ELBOW JOINT: The elbow joint is a uniaxial joint capable of movements of flexion and extension in the sagittal plane about a frontal horizontal axis with a range of 0-150 degrees. It is a type of duplicated or double joint with the humero-radial and the humero-ulnar joints forming the elbow joint.
It is a synovial joint of the hinge variety.(Robert S. Behnke, Kinetic Anatomy, 2006)Possible movements at the elbow joint: Flexion and Extension. Flexion is produced by the Brachialis, Brachioradialis and the biceps brachii i.
e. the group of anterior muscles and extension is produced by the triceps brachii and anconeus i.e. the group of posterior muscles.
The humero radial joint, a ball and socket joint, not only helps in flexion and extension but also in forearm rotation. The humero ulnar joint is a hinge joint. During pronation and supination of the forearm, a small degree of abduction and adduction respectively can occur. When the elbow is fully extended, a small degree of anduction and adduction is possible, an accessory movement.
(Nigel Palastanga, Derek Field, Roger Soames,The Elbow joint, Anatomy and Human Movement)List of muscles: The list of muscles at the elbow joint are the Brachialis, Brachioradialis, Biceps brachii (the anterior muscles) and triceps brachii and anconeus (the posterior muscles). The prime flexors are biceps, brachialis and brachioradialis. When the prime flexors paralyze, all muscles which span across the elbow anteriorly can help in flexion. The main extensor is the triceps brachii and the anconeus also helps in extension.
In elbow flexion, the three heads of the triceps and anconeus are antagonists. The flexor group of muscles have an antagonistic function as compared to the extensor group of muscles. The biceps, brachialis both function as agonists.At the elbow, when the forearm is supinated, the biceps brachii is the prime mover and brachialis is the is an assistive muscle .
When the forearm is pronated the brachialis muscle is the prime mover and the biceps brachii is an assistive muscle.(Tatsuya Tajima, editor D.Kashiwagi, Elbow Joint, 1985) Stabilizers: The triceps brachii and brachialis fixate/stabilize the ulna so that the radius and finger flexors and extensors can produce the desired movement The stabilizing elements of the elbow joint are the medial and lateral collateral ligaments, the anterior capsule and the articular surfaces. The biceps brachii and brachialis are spurt muscles for elbow flexion supporting the motion that contributes rotatory force.
The Brachioradialis is a shunt muscle which stabilizes the joint during isometric or isotonic contractions.Plane of axis: It has a frontal horizontal axis/transverse axisPlane of motion : Sagittal plane with flexion and extension movements.Type of contraction: When the elbow flexors are used to lift an object, this is concentric contraction which is the normal, muscle shortening process. When the elbow flexors lengthen to place the object back, this is eccentric contraction which is a lengthening contraction.
(James,L.Poland, Donald J, Hobart, Otto, D.Payton, The Musculoskeletal system, Kinesiology,1997) RADIO-ULNAR JOINT:The radio-ulnar joint is composed of the proximal, middle and the distal radio-ulnar joints. The proximal radio-ulnar joint is a pivot joint between the radius and the ulna and the movements at this joint are pronation and supination.
The middle radio-ulnar joint is more of a syndesmosis/ligamentous attachment than a proper joint and there is very slight to no movement at this joint. The distal radio-ulnar joint is a pivot joint again and the movements at this joint are also pronation and supination. (Robert S. Behnke, Kinetic Anatomy, 2006).
Possible movements at this joint: Pronation and supination. Pronation is the internal roration of the forearm which causes the palm to face downwards and supination is the external roration of the forearm which makes the palm face upwards. At the superior radio-ulnar joint, the head of the radius rotates in the fibro osseous ring of the annular ligament. The head of the radius can be slightly moved antero posteriorly by holding it between the thumb and index finger.
The inferior joint is between the head of the ulna and the ulnar notch of the radius. The lower end of the radius rotates around the head of the ulna. Also, the head of the ulna can be slightly moved antero posteriorly by holding it between the thumb and index finger. The interosseous membrane hod the two bones together.
(Forearm Articulations,Radio-ulnar)List of muscles at these joints: The prime pronator is pronator teres along with pronator quadratus. Flexor carpi radialis and Palmaris longus assist in pronation as accessory pronators. The prime supinator is the supinator muscle and the biceps brachii. However with the elbow fully extended, supinator is the prime mover for supination.
Accessory supinator is the extensor carpi radialis longus. (Nigel Palastanga, Derek Field, Roger Soames, The Elbow joint, Anatomy and Human Movement, 2002)Stabilizers: The interosseous membrane maintains the stability at both the joints and the pronator quadratus and articular disc maintain the stability of the inferior radio-ulnar joint. The superior radio-ulnar joint has inherent stability and the annular ligament helps hold the head of the radius in place. Radial collateral ligaments provide stability to the superior radio-ulnar joint.
