@article {887, title = {Predictive Dynamic Simulation of Olympic Track Cycling Standing Start Using Direct Collocation Optimal Control}, journal = {Multibody System Dynamics}, year = {2020}, abstract = {

Much of the previous research on modeling and simulation of cycling has focused on seated pedaling, modeling the crank load with an effective resistive torque and inertia. This study focuses on modeling standing starts, a component of certain track cycling events in which the cyclist starts from rest and attempts to accelerate to top speed as quickly as possible. A ten degree-of-freedom, two-legged cyclist and bicycle model was developed and utilized for predictive dynamic simulations of standing starts. Experimental data including crank torque, cadence, and joint kinematics were collected for a member of the Canadian Olympic team performing standing starts on the track. Using direct collocation optimal control to maximize the simulated distance traveled, the predictive simulations aligned well with the experiments and replicated key aspects of the standing start technique such as the drive and reset. The model\’s use in \“What if?\” scenarios presents interesting possibilities for investigating optimal techniques and equipment in cycling.\ 

}, keywords = {Optimal Control, Sports Biomechanics, Sports Engineering}, issn = {1573-272X}, doi = {10.1007/s11044-020-09723-3}, url = {https://link.springer.com/article/10.1007/s11044-020-09723-3}, author = {Conor Jansen and John McPhee} } @article {888, title = {Predictive Forward Dynamic Simulation of Manual Wheelchair Propulsion on a Rolling Dynamometer}, journal = {ASME Journal of Biomechanical Engineering}, year = {2020}, abstract = {

Research studies to understand the biomechanics of manual wheelchair propulsion often incorporate experimental data and mathematical models. This project aimed to advance this field of study by developing a two-dimensional model to generate first of its kind forward dynamic fully predictive computer simulations of a wheelchair basketball athlete on a stationary ergometer. Subject-specific parameters and torque generator functions were implemented in the model from dual x-ray absorptiometry and human dynamometer measurements. A direct collocation optimization method was used in a wheelchair propulsion model for the first time to replicate the human muscle recruitment strategy. Simulations were generated for varying time constraints and seat positions. Similar magnitudes of kinematic and kinetic data were observed between simulation and experimental data of a first push. Furthermore, seat heights inferior to the neutral position were found to produce similar joint torques to those reported in previous studies. An anterior seat placement produced the quickest push time with the least amount of shoulder torque required. The work completed in this project demonstrates that fully predictive simulations of wheelchair propulsion have the potential of varying simulation parameters to draw meaningful conclusions.

}, keywords = {Biomechanics, Optimal Control, Predictive Simulation, Sports Engineering, Wheelchair}, doi = {10.1115/1.4046298}, url = {https://asmedigitalcollection.asme.org/biomechanical/article/doi/10.1115/1.4046298/1074477/Predictive-Forward-Dynamic-Simulation-of-Manual}, author = {Colin Brown and John McPhee} } @article {841, title = {Optimization-Based Motor Control of a Paralympic Wheelchair Athlete}, journal = {Sports Engineering}, volume = {21}, year = {2018}, abstract = {

The following research approximated how the central nervous system of Paralympic wheelchair athletes resolve kinematic redundancies during upper-limb movements. A multibody biomechanical model of a tetraplegic Paralympic athlete was developed using subject-specific body segment parameters. The angular joint kinematics throughout a specified Paralympic sport movement (i.e., wheelchair curling) were experimentally measured using inertial measurement units. The motor control system of the Paralympian was mathematically modelled and simulated using forward dynamics optimization. The predicted kinematics from different optimization objective functions (i.e., minimizing resultant joint moments, mechanical joint power, and angular joint velocities and accelerations) were compared with those experimentally measured throughout the wheelchair curling movement. Of the optimization objective functions under consideration, minimizing angular joint accelerations produced the most accurate predictions of the kinematic trajectories (i.e., characterized with the lowest overall root mean square deviations) and the shortest optimization computation time. The implications of these control findings are discussed with regards to optimal wheelchair design through predictive dynamic simulations.

