Elbow Flashcards
The elbow
The elbow’s primary function is to help an individual position their hand in the appropriate location to perform its function
Anatomy of the Elbow
The elbow consists of multiple joints that form a compound synovial joint
The ulnar and humeral articulations “fit” together quite intimately, which does not allow much “give” when an injury occurs
The elbow articulations are made up of the ulnohumeral joint and the radiohumeral joint and the superior radioulnar joint
These three joints make up the cubital articulations and their capsule and joint
cavity are continuous
These joints allows for 2 degrees of freedom at the elbow
The trochlear joint allows for 1 degree of freedom (flexion/ extension) and the radiohumeral and superior radioulnar joints allow the other degree of freedom (rotation)
Anatomy of the Ulnohumeral
(Trochlear Joint
Found between the trochlea of the humerus and the trochlear notch of the ulna
Classified as a uniaxial hinge joint
The axis of movement is not horizontal but instead passes downward and medially, going through an arc of movement. This position leads to the carrying angle at the elbow
On full extension, the medial part of the olecranon process is not in contact with the trochlea
On full flexion, the lateral part of the olecranon process is not in contact with the trochlea
This change allows the side-to side joint play movement necessary for supination and pronation
Resting position: 70 degrees elbow flexion, 10 degrees supination
Closed packed position: Extension with supination
Capsular pattern: Flexion, extension
Anatomy of the Radiohumeral Joint
Classified as a uniaxial hinge joint between the capitulum of the humerus and the head of the radius
Resting position: Full extension and full supination
Closed packed position: Elbow flexed to 90 degrees, forearm supinated to 5 degrees
Capsular pattern: Flexion, extension, supination, pronation
Ligaments of the Ulnohumeral and Radiohumeral Joints
• These joints are supported medially by the ulnar (medial) collateral ligament, a fan-shaped structure and laterally by the radial (lateral) collateral ligament, a cordlike structure.
• These ligaments along with the ulnohumeral articulation are the primary restraints to instability in the elbow
Lateral (Radial) Collateral Ligament
• The primary restraint to posterolateral instability which is the most common
Medial (Ulnar) Collateral Ligament
• The primary restraint to valgus instability
• Has three parts which along with the Flexor Carpi Ulnaris muscle form the cubital tunnel through which passes the ulnar nerve
• Any injury that increases the carrying angle puts an abnormal stress on the nerve as it passes through the tunnel
• This can lead to problems such as tardy ulnar palsy
Anatomy of the Superior Radioulnar Joint
Classified as a unaxial pivot joint
The head of the radius is held in proper relation to the ulna and humerus by the annular ligament which makes up ⅘ of the joint
Resting position: 35 degrees supination, 70 degrees elbow flexion
Closed packed position: 5 degrees supination
Capsular pattern: Equal limitation of supination and pronation
The elbow
• The three elbow articulations are innervated by branches from the musculocutaneous, median, ulnar and radial nerves
• The middle radioulnar articulation is not a true joint but is made up of the radius, ulna and the interosseous membrane between the two bones
• The interosseous membrane is tense only midway between supination and pronation (neutral position)
• The interosseous membrane prevents proximal displacement of the radius on the ulna. The displacement is most likely to occur with pushing movements or a fall on an outstretched hand
• The oblique cord connects the radius and ulna running from the lateral side of the ulnar tuberosity to the radius slightly below the radial tuberosity
• The cord assists in displacement of the radius on the ulna, especially during movements involving pulling or when a distractive force is exerted on the radius
Patient history
• Age?
• Mechanism of injury?
Did the client feel a “pop”? If it was followed by pain and swelling on the medial side of the elbow, it may indicate an ulnar collateral ligament sprain
• A centralized pop and weakness of elbow flexion may be the result of a distal biceps rupture
• How long has the client had the problem? What aggravates the condition?
• What are the details of the pain and other symptoms?
• Aching pain over the lateral epicondyle that radiates may indicate a tennis-elbow problem
• Is there any positions that relieve the pain?
• Is there any indication of deformity, bruising, wasting, muscle spasm or instability?
• Are any movements impaired?
• If flexion or extension is limited, two joints may be involved, the ulnohumeral or the radiohumeral If supination or pronation is
problematic, any one of the five joints (elbow or wrist) could be involved
What is the client unable to do functionally?
• A neuropathy at the elbow may result in hand and grip problems
• What is the client’s typical ADL’s? Have any of these activities been altered or increased in the past month?
• Does the client complain of any abnormal nerve distribution pain?
• Snapping on the medial side may indicate recurrent dislocation of the ulnar nerve or the medial head of the triceps dislocating over the medial epicondyle
• Does the client have a history of previous overuse injury or trauma?
Observation:
Carrying Angle
• Place the client’s arm in the anatomic position to determine whether there is a normal carrying angle
• This is the angle formed by the long axis of the humerus and the long axis of the ulna when the forearm is supinated and the elbow is extended
• In males, the normal carrying angle is 11-14°
• In females, the normal carrying angle is 13-16°
• If the carrying angle is more than 15°, it is called cubitus valgus
• If the carrying angle is less than 5-10° it is called cubitus varus
• Due to the shape of the humeral condyles that articulate with the radius and ulna, the carrying angle changes linearly depending on the degree of extension or flexion
• Cubitus valgus is greatest in extension
• The angle decreases as the elbow flexes, reaching varus in full flexion
• If there has been a fracture or epiphyseal injury to the distal humerus and a cubitus varus results, a gunstock deformity may occur in full extension. This usually results from damage to the epiphyseal growth plate in the presence of a supracondylar fracture in the adolescent
Observation:
Anterior View
• If swelling exists, all 3 joints of the elbow complex are affected as they have a common capsule
• With swelling, the joint would be held in its resting position, with the elbow held in approx. 70° of flexion because it is the resting position that the joint has maximum volume
• It should be noted whether the client can assume the normal position of function of the elbow which is 90° of flexion with the forearm midway between supination and pronation
Active Movements of the Elbow
Flexion: 140-150 degrees
Extension: 0-10 degrees
Supination: 90 degrees
Pronation: 80-90 degrees
• Loss of elbow extension is a sensitive indicator of intra-articular pathology.
It is the first movement lost after injury to the elbow and the first regained with healing
• Terminal flexion loss is more disabling than the same degree of terminal extension loss because of the need of flexion for many ADL’s
• Loss of either motion affects the area of reach of the hand, which in turn affects function
Passive Movements of the Elbow
Flexion: Tissue approximation
Extension: Bone-to-bone
Supination: Tissue stretch
Pronation: Tissue stretch
• Although tissue approximation is the normal end feel of elbow flexion, in thin clients, the end feel may be bone-to-bone
• The capsular pattern of restriction is more limitation of flexion than extension
Resisted Isometric Movements
• Proper testing of the muscles of the elbow complex, the movement must be resisted and isometric
• Muscle flexion power around the elbow is greatest in 90°-110° with the forearm supinated
• To perform the resisted isometric tests, the client is seated
• If resisted isometric contraction is weak and pain-free, a consideration of a major injury to the contractile tissue (3rd degree strain) or neurological injury should be considered
• Ex. weakness of elbow flexion and supination may occur with a rupture of the distal biceps tendon. May result in a Popeye sign indicating either a tear of the long head of the biceps tendon at the shoulder or a tear in the distal end of the biceps tendon at the elbow
