Search GoToMy Page	Functional Anatomy The shoulder joint is a ball and socket joint formed between the head of the humerus (arm bone) and the scapula (shoulder blade). The important parts of the shoulder are:- Glenohumeral Joint - The joint between the head of the humerus and the glenoid (socket) of the scapula. The humeral head is covered by cartilage over 2/3 of its surface and  articulates with the shallow cup of the glenoid. Joint Capsule - flexible sac around the joint allowing a wide range of movements. The capsule keeps in place the lubricating synovial fluid. Sub-acromial Space - the space between the top of the humeral head and the acromion. If this space is narrowed for any reason, then the top of the humeral head (greater tuberosity) may catch on the acromion and the coraco-acromial ligament. This produces the clinical picture of impingement with a Painful Arc on examination. Acromio-clavicular Joint - the joint between the acromion and the outer end of the clavicle (collar bone). Sterno-clavicular Joint - the joint between the sternum (breast bone) and the inner end of the clavicle. Rotator Cuff Muscles - muscles which operate the shoulder. To demonstrate shoulder movements, stand with your arm hanging loosely by your side, with your palm against the side of your thigh:- Flexion - move your arm forwards. Extension - move your arm backwards. Abduction - move your arm away from your side. Adduction - move your arm towards your side. Internal Rotation - rotate your arm so that your palm faces backwards. External Rotation - rotate your arm so that your palm faces forwards. Compound movements - many movements of the shoulder and arm involve combination of the above movements:- Putting your hand between your shoulder blades - abduction, then internal rotation, then extension. Putting your arm behind the back of your head - abduction, scapular protraction (see below), then external rotation. Scapulo-thoracic Joint - the articulation between the scapula and the back part of the rib cage. It is not really a joint in the true sense as there is no articular surface between two bones. Its movements are controlled by the peri-scapular muscles. The scapula has the following movements:- Protraction - the scapula glides forwards around the rib cage e.g. place both palms against the wall in front of you and feel the stretch in your shoulder blades. Retraction - the scapula glides backwards around the rib cage e.g. try to make your shoulder blades touch each other.  Rotation - the scapula rotates so that the inside top edge moves towards the midline, while the bottom corner moves outwards e.g. put your hand in the air and try to touch the ceiling. Supraspinatus Tendon Anatomy Supraspinatus is one of the rotator cuff muscles and contributes to the first 15 degrees of shoulder abduction (moving the arm away from the side). The belly of the muscle lies above the spine of the scapula. The tendon runs under the acromion where it is separated from it by the subacromial bursa (lubricating fluid sac). It attaches to the front of the greater tuberosity of the humeral head. See Trigger Point Map for the location of common Supraspinatus muscle trigger points. Supraspinatus Tendinitis - is the most common tendon lesion of the shoulder. Causes - overuse in a degenerated supraspinatus tendon. May be associated with chronic subacromial bursitis. Clinical Findings - History of relapses and remissions of shoulder pain. Examination reveals pain on resisted abduction. There is usually a painful arc during active shoulder abduction between 60-120 degrees when the tendon is compressed between the tuberosity of the humerus and the acromion. Maximum tenderness can be over one of four sites (see diagram above). Treatment / initial rest, analgesics, LA/Steroid Injection . Prevention / strong muscles are less prone to sprains / see Exercises. Complications Incomplete Tendon Rupture / the tendon may become frayed by constant rubbing under the acromion. More common in the elderly, and in sportsmen who overuse the shoulder. Calcification common in the elderly. Produces the same symptoms as for tendinitis. An Arthrogram and MRI scanning may confirm the diagnosis. Surgical repair is usually performed in younger athletes. Complete Tendon Rupture Causes - more common in the elderly with long standing degenerative changes (calcification on x-ray). May hear a sudden snap. Clinical Findings - Loss of active shoulder abduction, the patient compensating by upwards shrugging of the shoulder. No pain on passive abduction, no painful arc. Resisted movements reveal painless weakness of abduction. Treatment - Tendon repair, tendon relocation, subacromial decompression mainly in younger patients. Biceps Tendon Anatomy The biceps muscle has two parts (short head and long head), and contributes to flexion of the elbow and