Joints of the Upper Limb

Shoulder Joint

                         The synovial  ball and socket variety of joint is formed by the glenoid cavity of the scapula and head of the humerus. It is the most mobile joint of the body.This joint is also known as glenohumeral joint. The joint has the following characteristics.

• Articular Capsule 

                        The joint surface is covered with the sleeve of hyaline cartilage called as articular capsule. The articular capsule starts from the superior border of glenoid cavity and ends at the anatomical neck of the humerus. The inferior portion of the capsule is very weak.

• Glenohumeral Ligament

                         This ligament starts from the glenoid cavity and ends at the anatomical neck of the humerus. It is made up of three bands of fibrous tissue.

• Coracohumeral ligament  

                         It starts from the coracoid process of humerus and ends at the greater tuberosity of the humerus. It strengthens the shoulder joint.

• Transverse Humeral Ligament

                         It starts from the greater tuberosity and ends at the lesser tuberosity. This ligament provide stability to the shoulder joint.

• Glenoid Lambrum

                         The glenoid rim is the fibro-cartilage which deepens the shoulder joint and also provide extra stability to the shoulder joint.

• Bursa

                         There are four bursa present around the shoulder joint.

1.    Sub-acromial bursa
2.    Sub-coracoid bursa
3.    Sub-scapular bursa
4.    Sub-deltoid bursa

• Movements

              Flexion:
                            Anterior fibres of deltoid
                            Pectoralis major
                            Biceps
                            Coracobrachialis
              Extension:
                                Posterior fibres of deltoid

                                 Latissimus dorsi
                                Teres major
              Abduction:                             
                                Middle fibres of deltoid
                                Supraspinatus
              Adduction:
                                Pectoralis major
                                 Latissimus dorsi
                                Teres major
                                Teres minor
              Lateral rotation:
                                 Infraspinatus
                                 Teres minor
              Medial rotation:
                                 Subscapularis
                                 Latissimus dorsi
                                 Teres major

Elbow Joint

                         The synovial hinge joint formed by the articulation of trochlear notch of ulna and head of radius with trochlea and capitulum of the humerus. It is extremely stable joint of the body having the following characteristics.

• Articular Capsule

                         The joint surface is covered by the articular capsule which starts anterioly from the radial and coronoid fossa and ends at the annular ligament and coronoid process. The articular capsule protects the inner parts of the elbow joint.

• Annular Ligament

                          The annular ligament is round in shape which surrounds the radial head.

• Ulnar Collateral Ligament

                          It starts from the medial epicondyle and ends at the coronoid and olecranon processes of ulna.

• Radial Collateral Ligament

                          It starts from the lateral epicondyle and ends at the annular ligament and radial notch of ulna.

• Movements

             Flexion:
                           Brachialis
                           Biceps brachii
                           Brachioradialis
                           Pronator teres    
             Extension:
                           Triceps
                            Anconeus

Proximal Radioulnar Joint

                       The  pivot type of synovial joint formed by the articulation of radial head with radial notch of ulna.
Distal Radioulnar Joint
                       The pivot type of  synovial joint which is formed by the articulation of ulnar head with ulnar notch of radius.

• Movements

             Pronation:

                               Pronator teres
                                Pronator quadratus
             Supination:
                                Biceps brachii
                                 Supinator  


   
Wrist Joint

                      The condyloid type of synovial joint formed by the distal end of the radius and the articular disc of the distal radioulnar joint with the proximal row of carpal bones except the pisiform i.e scaphoid, lunate and triquetrium.

• Movements

              Flexion/extension  
              Radial (abduction) deviation
              Ulnar (adduction) deviation
              Circumduction 

    
Carpometacarpal and Intermetacarpal Joints
                      These all are plane synovial joints except that of thumb which is saddle joint.

• Movements

               Only Gliding

Metacarpophalangeal Joints
                       These are condyloid type of synovial joints which allow movement in two directions.

• Movements 

               Flexion

               Extension
               Abduction
               Adduction
               Circumduction

Interphalangeal Joints
                           These are uniaxial hinge joints which allow movement in only on direction.

• Movements

              Flexion
             Extension

Pectoral Girdle
                            The pectoral girdle(clavicle and scapula) connects the upper limb to the trunk, therefore, its articulations are includeed with those of upper limb.

Sternoclavicular Joint
                             This is a saddle type of synovial joint and is the only bony articulation between the upper limb and the axial skeleton.The medial end of the clavicle articulates with the manubrium of the sternum.

• Movements

             Allows movements of the pectoral girdle and upper limb. In flexion of the upper limb, the SC joint (i.e., clavicle on sternum) moves anteriorly, posteriorly and inferiorly.

Acromioclavicular Joint
                                This is a plane type of synovial joint. Acromial end of the clavicle articulates with the acromion of the scapula.

• Movements

              The acromion of the scapula rotates on the acromial end of the clavicle.

Posted in: Anatomy; Joints