MECHANICAL EFFICIENCY IN BASEBALL PITCHING

Efficient pitching mechanics should maximize ball velocity while minimizing stress on the pitching arm. The purpose of this study was to quantify the relationship between ball velocity and upper extremity kinetics (UEKs) and define the kinematic patterns that achieve the most efficient pitching mechanics. Healthy collegiate and professional pitchers (n=147) threw maximal effort pitches from the wind-up. After determining the overall relationship between ball velocities and UEKs, two subgroups of pitchers were identified as efficient and inefficient. Efficient pitchers had significantly more ball velocity and similar or lower kinetic values. 10 of 23 kinematic variables were significantly different between the groups. It is recommended that coaches and researchers use the efficient group’s mechanics as a point of reference when analyzing and teaching pitching biomechanics

PRELIMINARY STUDY: INTERPRETATION OF BARBELL BACK SQUAT KINEMATICS USING PRINCIPAL COMPONENT ANALYSIS

The purpose of this study was to reduce the number of kinematic variables of the barbell back squat for easier interpretation by coaches and athletes. Young active adults (N=25) performed the back squat with an intensity of 60%. A total of 10 lower body and trunk measurements were considered for principal components analysis (PCA). Based on the PCA, two components were revealed. The primary component related range of motions (ROMs) in the ankle and knee joints with greater peak flexion angles of ankle, knee, and shank and thigh segments. A secondary component related hip ROMs and hip posterior displacement with greater hip and trunk segment peak flexion angles. Based on this analysis, coaches teaching the barbell back squat should consider two sources of movement variability, one above and one below the hip

COMING DOWN: THROWING MECHANICS OF BASEBALL CATCHERS

Catchers are asked to make quick, highly accurate throws from a deep squat starting position. The purpose of this study was to define the throwing mechanics of catchers. Comparisons of their throwing biomechanics were made with pitching and long toss. Motion data were collected on collegiate catchers (n=8) and pitchers (n=22) making such throws in game-like situations. Catchers exhibited a significantly different stride pattern, greater elbow flexion through arm cocking, and less forward trunk tilt at ball release. The stresses on the shoulder and elbow during catchers’ throws were similar to pitching and long toss, but produced significantly less ball velocity, suggesting a less efficient motion. This inefficiency is most likely compensation in order to complete the throw in less time. Coaches should be aware of this tendency when teaching catchers throwing mechanics

THE EFFECTS OF WEIGHTLIFTING SHOES ON SQUAT KINEMATICS

Athletes may not always consider footwear when performing the barbell back squat during training. Several footwear companies have designed shoes claimed to enhance performance in weightlifting and powerlifting. The purpose of this study was to compare the kinematics of the barbell back squat wearing either running shoes (RS) or weightlifting shoes (WLS). Young, healthy active adult males (N=20) were filmed in the sagittal plane while performing barbell back squats for each shoe condition at an intensity of 60% of one repetition maximum (1RM). While a number of kinematic parameters were similar between conditions, the shank maintained a more vertical position and the bar and hip were displaced less when wearing WLS, suggesting a more erect trunk posture. WLS may make small changes that allow for a safer, more effective squat performance

The Causal Structure of Emotions in Aristotle: Hylomorphism, Causal Interaction between Mind and Body, and Intentionality

Recently, a strong hylomorphic reading of Aristotelian emotions has been put forward, one that allegedly eliminates the problem of causal interaction between soul and body. Taking the presentation of emotions in de An. I 1 as a starting point and basic thread, but relying also on the discussion of Rh. II, I will argue that this reading only takes into account two of the four causes of emotions, and that, if all four of them are included into the picture, then a causal interaction of mind and body remains within Aristotelian emotions, independent of how strongly their hylomorphism is understood. Beyond the discussion with this recent reading, the analysis proposed of the fourfold causal structure of emotions is also intended as a hermeneutical starting point for a comprehensive analysis of particular emotions in Aristotle. Through the different causes Aristotle seems to account for many aspects of the complex phenomenon of emotion, including its physiological causes, its mental causes, and its intentional object

Shifting attention in viewer- and object-based reference frames after unilateral brain injury

The aims of the present study were to investigate the respective roles that object- and viewer-based reference frames play in reorienting visual attention, and to assess their influence after unilateral brain injury. To do so, we studied 16 right hemisphere injured (RHI) and 13 left hemisphere injured (LHI) patients. We used a cueing design that manipulates the location of cues and targets relative to a display comprised of two rectangles (i.e., objects). Unlike previous studies with patients, we presented all cues at midline rather than in the left or right visual fields. Thus, in the critical conditions in which targets were presented laterally, reorienting of attention was always from a midline cue. Performance was measured for lateralized target detection as a function of viewer-based (contra- and ipsilesional sides) and object-based (requiring reorienting within or between objects) reference frames. As expected, contralesional detection was slower than ipsilesional detection for the patients. More importantly, objects influenced target detection differently in the contralesional and ipsilesional fields. Contralesionally, reorienting to a target within the cued object took longer than reorienting to a target in the same location but in the uncued object. This finding is consistent with object-based neglect. Ipsilesionally, the means were in the opposite direction. Furthermore, no significant difference was found in object-based influences between the patient groups (RHI vs. LHI). These findings are discussed in the context of reference frames used in reorienting attention for target detection

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 situational baseball: Execution and perception of left-handed pitcher’s pick-off moves to first base

The aim of this study was to provide an in-depth analysis of the pick-off play in baseball. Ten collegiate left-handed pitchers and nine base-runners participated in this study. The pitchers were videotaped with four cameras to derive three-dimensional data while performing deliveries in the directions of first base and home plate in a laboratory setting. Deliveries were performed from flat ground. Differences between these deliveries were measured through ten selected joint and segment angles. The base-runners completed two distinct procedures in which they viewed video footage of left-handed pitchers and estimated the intended delivery direction. Base-runners were subsequently interviewed to determine the reasoning behind their decisions. The pitchers\u27 data revealed differences between delivery types in nearly all of the selected angles (P \u3c 0.01). The base-runners\u27 data demonstrated that their ability to discriminate delivery types improved when allowed more viewing time per trial (P \u3c 0.01). Additionally, commonalities exist among the base-runners\u27 focal points on the pitcher while making decisions regarding delivery direction and the kinematic differences between deliveries in left-handed pitchers. The practical significance of these results, however, may be more difficult to interpret