Unit 1_Forearm Flashcards
What is another name for the forearm?
Antebrachium
What are the bony structures of the forearm?
Radius
Ulna
3 Radioulnar Joints: Proximal (Superior), Distal (Inferior), Middle
If a person lands on their hand, and there is a force that goes up the radius, what fibers prevent the radius from dislocating superiorly?
Interosseous membrane of the forearm
What keeps the proximal and distal radioulnar joints together in the forearm? It doesn’t stretch, but folds well.
Interosseous membrane of the forearm
What bone rotates in the forearm?
The radius rotates over the ulna in the forearm
What bone is small at the distal forearm?
The ulna
What bone is big at the distal forearm and provides stability?
The radius
What bone stays put in supination/pronation?
The ulna; radius rotates
What bone rotates in supination/pronation?
The radius; the ulna stays put
What joint rotates at the distal end of the forearm?
The radioulnar joint
What bone structure is easy to palpate in the forearm and used as a place to find the anatomical snuff box?
The radial styloid process
What bony structures in the forearm are sharp like a pen?
The radial styloid process and the ulnar styloid process
What joint in the forearm is a pivot joint that provides rotation of the radial head in the radial notch of the ulna?
Proximal radioulnar joint
What joint in the forearm is a pivot joint that provides rotation of the distal radius around the ulnar head and articulation at the ulnar notch of the radius?
Distal radioulnar joint
What joint in the forearm is a syndesmosis joint (not a true joint), has parallel shafts of the radius and ulna, and is stabilized by the interosseous membrane?
Middle radioulnar joint
What ligaments in the forearm provide distal radioulnar joint support?
Anterior (Palmer) Radioulnar Ligament
Posterior Radioulnar Ligament
What is a pillow-like structure that has superficial and deep radial-ulnar ligaments, has two disc carpal ligaments (disc-lunate (D-L) and Disc-triquetral (D-T)), a central articular disc that is fibrocartilage and prevents the ulna from damaging the hand or carpal bones?
Triangular Fibrocartilage Complex (TFCC)
What motion is provided by dynamic stabilizers in the forearm?
Pronation
What muscles in the forearm work together to pull the radius over the ulna to provide pronation as well as stability?
Pronator Teres
Pronator Quadratus
What muscle in the forearm provides function in active pronation, passive stabilization during supination, and protects the distal radiulnar joint?
Pronator Quadratus
What is continuation of the brachial fascia that begins at the humeral epicondyles and provides stability in the forearm?
Antebrachial Fascia
What artery bifurcates at the cubital fossa into the radial artery and ulnar artery?
Brachial artery
What structures make up the interosseous membrane?
Common interosseous membrane (off the ulnar nerve)
Posterior interosseous membrane (Back of forearm)
Anterior interosseous membrane (Front of forearm)
Where is the pulse typically taken?
The radial artery side, but can still take pulse on ulnar artery side because the artery wraps around the hand
What muscle compartments make up the forearm/wrist and extrinsic hand?
Volar (Palmer, Anterior) Compartment
Dorsal (Posterior) Compartment
Mobile Wad of Three Compartment
What muscles make up the Volar (Palmer, Anterior) Compartment in the forearm/wrist and extrinsic hand?
Flexor Carpi Radialis
Flexor Pollicis Longus
Flexor Digitorum Superficialis
Flexor Digitorum Profundus
Flexor Carpi Ulnaris
What muscles make up the Dorsal (Posterior) Compartment in the forearm/wrist and extrinsic hand?
Extensor Carpi Ulnaris
Extensor Digitorum Communis
Extensor Digiti Minimi
Extensor Pollicis Longus
Abductor Pollicis Longus
What muscles make up the Mobile Wad of Three Compartment in the forearm/wrist and extrinsic hand?
Brachioradialis (elbow)
Extensor Carpi Radialis Longus
Extensor Carpi Radialis Brevis
What muscles provide flexion of the wrist?
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus (13% of the population doesn’t have; we don’t use as we don’t have claws (cats use to retract claws))
What is an injury to the common flexor tendon?
Golfer’s Elbow (Medial Epicondylitis)
Many flexor muscles originate at the medial epicondyle
What muscles flex the digits (extrinsic hand muscles)?
Flexor digitorum superficialis (radial attachment)
Flexor digitorum profundus
Flexor pollicis longus
What are two flexor muscles that support the grip in our hand?
Flexor Digitorum Superficialis (FDS)
Flexor Digitorum Profundus (FDP)
What flexor muscle attaches to the index through the small fingers, including the distal phalanx?
Flexor Digitorum Profundus
What flexor muscle attaches to the middle phalanx via 2 tendons?
Flexor Digitorum Superficialis
What nerves make up the forearm?
Median nerve
Radial nerve
Ulnar nerve
What nerve in the forearm is the dominant nerve to the anterior compartment of the forearm and comes through the carpal tunnel when it gets to the wrist that provides fine motor and thumb control?
Median nerve
What nerve supports the posterior compartments of the arm and forearm?
Radial nerve
What nerve is the dominant nerve to the muscles of the hand, and comes from the funny bone down the medial side, and switches sides to the radial side of the hand?
Ulnar nerve
What does the musculocutaneous nerve provide to the forearm?
Sensation for the forearm via the cutaneous nerve
What occurs when the ulnar nerve gets pinched at the elbow?
Cubital Tunnel Syndrome; numbness
What nerves provide forearm sensation?
Lateral/anterolateral-Lateral antebrachial cutaneous nerve (Musculocutaneous nerve branch)
Medial/anteromedial-Medial antebrachial cutaneous nerve
Posterior-Posterior antebrachial cutaneous nerve (Radial nerve branch)
What innervates the forearm flexors (Pronator Quadratus and Flexor Pollicis Longus)?
Anterior interosseous branch of median nerve
What superficial forearm muscles originate at the lateral epicondyle via the common extensor tendon?
Extensor Carpi Ulnaris
Extensor Digitorum
Extensor Digiti Minimi
Extensor Carpi Radialis Brevis
What superficial forearm muscles originate at the lateral supracondylar ridge?
Extensor Carpi Radialis Longus
Supinator
Brachioradialis
What condition occurs when finger and extensor muscles become irritated and is also known as Lateral Epicondylitis?
Tennis elbow
What muscles extend the wrist?
Extensor carpi radialis longus (ECRL) (origin is the lateral supracondyle ridge)
Extensor carpi radialis brevis
Externsor carpi ulnaris
What muscles originate at the Lateral Epicondyle via the Common Extensor Tendon?
Extensor Carpi Ulnaris
Extensor Digitorum
Extensor Digiti Minimi
Extensor Carpi Radialis Brevis
What muscles originate at the Supracondyler Ridge?
Extensor Carpi Radialis Longus
Supinator
Brachioradialis
What muscles contribute to supination of the forearm?
Supinator/Biceps
Brachioradialis
What muscles extend the digits?
Extensor Digitorum
Extensor Digiti Minimi
Extensor Indicis
What muscles extend/radially abduct the thumb?
Abductor Pollicis Longus
Extensor Pollicis Brevis
Extensor Pollicis Longus
What is an important feature of the distal radius that gives the ability to extend the tip of the thumb?
Lister’s Tubercle
What 3 muscles surround the anatomical snuff box?
Abductor Pollicis Longus
Extensor Pollicis Brevis
Extensor Pollicis Longus
What 3 structures are included in the anatomical snuff box?
Radial artery
Cephalic vein
Superficial radial nerve
