EFFECTS OF THE BENCH SHIRT ON SAGITTAL BAR PATH

Powerlifting, like many sports, uses performance-enhancing equipment. The purpose of this study was to explore whether wearing a bench shirt would alter the natural mechanics of the bench press. Participants (n=5) completed two bench press tests; the first was raw (no shirt), while the second utilized the bench shirt. Vertical bar path ranges were significantly smaller in the shirted condition compared to the raw condition. Significant differences were found between the optimal and observed values while benching during the raw condition, but no significant differences were found in the shirted condition. Assuming a straight line bar path is optimal, findings suggest the bench shirt may provide a more efficient bar path, improving load capability and decreasing the forces that act on the shoulder and thus the likelihood of injury

When here becomes there: attentional distribution modulates foveal bias in peripheral localization

Much research concerning attention has focused on changes in the perceptual qualities of objects while attentional states were varied. Here, we address a complementary question—namely, how perceived location can be altered by the distribution of sustained attention over the visual field. We also present a new way to assess the effects of distributing spatial attention across the visual field. We measured magnitude judgments relative to an aperture edge to test perceived location across a large range of eccentricities (30°), and manipulated spatial uncertainty in target locations to examine perceived location under three different distributions of spatial attention. Across three experiments, the results showed that changing the distribution of sustained attention significantly alters known foveal biases in peripheral localization

The Biomechanics of the Baseball Swing

Success in baseball batting is fundamental to the sport, however it remains one of, if not the most, challenging skills in sports to master. Batters utilize the kinetic chain to transfer energy from the lower body to the upper body to the bat, hoping to impart the maximum amount of energy into the ball. Scientists and coaches have researched the swing and developed theories on the keys for successful batting, but most of this research has been inadequate in attempting to fully describe the biomechanics of batting. The purposes of this study were to improve upon the methodology of previous researchers, provide a full biomechanical description of the swing, and compare swings against pitches thrown to different locations and at different speeds. AA-level Minor League Baseball players (n=43) took extended rounds of batting practice in an indoor laboratory against a pitcher throwing a mixture of fastballs and changeups. An eight camera motion analysis system and two force plates recording at 300 Hz captured the biomechanical data. The swing was divided into six phases (stance, stride, coiling, swing initiation, swing acceleration, and follow-through) by five key events (lead foot off, lead foot down, weight shift commitment, maximum front foot vertical ground reaction force, and bat-ball contact). Twenty-eight kinematic measurements and six ground reaction force measurements were computed based on the marker and force plate data, and all were assessed throughout the phases. First, a comprehensive description of a composite of the batters’ swings against fastballs “down the middle” was provided. Second, successful swings against fastballs thrown to one of five pitch locations (HIGH IN, HIGH OUT, LOW IN, LOW OUT, MIDDLE) were compared in terms of selected kinematics at the instant of bat-ball contact, timing and magnitude of peak kinematic velocities, and timing and magnitude of peak ground reaction forces. Third, these variables were once again compared for swings against fastballs and changeups. A large number of biomechanical differences were seen among the swings against various pitch locations. More fully rotated positions, particularly of the pelvis and bat were critical to the batters’ successes on inside pitches while less rotated positions keyed successes against outside pitches. The trail and lead arms worked together as part of a closed chain to drive the hand path. Successful swings had the trail elbow extended more for HIGH IN and flexed more for LOW OUT, though batters often struggled to execute this movement properly. A distinct pattern among successful swings against fastballs, successful swings against changeups, and unsuccessful swings against changeups was witnessed; namely a progressive delay in which the batter prematurely initiated the events of the kinetic chain, especially when unsuccessful in hitting a changeup. It was believed that this study was much more effective in capturing the essence of baseball batting than previous scientific works. Some recommendations to batting coaches would be to get batters to take a consistent approach in the early phases of every swing (particularly for the lower body), identify both pitch type and location as early as possible, use the rotation of the pelvis to propagate the energy transfer of the kinetic chain from the group to the upper body, and use the pelvis, and subsequently, the upper body, to orient the trunk and hands to an optimal position to drive the ball to the desired field. Limitations of the current study and ideas for future work were also presented to better interpret the findings of this research and further connect science and sport

Comparison of Back Squat Kinematics Between Barefoot and Shoe Conditions

The purpose of the study was to compare the kinematics of the barbell back squat between two footwear conditions and to evaluate the results with respect to recommendations put forth in the National Strength and Conditioning Association position statement for proper squat technique. Twenty-five subjects with 5 - 7 years of resistance training experience participated. Selected kinematics were measured during a 60% of 1RM barbell back squat in both barefoot and athletic shoe conditions. Paired-samples T tests were performed to compare the two footwear conditions. Significant differences were found in trunk (50.72±8.27 vs. 46.97±9.87), thigh (20.94±10.19 vs. 24.42±11.11), and shank segment angles (59.47±5.54 vs. 62.75±6.17), and knee joint angles (81.33±13.70 vs. 88.32±15.45) at the peak descent position. Based on the kinematic analysis of the barefoot squat, two kinematic advantages are countered by two disadvantages. Coaches and instructors should acknowledge these results with respect to a performer\u27s capability, and be aware the advantages and disadvantages of barefoot squat from a kinematic perspective

Interpersonal early‐life trauma alters amygdala connectivity and sustained attention performance

Abstract Introduction: Interpersonal early life trauma (I‐ELT) is associated with a myriad of functional impairments in adulthood, increased risk of drug addiction, and neuropsychiatric disorders. While deficits in emotional regulation and amygdala functioning are well characterized, deficits in general cognitive functioning have also been documented. However, the neural underpinnings of cognitive dysfunction in adults with a history of I‐ELT and the potential relationship between amygdala‐based functional connectivity and behavioral performance are currently poorly understood. This study examined how I‐ELT affects the cognitive and neural mechanisms supporting sustained attention. Methods: A total of 66 Veterans (18 with and 48 without a history of I‐ELT) completed a nonemotional sustained attention task during functional MRI. Results: The individuals with I‐ELT showed significant impairments in sustained attention (i.e., higher error rates, greater response variability). This cohort exhibited increased amygdala functional connectivity with the prefrontal cortex and decreased functional connectivity with the parahippocampal gyrus when compared to those without I‐ELT. These connections were significantly correlated with individual differences in sustained attention performance. Notably, classification analyses revealed that the pattern of amygdala connectivity across the whole brain was able to classify I‐ELT status with 70% accuracy. Conclusion: These results provide evidence of a lasting negative impact for those with a history of I‐ELT on sustained attention ability. They also highlight a critical role for amygdala functioning in cognitive control and sustained attention for those with a history of I‐ELT, which may underlie the observed attention deficits in clinical assessments and cognitive tests involving both emotional and nonemotional stimuli