Related Experiment Videos
Normal and abnormal motion of the shoulder
The Journal of Bone and Joint Surgery. American Volume
|March 1, 1976
Summary
This study analyzed shoulder motion using roentgenographic parameters in healthy individuals and patients. Abnormal shoulder mechanics and pain were linked to deviations in glenohumeral-scapulothoracic movement ratios and humeral head excursion.
Area of Science:
- Orthopedics
- Biomechanics
- Radiology
Background:
- Shoulder joint motion is complex, involving coordinated movements of the scapula and glenohumeral joint.
- Understanding normal shoulder kinematics is crucial for diagnosing and managing shoulder pathologies.
Purpose of the Study:
- To determine roentgenographic parameters of shoulder motion in normal and abnormal shoulders.
- To assess the relationship between specific motion parameters and shoulder pain or injury.
Main Methods:
- Twelve normal subjects and fifteen patients underwent roentgenographic analysis of shoulder motion.
- Measurements included scapular movement, arm angle, glenohumeral angle, scapulothoracic angle, humeral head excursion, and instant center of motion.
Main Results:
- The scapula externally rotated with abduction, and the glenohumeral to scapulothoracic movement ratio was approximately 5:4 after 30 degrees of abduction.
- In normal subjects, average humeral head excursion was <1.5 mm. Abnormal excursion and instant center values correlated with previous injury.
- An abnormal glenohumeral-to-scapulothoracic ratio was associated with significant shoulder pain.
Conclusions:
- Roentgenographic parameters of shoulder motion are sensitive indicators of normal and abnormal joint mechanics.
- These parameters show potential for diagnostic clinical application in evaluating shoulder conditions.