}, keywords = {Forward Dynamics Modelling, Human Motor Control, Optimal Control, Optimization, Sports Biomechanics, Sports Engineering}, issn = {1460-2687}, doi = {10.1007/s12283-018-0265-2}, url = {https://link.springer.com/article/10.1007/s12283-018-0265-2}, author = {Brokoslaw Laschowski and Naser Mehrabi and John McPhee} } @article {1193, title = {Body Segment Parameters of Paralympic Athletes from Dual-Energy X-Ray Absorptiometry}, journal = {Sports Engineering}, volume = {19}, year = {2016}, abstract = {

This research represents the first documented investigation into the body segment parameters of Paalympic 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.

}, keywords = {Medical Imaging, Sports Biomechanics, Sports Engineering}, issn = {1460-2687}, doi = {10.1007/s12283-016-0200-3}, url = {https://link.springer.com/article/10.1007/s12283-016-0200-3$\#$citeas}, author = {Brokoslaw Laschowski and John McPhee} } @article {1201, title = {Modelling the Deflection of Rowing Oar Shafts}, journal = {Sports Biomechanics}, volume = {16}, year = {2016}, abstract = {

The deflection of rowing oar shafts subjected to a static load was investigated. Two sets of sculling oars of different design stiffness were tested at three different lengths from 2.66 to 2.70\ m. Loads up to 201\ N were applied to the blade end of the oar shafts, and deflections were measured at six positions along the length of the shafts. The experimental results were compared with theoretical predictions obtained by modelling the oar shafts as homogenous end-loaded cantilever beams. The results show that the oar shafts are not uniform, in contradiction to the assumed model, but rather are most compliant near the sleeves and up to 80\% stiffer towards the blades. The effect of oar shaft stiffness and length on the deflection angle at the blade end of the oar shaft was at most 1.18\ \±\ 0.01\°. The measured variation of stiffness along the shaft has implications for boat propulsion and rowing performance.

}, keywords = {Beam Modelling, Sports Biomechanics, Sports Engineering}, doi = {10.1080/14763141.2016.1194890}, author = {Brokoslaw Laschowski and Cameron C Hopkins and John R de Bruyn and Volker Nolte} } @proceedings {1199, title = {Quantifying Body Segment Parameters Using Dual-Energy X-Ray Absorptiometry: A Paralympic Wheelchair Curler Case Report}, volume = {147}, year = {2016}, publisher = {Procedia Engineering}, abstract = {

The body segment parameters of a Paralympic wheelchair curler were experimentally investigated; the athlete has an incomplete cervical spinal cord injury. 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 using dual-energy x-ray absorptiometry (DXA). In addition to measuring the body segment parameters in the interest of developing a subject-specific multibody biomechanical model, 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. The composition of each body segment (i.e., percentage of skeletal muscle, bone mineral content, and adipose tissue) was additionally investigated.

}, keywords = {Body Segment Parameters, Medical Imaging, Sports Biomechanics, Sports Engineering}, doi = {10.1016/j.proeng.2016.06.207}, url = {https://www.sciencedirect.com/science/article/pii/S1877705816306543}, author = {Brokoslaw Laschowski and John McPhee} } @article {1190, title = {The Effects of Oar-Shaft Stiffness and Length on Rowing Biomechanics}, journal = {Journal of Sports Engineering \& Technology}, volume = {229}, year = {2015}, abstract = {

This work experimentally investigates the effects of oar-shaft stiffness and length on rowing biomechanics. Elite rowers were tested in instrumented single sculling boats over a set distance using oar-shafts of different stiffness and length. There were slight differences in the measured boat accelerations and oarlock forces between rowing with the different oar configurations. However, the rower\’s inter-stroke inconsistencies in the biomechanical parameters were on the same order of magnitude as the measured differences between rowing with the different oar configurations. The results are discussed in relation to oar-shaft deflection and lever theory.

}, keywords = {Biomechanics, Sports Biomechanics, Sports Engineering}, doi = {10.1177/1754337115582121}, url = {http://journals.sagepub.com/doi/abs/10.1177/1754337115582121?journalCode=pipa}, author = {Brokoslaw Laschowski and Volker Nolte} }