Muscle Activity During Scapular Muscle Exercises With Multijoint Compound Movement: Analysis Using Fine-Wire and...

Area of Science:

• Biomechanics of human movement
• Exercise physiology
• Sports medicine

Background:

• Scapular muscle motor control is crucial for preventing and rehabilitating shoulder and elbow injuries in overhead athletes.
• Understanding scapular muscle activation during compound exercises informs targeted training strategies.

Purpose of the Study:

• To investigate and compare scapular muscle activity during various multijoint compound movement exercises.
• To utilize fine-wire and surface electromyography for precise muscle activation measurements.

Main Methods:

• Sixteen healthy males performed five exercises: cat and dog, trunk rotation, A-exercise, T-exercise, and Y-exercise.
• Muscle activity was quantified as %MVIC for rhomboid major (Rhom), upper (UT), middle (MT), and lower (LT) trapezius, and serratus anterior (SA).
• Muscle activity ratios (e.g., SA/UT) were calculated and analyzed using one-way ANOVA.

Main Results:

• No significant differences in rhomboid major (Rhom) activity were observed across exercises.
• Trunk rotation and Y-exercise showed significantly higher lower trapezius (LT) activation compared to cat and dog scapular retraction and A-exercise.
• Cat and dog scapular protraction and Y-exercise demonstrated significantly greater serratus anterior (SA) activity, with the former also showing a higher SA/UT ratio.

Conclusions:

• All tested exercises effectively activated the rhomboid major (Rhom).
• Trunk rotation and Y-exercises are effective for lower trapezius (LT) activation.
• Cat and dog scapular protraction effectively activates the serratus anterior (SA) while downregulating upper trapezius (UT) activity.