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Investigating Kinetics in the Freestyle Flip Turn Push-Off

Andrew D. Lyttle, Brian A. Blanksby, Bruce C. Elliott, and David G. Lloyd

Thirty experienced male swimmers with body types ± 1 SD of the mean of selected body form parameters reported for elite male swimmers were recruited for the study. During three freestyle flip turns, selected kinetic, hydrodynamic, and kinematic variables of the push-off following a flip turn were recorded. Kinetics were recorded via a 2D vertically mounted forceplate that recorded peak push-off force and total impulse. The acceleration of each swimmer’s center of gravity and wall exit velocity were calculated from underwater videography. Hydrodynamic peak drag force and drag impulse were calculated from the kinetic and kinematic data using a derivative of Newton’s second law. A stepwise regression yielded peak drag force, peak propulsive force, and push-off time in the final regression equation (R = 0.80; R 2 = 0.64). Beta values indicated that the peak drag force carried the highest weighting of the three variables. The results of the stepwise regression indicated that a combination of a low peak drag force high peak propulsive force, and increased wall push-off time produced the fastest final push-off velocity.

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Persons With Multiple Sclerosis Show Altered Joint Kinetics During Walking After Participating in Elliptical Exercise

Jessie M. Huisinga, Kendra K. Schmid, Mary L. Filipi, and Nicholas Stergiou

Patients with multiple sclerosis (MS) experience abnormal gait patterns and reduced physical activity. The purpose of this study was to determine if an elliptical exercise intervention for patients with MS would change joint kinetics during gait toward healthy control values. Gait analysis was performed on patients with MS (n = 24) before and after completion of 15 sessions of supervised exercise. Joint torques and powers were calculated, while also using walking velocity as a covariate, to determine the effects of elliptical exercise on lower extremity joint kinetics during gait. Results show that elliptical exercise significantly altered joint torques at the ankle and hip and joint powers at the ankle during stance. The change in joint power at the ankle indicates that, after training, patients with MS employed a walking strategy that is more similar to that of healthy young adults. These results support the use of elliptical exercise as a gait training tool for patients with MS.

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Kinetics of Crimp and Slope Grip in Rock Climbing

Andreas Schweizer and Robert Hudek

The aim was to investigate differences of the kinetics of the crimp and the slope grip used in rock climbing. Nine cadaver fingers were prepared and fixated with the proximal phalanx in a frame. The superficial (FDS) and deep (FDP) flexor tendons were loaded selectively and together with 40 N in the crimp grip (PIP joint flexed 90°/DIP joint hyperextended) and the slope grip position (<25° flexed/50° flexed respectively). Five different grip sizes were tested and the flexion force which was generated to the grip was measured. In the crimp grip the FDP generated more flexion force in small sized holds whereas the FDS generated more force in the larger holds. During the slope grip the FDP was more effective than the FDS. While both tendons were loaded, the flexion force was always greater during crimp grip compared with the slope grip. The FDP seems to be most important for very small holds using the crimp grip but also during slope grip holds whereas the FDS is more important for larger flat holds.

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The Kinetics of Swinging a Baseball Bat

Joseph J. Crisco, Nikolas J. Osvalds, and Michael J. Rainbow

addition, the swing used in the analysis did not hit a baseball. To the best of our knowledge, this was the only study that examined the kinetics of swinging a baseball bat. What effect a bat’s moments of inertia (MOI), swings across multiple batters, and swings of actual batted baseballs have on these

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The Relationship Between Vertical Ground Reaction Force, Loading Rate, and Sound Characteristics During a Single-Leg Landing

Caroline Lisee, Tom Birchmeier, Arthur Yan, Brent Geers, Kaitlin O’Hagan, Callum Davis, and Christopher Kuenze

improving their movement quality and reduce subsequent injury risk. 3 Unfortunately, these attempts to evaluate and intervene to improve movement patterns have significant shortcomings as they fail to consider the role that kinetics, such as loading characteristics, play in the risk of primary or secondary

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Kinetics and Stabilization of the Tuck Jump Assessment

Lucy S. Kember, Rhodri S. Lloyd, Gregory D. Myer, and Isabel S. Moore

sensitivity. Previous research has suggested that kinetics during rebounding tasks can be predictors of ACL injury. 7 , 8 Stiff landings with minimal knee flexion have been shown to produce large vertical ground reaction forces (Fz) and result in high knee joint loads and strain on the ACL, which may

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Oxygen Uptake Kinetics in Youth: Characteristics, Interpretation, and Application

Melitta A. McNarry

Pulmonary oxygen uptake ( V ˙ O 2 ) kinetics following the onset of constant work rate exercise provides a useful assessment of the integrated capacity of the organism to transport and utilizes O 2 to support the increased rate of energy turnover in the contracting myocytes ( 104 ). The onset of

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Recovery Kinetics After Speed-Endurance Training in Male Soccer Players

Theofanis Tzatzakis, Konstantinos Papanikolaou, Dimitrios Draganidis, Panagiotis Tsimeas, Savvas Kritikos, Athanasios Poulios, Vasiliki C. Laschou, Chariklia K. Deli, Athanasios Chatzinikolaou, Alexios Batrakoulis, Georgios Basdekis, Magni Mohr, Peter Krustrup, Athanasios Z. Jamurtas, and Ioannis G. Fatouros

. Study of recovery kinetics following SEPT would facilitate the optimization of its frequency during a microcycle. Therefore, this study aimed to (1) determine the recovery kinetics of fatigue, EIMD, and performance following SEPT; (2) examine whether work-to-rest ratio of SEPT affects recovery kinetics

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High-Intensity Interval Training, Performance, and Oxygen Uptake Kinetics in Highly Trained Traditional Rowers

Iñigo Mujika, Nicolas Bourdillon, Rafa González De Txabarri, and Gregoire P. Millet

Pulmonary oxygen uptake kinetics (VO 2 kinetics) is considered a noninvasive measure of an athlete’s capacity to utilize O 2 and respond to variations in energy demands. It is an important assessment of an athlete’s integrative physiological response 1 in both endurance sports 2 , 3 and team

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Effect of Sampling Frequency on Isometric Midthigh-Pull Kinetics

Thomas Dos’Santos, Paul A. Jones, Jonathan Kelly, John J. McMahon, Paul Comfort, and Christopher Thomas

athletes. 19 Variations in IMTP kinetics reported across the literature may be partially explained by methodological differences. 2 , 8 , 13 , 16 , 18 Early research used a sampling frequency of 500 Hz and 600 Hz, 8 , 13 whereas more recent investigations have implemented a sampling frequency of 1000 Hz