傳球動作是一種需要高度技巧與爆發力的運動，且必須與投擲者的身體肢段在時間與協調上達到精確的結合。捕手於比賽及訓練中，必須長時間採取蹲姿，並以蹲姿起身完成傳球動作，可想而知捕手下肢之負擔大於任何守備位置。捕手所採取的蹲姿動作常有個別差異，且不同蹲寬下還會涉入不同傳球方式，不同蹲寬與不同傳球動作是否會對蹲姿起身傳球動作有影響，以及蹲姿起身傳球動作下肢的角色為何，目前相關研究並不完整。本研究將藉由三維動作分析系統、測力板與肌電圖，探討棒球捕手採取不同蹲姿與不同傳球動作過程中，下肢各關節之運動學、軸心腳地面反作用力以及下肢各肌肉活動之差異。研究結果發現，棒球捕手寬蹲姿在蹲寬上顯著大於一般蹲姿 (p<.05)，且捕手在蹲姿動作上較少使用窄蹲寬。墊步傳球動作在球速上顯著大於跨步傳球 (p<.05)。不同蹲姿的傳球動作的主要影響在傳球動作的前期，進入加速期，不同蹲姿與不同傳球動作有相似的下肢關節運動。寬蹲姿與墊步傳球動作在軸心腳左右方向地面反作用力顯著大於一般蹲姿與跨步傳球 (p<.05)。無論使用何種傳球方式，以寬蹲姿時軸心腳的足底壓力中心位移範圍顯著大於一般蹲姿 (p<.05)。墊步傳球動作對於捕手傳球速度與力量有明顯的正面效果，墊步傳球與寬蹲姿卻可能會對捕手接傳動作動作中的平衡有負面影響。

Catching-and-throwing is a highly-skilled sport requiring both precise timing and coordination of thrower’s body segments. As catchers have to squat for long period of time and complete the ball throwing with a squat posture, it is not surprising that catchers bear larger load on the lower limbs’ joints than anyone at defense. Related studies of this issue are, however, quite limited. Individual difference is often observed in each catcher’s squat posture, and different squatting width, which affects catcher’s performances and lower limbs’ knee load, has seldom been studied. The incomplete research is unable to provide a clearer picture of the role of lower extremity in catcher’s performance and the risk of sports injury. So far, the impact of different squatting width and throwing types on catcher’s performance is still limited. Therefore, the 3-D motion analyses system, EMG and force plate would be utilized in this study to quantify the kinematic, kinetic and EMG data of lower extremity. The purposes of this study will be 1) to investigate the joint kinematics data in lower extremity when catchers perform throwing with a squat posture, 2) to investigate ground reaction force of pivot foot in lower extremity when throwing is performed with a squat posture, 3) to investigate each muscle activity in lower extremity when throwing is performed with a squat posture. The results showed larger width in wide squatting than in normal stance (p<.05), besides, the narrow squatting was less used by catchers . The stepping throwing tended to generate more baseball velocity than the pivot throwing (p<.05). In kinematics of lower limbs, the result indicated significant influence of the width of squatting on the early phase of catcher’s throwing . Similar kinematic pattern of lower limbs was found after the throwing proceded into acceleration phase when throwing was performed with varying squatting widths and varying types. The wide squatting and the stepping throwing had more medial-lateral GRF than the normal squatting and the pivot throwing when catchers perform throwing with a squat posture (p<.05). The large range of COP displacement was found in pivot-foot when the wide squatting was used on both throwing types. In conclusion, the data provided in this study indicated that the stepping throwing has had a significantly positive effect on velocity and power. On the other hand, the stepping throwing and the wide squatting may yield negative results to the balance of motion when catchers perform catching-and-throwing.

參考文獻
一、中文部分
謝凱賀（2007）。棒球捕手膝關節輔助墊對動作時間、肌肉活性與關節力矩之影響。未出版碩士論文，台北市立體育學院運動器材研究所，台北市。
二、英文部分
Aura, O., & Komi, P. V. (1986). The mechanical efficiency of locomotion in men and women with special emphasis on stretch-shortening cycle exercises. European Journal of Applied Physiology And Occupational Physiology, 55(1), 37-43.
