肩關節伸展與肌力訓練介入對盂肱關節內旋活動度缺損之棒球選手生物力學上的效益

Effects of Shoulder Stretching and Strength Training Program on Pitching Biomechanics in Baseball Players with Glenohumeral Internal Rotation Deficit

江育任(Yu-Jen Chiang)

指導教授 ： 周伯禧

高雄醫學大學/醫學院/運動醫學系碩士班/碩士(2016年)

摘要

背景：棒球選手的運動傷害常和反覆投擲動作有關。過肩 (Overhead) 運動員在成長的過程中，因長期的練習和比賽，可能出現上肢關節與軟組織的代償機轉，造成投擲臂 (Throwing arm) 肩關節外旋角度變大而內旋角度變小的現象，而形成盂肱關節內旋活動度缺損 (Glenohumeral Internal Rotation Deficit；GIRD)。研究指出GIRD可能改變投球運動模式的動力鏈能量傳遞，而增加棒球選手肩關節唇 (SLAP)、旋轉肌 (Rotator Cuff) 與肘關節內側韌帶 (UCL) 損傷的風險。近期有關GIRD的研究中，皆證實後側肩關節囊伸展能改善盂肱關節內旋不足問題，而對於過肩運動員來說，除了有良好的肩關節活動度外，必須兼具動態時的穩定性。然而，目前仍缺乏生物力學相關研究探討伸展或伸展搭配肌力訓練後，對過肩運動員肩、肘關節之影響。
目的：本研究目的為探討單獨介入伸展或是伸展搭配肌力訓練計畫，對於 GIRD 族群投手其盂肱關節活動度、最大自主等長收縮肌力和投擲生物力學之影響。
研究方法：本研究共收錄了20位GIRD族群之投手，隨機分為伸展組 (Stretch group；S-group) 將介入每日伸展計畫；與伸展兼肌力訓練組 (Stretch & strength group；SS-group) 將介入每日伸展計畫與每週至少四天的肌力訓練計畫，兩組計畫皆須執行長達12週；並於開始執行計畫前與12週結束時，進行盂肱關節活動度、最大自主等長收縮肌力和投擲動作分析之測量。統計方法使用獨立樣本t檢定 (Independent-samples t-test) 比較組間基本資料和執行計畫後變化量之差異；兩組前 (Pre-test) 與後 (Post-test) 測之參數則使用配對t檢定 (Paired t-test) 進行分析，設P < 0.05達到統計上顯著差異。
研究結果：盂肱關節活動度方面，兩組於投擲側內旋 (IR) 活動度皆有顯著上升，和GIRD (NTIR-IR) 值皆顯著下降。肩關節最大自主等長收縮肌力 (MVIC) 方面，S-group於伸展肌、棘上肌、中斜方肌、下斜方肌和菱形肌的 MVIC 皆有達到顯著上升；SS-group於伸展肌、內收肌、中斜方肌、下斜方肌和菱形肌的MVIC皆有達到顯著上升，而SS-group下斜方肌MVIC的上升顯著優於S-group。投擲動作之運動學的部分，在前導腳著地 (FC) 時S-group於肩關節水平外展角度 (Horizontal abduction) 有達顯著上升，而SS-group肩關節外旋 (External rotation) 增加顯著優於S-group。在手臂後拉時期 (AC) 兩組肩關節最大水平內收角度 (Max horizontal adduction) 皆有達到統計上升，而SS-group於最大伸直角速度 (Max extension angular velocity) 有達顯著上升。最大肩關節內旋 (MIR) 時S-group於肘關節屈曲角度 (Flexion) 有顯著增加。投擲動作之動力學的部分，在AC時SS-group於肩關節內旋力矩 (Internal rotation torque) 和肘關節前側力 (Anterior force) 皆有顯著上升，並在內旋力矩顯著優於S-group。在AA時S-group於肩關節近端軸向力 (Proximal force) 有達顯著下降。在手臂減速時期 (AD) S-group於肩關節近端軸向力有達顯著下降，而肘關節屈曲力矩 (Flexion torque) 有達到顯著下降；SS-group於肩關節內旋力矩、後側力 (Posterior force)、下側力 (Inferior force) 皆有達到顯著上升，並於下側力增加顯著優於S-group。
結論：本研究為首例嘗試，針對GIRG族群制定了一套簡單而便利的自我伸展課程，不僅增加盂肱關節內旋角度並改善GIRD的現象，也提高了投擲過程中肩關節的流動性，更重要是能夠降低肩關節上盂唇前後側撕裂 (Superior Labrum Anterior Posterior；SLAP) 的風險。此外，伸展並不會因為合併肌力訓練而影響其效果，並且可以透過搭配肌力訓練，提高加速時期投擲的效益，並增加肩關節後側肌力，來保護減速時期的盂肱關節。最終，還是建議能夠透過伸展合併肩關節肌力的訓練來增加肩關節後側肌群的力量和控制能力，來平衡這減速負擔，以預防肩關節受傷的風險。

