By Chris Faubel, M. D. Bertolottis syndrome is an atypical cause of axial low back pain or buttock pain caused by a transitional lumbar vertebrae with a large. The Shoulder Joint Structure Movement. The shoulder joint glenohumeral joint is a ball and socket joint between the scapula and the humerus. It is the major joint connecting the upper limb to the trunk. It is one of the most mobile joints in the human body, at the cost of joint stability. Alabama Football Weight Lifting Program on this page. In this article, we shall look at the anatomy of the shoulder joint and its important clinical correlations. Structures of the Shoulder Joint. Articulating Surfaces Fig 1. The articulating surfaces of the shoulder joint. The shoulder joint is formed by the articulation of the head of the humerus with the glenoid cavity or fossa of the scapula. This gives rise to the alternate name for the shoulder joint the glenohumeral joint. Both the articulating surfaces are covered with hyaline cartilage which is typical for a synovial type joint. The head of the humerus is much larger than the glenoid fossa, giving the joint inherent instability. To reduce the disproportion in surfaces, the glenoid fossa is deepened by a fibrocartilage rim, called the glenoid labrum. Shoulder-Workout-Rob-Riches.jpg' alt='Deltoid Ligament Upper Arm' title='Deltoid Ligament Upper Arm' />Joint Capsule and Bursae. The joint capsule is a fibrous sheath which encloses the structures of the joint. It extends from the anatomical neck of the humerus to the border of the glenoid fossa. The joint capsule is lax, permitting greater mobility particularly abduction. The synovial membrane lines the inner surface of the joint capsule, and produces synovial fluid to reduce friction between the articular surfaces. To reduce friction in the shoulder joint, several synovial bursae are present. A bursa is a synovial fluid filled sac, which acts as a cushion between tendons and other joint structures. The bursae that are important clinically are Subacromial Located inferiorly to the deltoid and acromion, and superiorly to the supraspinatus tendon and the joint capsule. It supports the deltoid and supraspinatus muscles. Inflammation of this bursa is the cause of several shoulder problems. Subscapular Located between the subscapularis tendon and the scapula. It reduces wear and tear on the tendon during movement at the shoulder joint. There are other minor bursae present between the tendons of the muscles around the joint, but this is beyond the scope of this article. Ligaments. In the shoulder joint, the ligaments play a key role in stabilising the bony structures. The majority of the ligaments are thickenings of the joint capsule Fig 1. The ligaments of the shoulder joint. The transverse humeral ligament is not shown on this diagram. Glenohumeral ligaments superior, middle and inferior  Consists of three bands, which runs with the joint capsule from the glenoid fossa to the anatomical neck of the humerus. They act to stabilise the anterior aspect of the joint. Coracohumeral ligament Attaches the base of the coracoid process to the greater tubercle of the humerus. It supports the superior part of the joint capsule. Transverse humeral ligament Spans the distance between the two tubercles of the humerus. It holds the tendon of the long head of the biceps in the intertubercular groove. The other major ligament is the coracoacromial ligament. Unlike the others, it is not a thickening of the joint capsule. It runs between the acromion and coracoid process of the scapula, forming the coraco acromial arch. This structure overlies the shoulder joint, preventing superior displacement of the humeral head. Neurovascular Supply. Arterial supply to the glenohumeral joint is via the anterior and posterior circumflex humeral arteries, and the suprascapular artery. Branches from these arteries form an anastomotic network around the joint. Deltoid Ligament Upper Arm' title='Deltoid Ligament Upper Arm' />The joint is supplied by the axillary, suprascapular and lateral pectoral nerves. These nerves are derived from roots C5 and C6 of the brachial plexus. Street Magic Tricks there. Thus, an upper brachial plexus injury Erbs palsy will affect shoulder joint function. Movements As a ball and socket synovial joint, there is a wide range of movement permitted Extension upper limb backwards in sagittal planeProduced by the posterior deltoid, latissimus dorsi and teres major. Flexion upper limb forwards in sagittal planeProduced by the biceps brachii both heads, pectoralis major, anterior deltoid and coracobrachialis. Abduction upper limb away from midline in coronal planeThe first 0 1. The middle fibres of the deltoid are responsible for the next 1. Past 9. 