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## Inverse Dynamics Modeling of Paralympic Wheelchair Curling

mathematically represented by 4 ordinary differential equations and 1 algebraic equation (ie, indicative of the model’s kinematic constraints). Kinematic Constraints The experimental kinematics were mathematically optimized to satisfy the kinematic constraints of the multibody biomechanical model. A nonlinear

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## Forward Dynamics of Two-Dimensional Skeletal Models. A Newton-Euler Approach

Mathematical modeling and computer simulation play an increasingly important role in the search for answers to questions that cannot be addressed experimentally. One of the biggest challenges in forward simulation of the movements of the musculoskeletal system is finding an optimal control strategy. It is not uncommon for this type of optimization problem that the segment dynamics need to be calculated millions of times. In addition, these calculations typically consume a large part of the CPU time during forward movement simulations. As numerous human movements are two-dimensional (2-D) to a reasonable approximation, it is extremely convenient to have a dedicated, computational efficient method for 2-D movements. In this paper we shall present such a method. The main goal is to show that a systematic approach can be adopted which allows for both automatic formulation and solution of the equations of kinematics and dynamics, and to provide some fundamental insight in the mechanical theory behind forward dynamics problems in general. To illustrate matters, we provide for download an example implementation of the main segment dynamics algorithm, as well as a complete implementation of a model of human sprint cycling.

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## Dynamics of the In-Run in Ski Jumping: A Simulation Study

A ski jumper tries to maintain an aerodynamic position in the in-run during changing environmental forces. The purpose of this study was to analyze the mechanical demands on a ski jumper taking the in-run in a static position. We simulated the in-run in ski jumping with a 4-segment forward dynamic model (foot, leg, thigh, and upper body). The curved path of the in-run was used as kinematic constraint, and drag, lift, and snow friction were incorporated. Drag and snow friction created a forward rotating moment that had to be counteracted by a plantar flexion moment and caused the line of action of the normal force to pass anteriorly to the center of mass continuously. The normal force increased from 0.88G on the first straight to 1.65G in the curve. The required knee joint moment increased more because of an altered center of pressure. During the transition from the straight to the curve there was a rapid forward shift of the center of pressure under the foot, reflecting a short but high angular acceleration. Because unrealistically high rates of change of moment are required, an athlete cannot do this without changing body configuration which reduces the required rate of moment changes.

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## Stiffness and Damping Response Associated with Shock Attenuation in Downhill Running

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## When Children’s Perceived and Actual Motor Competence Mismatch: Sport Participation and Gender Differences

-0027 10.1123/pes.2013-0027 Stodden , D.F. , Langendorfer , S.J. , Fleisig , G.S. , & Andrews , J.R. ( 2006 a). Kinematic constraints associated with the acquisition of overarm throwing part I: Step and trunk actions . Research Quarterly for Exercise and Sport, 77 , 417 – 427 . Stodden , D

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## Examining the Feasibility of Supine-to-Stand as a Measure of Functional Motor Competence

:10.1080/00336297.2008.10483582 10.1080/00336297.2008.10483582 Stodden , D.F. , Langendorfer , S.J. , Fleisig , G.S. , & Andrews , J.R. ( 2006a ). Kinematic constraints associated with the acquisition of overarm throwing Part I: Step and trunk actions . Research Quarterly for Exercise and

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## The Influence of Guided Practice on Overhand Throwing Competence in Preschool Children in a Mastery Motivational Climate

constraints associated with the acquisition of overarm throwing Part I: Step and trunk actions . Research Quarterly for Exercise and Sport, 77 , 417 – 427 . Stodden , D.F. , Langendorfer , S.J. , Fleisig , G.S. , & Andrews , J.R. ( 2006b ). Kinematic constraints associated with the acquisition of

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## Chronic Ankle Instability Does Not Influence Tibiofemoral Contact Forces During Drop Landings Using a Musculoskeletal Model

. 31 Kinematic constraints were then removed, and a forward dynamics simulation was performed with muscles serving as actuators and experimental GRFs applied to replicate the landing motion. A proportional–integral–derivative feedback controller was implemented to calculate each muscle force magnitude

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## Examining Impulse-Variability Theory and the Speed-Accuracy Trade-Off in Children’s Overarm Throwing Performance

, 60 ( 2 ), 290 – 306 . doi:10.1080/00336297.2008.10483582 10.1080/00336297.2008.10483582 Stodden , D.F. , Langendorfer , S.J. , Fleisig , G.S. , & Andrews , J.R. ( 2006 ). Kinematic constraints associated with the acquisition of overarm throwing part I: Step and trunk actions . Research

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## A Communal Language for Decision Making in Team Invasion Sports

probability information . Perception, 30 ( 2 ), 233 – 252 . PubMed ID: 11296504 doi: 10.1068/p2872 Abernethy , B. , Zawi , K. , & Jackson , R.C. ( 2008 ). Expertise and attunement to kinematic constraints . Perception, 37 ( 6 ), 931 – 948 . PubMed ID: 18686711 doi: 10.1068/p5340 Abraham