關鍵字

盂肱關節內旋活動度缺損 ； 肩關節 ； 投擲生物力學 ； 傷害預防

並列摘要

Background：Most baseball injuries result from repetitive throwing movement. Because of chronic practicing and participating in games, many overhead athletes developed decreased shoulder rotation angle of the throwing arm during the adolescent years, which is described as Gleno-Humeral Internal Rotation Deficit (GIRD). Epidemiologic studies reported overhead athletes with GIRD have higher risk of Superior Labrum Anterior to Posterior Lesion (SLAP), partial tear of the rotator cuff, and Ulnar Collateral Ligament (UCL) tear. In recent GIRD studies have proved that stretching posterior shoulder capsule can improve the problem of GIRD. To overhead athletes, they should not only possess suitable range of movement, but with dynamic stability. However, there is very little biochemical relative information on the effect of stretch or stretch combing strength training on overhead athletes’ shoulders and elbows.
Purpose：The purpose of this study is to investigate the effect of stretch or stretch combing strength training program on ROM of Gleno-Humeral Joint, maximal voluntary isometric contraction and throwing biochemistry.
Method：Twenty pitchers with GIRD were recruited in this study. These subjects were randomly divided into two groups, Stretch group: S-group and Stretch & strength group: SS-group. The intervention of everyday stretching program and at least four times a week strength training program were conducted for 12 weeks. ROM of Gleno-Humeral Joint and maximal voluntary isometric contraction were tested before and after the training programs. The pitching motion before and after the 12-week training programs was also analyzed. Independent-samples t-test was used to compare the differences between the basic information of two groups (S-group and SS-group), and was also used to compared the differences before and after the 12-week training programs. Paired t-test was used to analyze the value of Pre-test and Post-test. Assume p-value= 0.05 as significant level.
Results：There were significant increase in the ROM of internal rotation and significant decrease in GIRD (NTIR-IR). Regarding to MVIC data, there were significant increase in extensor, supraspinatus, middle trapezius, lower trapezius and rhomboid of S-group; there were significant increase in extensor, supraspinatus, middle trapezius, lower trapezius and rhomboid of SS-group. The increase of lower trapezius MVIC in SS-group is significantly greater than in S-group. The kinematics of pitching motion analysis found that there were significant increase in shoulder horizontal abduction of S-group at FC. Also at FC, the increase of external rotation in SS-group is significantly greater than in S-group. At AC, max horizontal adduction of both groups both reached statistical increase. There were significant increase in max extension angular velocity of SS-group。At MIR, there were significant increase in elbow flexion of S-group. Kinetics of pitching motion analysis showed that there were significant increase in internal rotation torque and anterior force of SS-group at AC, and was increase significantly greater than S-group in internal rotation torque. There were significant decrease in proximal force of S-group at AA and at AD. There were significant decrease in flexion torque of S-group at AD. There were significant increase in shoulder internal rotation, posterior force and inferior force of SS-group, and the increase of shoulder inferior force is significantly greater than S-group.
Conclusion：This study is the first example that attempt to carry out a convenient self-conducting stretching program aiming for GIRD population. Not only does it increase the internal rotation in glenohumeral joint to improve GIRD, but it also raise the fluency of shoulder during pitching. The most important of all is that it can decrease the risk of Superior Labrum Anterior Posterior (SLAP). Besides, the effects of stretching do not affect by combining it with strength training program. With the addition of strength training, it can be more beneficial to AA, and increase the strength of posterior shoulder to protect glenohumeral joint during AD. All in all, this study suggests that combining strength training and stretching to increase strength and controllability of posterior shoulder muscle group can balance out the burden during AD, which can cut down the risk of shoulder injuries.

並列關鍵字

GIRD ； Shoulder ； Pitching Biomechanics ； Injury Prevention

參考文獻

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