics of a Paralympic wheelchair curler throughout the delivery. The angular joint kinematics of the upper extremity were experimentally measured using an inertial measurement unit system; the translational kinematics of the curling stone were additionally evaluated with optical motion capture. The experimental kinematics were optimized to satisfy the kinematic constraints of a subject-specific multibody biomechanical model. The optimized kinematics were subsequently used to compute the resultant joint moments via inverse dynamics analysis. The main biomechanical demands throughout the delivery (i.e., in terms of both kinematic and dynamic variables) were about the hip and shoulder joints, followed sequentially by the elbow and wrist. The implications of these findings are discussed in relation to wheelchair curling delivery technique, musculoskeletal modelling, and forward dynamic simulations.This research was funded by Dr. John McPhee’s Tier I Canada Research Chair in Biomechatronic System Dynamics

Body segment parameters of Paralympic athletes from dual-energy X-ray absorptiometry

The final publication is available at Springer via http://dx.doi.org/10.1007/s12283-016-0200-3This research represents the first documented investigation into the body segment parameters of Paralympic athletes (e.g., individuals with spinal cord injuries and lower extremity amputations). Two-dimensional body segment parameters (i.e., mass, length, position vector of the center of mass, and principal mass moment of inertia about the center of mass) were quantified from dual-energy X-ray absorptiometry (DXA). In addition to establishing a body segment parameter database of Paralympic athletes for prospective biomechanists and engineers, the mass of each body segment as experimentally measured via the DXA imaging was compared with that reported by previous research of able-bodied cadavers. In general, there were significant differences in the body segment masses between the different methods. These findings support the implementation of the proposed database for developing valid multibody biomechanical models of Paralympic athletes with distinct physical disabilities.This research was funded by Dr. John McPhee’s Tier I Canada Research Chair in Biomechatronic System Dynamics