0 degrees, the scapula needs to be rotated to achieve abduction that is carried out by the trapezius and serratus anterior. Adduction upper limb towards midline in coronal planeProduced by contraction of pectoralis major, latissimus dorsi and teres major. Medial Rotation rotation towards the midline, so that the thumb is pointing mediallyProduced by contraction of subscapularis, pectoralis major, latissimus dorsi, teres major and anterior deltoid. Lateral Rotation rotation away from the midline, so that the thumb is pointing laterallyProduced by contraction of the infraspinatus and teres minor. Deltoid muscle The large, triangular shoulderpad muscle which raises the arm sideways. Disloc and sprain of joints and ligaments of shoulder girdle any associated open wound strain of muscle, fascia and tendon of shoulder and upper arm S46. Instability upper cervical spine can be catastrophic if not recognised and treated at the right time. Visit us to know more,North Sydney Physiotherapy. The upper limb or upper extremity is the region in a vertebrate animal extending from the deltoid region up to and including the hand, including the arm, axilla and. Mobility and Stability. The shoulder joint is one of the most mobile in the body, at the expense of stability. Here, we shall consider the factors the permit movement, and those that contribute towards joint structure. Factors that contribute to mobility Type of joint  It is a ball and socket joint. Bony surfaces  Shallow glenoid cavity and large humeral head there is a 1 4 disproportion in surfaces. A commonly used analogy is the golf ball and tee. Laxity of the joint capsule. Deltoid Ligament Upper Arm' title='Deltoid Ligament Upper Arm' />Factors that contribute to stability Rotator cuff muscles These muscles surround the shoulder joint, attaching to the tubercles of the humerus, whilst also fusing with the joint capsule. The resting tone of these muscles act to pull the humeral head into the glenoid cavity. Deltoid Ligament Upper Arm' title='Deltoid Ligament Upper Arm' />Glenoid labrum  This is a fibrocartilaginous ridge surrounding the glenoid cavity. It deepens the cavity, reducing the risk of dislocation. Ligaments  The ligaments act to reinforce the joint capsule, and forms the coraco acromial arch. Fig 1. 3 The rotator cuff muscles, which act to stabilise the shoulder joint. Clinical Relevance Common Injuries. Dislocation of the Shoulder Joint. Clinically, dislocations at the shoulder are described by where the humeral head lies in relation to the infraglenoid tubercle. Anterior dislocations are the most prevalent, although posterior dislocations can sometimes occur. Superior movement of the humeral head is prevented by the coraco acromial arch. An anterior dislocation is usually caused by excessive extension and lateral rotation of the humerus. The humeral head is forced anteriorly and inferiorly into the weakest part of the joint capsule. Tearing of the joint capsule is associated with an increased risk of future dislocations. The axillary nerve runs in close proximity to the shoulder joint, and can be damaged in the dislocation. Injury to the axillary nerve causes paralysis of the deltoid, and loss of sensation over regimental badge area. A dislocation can also stretch the radial nerve, as it is tightly bound in the radial groove. By MB CC BY SA 2. Wikimedia Commons Fig 1. Anterior dislocation of the shoulder joint. Rotator Cuff Tendonitis. The rotator cuff muscles have a very important role in stabilising the glenohumeral joint. They are often under heavy strain, and therefore injuries of these muscles are relatively common. Tendonitis refers to inflammation of the muscle tendons usually due to overuse. Over time, this causes degenerative changes in the subacromial bursa, and the supraspinatus tendon. Rotator Cuff Muscle Teres Minor Upper Arm Pain, Numbness and Tingling In Fingers. Self Treatment For Teres Minor Muscle and Frozen Shoulder. The Frozen Shoulder Workbook Trigger Point Therapy for Overcoming Pain and Regaining Range of Motion is a book to consider if you are suffering from frozen shoulder or unresolved shoulder pain. Coauthor Claire Davies bout with frozen shoulder lead him to research trigger point therapy and use the methodology to resolve his pain and regain the range of motion in his shoulder and arm. In his book Davies explains adhesive capsulitis frozen shoulder in laymans language and gives step by step self treatment methods as well as stretching and strengthening exercises. Many people have used the treatment methods to overcome frozen shoulder. For others, it is a tool to help them manage their pain and maintain movement. There are a few for which the methods do not help, however even many of these people recommend the book for a better understanding of the condition and to help formulate questions and discussion with medical professionals.