前言：
　　投手在投球方式的選擇上的考量因素有很多，要成為一名優秀的投手，除了先天上的才能和苦練之外，找到屬於適合的自己投球方式將會是成為一名偉大投手的重大分水嶺，適合投手本身的投球姿勢，也將減少投手在投球時受傷的風險。

目的：
　　探討國內上肩投手及側肩投手在投擲直球及滑球過程中運動學及動力學參數差異，探討國內側肩投手在投擲直球及滑球過程中運動學及動力學參數差異。
　　探討國內上肩投手及側肩投手在投球前後的肌力衰退變化。

研究方法：
　　本研究以十位16至22歲的側肩投手及十一位16至22歲上肩投手做為受測者。利用Biodex等速肌力測試訓練系統量測受測者投球前、投球後肌力，來觀察其投球後的肌力變化。使用三維動作分析系統擷取側肩投法(Sidearm)及上肩投法(Overhead)動作的過程，投球內容為直球、滑球兩種球路。統計方法用重複測量變異數分析及配對t檢定分析。設定p<0.05即達顯著差異。
 
結果:
　　側肩投手與上肩投手投擲直球的分析結果，81項運動學參數中，有41項有達到統計上顯著差異，33項動力學參數中，有20項有達到統計上顯著差異，標準化後則有21項達統計上顯著差異；側肩投手與上肩投手投擲滑球的分析結果，81項運動學參數中，有52項有達到統計上顯著差異，33項動力學參數中，有15項有達到統計上顯著差異，標準化後則有18項達統計上顯著差異；側肩投手投擲直球與滑球的分析結果，81項運動學參數中，有20項有達到統計上顯著差異，33項動力學參數中，有15項有達到統計上顯著差異，標準化後則有7項達統計上顯著差異。
　　肌力結果，由於本研究投手的投球數量只有30球，投手在投球過後在疲勞量表的統計結果上均顯示輕鬆，因此在慣用手肌力的衰退率上，側肩投手與上肩投手皆無太明顯的衰退現象。

結論:
　　投擲直球或滑球時，側肩投手的手臂加速時期所經歷的時間皆高於上肩投手，而在手臂加速時期，側肩投手的肩關節及肘關節所承受到的力及力矩多大於上肩投手。另外，側肩投手不論是在投擲直球還是滑球，肩關節及肘關節的11項動力學參數，其最大值有5項皆發生在手臂加速時期。因此，側肩投手在關節受力大於上肩投手且暴露在較長時間的情況底下，側肩投手發生運動傷害的風險將大於上肩投手。
　　側肩投手在投擲直球及滑球時，球離手的時間點只有3項運動學參數達統計上顯著差異，可看出側肩投手投擲直球及滑球時並沒有太大的差異性，打者很難從側肩投手的投球動作判斷出是投擲直球還是滑球，只能藉由球的軌跡判斷球種，能夠更有效率的壓制打者。然而在這樣的投球優勢背後，側肩投手在投擲滑球時，在肘關節內側力、肘關節內翻力矩的負擔卻是明顯大於直球的，與過去本實驗室中針對上肩投手的研究其結果是相反的，因此側肩投手在投擲直球時，其數量得嚴加控管，以避免在反覆投球後造成運動傷害的發生。

To be a great baseball pitcher, In addition to the innate and again and over again practice, a proper pitching motion maybe increase the pitching skill and avoid sport injury risk. In the thesis, we study the kinematic and kinetic differences among the fastball and slider in sidearm and overhand pitcher.
In the thesis, biomechanical analysis between sidearm and overhand pitchers. Our subject is ten sidearm pitchers and eleven overhand pitchers who come from senior and collegiate baseball pitcher.The twenty-one baseball players pitched off a outdoor mound during three dimensional motion analysis (Raptor-E Cameras, Motion Analysis Corp., Santa Rosa, C.A., U.S.A) to measure whole body kinematics and kinetics at 300 Hz. These pitcher pitched fifteen fastball and fifteen slider and every pitch scored by catcher.We choose five pitches which highest score to analyze.
When throwing the fastball and slider, sidearm pitcher's arm acceleration phase during time is longer than overhand pitcher.In arm acceleration phase, sidearm pitcher's joint force and moment is bigger than overhand pitcher.
The result of fastball and slider analysis in sidearm pitcher.In this study, only 3 kinematic parameters P<0.05 at ball release. 33 kinetic parameters, there are 15 parameters reached statistical significance, all the parameters is slider bigger than fastball. Thus, fastball and slider is small differences in pitching motion in sidearm pitcher, but force and moment slider is bigger than fastball.
In sidearm pitcher, by the kinematic parameters, we find fastball and slider have high similarity in pitching motion, only 3 parameters P<0.05 at ball release. But in the joint loading slider is greater than fastball, and the result is opposite of the overhand pitcher, so sidearm pitcher need to limit the pitches of slider to avoid the sports injuries after pitching.

