Abstract：
BACKGROUND: Fatigue of the scapular stabilizing muscles resulting from repeated arm motion has been reported to alter scapular kinematics, which could result in shoulder pathology, especially impingement.
OBJECTIVE: This study aimed to examine the effects of fatigue of the serratus anterior muscle on scapular kinematics, specifically, decrease scapular posterior tilt and upward scapular rotation during arm elevation.
METHODS: Repeated measures.
METHODS: Laboratory.
METHODS: Thirty participants were included in the investigation.
METHODS: Scapular kinematics and shoulder strength were measured before and immediately following a serratus anterior fatigue protocol.
RESULTS: Scapular 3-dimensional position during arm elevation.
RESULTS: No difference in upward rotation of the scapula between prefatigue and postfatigue conditions (ascending: P = .188; descending: P = .798). Scapular posterior tilt decreased during arm elevation following the fatigue protocol between 60° and 90° and 90° and 120° of arm elevation during the ascent (P = .004) and the descent (P = .013). Fatigue by arm elevation angle interaction was found for clavicular elevation during the ascent (P = .050) between 90° and 120° of arm elevation. Scapular internal rotation increased during the ascent (P = .027). There was no difference in clavicular protraction between the prefatigue and postfatigue conditions (ascending: P ≤ .001; descending: P ≤ .001).
CONCLUSIONS: Fatigue of the serratus anterior decreases posterior scapular tilt and greater clavicular elevation and scapular internal rotation at higher arm elevation angles. These findings are consistent with the scapular kinematic patterns associated with shoulder pain. Improving serratus anterior endurance might delay the changes in scapular kinematics associated with repeated arm motion and shoulder injury mechanisms.
OBJECTIVE: This study aimed to examine the effects of fatigue of the serratus anterior muscle on scapular kinematics, specifically, decrease scapular posterior tilt and upward scapular rotation during arm elevation.
METHODS: Repeated measures.
METHODS: Laboratory.
METHODS: Thirty participants were included in the investigation.
METHODS: Scapular kinematics and shoulder strength were measured before and immediately following a serratus anterior fatigue protocol.
RESULTS: Scapular 3-dimensional position during arm elevation.
RESULTS: No difference in upward rotation of the scapula between prefatigue and postfatigue conditions (ascending: P = .188; descending: P = .798). Scapular posterior tilt decreased during arm elevation following the fatigue protocol between 60° and 90° and 90° and 120° of arm elevation during the ascent (P = .004) and the descent (P = .013). Fatigue by arm elevation angle interaction was found for clavicular elevation during the ascent (P = .050) between 90° and 120° of arm elevation. Scapular internal rotation increased during the ascent (P = .027). There was no difference in clavicular protraction between the prefatigue and postfatigue conditions (ascending: P ≤ .001; descending: P ≤ .001).
CONCLUSIONS: Fatigue of the serratus anterior decreases posterior scapular tilt and greater clavicular elevation and scapular internal rotation at higher arm elevation angles. These findings are consistent with the scapular kinematic patterns associated with shoulder pain. Improving serratus anterior endurance might delay the changes in scapular kinematics associated with repeated arm motion and shoulder injury mechanisms.
摘要：
背景：据报道，重复手臂运动导致的肩胛骨稳定肌肉的疲劳会改变肩胛骨运动学，这可能会导致肩部病理，尤其是撞击。
目的：本研究旨在研究前锯齿肌的疲劳对肩胛骨运动学的影响，具体来说,手臂抬高期间减少肩胛骨向后倾斜和肩胛骨向上旋转。
方法：重复措施。
方法：实验室。
方法：30名参与者被纳入调查。
方法：在前锯肌疲劳方案之前和之后立即测量肩胛骨运动学和肩关节力量。
结果：手臂抬高期间肩胛骨三维位置。
结果：疲劳前和疲劳后肩胛骨向上旋转没有差异（上升：P=.188；下降：P=.798）。在上升（P=.004）和下降（P=.013）期间，按照疲劳协议，在手臂抬高的60°和90°以及90°和120°之间，肩胛骨向后倾斜减小。在手臂抬高90°至120°的上升过程中（P=.050），发现了手臂仰角相互作用引起的疲劳。肩胛骨内旋在上升过程中增加(P=.027)。疲劳前和疲劳后条件之间的锁骨前牵引没有差异（上升：P≤.001；下降：P≤.001）。
结论：前锯齿肌的疲劳减少了肩胛骨的后倾斜和较大的锁骨抬高和肩胛骨内旋在较高的手臂仰角。这些发现与肩关节疼痛相关的肩胛骨运动学模式一致。改善前锯肌耐力可能会延迟与重复手臂运动和肩部损伤机制相关的肩胛骨运动学变化。
目的：本研究旨在研究前锯齿肌的疲劳对肩胛骨运动学的影响，具体来说,手臂抬高期间减少肩胛骨向后倾斜和肩胛骨向上旋转。
方法：重复措施。
方法：实验室。
方法：30名参与者被纳入调查。
方法：在前锯肌疲劳方案之前和之后立即测量肩胛骨运动学和肩关节力量。
结果：手臂抬高期间肩胛骨三维位置。
结果：疲劳前和疲劳后肩胛骨向上旋转没有差异（上升：P=.188；下降：P=.798）。在上升（P=.004）和下降（P=.013）期间，按照疲劳协议，在手臂抬高的60°和90°以及90°和120°之间，肩胛骨向后倾斜减小。在手臂抬高90°至120°的上升过程中（P=.050），发现了手臂仰角相互作用引起的疲劳。肩胛骨内旋在上升过程中增加(P=.027)。疲劳前和疲劳后条件之间的锁骨前牵引没有差异（上升：P≤.001；下降：P≤.001）。
结论：前锯齿肌的疲劳减少了肩胛骨的后倾斜和较大的锁骨抬高和肩胛骨内旋在较高的手臂仰角。这些发现与肩关节疼痛相关的肩胛骨运动学模式一致。改善前锯肌耐力可能会延迟与重复手臂运动和肩部损伤机制相关的肩胛骨运动学变化。