Barzun, J. (1973). God's Country and Mine. Connecticut: Greenwood Press Reprint.
Bynum, E. B., Barrack, R. L., & Alexander, A. H. (1995). Open versus closed chain kinetic exercises after anterior cruciate ligament reconstruction. A prospective randomized study. American Journal of Sports Medicine, 23(4), 401-406.
Dun, S., Fleisig, G. S., Loftice, J., Kingsley, D., & Andrews, J. R. (2007). The relationship between age and baseball pitching kinematics in professional baseball pitchers. Journal of Biomechanics, 40(2), 265-270.
Elliott, B., Grove, J. R., & Gibson, B. (1988). Timing of the Lower Limb Drive and Throwing Limb Movement in Baseball Pitching. International Journal of Sport Biomechanics, 4, 59-67.
Escamilla, R. F. (2001). Knee biomechanics of the dynamic squat exercise. Medicine and Science in Sports and Exercise, 33(1), 127-141.
Escamilla, R. F., Barrentine, S. W., Fleisig, G. S., Zheng, N., Takada, Y., Kingsley, D., et al. (2007). Pitching biomechanics as a pitcher approaches muscular fatigue during a simulated baseball game. The American Journal of Sports Medicine, 35(1), 23-33.
Escamilla, R. F., Fleisig, G. S., Lowry, T. M., Barrentine, S. W., & Andrews, J. R. (2001). A three-dimensional biomechanical analysis of the squat during varying stance widths. Medicine and Science in Sports and Exercise, 33(6), 984-998.
Escamilla, R. F., Fleisig, G. S., Zheng, N., Barrentine, S. W., Wilk, K. E., & Andrews, J. R. (1998). Biomechanics of the knee during closed kinetic chain and open kinetic chain exercises. Medicine and Science in Sports and Exercise, 30(4), 556-569.
Escamilla, R. F., Fleisig, G. S., Zheng, N., Lander, J. E., Barrentine, S. W., Andrews, J. R., et al. (2001). Effects of technique variations on knee biomechanics during the squat and leg press. Medicine and Science in Sports and Exercise, 33(9), 1552-1566.
Fleisig, G. S., Kingsley, D. S., Loftice, J. W., Dinnen, K. P., Ranganathan, R., Dun, S., et al. (2006). Kinetic comparison among the fastball, curveball, change-up, and slider in collegiate baseball pitchers. The American Journal of Sports Medicine, 34(3), 423-430.
Hardin, W. (2004). The Catcher's Five Toughest Plays. Coach and Athletic Director, 73(10), 26-28.
Isear, J. A., Jr., Erickson, J. C., & Worrell, T. W. (1997). EMG analysis of lower extremity muscle recruitment patterns during an unloaded squat. Medicine and Science in Sports and Exercise, 29(4), 532-539.
Larson, D. E., Fry, A. C., Greenwood, M., Schilling, B. K., & Chiu, Z. F. (2007). Ground Reaction Forces of Throwing Motions for a Baseball Catcher, Sport Biomechanics (Vol. 39, pp. S94-S95): ©2007The American College of Sports Medicine.
Loughin, T. M., & Bargen, J. L. (2007). Assessing pitcher and catcher influences on base stealing in Major League Baseball. Journal of Sports Sciences, 1-6.
MacWilliams, B. A., Choi, T., Perezous, M. K., Chao, E. Y., & McFarland, E. G. (1998). Characteristic ground-reaction forces in baseball pitching. The American Journal of Sports Medicine, 26(1), 66-71.
McCaw, S. T., & Melrose, D. R. (1999). Stance width and bar load effects on leg muscle activity during the parallel squat. Medicine and Science in Sports and Exercise, 31(3), 428-436.
Mullaney, M. J., McHugh, M. P., Donofrio, T. M., & Nicholas, S. J. (2005). Upper and lower extremity muscle fatigue after a baseball pitching performance. The AmericanJjournal of Sports Medicine, 33(1), 108-113.
