The Shoulder Lever Test - Technical Tip for Instability Assessment in Large Shoulders

Area of Science:

• Orthopedics
• Biomechanics
• Sports Medicine

Background:

• Classical shoulder instability tests like the load and shift and drawer tests involve gripping the humeral head.
• Accurate assessment of glenohumeral joint translation can be difficult in obese individuals and muscular athletes due to anatomical challenges.

Observation:

• The shoulder and upper arm function as a Class 3 lever system.
• Utilizing the elbow as a fulcrum and applying translational force to the humerus leverages mechanical advantage.
• This allows for maximal displacement at the glenohumeral joint with minimal applied force.

Findings:

• The shoulder lever test bypasses the need to grip the humeral head.
• This method enables accurate judgment of glenohumeral joint translation in challenging patient populations.
• The modified Hawkins scale can be used to grade the observed translation.

Implications:

• The shoulder lever test enhances the clinical yield of instability assessments in obese and muscular individuals.
• This technique provides a more reliable method for diagnosing glenohumeral joint instability.
• Improved diagnostic accuracy can lead to more effective treatment strategies for shoulder instability.