Elbow Lab Handout PDF

**[Clinical Conference I]** **Upper Extremity: The Elbow Complex** **Introduction (Review on your own): identify each joint in terms of shape, number of articular surfaces, degrees of freedom and movements available:** **[Elbow Joint: Humeral Ulnar Joint (HUJ), Humeral Radial Joint (HRJ)]** -...

**[Clinical Conference I]** **Upper Extremity: The Elbow Complex** **Introduction (Review on your own): identify each joint in terms of shape, number of articular surfaces, degrees of freedom and movements available:** **[Elbow Joint: Humeral Ulnar Joint (HUJ), Humeral Radial Joint (HRJ)]** - Comprised of 4 articulating surfaces; compound synovial joint - HUJ, HRJ articulations - Humerus: distal end comprised of 2 articulating surfaces facing 45° from the shaft of the humerus - Trochlea-medially; spindle shaped with a central depression - concave-medial to lateral - convex-anterior to posterior - Capitulum-laterally; 1 spheroidal rounded convexity - Proximal radius-1 shallow concavity - Proximal ulna-1 deep concavity; longer Sup-Inf than Med-Lat; ridges located sup & inf **[Proximal Radio-ulnar joint (PRUJ)]** Mechanically linked to the Distal Radio-ulnar joint - PRUJ; compound - Pivot Joint - 1 DOF-2 directions of motion (pronation/supination) - Demonstrate the motions available to these joints: supination/pronation **Elbow Surface Anatomy** **[Bony Reference Points]**: - Olecranon - Medial Epicondyle - Lateral Epicondyle - Capitulum - Radial Head - **Olecranon** - elbow flexed and the forearm positioned in neutral - palpate the **olecranon** and move along the sharp posterior border of the ulna - divides the flexors from the extensor muscles - can be followed all the way to the ulnar styloid process of the hand - **Medial Epicondyle** - significantly larger; has a sharp medial edge - can fall posterior into the cubital tunnel where the ulnar nerve courses - ventral surface of the medial epicondyle can be appreciated as well - **Lateral Epicondyle** - Slide laterally to the lateral epicondyle - **Capitulum** - move 3mm distally from lateral epicondyle and then perform either active or passive pronation and supination of the forearm - the bony structure will [not] move under the palpating finger confirming you are still on the **capitulum** of the humerus. ' - **Radial head** - move a few more mm distally you will note a concavity representing the space between the humerus and radius (humeral radial joint (HRJ)) - as you continue distally you now rise out of the concavity onto a convexity, a bony structure representing the **radial head** - confirm with passive or active pronation and supination of the forearm - you should feel the bony structure of the radial head moving under your palpating finger IMG\_4520 [Soft Tissue Structures- Muscles and tendons] - Extensor Carpi Radialis Longus - Extensor Carpi Radialis Brevis - Common Flexor Tendon - Biceps Brachii - Tricep Brachii - **Extensor carpi radialis longus (ECRL)** - extend the wrist but primarily radial deviate - In a well-defined arm the distal end of the muscle will pop up when activated - is shaped like an egg - Its insertion is on the distal 1/3 of the lateral supracondylar ridge - Proximally the muscle belly of the ECRL is very short and continues as tendon all the way to the wrist - **Extensor carpi radialis brevis (ECRB)** - Where the muscle belly of the ECRL ends can find the belly of ECRB - Continue giving radial deviation resistance and see a long muscle belly that begins right where the ECRL muscle belly ends - has a long tendon, which leads to the muscle belly - insertion of this tendon is on the lateral epicondyle - insertion of the tendon can be found in the groove, which lies directly posterior of the muscle belly of the ECRL  - **Common flexor tendon** - has two areas of interest - musculotendinous junction and its muscle belly - insertion is about 5 mm at the anterior surface of the medial epicondyle - asking for slight flexion of the wrist and fingers the tendon of this muscle group - becomes very taut - extends for about 1 cm in the distal direction and feels like a pencil - it's about the size and hardness of a pencil - From there it becomes a relatively broad musculotendinous junction and then you can palpate the softness of the muscle belly - **Biceps brachii** - activated with elbow flexion we can appreciate both the medial and lateral edges of the muscle belly as well as a thick tendon. - tendon divides in the middle of the cubital fossa - dives deep into the forearm musculature between the brachioradialis and the flexor muscle group - Clinical Note: A fibrous branch of the tendon branches off and inserts into the fascia of the forearm medially; this is called the lacertus fibrosis, clinically this structure is important because it can be a sight of compression of the median nerve at the elbow. - **Triceps brachii** - Prone with arm off side of the table - Locate olecranon process to outline distal tendon of triceps - Ask your partner to extend their elbow as you apply resistance at forearm - Slide other hand off olecranon moving proximally onto broad triceps tendon - Widen your finders and palpate the medial and lateral heads (either side of tendon) while your partner is still contracting - **Brachial artery** - medial to the musculotendinous junction of the biceps - round structure and will have a pulse - **Median nerve** - lies medial to the brachial artery - another round structure [absent] of a pulse - **Ulnar nerve** - half-way between the musculotendinous junction of the biceps and medial epicondyle - round structure - can be followed as it dives behind the medial epicondyle - a large bulk of the nerve can be palpated between the medial epicondyle of the humerus and the olecranon of the ulna. IMG\_4524 IMG\_4527