There is little research specifically examining fast-pitch softball pitchers. However of the few studies completed, pitchers have been reported to exhibit a high incidence of injury. How and why these pitchers are suffering from injuries has not been elucidated.The purpose of this study was to investigate the injuries occurring to collegiate softball pitchers and factors that may influence these injuries such as demographic, pitching, training, and injury information.A cross-sectional survey of collegiate softball pitchers from Divisions I, II, and III was conducted using InQsit, a web-based survey system. Instructions on how to complete a web-based survey was sent and completed over a two-week period, by 181 Division I, II, and III collegiate softball pitchers. The survey was composed of questions addressing: 1) demographic information, 2) pitching and game data, 3) training program information, and 4) injury reporting.The results showed that demographic information, pitching and game data, and training were not statistically significant (p<0.05) in relation to injury. Among the 131 reported injuries, 36 were acute, 92 chronic, and 3 unspecified. Of the 92 chronic/overuse injuries, 10 were Grade I, 30 Grade II, 39 Grade III, and 13 Grade IV. Of the total injuries, 80 were a direct result from pitching, with 36 relating to the shoulder and 17 to the lower back. Among the injured pitchers, 109 took Non-Steroidal AntiInflammatory Drugs, 140 used modalities, 11 received surgeries, and 95 saw additional specialists. This study revealed that a high percentage (72.8%) of collegiate pitchers are suffering injuries across the nation and more research focused on this area is needed. In addition, coaches need to continue to be informed of ways they can improve the health and training programs of their pitchers. / School of Physical Education

Research has shown that motor skill performance can be improved with the use of a dynamic visual model that helps to create a cognitive representation and serve as a standard for learning. The purpose of this project is to produce a demonstration videotape that thoroughly analyzes the basic actions involved with pitching a softball for strikes.

The problem of this study was to determine the relative contribution of the strength of shoulder internal rotators among various muscle groups to ball speed in the fastball pitch as exhibited by college pitchers. An objective of the study was to explain at least 40% of the contribution of ball speed. The literature appears to be somewhat inconclusive as to the quantification of component contributors of muscle groups m the upper extremity to ball speed. It appears in the literature that variables other than upper extremity strength account for approximately 50% of ball speed. Some research has indicated that strength of the shoulder internal rotators is a major contributor while most research of this type has either been inconclusive or qualitative m nature. Eighteen college pitchers were tested for upper extremity peak torque production on the Cybex II Isokinetic Dynamometer at speeds of 90 and 240 degrees/second. Fastball speed was measured with a hand held radar gun. Results of regression analyses performed on the data indicate a strong correlation between the internal rotators of the upper extremity and fastball speed. A regression equation using a hierarchical strategy to maximize R2 accounted for 40% of contribution to ball speed using independent variables of shoulder internal rotation at 90° /sec. (X1) and elbow flexion at 240°/sec. (X2); ie, Speed=62.861+245X1 +.39X2. The standardized beta weights for this equation indicate that the greater contributor to ball speed was Sho/Int/Rot-90 when the effects of Elb/Fl-240 are controlled. When elbow extension at 90° /sec. was added to the equation as X3 approximately 59% of ball speed is explained; ie, Speed=68.605 + 268X1 + 807 X2 - .430X3.

本研究の目的は，無症状の野球選手における肩甲骨の運動異常(SD)の発生状況とSDを有する野球選手における投球中の肩関節の運動学・動力学的な特徴を評価することとした．この結果，無症状の野球選手はSD type Ⅰ(肩甲骨後傾の低下)の発生割合が最も多かったこと，とくにSD type Ⅰを有する野球選手はSDを有さない野球選手と比較して，投球中のレイトコッキング期の肩甲上腕関節(GH)の外旋角度と前方間力が増加し，肩甲骨後傾が低下していることが明らかになった． / 博士(スポーツ健康科学) / Doctor of Philosophy in Health and Sports Science / 同志社大学 / Doshisha University

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Harmonic oscillatory tests for a fighter aircraft using the Dynamic Plunge--Pitch--Roll model mount at Virginia Tech Stability Wind Tunnel are described. Corresponding data reduction methods are developed on the basis of multirate digital signal processing. Since the model is sting mounted, the frequencies associated with sting vibration are included in balance readings thus a linear filter must be used to extract out the aerodynamic responses. To achieve this, a Finite Impulse Response (FIR) is designed using the Remez exchange algorithm. Based on the reduced data, a state–space model is developed to describe the unsteady aerodynamic characteristics of the aircraft during roll oscillations. For this model, we chose to separate the aircraft into panels and model the local forces and moments. Included in this technique is the introduction of a new state variable, a separation state variable which characterizes the separation for each panel. This new variable is governed by a first order differential equation. Taylor series expansions in terms of the input variables were performed to obtain the aerodynamic coefficients of the model. These derivatives, a form of the stability derivative approach, are not constant but rather quadratic functions of the new state variable. Finally, the concept of the model was expanded to allow for the addition of longitudinal motions. Thus, pitching moments will be identified at the same time as rolling moments. The results show that the goal of modeling coupled longitudinal and lateral–directional characteristics at the same time using the same inputs is feasible. / Master of Science

A computational approach to analyze the hydrodynamic performance of a hydrofoil or a marine propeller undergoing unsteady motion has been developed. In order to simulate heave and pitch motion of a hydrofoil, an unsteady boundary element method based modeling is performed. The wake of the hydrofoil is modeled by a continuous dipole sheet and determined in time by applying a force-free condition on its surface. An explicit vortex core model is adapted in this model to capture the rolling up shape and to avoid instability due to roll-up deformation of the wake. The numerical results of the developed model are compared with analytical results and those from the commercial Reynolds-Averaged Navier-Stokes solver (ANSYS/FLUENT). The results show close level of agreement with each other. The problem of flow around a marine propeller performing surge, roll and heave motion in an unbounded fluid is formulated and solved using both a vortex-lattice method and a boundary element method. A fully unsteady wake alignment algorithm is implemented into the vortex-lattice method in order to satisfy the force-free condition on the propeller wake surface. Finally, a comparative study of transient propeller forces on a propeller blade obtained from BEM and VLM (with or without fully aligned wake) is carried out and results are presented. In some cases, results from the presented methods are compared with those from RANS or other numerical methods available in the literature. / text