Joints - Upper Extremity Flashcards
Sternoclavicular Joint
Saddle Type Synovial Joint - sternal end of clavicle with manubrium of sternum
Divided into 2 compartments by a fibrocartilaginous articular disc that divides the joint cavity into 2 compartments
Joint surface is fibrocartilage rather than the typical hyaline cartialge
Ligaments:
1. Interclavicular ligament - located on top of the manubrium between the clavicles
Strengthens the capsule superiorly
2. Anterior and posterior sternoclavicular ligaments - run from the clavicle to the manubrium anteriorly and posteriorly
Restrain anterior and Posterior movement of the joint
3. Costoclavicular ligament - runs from first rib to inferior surface of the sternal end of the clavicle
Located external to the joint but it is the primary stabilizer
Orientation allows it to limit extremes of all motion (except depression since it is under the clavicle)
Movements of the SC joint: participates in scapulohumeral rhythm, producing elevation/depression, protraction/retraction, and upward and downward rotation of the scapula
Acromioclavicular Joint
Plane type synovial joint between acromial end of the clavicle and the acromion of the scapula
Capsule is split into 2 compartments by a fibrocartilaginous disc
Fibrocartilage on articulating surfaces
Ligaments:
1. Acromioclavicular ligament - runs from acromion to clavicle on top of the joint
Reinforces the joint superiorly
2. Coracoclavicular Ligament - external to the joint; runs the scapula to the clavicle in 2 parts; together the parts anchor the clavicle to the scapula helping to maintain joint integrity and anchoring the clavicle to the coracoid process
Conoid Ligament: runs form the caracoid process of the scapula to the conoid tubercle of the clavicle
Trapezoid ligament: runs from the coracoid process to the trapezoid line
Movements of the AC joint: participates in scapulohumeral rhythm, producing elevation/depression, protraction/retraction, and upward and downward rotation of the scapula
Scapulothoracic Joint
Physiological Joint between musculoskepetal structures
Function: orientation of the glenoid fossa of the scapula
Movements: Same as AC and SC (closed kinematic chain)
Glenohumeral Joint
Ball and socket type synovial joint between the head of the humerus and the glenoid cavity (which is enlarged by the glenoid labrum)
Poor joint congruity and laxity of the joint capsule help contribute to large ROM at this joint
Joint capsule runs from margin oft he glenoid cavity to the anatomical neck of the humerus and therefore encloses the biceps long head tendon. The capsule has 2 apertures:
One for the tendon of the long head of the biceps (between the tubercles)
One inferior to the coracoid process for communication between the bursa of subscalpularis and the synovial cavity of the GH joint
Movement: flexion and abduction require movement of the scapula; scapulohumeral rhythm –> 2:1 ratio; movement at ST created half form movement at AC and half from movement at SC
Arteries that supply the joint: circumflex humeral and suprascapular
Nerves that supply the GH joint: suprascapular, axillary, lateral pectoral
Bursae:
Subscapular: feeds into synovial capsule of joint
Subacromial: facilitates movement of supraspinatus tendon under the coracoacromial arch and the deltoid tendon over the GH joint capsule
Elbow Joint - Overview
modified hinge synovial joint
function: position the hand for manipulation; primarily used for flexion and extension (does some passive abduction and adduction); also active in pronation/supination
AT least 15 muscles cross the elbow but only brachialis acts exclusively at the elbow
Typical joint capsule unique in that it encloses 3 joints: humeroulnar, humeroradial, and proximal radioulnar; capsule is not as strong anteirorly because there are no reinforcing ligaments there
Vascular and neural elements:
Nerves: MC, ulnar, and radial
Arteries: Brachial Artery - splits into radial and ulnar arteries
Bursae:
1. Olecranon Bursae: subtendinous, tendonous, and subcutaneous
Elbow Joint - Ligaments
- Radial Collateral Ligament: aka lateral collateral lig. of the elbow
one strong, fanlike band that starts the lateral epicondyle of the humerus and blends with the annular ligament; RESISTS VARUS STRESS AT THE ELBOW (pushing form medial to lateral) - Ulnar Collateral Ligament: aka medial collateral lig of the elbow
made up of 3 bands: anteiror (cord-like, strongest) posterior (fan-like, weakest) oblique (deepens the socket to reduce incongruency in the joint; RESISTS VALGUS STRESS; prevents gapping
Glenohumeral Joint - Ligaments
- Glenohumeral Ligament
Has 3 bands: superior, middle, inferior
on the anterior aspect of the joint capsule, reinforces the joint anteriorly - Coracohumeral ligament
Runs from the base of the coracoid process to the greater tubercle of the humerus –> RESTRAINS inferior movement, and posterior movement in the adducted arm - Coracoacromial Arch
completely extrinsic tot he joint; formed by the coracoacromial ligament which runs between the coracoid process and the acromion
prevents superior displacement of the humerus
Radiocarpal Joint
Wrist Joint
between the articular disc of the distal radioulnar joint at the distal end of the radius and the proximal row of carpal bones except the pisiform
Intercarpal Joints
Articulations between adjacent bones of the proximal row, adjacent bones of the distal row, and between the distal and proximal rows of carpal bones.
Ligaments can be anterior, posterior, or interosseous
Movements: Gliding
Midcarpal joints are the ones between the proximal and distal rows of carpal bones - there is some flexion/extension and radial/ulnar deviation there
Carpometacarpal Joints
First CMC is the most unique - it is the only one that is a saddle joint; most digit 1 movement happens at CMC (it has flexion/extension, abduction/adduction, and circumduction at this joint
2, 3, and 4 are relatively stable at this joint
digit 5 also has some movement
between the distal row of carpal bones and the 5 metacarpal bones
Intermetacarpal Joints
4 articulations between the bases of adjacent metacarpals; facilitate movement between the metacarpals at the carpometacarpal joints
Metacarpophalangeal joints
Between the 5 metacarpals and the 5 proximal phalanges
This is where the most movement occurs for digits 2-5
There are COLLATERAL LIGAMENTS supporting the joint on both sides
Deep Transverse Metacarpal ligament binds the metacarpals to the proximal phalanges
In the thumb, this joint only allows flexion and extension; there is a lot of movement at the joint proximally
the other digits can flex, extend, abduct, adduct, and passively rotate at these joints
Proximal Interphalangeal Joints
Between proximal and middle (distal in the case of the thumb) phalanges of all digits
Ovoid articulations hwere the proximal part of the joint is the concave surface
Collateral ligaments on both sides of joints
Distal Interphalangeal Joints
Between Middle and Distal Phalanges of digits 2-5
Collateral ligaments on both sides of joints
Proximal Radioulnar Joint
Pivot Type Synovial Joint
Enclosed in the articular Capsule of the elbow joint
active in pronation and supination with the DRU joint
Ligaments: annular ligament - encircles the head of the radius and holds it in the radial notch of the ulna