(James,L.Poland, Donald J, Hobart, Otto, D.Payton, The Musculoskeletal system, Kinesiology,1997)Plane of axis:Proximal radio-ulnar: The axis is longitudinal and runs through the head of the radius.Distal radio-ulnar: The axis is longitudinal.
Plane of motion: Proximal radio-ulnar: Transverse or horizontal planeDistal radio-ulnar: Transverse or horizontal plane.Type of contraction: Concentric/eccentric contraction WRIST JOINT:It is not a single joint but is composed of articulations between the carpal bones i.e. intercarpal joints and the articulation with the forearm i.
e. the radio carpal joint. The carpal bones are arranged in two rows, the proximal row of scaphoid, lunate, triquetral and pisiform from lateral to medial and the distal row comprising of trapezium, trapezoid, capitate and hamate from lateral to medial. It is a condyloid articulation.
Possible movements at the wrist: At the radio-carpal joints, flexion, extension, abduction or radial deviation and adduction or ulnar deviation can take place with contribution from the movements at the intercarpal joints. At the intercarpal joints, gliding movements take place. (Robert S. Behnke, Kinetic Anatomy, 2006).
At the mid carpal joint, flexion, extension, abduction and adduction occur.List of muscles: There are 5 main muscles that are the volar group of muscles which are the common flexor tendon formed by the flexor carpi radialis, flexor carpi ulnaris, flexor digitorum superficialis and the Palmaris longus, these four originating at the medial epicondyle and the fifth muscle is the flexor digitorum profundus which originates from the volar surface of the ulna and divides into four tendons passing through the carpal tunnel. The main flexor of the wrist is this muscle, the flexor digitorum profundus. Six muscles are present on the dorsalor the posterior aspect which are the common extensor tendon formed by extensor carpi radialis brevis, extensor carpi ulnaris, extensor digitorum, extensor digiti minimi.
The other two muscles which ar extensors are the extensor carpi radialis longus and the extensor indicis. (Robert S. Behnke, Kinetic Anatomy, 2006)The prime flexors are flexor carpi radialis and flexor carpi ulnaris and the prime extensors are extensor carpi ulnaris and radialis longus and radialis brevis.Stabilizers: The joint is surrounded by a capsule and is strengthened by the Volar intercarpal, Dorsal intercarpal, Ulnar Collateral and the Radial Collateral ligaments.
The flexor retinaculum provides stability along with the numerous tendons that cross the wrist both anteriorly and posteriorly. (Nigel Palastanga, Derek Field, Roger Soames, The Elbow joint, Anatomy and Human Movement, 2002)Plane of axis: Transverse axis for flexion and extension movements. Anteroposterior axis for the abduction and adduction movements.Plane of motion: The plane is sagittal for the flexion and extension movements and the plane is frontal for the ulnar deviation and radial deviation movements.
Type of contraction: The type of contraction at the wrist is either concentric or eccentric. The wrist flexors are the agonist muscles and the type of contraction is concentric and the wrist extensors are antagonist muscles with eccentric contraction. ReferencesElbow Joint:Nigel Palastanga, Derek Field, Roger Soames, The Elbow joint, Anatomy and Human Movement, 4th edition, 2002, pages 142-154 Butterworth-Heinemann Publication.James,L.
Poland, Donald J, Hobart, Otto, D.Payton, The Musculoskeletal system, Kinesiology,1997, pages 344- 351, Medical Examination Publishing Co. Inc.Tatsuya Tajima, editor D.
Kashiwagi, Elbow Joint, 1985, Elsevier Science Publishers.Robert S. Behnke, Kinetic Anatomy, 2006, chapter 4, pages 61-73, Human Kinetic Inc. Radio-Ulnar Joint:Robert S.
Behnke, Kinetic Anatomy, 2006, page 108, Human Kinetic Inc.Nigel Palastanga, Derek Field, Roger Soames, The Elbow joint, Anatomy and Human Movement, 4th edition, 2002, pages 154-163, Butterworth-Heinemann Publication.Forearm articulations, radio-ulnar, retrieved from world wide web, May 15, 2006 from http://www.exrx.
net/Articulations/Forearm.htmlJames,L.Poland, Donald J, Hobart, Otto, D.Payton, The Musculoskeletal system, Kinesiology,1997, pages 344- 351, Medical Examination Publishing Co.
Inc. Wrist joint:Robert S. Behnke, Kinetic Anatomy, 2006, page 108, Human Kinetic Inc.Nigel Palastanga, Derek Field, Roger Soames, The Elbow joint, Anatomy and Human Movement, 4th edition, 2002, pages 142-154 Butterworth-Heinemann Publication.Julio Taleisnik, The Wrist, 1985, Churchill Livingstone publications.
