Loading....
Coupon Accepted Successfully!

 

Elbow joint

Elbow joint is a hinge joint composed of humeroulnar(trochlear notch of ulna with trochlea of humerus) and humeroradial (radial-head with capitulum of humerus) articulations. Joint is stabilized by radial collateral ligament (laterally) and ulnar collateral ligament (medially). Ulnar collateral ligament is closely related to ulnar nerve.

The movements at elbow joint are flexion and extension.

 


 

Movement Muscles causing movement
Flexion Primary muscles: - Brachialis, biceps brachii (acts best in supination),
brachioradialis (acts best in mid prone).
Supportive muscles: -Pronatorteres, flexor carpi radialis.
 
Extension
Triceps, Anconeus.

 

Applied Anatomy

  1. Student's elbow (miner's elbow) is inflammation of olecranon bursa (olecranon bursitis).
  2. Pulled elbow (Nursemaid's elbow) is subluxation of radial head.
  3. Elbow dislocation is common in posterior direction, i.e. posterior dislocation.
  4. Carrying angle is formed between the upper arm and forearm, when the elbow is extended and forearm is supinated. The normal carrying is 163° (some book gives a value of 11° for male and 14° for females). It is more in females. Carrying angle disappears in full flexion of elbow and pronation of forearm. Cubitus valgus is an increase in carrying angle and cubitusvarus is a decrease in carrying angle.

Radio-ulnar joints

The radius and the ulna are united by three radio-ulnar joints: - Superior (proximal), middle and inferior. Whereas the superior and inferior joints are synovial joints, the middle radio-ulnar joint is a syndesmosis type of fibrousjoint:

  1. Proximal (superior) radio-ulnar - It is a pivot joint between the circumference of head of radius and radial notch of ulna.
  2. Middle radio-ulnar joint - It is a syndesmosis type of fibrous joint, formed by interosseous membrane connecting the shafts of radius and ulna.
  3. Distal radio-ulnar joint - It is a pivot joint between head of ulna and ulnar notch of radius.

Movements at radioulnar joints are pronation and supination.

Movement

Muscles causing movement

Pronation

Pronator quadratus (strong pronator), Pronator teres (Rapid pronator).

Supination

Supinator (when elbow is extended), Biceps (when elbow is flexed).

 

 

Radiocarpal (wrist) and midcarpal joints

Wrist is a biaxial ellipsoid jointformed proximally by distal end of radius and articular disc articulating distally with scaphoid, lunate and triquetral bones. Midcarpal joint is formed between proximal and distal rows of carpal bones.

 

Movement
 

Joint involved
 

Muscles causing movements

 

Flexion

 

Radiocarpal and
midcarpal

 

Flexor carpi radialis, flexor carpi ulnaris, and palmaris
longus assisted by flexor digitorum superficialis and
profundus, and flexor pollicis longus (muscles of
anterior compartment of forearm).

 

Extension

 

Wrist

 

Extensor carpi radialis longus and brevis, and extensor
carpi ulnaris, assisted by extensor digitorum, extensor
pollicis longus, and extensor indicis and extensor digit
minimi (muscles of posterior compartment of forearm).

Adduction (Ulnar
deviation).

 

Wrist

Flexor carpi ulnaris and extensor carpi ulnaris.

 

Abduction (radial
deviation).

Mainly occurs at
Midcarpal joint

 

Flexor carpi radialis, extensor carpi radialis longus and brevis, abductor pollicis longus and extensor
pollicis brevis.

 

Carpometacarpal joint of thumb

  1. It is a saddle joint between base of first metacarpal and distal surface of trapezium. It enjoys greater freedom of movement.
  2. Movements at this joint are flexion, extension, abduction, adduction and circumduction.

Movement

Muscles producing movement

Flexion

 

Main muscles:-Flexorpollicis brevis, opponenspollicis.
Supportive: - Flexor pollicis longus.

Extension

Extensor pollicis brevis and longus; abductor pollicis longus.

Abduction

Abductor pollicis brevis and longus.

Adduction

Adductor pollicis.


Metacarpophalangeal joints

These are ellipsoid joints between head of metacarpals and base of proximal phalanx. Movement at MCP joints are flexion, extension, abduction and adduction.

 

Movement

Muscles producing movement

Flexion

 

Main muscles:-The lumbricals and the interossei.
Supportive: - Flexor digitorum profundus and superficialis.

Extension

 

Main muscles: - Extensor digitorum.

Supportive muscles; - Extensor indices (for index finger), Extensor digiti minimi. (for little finger)

Abduction

Palmar interossei

Adduction

Dorsal interossei

 

Important facts

MCP joint is functionally is an ellipsoid joint, It is condylar joint structurally.

 

Interphalangeal joints

These are hinge joints between the distal end of one phalanx, and proximal end of the other. IP joints are 2 in each finger except in thumb where there is only one IP joint. Thus each finger has a proximal interphalangeal (PIP) joint and a distal interphalangeal (DIP) joint. Movements at IP joints are flexion and extension.

 

Movement

Muscles producing movement

Flexion

Thumb: - Flexor pollicis longus.

Fingers :- Flexor digitorum superficialis (for PIP joints)

Flexordigitorum profundus (for DIP joints)

Extension

Thumb: - Extensor pollicis longus.

Fingers :-Extensor digitorum (for PIP joints)
Lumbricals and interossei (for DIP joints)






Test Your Skills Now!
Take a Quiz now
Reviewer Name