shoulder, as well as supination of the forearm (turning your palm upwards). The short head originates from the coracoid process (see x-ray picture at the top of the page). The long head originates from the top of the glenoid process, its tendon running in front of the shoulder joint under the transverse humeral ligament, and then passing through a groove in the front of the humerus (bicipital groove). The two biceps muscles join together to form a tendon which attaches to the top of the radial bone in the forearm (radial tuberosity) and the biceps aponeurosis. Bicipital Tendinitis - is the second commonest tendon lesion in the shoulder. Causes - Overuse in a degenerated tendon causes inflammation of the tendon sheath where the long head travels in the bicipital groove. Clinical Findings - Patients often complain of recurrent anterior shoulder pain which may also radiate down the front of the arm. Pain is reproduced during examination by resisted arm flexion, and also by resisted forearm supination. The tendon and tendon sheath are usually very painful to palpation at the level of the bicipital groove. Treatment / initial rest, analgesics, injection of LA/steroid  around the tendon sheath in the bicipital groove , and tendon transfer surgery in resistant cases. Prevention / strong muscles are less prone to sprains / see Exercises. Complications Complete Tendon Rupture - rupture of the long head of biceps tendon is not uncommon in the elderly, and occurs after lifting heavy objects or falls on the out stretched arm. May be associated with a snapping sound. After the initial bruising has settled, the patient may notice a lump in the biceps region (contracted muscle belly of the long head). which becomes exaggerated by elbow flexion. As the short head of biceps remains in tact, the patient does not normally note any change in functional ability. Surgical repair is not normally indicated. Tendon Subluxation - Shoulder trauma (rugby tackle) can lead to rupture of the transverse humeral ligament, allowing the tendon to slip out of the bicipital groove, causing a sudden painful click in the front of the shoulder joint. Subluxation is often provoked by certain arm positions e.g. serving for tennis. Surgical reconstruction of the ligament is the treatment of choice. Infraspinatus Tendon Anatomy Infraspinatus is one of the rotator cuff muscles and contributes to external rotation of the shoulder joint. The belly of the muscle lies below the spine of the scapula. Its tendon runs over the back of the shoulder joint, fastening to the back of the greater tuberosity of the head of the humerus. See Trigger Point Map for the location of common Infraspinatus muscle trigger points. Infraspinatus Tendinitis - is a less common tendon lesion in the shoulder. Causes - Overuse of the shoulder (sportsmen and labourers) usually in the form of excessive external rotation movements. Clinical Findings - Pain and tenderness over the head of the humerus, or at the junction between the tendon and the muscle, reproduced by resisted external rotation during examination. Pain may radiate down the back of the arm to the elbow, and sometimes to the fingers. Treatment / initial rest, analgesics, LA/steroid injection . Prevention / strong muscles are less prone to sprains / see Exercises. Complications Complete tendon rupture - is associated with pain over the posterior aspect of the shoulder, painless weakness of resisted external shoulder rotation, and eventual wasting of the infraspinatus muscle. Subscapularis Tendon Anatomy Subscapularis is one of the rotator cuff muscles, contributing to internal rotation of the shoulder joint. The belly of the muscle lies between the scapula and the posterior ribs, attaching to the under surface of the scapula. Its tendon attaches to the humeral head between the lesser tuberosity and the bicipital groove (see right). See Trigger Point Map for the location of common Subscapularis muscle trigger points. Subscapularis Tendinitis - a not uncommon tendon lesion of the shoulder. Causes - Overuse of the shoulder usually in the form of excessive internal rotation movements. Clinical Findings - Pain and deep tenderness in the anterior shoulder near to the lesser tuberosity of the humerus, reproduced by resisted internal rotation during examination. Treatment / initial rest, analgesics, LA/steroid injection . Prevention / strong muscles are less prone to sprains / see Exercises. Complications - none. Subacromial Bursitis Anatomy  A bursa is a synovial lined sac containing synovial fluid for lubrication, whose function is to prevent excessive friction between two anatomical structures during movement. Excessive movement / trauma to a bursa causes acute inflammation and pain. The subacromial bursa lies between the acromial arch / coraco-acromial ligament and the supraspinatus muscle / tendon, and prevents excessive friction during shoulder abduction. Part of the bursa also lies underneath the deltoid muscle.  