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Updated: Jun 20, 2026
10:07
Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact
Published on: February 10, 2015
Scapula kinematic alterations following a modified push-up plus task
John D Borstad1, Kimberly Szucs, Anand Navalgund
1The Ohio State University, Atwell Hall, Columbus, OH 43210-1234, USA. borstad.1@osu.edu
Human Movement Science
|August 18, 2009
Summary
Shoulder muscle fatigue alters scapular movement, specifically decreasing posterior tilting and increasing internal rotation. This finding suggests muscle fatigue is a risk factor for subacromial impingement syndrome.
Area of Science:
- Biomechanics
- Musculoskeletal health
- Sports medicine
Background:
- Subacromial impingement syndrome (SAIS) is linked to altered scapular kinematics and muscle activity, particularly in overhead athletes.
- Serratus anterior muscle fatigue is hypothesized to cause these kinematic changes, but direct evidence is lacking.
Purpose of the Study:
- To investigate the effects of serratus anterior fatigue on three-dimensional scapular kinematics in asymptomatic individuals.
- To determine if experimentally induced muscle fatigue leads to measurable changes in scapular motion.
Main Methods:
- Twenty-eight asymptomatic participants underwent a fatigue protocol involving isometric serratus anterior contraction.
- Three-dimensional scapular kinematics were measured before and after the fatigue task.
- Electromyography and Borg CR10 scale assessed muscle fatigue objectively and subjectively.
Main Results:
- The fatigue protocol successfully induced muscle fatigue, evidenced by decreased median power frequency and increased Borg scores.
- Significant kinematic alterations included decreased scapular posterior tilting and increased internal rotation post-fatigue.
- No significant changes were observed in scapular upward rotation.
Conclusions:
- Experimental shoulder muscle fatigue contributes to scapular kinematic alterations.
- These fatigue-induced kinematic changes are a plausible risk factor for developing subacromial impingement syndrome.
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