One of the most essential components of testing the shoulder or addressing any dysfunction in the neck, upper back, and arms is shoulder flexion.
The shoulder complex is the link between the arms and trunk, which means that imprecise motion in the shoulder can have implications in the neck, upper back, and down the arm.
7 Elements of Proper Shoulder Flexion
There are a few key elements to watch for during shoulder flexion, specifically bilateral shoulder flexion (raising both arms in front of you over head). Faulty motion or position in any of these areas can lead to shoulder pain with overhead motions.
- Acromion Position
- Scapular Position – Rotation and Tilt
- Scapulohumeral Rhythm
- Inferior Angle of Scapula
- Glenohumeral Creases
- Glenohumeral Rotation
- Shoulder Range of Motion
In order to accurately assess someone’s movement pattern with shoulder flexion, a consistent cue should be given. Here’s a basic cue for bilateral shoulder flexion:
“Start with your arms at your sides. Lead with straight arms, raising your arms forward in an arc overhead.”
This will show you their preferred pattern, which may need corrections. Cues for corrections should be based on the key elements listed above. The specific findings and corrections for each element are listed below.
1. Acromion Position
The acromion should elevate slightly with shoulder flexion just after the first 30˚ in the range of arm elevation. The acromion should not depress during the first 90˚ of arm elevation.
At the end range, the acromion should be aligned with C6-7.
2. Scapular Position
During shoulder flexion, the scapula should: upwardly rotate, posteriorly tilt, and externally rotate slightly at end range. Watch that these motions occur without too much adduction or abduction.
Upward Rotation of the scapula– The vertebral border of the scapula should upwardly rotate about 60˚ relative to the spine.
Posterior Tilt of the scapula – The scapula should posteriorly tilt about 10˚ at end range shoulder flexion.
External Rotation of the scapula – The scapula should externally rotate at end range, positioning it 10-20˚ anterior to the frontal plane. (The scapula starts in about 30-40˚ of internal rotation, so with flexion it externally rotates about 20˚, which means that it is still in a position of internal rotation, even after it externally rotated during flexion.)
Scapular Abduction and Adduction – Normal scapular position at end range shoulder flexion is about 3” from the vertebral spine to the root of the spine of the scapula.
Excessive Abduction is greater than 3.5” at end range shoulder flexion.
Excessive Adduction is less than 2.5” at end range shoulder flexion.
3. Scapulohumeral Rhythm
The arm and scapula should move at a 2:1 ratio. Monitor the rhythm by tracking the degrees of humeral flexion as well as the upward rotation of the scapula.
Scapular upward rotation can be monitored by placing your hand on the inferior angle of the scapula as shoulder flexion is performed.
4. Inferior Angle of the Scapula
In normal shoulder flexion, the scapula should move so that it’s inferior angle reaches the midaxillary line by end range arm elevation.
5. Glenohumeral Creases
Monitoring the symmetry of the glenohumeral creases can show you if one joint is moving differently than the other.
6. Glenohumeral Rotation
With shoulder flexion, the Humerus should laterally rotate about 60˚ during the motion. Cues may be provided to lead with the thumb pointed to the ceiling.
7. Shoulder Range of Motion
Normal shoulder flexion is about 170˚. Viewing shoulder flexion from the side, it may be noted that the clavicle retracts about 16˚ and elevates about 10˚.
Correcting Scapular Motion
It’s important to see the natural motion of someone’ shoulder flexion before providing specific cues. Make sure to monitor the motion slowly. Corrective cues may include:
Slightly shrug your shoulders when your thumb reaches the level of your nose. (This assists with acromion elevation and upward rotation.)
Lead with the thumb pointed to the ceiling (this encourages humeral lateral rotation)
Manually assist the scapula if it does not upwardly rotate. Ask if this assistance helps alleviate any symptoms. (This provides a cue that the scapular upward rotators need to be strengthened.)
The simple motion of shoulder flexion can tell us a lot if we pay attention. Precise motion is the key to pain free motion and making small corrections to this basic movement pattern can make a big difference.