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The effect of active or passive end-range determination on shoulder axial rotation is unclear on overhead-throwing athletes. Twenty-two healthy males were equally divided into athletes and non-athletes groups and their throwing arm was tested during internal and external arm rotation and on active and passive end-range determination conditions. The humeral and scapular 3D position were recorded at the shoulder rotational endrange and compared across groups using two-way repeated-measures ANOVA. No differences were found between groups for all humeral and scapular variables. The active internal Thoracohumeral (TH) and Glenohumeral (GH) arches were significantly (p=0.00) higher than internal passive TH and GH. At the end-range of external rotation athletes showed a scapula less in protraction (p=0.027) and less in scapular posterior tilt (p=0.00). External passive TH and GH were significantly higher than external active TH and GH. [ABSTRACT FROM AUTHOR]

This study investigated the effect whole body vibration (WBV) on the dynamic stability of NCAA Division I women basketball players. Eleven subjects were evaluated in two test conditions including one with and one without WBV. After each condition, subjects were tested for time to stabilization (TTS) on a force platform during bilateral, right leg, and left leg countermovement jumps (CMJ). Results of the statistical analysis revealed no significant difference in TTS between the vibration and non-vibration conditions for the bilateral (p = 0.24) and right leg (p = 0.48) CMJ. A significant difference was found between the conditions demonstrating a shorter TTS in the non-vibration condition for the left leg CMJ (p = 0.04, d = 0.57, ηp2 = 0.36). Acute WBV has no effect on and in some cases impairs dynamic. [ABSTRACT FROM AUTHOR]

The purpose of this study is to compare the velocity of the barbell with the criterion of the velocity of the center of gravity during the explosive bench press lift with different loads. Fifteen highly trained soccer players participated in this study. Three-dimensional upper extremities kinematic data during the bench press were collected. Participants lifted loads of 10, 30, 50, 70 and 90% of one repetition maximum (1RM) with maximal velocity. All upper extremity segments and barbell were modeled as frustra of cones while the barbell was modeled as a cylinder. One way repeated ANOVA revealed that peak barbell velocity was significantly higher with 10, 30 and 50% and the mean barbell velocity was significantly higher with 10 and 30% of 1RM. Additionally, kinematic methods based on the barbell velocity measurement overestimate the velocity of the center of mass. [ABSTRACT FROM AUTHOR]

Subjects performed drop jumps from 46 cm, a single leg jump, counter movement jump, and squat jump on a hard surface, wrestling mat and in water. Ground reaction force data obtained via a force platform were used to determine the time to takeoff, takeoff peak ground reaction force, power, jump height, and landing peak ground reaction force. A one way repeated measures ANOVA demonstrated differences between plyometic exercises assessed for all of the variables assessed (P ≤ 0.05), with post hoc analysis demonstrating the specific differences. Results indicate that the hard surface and mat conditions were similar for almost all of the plyometric exercises assessed for most outcome variables whereas the plyometric exercises performed in water were different than those performed on the hard surface or mat in most cases. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore how specific shoulder stabilizing exercises influenced the shoulder strength balance, incidence of practice time lost due to shoulder ailments and swim performance. Two US high school varsity swim teams participated in the study. The treatment team (N = 59) performed thrice weekly 20-minute dryland activities to improve shoulder and scapular stability, whereas the control team (N = 68) did not explicitly train their athletes in this manner. In addition to the shoulder ailment incidence and lost practice time, we also monitored changes in athletic performance. The results indicate that shoulder-stabilizing exercises reduce the incidence and duration of shoulder ailments in swimmers, without being detrimental to swim performance. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the load of elbow joint based on the kinetic analysis of the primary school dodgeball players' throwing motion. Four male primary school dodgeball players performed the overhand throwing motion while recorded by a Vicon three-dimensional motion analysis system. Changing patterns of elbow joint torques are similar to those for baseball pitching. The varus torque was the largest value among all elbow joint torques . The extension/flexion angle of elbow joint was -64.8° at peak varus torque. It is possible that the varus torque may lead to medial elbow injury, including ligament, muscle, joint surface and ulnar nerve damage. For healthy growth of children, it would be necessary to set some rules for preventing acute and chronic sports injuries, for example, the number of times of throwing in day should be limited. [ABSTRACT FROM AUTHOR]

One potentially simple way to maximize jumping effort and thus intensity is to have athletes jump to and attempt to touch challenging overhead goals during training. The purpose of this study was to compare the effect of jumping with and without the use of an overhead goal. Subjects performed 3 countermovement jumps in conditions with and without an overhead goal. Jump performance was evaluated using a force platform to determine peak ground reaction force, time to takeoff, power, and jump height. Data were evaluated with a two way ANOVA with results demonstrating no significant (p > 0.05) difference between goal conditions for any of the variables assessed and no interaction between goal condition and gender (p > 0.05). [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the feasibility of developing a cost-effective, automated performance feedback system to support sprint coaching. The proposed system is designed to deliver step length, step frequency, contact time and 10 m split time information of multiple athletes training on an indoor track. An integrated systems approach was chosen combining the novel Pisa Light-Gate (PLG) and Step Information Monitoring Systems (SIMS). Current results indicate data accuracy of RMS 1.662 cm for step length, RMS 0.977 ms for foot contact time and a split time detection accuracy of 8.45 ± 6.85 ms. These results suggest that the proposed integrated system, using off-the-shelf equipment, would go beyond currently available coaching tools by providing automated and highly accurate sprint performance information for multiple athletes. [ABSTRACT FROM AUTHOR]

Non-intrusive ultrasonic detection scheme has been implemented to monitor and quantify the loading effect of training sessions on athletes. The detection is obtained along a line between two acoustic transducers with similar size and shape as stick-on electrodes. All the data is derived from the transmission time-of-flight of the ultrasonic chirp signal passing through the muscle and the ultrasonic force sensor. Muscle dynamics and force generated due to maximum isometric contraction was synchronously detected with the aid of an arbitrary function generator and a two channels transient recorder. At least 16 performance deciding parameters of athletes are quantified. The achieved spatial and temporal resolutions are ± 0.01 mm and 0.01 ms respectively. Detected movement reaction time could be used as a potential indicator to identify false-start in athletics, swimming and other necessary fields. [ABSTRACT FROM AUTHOR]