Search Results

You are looking at 1 - 10 of 2,069 items for :

  • "optimization" x
  • Refine by Access: All Content x
Clear All
Restricted access

Dhruv Gupta, Jeffrey A. Reinbolt, and Cyril J. Donnelly

, Donnelly et al 11 used optimization methods with computer simulations to find optimal whole-body kinematics during the high-velocity sporting task of side stepping. They found that the general kinematic strategy to reduce the peak valgus knee moment during the sidestepping task was to redirect the whole

Restricted access

Yujiang Xiang

Human carrying is simulated in this work by using a skeletal digital human model with 55 degrees of freedom. An optimization-based approach is used to predict the carrying motion with symmetric and asymmetric loads. In this process, the model predicts joint dynamics using optimization schemes and task-based physical constraints. The results indicate that the model can predict different carrying strategies during symmetric and asymmetric load-carrying tasks. The model can also indicate the risk factors for extreme loading situations. With such robust prediction capability, the model could be used for biomedical and ergonomic studies.

Restricted access

Brianne N. Schwark, Sasho J. Mackenzie, and Eric J. Sprigings

The primary purpose of this study was to determine the optimal release conditions and corresponding arm movement pattern for the free throw for players classified as 3 to 4.5 on the international player classification system in wheelchair basketball. A 2-D, three-segment simulation model was used to investigate this problem. The computational process involved a two-step optimization scheme in which an outer computational loop was used to optimize the magnitude and timing of the muscle torques that generate the arm's motion, and an inner computational loop was used to determine the optimal angle and speed of the ball at the moment of release. The inner optimization loop revealed that Brancazio's (1981) and Hay's (1993) approaches to determining the optimal release angle produced identical results. The lowered seated height of the wheelchair basketball player required that the ball be released at a steeper angle with greater vertical velocity, and hence the need for greater shoulder torque. For the wheelchair player, the peak shoulder flexion torque generated by the model was reduced by approximately 43% when the upper arm was initially positioned at an angle approximately 40° below the horizontal, as compared to being positioned at an angle of 10° above the horizontal. For the wheelchair player, the optimal release angle and speed for a ball released at a horizontal distance of 4.09 m from the center of the basket, and 1.30 m below the rim, was computed to be 53.8° and 7.4 m/s, respectively.

Restricted access

Reza Abdollahipour, Ludvík Valtr, and Gabriele Wulf

According to the OPTIMAL (Optimizing Performance Through Intrinsic Motivation and Attention for Learning) theory of motor learning ( Wulf & Lewthwaite, 2016 ), three factors are key to optimal motor performance and learning. Two of these factors are motivational in nature (enhanced expectancies

Restricted access

Gianluca Vernillo, Adrien Mater, Gregory Doucende, Johan Cassirame, and Laurent Mourot

Our concern in this study was with the consequences of a fatiguing ultratrail on self-optimizing capability during uphill and downhill (DR) running. We showed that similar dynamics of stride frequency (SF) adjustments occurred as those found in a nonfatigued state after a 6-hour run. 1 This

Restricted access

David L. Carey, Justin Crow, Kok-Leong Ong, Peter Blanch, Meg E. Morris, Ben J. Dascombe, and Kay M. Crossley

Australian football. 3 Currently, physical-preparation staff are tasked with balancing the training guidelines associated with injury-risk reduction and performance improvement when prescribing training loads. Mathematical optimization is a method that may help in this process, particularly as more data on

Restricted access

Sarah A. Roelker, Elena J. Caruthers, Rachel K. Hall, Nicholas C. Pelz, Ajit M.W. Chaudhari, and Robert A. Siston

simulated joint mechanics and muscle function. 10 – 12 In addition to model selection, users must choose an optimization technique to estimate muscle activations and forces. OpenSim includes 2 optimization techniques, static optimization (SO) 15 and computed muscle control (CMC), 16 , 17 which apply

Open access

Trent Stellingwerff, Ingvill Måkestad Bovim, and Jamie Whitfield

Middle-distance running events are highly complex from a performance optimization point of view. For example, elite middle-distance specialists need to have the aerobic system development approaching marathoners, coupled with some of the mechanical properties of elite sprinters, while concurrently

Open access

Gary J. Slater, Jennifer Sygo, and Majke Jorgensen

sprint performance ( Hargreaves et al., 1997 ). Taken together, this provides potential opportunities for nutritional interventions that could impact on training and performance, including buffering against acidosis for longer sprints (i.e., 400 m) and optimization of the phosphagen energy systems for

Restricted access

Mark S. Dyreson

The 2019 National Academy of Kinesiology (NAK) meetings gathered an array of scholars to explore the “Optimization of Human Performance.” In the program description he sketched for the assembly, Past President Bradley Hatfield (Fellow #452) offered a very modern vision of optimal performance