[1] Kindall J. Baseball: play the winning way. Sports Illustrated, Place, 1993.
[2] Fleisig GS, Andrews JR, Dillman CJ,Escamilla RF. Kinetics of Baseball Pitching with Implications About Injury Mechanisms. American Journal of Sports Medicine; 23: 233-239. 1995.
[3] Werner SL, Fleisig GS, Dillman CJ,Andrews JR. Biomechanics of the Elbow during Baseball Pitching. Journal of Orthopaedic & Sports Physical Therapy; 17: 274-278. 1993.
[4] Nadler SF. Injury in a throwing athlete: Understanding the kinetic chain. American Journal of Physical Medicine & Rehabilitation; 83: 79-79. 2004.
[5] Meister K. Injuries to the shoulder in the throwing athlete. Part one: Biomechanics/pathophysiology/classification of injury. Am J Sports Med; 28: 265-275. 2000.
[6] Stodden DF, Fleisig GS, McLean SP, Lyman SL,Andrews JR. Relationship of pelvis and upper torso kinematics to pitched baseball velocity. J Appl Biomech; 17: 164-172. 2001.
[7] Stevenson JM. Finger release sequence for fastball and curveball pitches. Can J Appl Sport Sci; 10: 21-25. 1985.
[8] Lyman S, Fleisig GS, Andrews JR,Osinski ED. Effect of pitch type, pitch count, and pitching mechanics on risk of elbow and shoulder pain in youth baseball pitchers. Am J Sports Med; 30: 463-468. 2002.
[9] Larsson L, Grimby G,Karlsson J. Muscle strength and speed of movement in relation to age and muscle morphology. J Appl Physiol; 46: 451-456. 1979.
[10] Fleisig GS, Escamilla RF, Andrews JR, Matsuo T, Satterwhite Y,Barrentine SW. Kinematic and kinetic comparison between baseball pitching and football passing. J Appl Biomech; 12: 207-224. 1996.
[11] Fleisig GS, Barrentine SW, Zheng N, Escamilla RF,Andrews JR. Kinematic and kinetic comparison of baseball pitching among various levels of development. J Biomech; 32: 1371-1375. 1999.
[12] Nissen CW, Westwell M, Ounpuu S, Patel M, Tate JP, Pierz K, Burns JP,Bicos J. Adolescent baseball pitching technique: a detailed three-dimensional biomechanical analysis. Med Sci Sports Exerc; 39: 1347-1357. 2007.
[13] Escamilla R, Fleisig G, Barrentine S, Andrews J,Moorman C, 3rd. Kinematic and kinetic comparisons between American and Korean professional baseball pitchers. Sports Biomech; 1: 213-228. 2002.
[14] Dun SC, Fleisig GS, Loftice J, Kingsley D,Andrews JR. The relationship between age and baseball pitching kinematics in professional baseball pitchers. J Biomech; 40: 265-270. 2007.
[15] Chu YC, Fleisig GS, Simpson KJ,Andrews JR. Biomechanical Comparison Between Elite Female and Male Baseball Pitchers. J Appl Biomech; 25: 22-31. 2009.
[16] Escamilla RF, Fleisig GS, Barrentine SW, Zheng NQ,Andrews JR. Kinematic comparisons of throwing different types of baseball pitches. J Appl Biomech; 14: 1-23. 1998.
[17] Fleisig GS, Kingsley DS, Loftice JW, Dinnen KP, Ranganathan R, Dun S, Escamilla RF,Andrews JR. Kinetic comparison among the fastball, curveball, change-up, and slider in collegiate baseball pitchers. American Journal of Sports Medicine; 34: 423-430. 2006.
[18] Escamilla RF, Barrentine SW, Fleisig GS, Zheng NQ, Takada Y,Andrews JR. Pitching biomechanics as a pitcher approaches muscular fatigue during a simulated baseball game. American Journal of Sports Medicine; 35: 23-33. 2007.
[19] Dun SC, Loftice J, Fleisig GS, Kingsley D,Andrews JR. A biomechanical comparison of youth baseball pitches - Is the curveball potentially harmful? American Journal of Sports Medicine; 36: 686-692. 2008.
[20] Aguinaldo AL, Chambers H. Correlation of Throwing Mechanics With Elbow Valgus Load in Adult Baseball Pitchers. Am J Sports Med; 37: 2043-8. 2009.
[21] Mullaney MJ, McHugh MP, Donofrio TM,Nicholas SJ. Upper and lower extremity muscle fatigue after a baseball pitching performance. American Journal of Sports Medicine; 33: 108-113. 2005.
[22] Dale RB, Kovaleski JE, Ogletree T, Heitman RJ,Norrell PM. The effects of repetitive overhead throwing on shoulder rotator isokinetic work-fatigue. N Am J Sports Phys Ther; 2: 74-80. 2007.
[23] Dempster WT. Space requirements of the seated operator. WADC Technical Report 55159; 55-159. 1955.
[24] 張劭任,台灣職業棒球投手直球、滑球和曲球的生物力學分析.2012
[25] Hislop HJ,Montgomery J. Daniels and Worthingham s muscle testing: techniques of manual examination. Philadelphia, Place, 1995.

[26] Woltring HJ. A Fortran Package for Generalized, Cross-Validatory Spline Smoothing and Differentiation. Advances in Engineering Software and Workstations; 8: 104-113. 1986.
[27] Barrentine SW, Fleisig GS, Whiteside JA, Escamilla RF, Andrews JR. Biomechanics of windmill softball pitching with implications about injury mechanisms at the shoulder and elbow. J Orthop Sports Phys Ther; 28: 405-15. 1998.
[28] Bartlett LR, Storey MD,Simons BD. Measurement of upper extremity torque production and its relationship to throwing speed in the competitive athlete. Am J Sports Med; 17: 89-91. 1989.
[29] Alderink GJ,Kuck DJ. lsokinetic Shoulder Strength of High School and College-Aged Pitchers. J Orthop Sports Phys Ther; 7: 163-172. 1986.