A stroke occurs when the blood flow in the brain is interrupted or decreased. The blood contains the oxygen supply and other nutrients that the brain cells need to function. Without it, brain cells will begin to die in just minutes and could cause neurological damage to an individual. This is the leading cause of disability among older people. Following this, several musculoskeletal complications may develop. One of them is the shoulder subluxation.
Shoulder subluxation, also known as Glenohumeral subluxation (GHS), is a very common post-stroke complication. It is a partial dislocation of the shoulder due to muscle weakness caused by a stroke.
A. The Shoulder Joint
Moreover, the shoulder joint, or glenohumeral joint is the most complicated joint of the body. It is a junction between the scapula (shoulder blade) and the humerus and connects the upper limb to the trunk. The shoulder joint has the ability to move in all planes. To achieve this, it has greater muscle stability than bone structures.
The shoulder joint is an articulation between the head of the humerus and the glenoid fossa of the scapula (shoulder blades), thus calling it the glenohumeral joint.
B. The Scapula
The scapula or also known as the shoulder blade is a triangular-shaped bone located at the upper back between the levels of the second and eighth ribs. Moreover, it is the origin of the four rotator cuff muscles namely supraspinatus, infraspinatus, teres minor, and subscapularis or SITS muscles. It has 4 processes, the spine, the acromion, the coracoid, and the glenoid.
C. The Clavicle
The clavicle is an S-shaped bone that is located on the anterior part of the shoulder girdle. It has two articulations, the sternoclavicular, which articulates with the manubrium, and the acromioclavicular joint. The clavicle also protects the subclavian artery, subclavian vein, and brachial plexus.
D. The Humeral Head
The humeral head is the proximal part of the humerus that articulates with the shallow glenoid cavity. The glenoid labrum provides additional stability since the glenoid fossa of the scapula is shallow and small.
E. Ligaments
There are 4 ligaments that play a major role in stabilizing the shoulder joint.
1. Glenohumeral ligaments (superior, middle, and inferior)
These ligaments are the main source of stability because it connects the humerus to the glenoid fossa. They help in stabilizing the anterior part and prevent anterior dislocation of the joint.
2. Coracohumeral joint
Attached to the base of the coracoid process to the greater tubercle of the humerus and supports the superior part of the joint.
3. Transverse humeral ligament
Runs in the distance of the two tubercles of the humerus to hold the tendon of the long head of the biceps.
4. Coraco–clavicular ligament.
Runs from the clavicle to the coracoid process of the scapula and works with the acromioclavicular ligament to maintain the alignment of the clavicle.
Additionally, the shoulder joint is a ball and socket joint that enables it to have movements in all planes.
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- Flexion – upper limb moving forward
- Extension – upper limb moving backward
- Abduction – upper limb moving away from the midline of the body
- Adduction – upper limb moving towards the midline of the body
- Internal Rotation – upper limb rotation that the thumb is pointing medially
- External Rotation – upper limb rotation that the thumb is pointing laterally
- Circumduction – upper limb in a circle motion
F. The Labrum
The Glenoid labrum is a fibro-cartilaginous rubbery structure that provides additional stability since the glenoid fossa of the scapula is shallow and small.
How does shoulder subluxation occur?
Shoulder subluxation, also known as Glenohumeral subluxation (GHS), is a partial dislocation of the humeral head and glenoid fossa while it is still in contact with the glenoid fossa. This is caused by the weakness of the rotator cuff muscles or laxity of glenohumeral ligaments resulting in subluxation.
Moreover, symptoms of a shoulder subluxation include pain, swelling, numbness or tingling sensation along the arm, limited or loss of range of motion, and a visibly deformed shoulder.
Fingerbreadth Palpation Method
One of the most commonly used methods in assessing shoulder subluxation is the fingerbreadth palpation method.
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How to do it:
Moreover, sit in a chair or wheelchair with both feet flat on the ground or footrest. Both shoulders must be neutrally positioned in rotation with arms hanging on the sides, and thumbs facing forward. The Physical Therapist will palpate the gap between the acromion and the humerus head on both unaffected and affected sides. With ½ fingerbreadth gap or more, shoulder subluxation is positive.
Fingerbreadth Grading Scale
| 0 | No subluxation |
| 1 | ½ fingerbreadth gap |
| 2 | 1 fingerbreadth gap |
| 3 | 1½ fingerbreadth gap |
| 4 | 2 fingerbreadth gap |
| 5 | 2½ fingerbreadth gap |
Treatment
Treatment can include the following:
- Closed Reduction – a doctor may try to attempt to maneuver it back to its position.
- Surgery – this may be done if there is damage to the nerves, blood vessels, or ligaments in the shoulder.
- Shoulder Brace – a splint, brace, or sling may be worn to prevent further injury.
- Medication – pain, and swelling may be treated with muscle relaxants and anti-inflammatory drugs.
- Rehabilitation – the goal of treatment is to improve the range of motion, strength, and stability of the shoulder joint
Physical Therapy Management
1. Passive Range of Motion Exercises
Moreover, passive range of motion is exercises done without the activation of the targeted muscles. Exercise in early rehabilitation of stroke can prevent shoulder subluxation. It prevents stiffness, helps with blood flow, and improves awareness of the arm. It can be performed on your own with the help of your unaffected arm or by another person, a Physical Therapist, or a caregiver.
A. Shoulder Flexion
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- Lie on your back on a firm bed. Interlace your fingers with your hands resting on your stomach.
- Slowly raise your arms to shoulder level, keeping your elbows straight.
- Return your hands to a resting position on your stomach.
- Do this for 10 reps. 1-2 sets.
Note: If pain occurs, it may be reduced by working within a range of motion that is relatively pain-free, then going up to the point where the pain is felt. The arm should not be forced if the pain is excessive, but effort should be made to daily increase the range of pain-free motion.
B. Shoulder Adduction
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- Lie on your back on a firm bed. Interlace your fingers with your hands resting on your stomach.
- Slowly raise your hands directly over your chest, straightening your elbows.
- Slowly move your hands to one side and then to the other.
- Do this for 10 reps. 1-2 sets.
- When all repetitions have
2. Slings/Supports
Supports such as slings and braces are used in managing shoulder subluxation following a stroke. It is used to support the weight of the arm and minimizes the downward pull in the humerus.
Takeaway
Knowledge about Hemiplegic Shoulder Subluxation could increase the chances of early recognition of the condition and can therefore prevent it or improve the outcomes of treatments.