Subacromial bursitis rarely occurs in isolation, and is often associated with supraspinatus tendinitis, subacromial impingement, and rotator cuff tears. Clinical Findings Pain in the shoulder, associated with a painful arc during active and passive shoulder abduction movements. Treatment Initial rest, analgesics, Subacromial LA/steroid injection . Subacromial Impingement Anatomy Impingement occurs when the greater tuberosity of the humerus catches underneath the acromial arch / coraco-acromial ligament. Certain shapes of acromion and bony spurs underneath the acromion are more likely to cause impingement. Commonly associated with subacromial bursitis, supraspinatus tendinitis, and rotator cuff tears. Clinical Findings Pain in the shoulder, associated with a painful arc during active and passive shoulder abduction movements. Pain on resisted movements depending on which tendon is inflamed. Investigations X-rays to reveal calcification and an abnormally shaped acromion. MRI scans are also useful. Treatment Subacromial LA/steroid injection . Surgery - arthroscopic subacromial decompression and repair to the rotator cuff - usually done at the same time. Adhesive Capsulitis Adhesive Capsulitis, also known as Frozen Shoulder, is a condition where the capsule of the shoulder joint becomes inflamed, thickened and contracted, leading to severe pain and restricted movements. The exact cause is unknown, but is more common in middle aged females, and in those where there has been prolonged immobilisation of the shoulder or arm after :- Trauma. Neurological conditions like Hemiplegic Stroke, Parkinson's Disease. Cardiac and Thoracic surgery. Myocardial Infarction (heart attack). Clinical Findings - Symptoms are similar to those of osteoarthritis of the shoulder i.e. pain stiffness and restricted movements. The onset may be gradual or sudden, and may develop in one shoulder followed by the other after a variable period of time. Capsulitis usually has 4 phases, and  during each there may be differing degrees of pain, stiffness, and movement restriction. Stage 1 - Pain in the shoulder made worse by movement. No noticeable stiffness. Stage 2 - Progressive worsening of the pain, disturbing sleep, associated with an inability to lie on the affected side. Pain reproduced by movement and jarring the shoulder. Progressive increase in stiffness, leading to severe functional impairment of the shoulder. Stage 3 - There is very little pain at rest, but sudden movements may still be painful. This stage is where the term "Frozen Shoulder" applies to. with pronounced shoulder stiffness in all directions due to adhesions and contraction of the shoulder capsule. Secondary wasting of shoulder muscles is common at this stage.  Stage 4 - Gradual resolution of the stiffness, with gradual return of shoulder mobility in most patients. Treatment Stages 1 and 2 / Rest is important in these stages as physical therapy often provokes severe pain. Avoid repetitive shoulder movements. Those in stage 2 may need to rest the arm in a sling. A series of Shoulder Injections via the posterior route has been shown to reduce pain and inflammation ,and to also help facilitate rehabilitation. See Analgesic Flow Chart for analgesic advice. Stages 3 and 4 - Physical therapy is appropriate for these stages as the main problem is stiffness and not pain. Therapy can be facilitated by an intra-articular joint injection (see above), with the emphasis here on pain relief during treatment, rather than exerting an anti-inflammatory effect. I usually combine the injection with firm stretching movements immediately afterwards to achieve a rapid improvement in the range of shoulder movements. As a final resort manipulation under general anaesthesia can help to break down resistant adhesions. Acromioclavicular Joint Anatomy The acromioclavicular joint (ACJ) is the joint between the outer (lateral) end of the clavicle and the acromion of the scapula. Like the knee joint it has a small washer (meniscus) between the ends of the bones to facilitate movement. The joint is supported by the acomioclavicular ligament. The trapezoid and conoid ligaments also help to stabilise the ACJ by connecting the clavicle to the coracoid process of the scapula. The ACJ participates in all shoulder movements. During glenohumeral movements (e.g. raising the arm forwards), the ACJ rotates along the long axis of the clavicle. During movements of the scapulothoracic joint (e.g. shrugging the shoulder upwards), the ACJ glides up an down. Clinical Patients with ACJ pain can usually localise it accurately with one finger on the spot. Pain in the joint can be reproduced by the scarf stretch , which tends to compress the joint along its long axis. If the joint is inflamed there is usually an obvious swelling over it. Injured acromioclavicular ligaments cause a step between the clavicle and the acromion. Recurrent subluxation causes an obvious clunking during shoulder movements. Injuries Ligamentous 1st degree tears are usually confined to the acromioclavicular ligament. Local anaesthetic / steroid injections may be helpful for pain relief. Prolotherapy may be useful for ligament healing. 