Murray, T. A., Cook, T. D., Werner, S. L., Schlegel, T. F., & Hawkins, R. J. (2001). The effects of extended play on professional baseball pitchers. The American Journal of Sports Medicine, 29(2), 137-142.
Nagura, T., Dyrby, C. O., Alexander, E. J., & Andriacchi, T. P. (2002). Mechanical loads at the knee joint during deep flexion. Journal of Orthopaedic Research, 20(4), 881-886.
Ninos, J. C., Irrgang, J. J., Burdett, R., & Weiss, J. R. (1997). Electromyographic analysis of the squat performed in self-selected lower extremity neutral rotation and 30 degrees of lower extremity turn-out from the self-selected neutral position. Journal of Orthopaedic and Sports Physical Therapy, 25(5), 307-315.
O'Shea, P. (1985). The parallel squat. Natl. Strength Condit. J, 6, 70-72.
Paoli, A., Marcolin, G., & Petrone, N. (2009). The effect of stance width on the electromyographical activity of eight superficial thigh muscles during back squat with different bar loads. Journal of Strength and Conditioning Research, 23(1), 246-250.
Pedegana, L. R., Elsner, R. C., Roberts, D., Lang, J., & Farewell, V. (1982). The relationship of upper extremity strength to throwing speed. The American Journal of Sports Medicine, 10(6), 352-354.
Sabick, M. B., Torry, M. R., Lawton, R. L., & Hawkins, R. J. (2004). Valgus torque in youth baseball pitchers: A biomechanical study. Journal of Shoulder and Elbow Surgery, 13(3), 349-355.
Signorile, J. F., Weber, B., Roll, B., Caruso, J. F., Lowensteyn, I., & Perry, A. C. (1994). An electromyographical comparison of the squat and knee extension exercises. Journal of Strength and Conditioning Research, 8(3), 178-183.
Stodden, D. F., Fleisig, G. S., McLean, S. P., & Andrews, J. R. (2005). Relationship of biomechanical factors to baseball pitching velocity: within pitcher variation. Journal of Applied Biomechanics, 21(1), 44-56.
Stuart, M. J., Meglan, D. A., Lutz, G. E., S., G. E., & An, K.-N. (1996). Comparison of Intersegmental Tibiofemoral Joint Forces and Muscle Activity During Various Closed Kinetic Chain Exercises. The American Journal of Sports Medicine, 24, 792-799.
Werner, S. L., Fleisig, G. S., Dillman, C. J., & Andrews, J. R. (1993). Biomechanics of the elbow during baseball pitching. The Journal of Orthopaedic and Sports Physical Therapy, 17(6), 274-278.
Werner, S. L., Guido, J. A., Jr., Stewart, G. W., McNeice, R. P., VanDyke, T., & Jones, D. G. (2007). Relationships between throwing mechanics and shoulder distraction in collegiate baseball pitchers. Journal of Shoulder and Elbow Surgery, 16(1), 37-42.
Wilk, K. E., Escamilla, R. F., Fleisig, G. S., Barrentine, S. W., Andrews, J. R., & Boyd, M. L. (1996). A comparison of tibiofemoral joint forces and electromyographic activity during open and closed kinetic chain exercises. American Journal of Sports Medicine, 24(4), 518-527.
Wretenberg, P., Feng, Y., Lindberg, F., & Arborelius, U. P. (1993). Joint moment of force and quadriceps muscle activity during squatting exercise. Scandinavian Journal of Medicine and Science in Sports, 3, 244-225-.
Wright, R. W., Steger-May, K., Wasserlauf, B. L., O'Neal, M. E., Weinberg, B. W., & Paletta, G. A. (2006). Elbow range of motion in professional baseball pitchers. The American Journal of Sports Medicine, 34(2), 190-193.
Yu, B., Queen, R. M., Abbey, A. N., Liu, Y., Moorman, C. T., & Garrett, W. E. (2008). Hamstring muscle kinematics and activation during overground sprinting. Journal of Biomechanics, 41(15), 3121-3126.