Subacromial Impingement and bursitis can cause severe pain in your shoulder and upper arm. Bursitis is the inflammation of the bursa, the fluid-filled sac found between different tissues of a joint and acts as a cushion. It helps in the smooth gliding motion of the various joint elements.

The subacromial bursa is present below the acromion process of the scapula (the shoulder bone) and above the greater tubercle of the humerus (the arm bone). It helps to reduce the friction in the space under the acromion process.

Subacromial impingement syndrome (SAIS) is the inflammation of the rotator cuff tendons resulting due to repeated irritation of the tendons as they pass through the subacromial space, accommodating the bursa.

SAIS umbrellas a range of interlinked conditions. These include rotator cuff tendinosis, sub-acromial bursitis, and calcific tendinitis. All these conditions result in slow wear and tear of the joint elements lying between the coracoacromial arch and the supraspinatus tendon or subacromial bursa.

Subacromial impingement represents 60% of all the causes of shoulder pain.

Anatomy of the subacromial space

The sub-acromial space lies below the coracoacromial arch of the scapula and above the head and greater tuberosity of the humerus.

The subacromial space accommodates the rotator cuff tendons, the long head of the biceps tendon, and the coracoacromial ligament. These are all surrounded by the subacromial bursa, which acts as a cushion and helps to reduce friction between these structures.

Causes of subacromial bursitis

Some extrinsic and intrinsic causes are related to the subacromial impingement syndrome. Any factor that cuts back the sub-acromial space leads to friction between the joint structures.

The intrinsic ones are usually the disease processes involving the rotator cuff tendons;

• Muscular weakness
• Overuse of the shoulder affects the soft tissue inflammation of the rotator cuff tendons and the subacromial bursa
• Degenerative tendinopathy as it happens in tearing of the rotator cuff

Extrinsic factors often involve the pathologies of the rotator cuff tendons caused by external compression. These include;

• Anatomical factors affecting the shape of the acromion
• A fault in the function of the scapular muscles (typically, the muscles allow the humerus to move past the acromion on overhead extension) leaves little space to move in the subacromial area.
• Any abnormality affecting the glenohumeral joint or weak rotator cuff muscles results in superior subluxation of the humerus, causing an increased contact between the acromion process and the tissues lying below it.

Bursitis of the sub-acromial bursa often develops as a secondary condition to injury, sub-acromial impingement, overuse of the muscle, or calcium deposits.

Some other causes of subacromial bursitis include;

• Trauma to the bursa
• Inflammation of the subacromial joint
• Overload and overuse of the shoulder cause chronic irritation and friction between the bursa and a tendon, bone, or ligament.
• Muscle weakness of the upper extremity
• Degeneration of muscle tendons
• Inflammation of the adjacent supraspinatus tendon
• Instability of the glenohumeral joint
• Degeneration of the acromioclavicular (AC) joint
• Injury and tears of the rotator cuff muscles
• Impingement by the coracoacromial ligament and coracoid

Signs and symptoms of subacromial impingement and bursitis

The most common symptom of subacromial impingement is pain which is;

• Progressive in nature
• Located in the superior anterior part of the shoulder
• Relieved by rest and exacerbated by abduction in the affected shoulder
• Associated with weakness and stiffness of the joint

Two signs are positive in SAIS;

• Neers Impingement test
• Hawkins test

Subacromial bursitis also presents with pain which;

• Develops gradually but is persistent (longer for one month but less than a year)
• Typically affects the lateral or anterior shoulder
• May refer to the elbow
• Is associated with a single traumatic event
• Is often worse at night and aggravated by sleeping on the affected side
• Is accompanied by discomfort and pain with overhead lifting or reaching activities
• May cause muscle weakness and local tenderness and crepitus accompany the pain

Treatment of the subacromial impingement and bursitis

Subacromial impingement and bursitis are usually treated conservatively with medicine, rest, and rehabilitation.

Education about proper warm-up and cool-down should be emphasized.

Some newer therapies include botox injections to relax the muscles and ease the pressure of the joint and bursa. These are fair options where corticosteroid is contraindicated, or long-term steroid therapy needs to be avoided.

Bursitis is often secondary to another condition, so treating the underlying cause is essential. Surgery is only opted when conservative treatment fails to bring relief, at least about after six months.

1. Immediately after the injury to the first week
   1. RICER

Rest your arm and shoulder as soon as you apprehend the injury. Apply a cold compress. Compression can be applied if swelling is present. Elevating the arm will cause pain, so immobilize the arm near your body. In case the pain worsens, consult with a specialist.

• Medication

Oral over-the-counter medication help relieve the pain and inflammation associated with injury.

For severe cases, analgesic and corticosteroid injections can be used. Bursitis is a painful condition and may require injection. An injection may be given in the muscle or the bursa; either route is effective. The ultrasound-guided injection is a more precise way to locate the bursa at the spot.

In case of inflammatory bursitis due to infections, an antibiotic injection can also be given into the joint.