2nd and 3rd degree tears involve the acromioclavicular ligament and the trapezoid / conoid ligaments. Subluxation of the joint occurs on shoulder elevation causing pain past 90 degrees. A step between the clavicle and the acromion becomes obvious during this movement. Options for treatment include surgical stabilisation and prolotherapy to all the ligaments injured. Meniscal Meniscal injuies are more common in young athletes. The joint may catch during shoulder movements. Treatment options include corticosteroid injections for initial pain relief followed by mobilization techniques, Ostenil injections, and surgical removal (menisectomy). Osteoarthritis Treatment options for a severely arthritic ACJ include:- Intra-articular Injection with local anaesthetic / steroid combined with physical therapy stretching techniques immediately afterwards. Oral Glucosamine supplements. Intra/articular Ostenil injections on 5 occasions performed using x/ray screening. Intra/articular prolotherapy performed using x/ray screening. Surgical removal. Sternoclavicular Joint Anatomy The sternoclavicular joint (SCJ) is the joint between the inner (medial) end of the clavicle and the manubrium of the sternum (upper part). Like the knee joint it has a small washer (meniscus) between the ends of the bones to facilitate movement. The joint is supported by the sternoclavicular ligament. The costoclavicular ligament joins the clavicle to the 1st rib and also helps to stabilise the joint. The SCJ acts as a ball socket joint, rotating on its long axis. The total range of rotation is about 30 degrees. Clinical When the joint is inflamed there is usually a small effusion which can be seen as a small bump over the joint. If the ligaments have been injured, the joint may sublux producing prominence of the inner end of the clavicle. Osteoarthritis OA is not as common in the SCJ as the ACJ. Pain is easily localised to the joint by the patient. Treatment options for a severely arthritic joint include:- Intra-articular Injection with local anaesthetic / steroid combined with physical therapy stretching techniques immediately afterwards. Oral Glucosamine supplements. Intra/articular Ostenil injections on 5 occasions performed using x/ray screening. Intra/articular prolotherapy performed using x/ray screening. Injuries The SCJ is usually injured by a direct blow to the end of the shoulder, where the force travels in line with the clavicle from lateral to medial. The intra-articular meniscus can be injured in younger athletes causing a catching sensation during shoulder movements. 1st degree ligament injuries can be treated with an LA/steroid injection , and / or prolotherapy. 2nd and 3rd degree ligament injuries can cause the joint to sublux. With subluxation the clavicle usually moves upwards and outwards, but in some cases the end of the inner clavicle moves behind the sternum with a potential to damage the lung and major blood vessels in the upper chest. Treatment includes surgical stabilisation and prolotherapy. Osteoarthritis Please also look at trigger points within the shoulder muscles which can mimic osteoarthritic joint pain. Gleno-humeral Joint Treatment options for a severely arthritic joint include:- Intra-articular Shoulder Injection with local anaesthetic / steroid combined with physical therapy stretching techniques immediately afterwards. Oral Glucosamine supplements. Intra/articular Ostenil injections on 5 occasions performed using x/ray screening. Intra/articular prolotherapy performed using x/ray screening. Surgical shoulder replacement. To buy Glucosamine, Chondroitin and MSM online, please click on one of the links below:-   Referred Pain The conditions above are examples of local shoulder pain problems. The following can cause referred pain to the shoulder area:- C5 nerve root irritation / compression Cervical Spine / Disc prolapse / Foraminal stenosis Brachial plexus / Cervical Rib / Scalene muscle entrapment Cervical Spine Facet Joint problems. Trigger points of the neck and shoulder muscles. Sprained Cervical Spine ligaments. Suprascapular Neuritis / entrapment of the Suprascapular Nerve. Gall bladder problems (right shoulder via phrenic nerve). Stomach problems (left shoulder via phrenic nerve). Carcinoma of the apex of the lung (Pancoast's Tumour) causing pain in the interscapular area between the shoulder blades.

(530) 343-8438

552 Vallombrosa

Chico, CA 95926