Scapular Stabilizers – An Often Neglected Group of Muscles
Topic at a Glance
- Scapular stabilizers are a group of muscles that support and control the movement of the shoulder blade (scapula).
- These muscles work together with the rotator cuff and deltoid to maintain proper shoulder motion and stability.
- Weak or underdeveloped scapular stabilizers can lead to shoulder pain, instability, and impingement injuries.
- Strengthening these muscles can help improve shoulder performance, posture, and injury prevention.
What Are The Scapular Stabilizers?
These muscles that surround the scapula (shoulder blade) and are along with the rotator cuff (infraspinatus, supraspinatus, teres minor, subscapularis) are crucial in maintaining normal shoulder function and biomechanics.
The muscles that make up the scapular stabilizers group are the:
- Serratus Anterior
- Trapezius muscles: Upper/Middle/Lower
- Levator Scapula
- Rhomboid
These muscles work synergistically with the deltoid and rotator cuff muscles to upwardly or downwardly rotate the scapula while the shoulder joint/arm is moving overhead, behind the back or reaching away from your trunk.
Take for example a baseball pitcher or competitive swimmer. Their shoulders rotate hundreds to thousands of times during a season and preseason. This can take quite a toll on their shoulders if they are not properly trained.
These muscles work synergistically to maintain proper scapular position and motor control with arm movements such as shoulder abduction, shoulder flexion, external/internal rotation, and shoulder extension.
The Scapular Stabilizers And Shoulder Function
The scapular stabilizers provide strength, joint stability and prevent impingement of the shoulder joint complex.
The muscles that comprise the scapular stabilizers are the:
- Serratus anterior– Which upwardly rotates the scapula.
- Trapezius – Upper fibers that elevate and upwardly rotate the scapula.
- Middle fibers – Adduct or retract the scapula.
- Lower fibers – Which depress and rotate the scapula.
- Levator Scapula and Rhomboids.
The shoulder joint complex is inherently at risk for instability. The glenohumeral (GH) joint is a ball and socket joint. The problem is that the ball or the humeral head goes into a very shallow socket of the glenoid fossa.
You will be at risk for shoulder injury if not properly supported by strong muscles – those muscles being the rotator cuff and scapular stabilizers.
Impingement can occur when the shoulder joint or glenohumeral (GH) hits the top of the scapula or acromion causing pain and inflammation.
If left untreated, it can lead to muscle inflammation or worse rotator cuff tears. Impingement can be caused by too much laxity in the GH joint or conversely an excessively stiff shoulder.
Shoulder Pain And The Scapular Stabilizers
Many of the patients that come into Paspa Physical Therapy with shoulder pain often have weak and under-developed scapular stabilizers. Clients work out the biceps, triceps, pectoralis major, and deltoid, but forget the look behind their backs. The scapular stabilizers are there and need to be exercised!
Dyskinesis or abnormal movement patterns occur leading to pain and dysfunction. In the clinic, we see many overuse injuries related to muscle weakness, not only of the rotator cuff muscles but more often of the scapular muscles.
You will find that training the scapular stabilizers will lead to improved athletic shoulder function and performance and a healthier pain-free shoulder joint.
To learn more about strengthening the scapular muscles and rotator cuff contact Paspa Physical Therapy.
FAQs About Scapular Stabilizers
What are the scapular stabilizer muscles?
Scapular stabilizers are the muscles that surround and control the movement of the shoulder blade (scapula). They help maintain proper shoulder mechanics during arm movements.
Key scapular stabilizer muscles include:
- Serratus anterior
- Trapezius muscles (upper, middle, and lower fibers)
- Levator scapulae
- Rhomboids
These muscles work together with the rotator cuff and deltoid muscles to support the shoulder joint during movements such as lifting the arm, reaching overhead, or rotating the shoulder.
Why are scapular stabilizers important for shoulder function?
Scapular stabilizers play an essential role in keeping the shoulder blade properly positioned during arm movement. This helps maintain proper alignment in the shoulder joint and allows smooth motion.
Their main functions include:
- Stabilizing the shoulder blade
- Supporting arm movement overhead or behind the back
- Improving shoulder strength and control
- Reducing stress on the shoulder joint
Without proper stabilization, the shoulder joint can become unstable or prone to injury.
What problems can occur when scapular stabilizers are weak?
Weak or poorly functioning scapular stabilizers can lead to abnormal shoulder movement patterns, known as scapular dyskinesis. This can cause several problems, including:
- Shoulder pain
- Reduced range of motion
- Shoulder impingement
- Rotator cuff irritation or tears
- Decreased athletic performance
Many shoulder injuries occur when the shoulder blade does not move correctly during arm motion.
Who is at risk for scapular stabilizer weakness?
People who frequently perform repetitive shoulder movements are more likely to develop weakness or imbalance in these muscles.
Common at-risk groups include:
- Athletes, such as baseball pitchers or swimmers
- Weightlifters who focus only on chest and arm muscles
Targeted exercises can help correct these imbalances.