Arm Flashcards
Describe the general characteristics and functions of the upper limb
The upper limb includes the shoulder, arm, forearm, and hand. It is characterized by its mobility and its ability to grasp and manipulate.
What are the major functions of the shoulder and elbow regions?
To position and stabilize the hand
Where is the scapulothoracic joint?
Not a true joint, but rather a fascial plane on the scapula
What is retraction?
To pull towards midline
Which muscles are responsible for the scapula’s retraction?
Trapezius and rhomboids
What is protraction?
To move away from midline
Which muscles are responsible for scapula protraction?
Serratus anterior and pectoralis minor
What is elevation?
To raise superiorly
Which muscles elevate the scapula?
Traps, levator scapulae, and rhomboids
What is depression?
To lower inferiorly
What is responsible for depression of scapula?
Gravity, pectoralis minor, traps
What is scapular rotation?
To point glenoid fossa more superiorly (superior rotation) or more inferiorly (inferior rotation)
What is responsible for scapula superior rotation?
Trapezius and serratus anterior
What is responsible for inferior rotation of scapula?
Gravity, rhomboids, pectoralis minor, arm adductors
What kind of joint is the sternoclavicular joint?
Synovial; rarely dislocated (clavicle fracture more common)
What is the only articulation of the upper limb with trunk?
Sternoclavicular joint
What does the sternoclavicular joint do?
Limit movement during rotation, elevation, depression, protraction, and retraction
What do the anterior and posterior sternoclavicular ligaments do?
Anterior and posterior reinforcement of capsule
What does the interclavicular ligament do?
Limits depression of arm
What does the costoclavicular ligament do?
Limit elevation
What does an articular disc do?
Divide joint cavity into two separate synovial lines cavities (increases mobility and acts as a shock absorber)
What is one of the most commonly broken bones?
Clavicle; medial portion is usually elevated by sternocleidomastoid and latter is usually depressed by weight of shoulder
What usually keeps the medial portion of the clavicle elevated in a break?
Sternocleidomastoid muscle
What kind of joint is the acromioclavicular joint?
Synovial
Which joint is stronger, sternoclavicular or acromioclavicular?
Sternoclavicular
What does the acromioclavicular joint do?
Stabilize movement during superior and inferior rotation of the scapula
Identify the acromioclavicular joint
Identify the conoid ligament
Identify the trapezoid ligament
What is this an example of?
Acromioclavicular dislocation; AC is weaker than sternoclavicular joint; shoulder separation; requires surgery
What kind of joint is the glenohumeral joint?
Synovial; most moveable and least stable
Where are the humeral ligaments located?
Primarily anteriorly and posteriorly
What else passes through the glenohumeral joint cavity that stabilizes the joint by not allowing the head of the humerus to be displaced superiorly?
Tendon of the long head of the biceps brachii
What are the rotator cuff muscles? What joint do they surround
Help maintain the integrity of glenohumeral joint
SITS:
S - supraspinous
I - infraspinatus
T - teres major
S - subscapularis
Where are most glenohumeral joint dislocations?
Inferiorly
Which ligament prevents superior displacement of head of humerus?
Coracoacromial ligament
What is the cartilaginous ring surrounding the glenoid fossa, thus deepening it?
Glenoid labrum
What do the many bursa do around the glenohumeral joint?
Describe a glenohumeral dislocation
Most commonly dislocated joint
Usually downward and then either anterior or posterior
Signs: pain, numbness, protruding acromnion process
Treatment: closed reduction and immobilization
What makes up the elbow joint?
Synovial joint between the condyles of the humerus with the head of the radius and trochlear notch of the ulna
Where is the radial collateral ligament?
Where is the ulnar collateral ligament?
What kind of movement does the elbow allow?
Extension and flexion
What kind of joint is the proximal radioulnar joint?
Synovial joint between the head of the radius and radial notch of the ulna
What movement does the proximal radioulnar joint allow?
Supination
What movement does the proximal radioulnar joint allow?
Supination
What holds the head of the radius in place against the ulna?
The annular ligament
Where is the middle radioulnar joint? What does it do?
Between radius and ulnar. Fibrous joint membrane stabilizing movement of radius and ulnar.
Where is the distal radioulnar joint? What does it do?
Synovial joint between the head of the ulna and ulnar notch of radius by the wrist
Describe subluxation of the head of the radius, also called nursemaid’s elbow
Occurs when the arm is jerked upward with the forearm pronated, tearing the annular ligament. As the immature head of the radius slips out of its socket, the ligament may become trapped between the radius and humerus.
Treatment: supinating the forearm while elbow is flexed
Describe supination and pronation
What kind of joint is the wrist/radio-carpal joint?
Synovial joint between forearm and hand. Occurs between the radius and a triangular fibrocartilaginous articular disc covering the distal end of the ulna and several carpal bones.
What strengthens the articular capsule?
Ulnar and radial collateral ligaments as well as palmar and dorsal radiocarpal ligaments can
What strengthens the articular capsule for the thumb?
Interphalangial ligaments
Describe the colles fracture
Common in 50yo+ (osteoporosis)
Complete fracture of distal radius with dorsal placement; ulnar styloid often avulsed (torn)
Dinner fork deformity - posterior angulation in the distal forearm due to shortened radius
