The majority of the research to date on weightlifting has focused on men competitors. This study attempted to bridge the sex-based gap evident in the scientific literature. The performances of 10 women weightlifters competing in the 1999 United States national championships were analyzed. The performance of the athletes competing in the 69-kg class was recorded and analyzed using a Peak5 2D Motion Analysis system. The purpose of this study was 3-fold: (a) analyze the horizontal bar displacement of women weightlifters, (b) analyze key kinematic variables related to performance, and (c) compare the power outputs of the first, second, and total pulls in the snatch. Less than half (<50%) of the snatch attempts demonstrated by the women weightlifters in this study displayed the optimal toward-away-toward horizontal bar trajectory reported elsewhere. The women in this study demonstrated greater drop displacement and drop under times than those previously reported for men weightlifters. They also demonstrated lesser maximal vertically velocities of the barbell than those reported for world class women weightlifters. These women weightlifters demonstrated statistically significant differences (p < 0.05) during each phase of the snatch, and total power output values were comparable to values previously reported. The results of this study suggest that women demonstrate performance characteristics that differ subtly from those reported in men weightlifters. Knowledge of performance measures during the snatch may help coaches and athletes more fully refine the training leading to competition.

The purpose of the present investigation was to compare the effects of weight training, training with weights and plyometrics, and training with weights and the VertiMax on vertical jump. Subjects were 37 intercollegiate athletes assigned to one of four training groups: strength (S), strength-plyometric (P), strength-VertiMax without arms (VNA), and strength-VertiMax with arms (VA). Each group completed a 6-week training program. There were no statistical increases in pre-post vertical jump within all groups. There were no significant differences for posttest vertical jump between the four training groups. Pre- and posttest effect sizes were minimal across all groups. The findings of this study demonstrate that there is no difference in vertical jump among strength training, plyometric training, and jump training over a 6-week timeframe.

The purpose of this study was to determine the difference in five kinematic variables (internal knee and elbow angles, elbow height, forearm angle from vertical, and shoulder flexion angle at ball release) between proficient and non-proficient free throw shooters and which variables had the greatest contributions to a successful free throw shooting outcome. Seventeen male basketball players shoot three sets of 10 free throws with a two-minute break between each set. A three-dimensional motion tracking system composed of 17 sensors sampling at 60 Hz was used for data collection. Proficient free throw shooters had greater knee and elbow flexion, lower elbow height, and a smaller forearm angle compared to non-proficient shooters. These results explained 89.5% of the total variance. While maintaining the optimal range of these kinematic variables allows each subject to reach an appropriate level of free throw shooting performance, the key variable capable of distinguishing between made and missed shots within the proficient group of shooters was the forearm angle. Positioning the forearm parallel, or close to parallel, with an imaginary vertical line during the preparatory phase of the shooting motion accounted for 23.9% of the total variance and was associated with a greater number of made shots.

Background: dorsaVi Professional Suite, founded in 2018, is a 3D wearable sensor technology system that monitors the kinematic data of the lower extremity and lumbar spine. The dorsaVi system is used in the clinical setting to assist with clinical rehabilitation and preventive measures. Objective: The purpose of this study was to compare the inertial motion capture systems: the dorsaVi Professional Suite and Xsens to determine validity and reliability. Methods: This study utilized nine participants (7 female, 2 male) with data collected on two separate sessions. Each subject performed 15 repetitions each of double leg squats, left single leg squat, and right single leg squat during session one and then repeated the same testing procedure 7-10 days later. Kinematic variables measured were tibial inclination, knee varus, and knee valgus. Pearson product moment correlation coefficients were used to demonstrate the relationship within and between the motion capture systems across the knee positions and squat trials. Results: Within system reliability measurements demonstrated strong correlations (r>0.90) of the lower extremity kinematic data between testing sessions. Between system validity measurements also demonstrated strong correlations (r>0.90) across all lower extremity movements. Conclusions: The dorsaVi Professional Suite knee module kinematic data showed strong correlations to the validated motion capture system (Xsens). Thus, a clinician should be confident in using the dorsaVi in the evaluation, diagnosis, and treatment of patients.

Stationary high-bandwidth experiments with a portable lasercom (laser communication) system were performed over a wide range of scintillation indices (< 0.1 to 1) at the Department of Energy's Nevada Test Site in the summer of 2003. Active alignment was performed with a quad-cell tracking detector at the transmitter transponder and a conical-scan tracking beam at the receiver transponder. During good scintillation conditions, 2-km 10-Gb/s and 11-km 2.5-Gb/s capabilities were demonstrated at error-free bit-error rates over continuous intervals on the order of half an hour. The experimental transponder configuration, which had 2.5-cm transmit-side and 8-cm receive-side aperture diameters, is described and test results are presented. Modifications to the stationary beacon-tracking transponder system that support a semi-autonomous (aided-pointing), mobile, lasercom capability are discussed.