Generic muscle parameters are often used in muscle-driven simulations of human movement to estimate individual muscle forces and function. The results may not be valid since muscle properties vary from subject to subject. This study investigated the effect of using generic muscle parameters in a muscle-driven forward simulation on muscle force estimation. We generated a normal walking simulation in OpenSim and examined the sensitivity of individual muscle forces to perturbations in muscle parameters, including the number of muscles, maximum isometric force, optimal fiber length, and tendon slack length. We found that when changing the number of muscles included in the model, only magnitude of the estimated muscle forces was affected. Our results also suggest it is especially important to use accurate values of tendon slack length and optimal fiber length for ankle plantar flexors and knee extensors. Changes in force production by one muscle were typically compensated for by changes in force production by muscles in the same functional muscle group, or the antagonistic muscle group. Conclusions regarding muscle function based on simulations with generic musculoskeletal parameters should be interpreted with caution.
Ming Xiao and Jill Higginson
Samuel Ryan, Emidio Pacecca, Jye Tebble, Joel Hocking, Thomas Kempton and Aaron J. Coutts
should display measurement characteristics of validity (the ability of a test to measure what it is designed to measure), reliability (the consistency of results from a test), and sensitivity (the extent to which a test can detect changes beyond the typical error [TE] in results). 10 , 11 Reliability
Sandra C. Webber, Francine Hahn, Lisa M. Lix, Brenda J. Tittlemier, Nancy M. Salbach and Ruth Barclay
SigmaPlot (version 11.0; Systat Software Inc., San Jose, CA). Sensitivity, specificity, Youden’s index, positive predictive value (PPV), and negative predictive value results were estimated using SAS software (version 9.4; SAS Inc., Cary, NC). Sensitivity ( Trevethan, 2017 ) of each analysis technique was
Carley O’Neill and Shilpa Dogra
for fear of an unknown outcome such as exercise-induced asthma symptoms; however, regular participation in low- and moderate-intensity exercise is effective for reducing general anxiety among adults with asthma. 2 , 3 Anxiety sensitivity, on the other hand, refers to the fearful belief that bodily
Simon A. Feros, Warren B. Young and Brendan J. O’Brien
sensitivity in measurements of consistency (speed and accuracy). Knowing the reliability and sensitivity of all pace-bowling performance measures would allow researchers to more accurately quantify pace-bowling performance after short- and long-term interventions. A standardized test would be beneficial to
Cédric Leduc, Jason Tee, Mathieu Lacome, Jonathon Weakley, Jeremy Cheradame, Carlos Ramirez and Ben Jones
between “velocity load” and “force load,” designated running load index (RLI), performed during a standardized running test presented small to moderate typical errors. Moreover, they found a session-dependent sensitivity of RLI while changes in “traditional” test results (CMJ and groin squeeze) were
Daniel C. McFarland, Alexander G. Brynildsen and Katherine R. Saul
model stabilizing forces in inherently stable glenohumeral joints for multiple outcomes would provide a valuable foundation for appropriate model decision making. Our goal is to present and compare predictions of simulated outputs using common types of stability constraints and characterize sensitivity
Greg Petrucci Jr., Patty Freedson, Brittany Masteller, Melanna Cox, John Staudenmayer and John Sirard
replacement for research-grade measurement devices, it is important to directly determine if the device can detect change in measures of activity behavior. Previous work has studied the sensitivity of research-grade accelerometers to detect change ( Lee, Clark, Winkler, Eakin, & Reeves, 2015 ; Montoye
Alyssa J. Wagner, Casey D. Erickson, Dayna K. Tierney, Megan N. Houston and Cailee E. Welch Bacon
Eating disorders in female athletes are a commonly underdiagnosed condition. Better screening tools for eating disorders in athletic females could help increase diagnosis and help athletes get the treatment they need.
Focused Clinical Question:
Should screening tools be used to detect eating disorders in female athletes?
Summary of Key Findings:
The literature was searched for studies that included information regarding the sensitivity and specificity of screening tools for eating disorders in female athletes. The search returned 5 possible articles related to the clinical question; 3 studies met the inclusion criteria (2 cross-sectional studies, 1 cohort study) and were included. All 3 studies reported sensitivity and specificity for the Athletic Milieu Direct Questionnaire version 2, the Brief Eating Disorder in Athletes Questionnaire version 2, and the Physiologic Screening Test to Detect Eating Disorders Among Female Athletes. All 3 studies found that the respective screening tool was able to accurately identify female athletes with eating disorders; however, the screening tools varied in sensitivity and specificity values.
Clinical Bottom Line:
There is strong evidence to support the use of screening tools to detect eating disorders in female athletes. Screening tools with higher sensitivity and specificity have demonstrated a successful outcome of determining athletes with eating disorders or at risk for developing an eating disorder.
Strength of Recommendation:
There is grade A evidence available to demonstrate that screening tools accurately detect female athletes at risk for eating disorders.
Justin W.Y. Lee, Ming-Jing Cai, Patrick S.H. Yung and Kai-Ming Chan
hamstring strength. The objectives of this study were to establish the test–retest reliability, validity, and sensitivity of a novel smartphone-based method designed for objective evaluation of hamstring strength among healthy male professional football players. Methods A cross-sectional study design was