• TENS

In the absence of any apparent injury and mild cases where the condition improves after a week or so, the application of TENS helps to relieve any lingering pain in the shoulder. Make sure to seek professional help if you do not know where to place the electrodes of the TENS device.

• After the first few weeks

1. Massage

When the injury has resolved, massage therapy should be started. Massage helps to relieve any pain, speeds up the healing process, and strengthens the muscles. However, massage may not help all cases of shoulder pain. It must be avoided in frozen shoulder and other inflammatory conditions.

Different techniques are used to rehabilitate the shoulder joint and ease off the pressure of the bursa. All of them increase the local temperature and blood circulation. In addition, it helps in the removal of the waste from the injury site and replenishing nutrient stores.

A direct message to the bursa would make the symptoms worse. However, massaging the rotator cuff muscles helps ease the pressure on the bursa and helps alleviate the bursitis symptoms.

Massage in case of subacromial impingement helps break down the scar tissue, release adhesions, reduce the chances of further impingement, increase joint flexibility and prevent additional injuries.

Techniques used for subacromial impingement include;

• Sports massage; increases the range of motion for athletes carrying out overhead shoulder movements. It involves gentle stretching techniques besides correcting muscle dysfunction.
• Trigger point therapy; trigger points are created in shoulder impingement which can cause lingering pain. It involves sustained pressure on the spots to release the tension in the muscle, thereby preventing recurrence.
• Myofascial massage; a soft tissue massage that treats skeletal muscle pain and stiffness by applying gentle pressure or sustained stretching to the shoulder joint and upper arm.

• Therapeutic ultrasound

Ultrasound therapy for about eight minutes helps relieve the shoulder pain in sub-acromial impingement. The treatment also benefits the flexibility and range of motion in cases of sub-acromial impingement.

Ultrasound therapy has its share of benefits in subacromial bursitis, but such a treatment should be employed once the inflammation has resolved.

• Active rehabilitation

Codman's pendulum exercises and those involving an active-assisted range of motion (AAROM exercises) should be taken up in the acute phase of the impingement and bursitis. They keep the joint in motion, prevent stiffness, and speed recovery.

Shoulder exercises in conjunction with an ultrasound-guided injection to treat sub-acromial bursitis effectively relieve pain as short and medium-term therapy.

Once the condition starts to stabilize, a therapist should design a customized program that includes strengthening and stretching the shoulder joint and muscles. Patients are taught ways to move the shoulder in such a way as to avoid inflammation and injury.

Some exercises for rehabilitative therapy include;

Table Slides (Flexion)

• Stand in front of a table facing it and place your hand on the table.
• Place a towel under your hand.
• Start stretching your arm in a forward direction by sliding the table.
• Stretch as far as it is comfortable for you.
• Repeat at least twenty to thirty times.

Scapular wall slides

• Stand at about two feet away from a wall.
• Make a plank position against the wall. The two-foot distance from the wall will allow you to make the plank at an angle with the wall.
• The plank position will keep your arms abducted at 90 degrees and elbows flexed at 90 degrees as well. Keep the elbows fixed to the wall.
• Keep your back straight and push through your elbows into your shoulder region.
• Now start sliding your injured side so that your arm moves upwards as far as you are comfortable.
• Do not bend your back during this exercise, and do not flex your neck. It will strain the neck otherwise.
• Slowly return to the starting position and switch sides or repeat on the same side. Do at least 12 reps.

Upper Trap (UT) Stretch

• Sit on a chair.
• Grab the chair using the hand of the affected side.
• With your other hand, grab your head and pull your head to the opposite side in a gentle stretch.
• Keep looking forward, do not bend your head downwards.
• Hold the stretch for thirty seconds and release slowly.
• Repeat two to three times and also switch sides.

Book Stretch

• Lie on the right side with both arms extended fully and resting on the floor. The arms should be at shoulder height.
• Keep your right leg straight on the ground while the left hip and leg should be bent at 90 degrees. The left knee should be resting on the floor.
• Now bring your left hand back to the opposite side to reach out on the other end (just as opening a book).
• Ensure that your right arm and left knee resting on the floor should keep touching the floor. This will ensure all the movement is being done at the left shoulder joint.
• As you move your left hand and arm back, move your head along with the arm simultaneously.
• Hold the stretch for a few seconds.
• Return to the starting position.
• Repeat at least three times.
• Surgery

Arthroscopic surgery is taken up in patients with a reduced range of motion. It involves;

• Surgical repair of the muscle tears (usually in the supraspinatus and long head of biceps tendon) to increase the range of motion
• Bursectomy or Surgical removal of the subacromial bursa to increase the subacromial space
• Acromioplasty or surgical removal of a section of the acromion process

Prevention of subacromial impingement and bursitis

• Proper warm-up before exercising, sports, or any other repetitive movements
• Start new exercises slowly and allow a gradual increase in the intensity.
• While doing repetitive tasks, take breaks.
• Practice good posture and adopt proper alignment when doing daily activities.
• Train the rotator cuff muscles along with the deltoid muscle. It helps to keep the strength around the shoulder in balance.