Unit 2- Antebrachial Flexors Flashcards
Role of the forearm
To assist the shoulder in application of force
Controlling placements of the hand in space
Allows free manipulation of the hand.
The bulk of the forearm musculature is located:
Proximal with long tendonous insertions on the distal bony structures
From a functional perspective, the forearm includes the:
Distal humerus
The structures of the forearm are divided into:
An anterior and posterior compartment
Flexors and pronators of the forearm are located:
In the anterior compartment
The muscles in the anterior compartment are innervated by:
Median nerve
Except for 1 1/2 are supplied by ulnar nerve
The brachioradialis is a(n) _______ (EXTENSOR/FLEXOR) located in the _________ compartment.
Flexor
Posterior
The brachioradialis is innervated by:
Radial nerve
What types of muscles are located in the posterior compartment?
Extensor and supinator
Muscles in the posterior compartment are innervated by the
Radial nerve
Function of fascia layers in the musculature of the forearm
Divides the forearm into functional units
Forms structures that assist in muscular function
Antebrachial fascia (3)
Palmar aponeurosis
Palmar carpal ligament
Flexor retinaculum (aka- transverse carpal ligament)
Where do the tendons of most flexors pass across?
The anterior surface of the wrist
The tendons of most flexors are held in place by:
The palmar carpal ligament and the flexor retinaculum (transverse carpal ligament)
Groups of the flexors
Superficial layer
Intermediate layer
Deep group
Flexor muscles in the superficial layer (5)
Pronator teres Flexor carpi radialis Palmaris longus Flexor carpi ulnaris Brachioradialis
All flexor muscles in the superficial layer are attached:
Proximally by the common flexor tendon to the medial epicondyle (common flexor origin)
Flexor muscle in the intermediate layer
Flexor digitorum superficialis
Flexor muscles in the deep group
Flexor digitorum profundus
Flexor polices longus
Pronator quadratics
What flexor groups cross the elbow joint?
Superficial and intermediate groups
OINA Pronator teres
OR: Humeral Head- from medial supracondylat ridge common flexor tendon
Ulnar head- from the medial side of the coronoid process
INS: Midway on lateral surface of radius
NS: Medial nerve
AC: Rotates the radius on the ulna
Helps flex the forearm
Used for quick powerful pronation
OINA of Flexor carpi radialis
OR: medial epicondyle of humerus
INS: base of 2nd and 3rd metacarpal bones
NS: Median
AC: Flexes hand at the wrist
Abducts wrist
OINA for Palmaris Longus
OR: Medial epicondyle of humerus
INS: Anterior aspect of the distal flexor retinaculum and palmar aponeurosis
NS: Median
AC: Flexes hand at the wrist
Tightens aponeurosis
Muscle absent in 10% of people
Palmaris longus
OINA for Flexor Carpi Ulnaris
OR: Humeral head- From the medial epicondyle
Ulnar head- from the medial margin of the olecranon and posterior border of ulna
INS: Into the pisiform bone with and extension to the hook of hamate and 5th metacarpal base
NS: Ulnar
AC: Flexes wrist
Adducts wrist
In the forearm, the Ulnar nerve runs:
Between 2 heads of the flexor carpi ulnaris and moves dismally
Cubital tunnel syndrome area of pain and numbness
Medial 2 fingers
OINA Brachioradialis
OR: Proximal 2/3rds of the lateral supracondylar ridge
INS: Styloid Process of radius
NS: Radial nerve
AC: Flexes forearm
Why is the brachioradialis an exception to the forearm muscle’s superficial layer rules?
It is technically located in the posterior compartment
It is innervated by the radial nerve
Is the a flexor of the forearm
OINA for Flexor digitorum superficialis
OR: Humeral head- Medial epicondyle, ulnar collateral ligament, coranoid process of the ulna
Radial head- Superior half of anterior radius
INS: Middle phalanx of digits 25
NS: Medial nerve
AC: Flexes proximal interphalangeal joints (PIP)
Contributes to flexion of all joints it crosses
-flexes MP
-Flexes wrist
Where does each tendon split?
At the base of the proximal phalanges
Why do the tendons split at the base of the proximal phalanges?
To allow the profunda tendon to pass through to the distal phalanx. These share a common synovial sheath
OINA for flexor digitorum profundus
OR: Proximal 3/4 of medial ulna
Interosseous membrane
INS: Distal phalanx of digits 2-5
NS: Medial 1/2- Ulnar nerve
Lateral 1/2- median nerve
AC: Flexes distal interphalangeal joints (DIP)
Contributes to flexion of all joints it crosses
Flexes PIP
Flexes MP
Flexes wrist
OINA for flexor pollicis longus
OR: Anterior aspect of radius
Interosseous membrane
INS: Base of the distal phalanx of the thumb
NS: Median nerve (AIN)
AC: Flexes IP Joint
Flexes MP joint
Flexes wrist
OINA for pronator quatratus
OR: Distal 1/4 of medial anterior surface of ulna
INS: Distal 1/4 of lateral anterior surface of radius
NS: Median nerve (AIN)
AC: Pronator the hand
Assisted by pronator teres when power and speed are needed
Long flexors of the digits that also flex the metacarpophalangeal and wrist joints
Flexor digitorum superficialis
Flexor digitorum profundus
(FDS and FDP)
_____ slowly flexes fingers, while ______ is recruited when speed and flexion against resistance are needed.
FDP
FDS
FDS flexes:
Middle phalanges
FDP flexes:
Distal phalanges
Prime pronator assisted by the pronator teres
Also plays a role in holding the radius and ulna together.
Pronator quadratus
