© 2007 McGraw-Hill Higher Education. All rights reserved. 6-1 Chapter 6 The Elbow and Radioulnar Joints

© 2007 McGraw-Hill Higher Education. All rights © 2007 McGraw-Hill Higher Education. All rights reserved.reserved. 6-6-11

Chapter 6 Chapter 6 The Elbow and Radioulnar The Elbow and Radioulnar

JointsJoints


ScheduleSchedule

• Today – finish shoulderToday – finish shoulder• Wed. Finish ElbowWed. Finish Elbow• SBSB• 3/25 – 3/31 Lab Quiz (Questions will be 3/25 – 3/31 Lab Quiz (Questions will be

posted by Wed.posted by Wed.• Monday 3/24 – wristMonday 3/24 – wrist• Wed. – Finish & ReviewWed. – Finish & Review• Monday 3/31 Exam 2Monday 3/31 Exam 2

• www.exrx.netwww.exrx.net


The Elbow & Radioulnar JointsThe Elbow & Radioulnar Joints

• Most upper extremity movements Most upper extremity movements involve the elbow & radioulnar jointsinvolve the elbow & radioulnar joints

• Usually grouped together due to Usually grouped together due to close anatomical relationshipclose anatomical relationship

• Elbow joint movements may be Elbow joint movements may be clearly distinguished from those of clearly distinguished from those of the radioulnar jointsthe radioulnar joints

• Radioulnar joint movements may be Radioulnar joint movements may be distinguished from those of the wrist distinguished from those of the wrist


BonesBones

• Ulna is much larger Ulna is much larger proximally than radiusproximally than radius

• Radius is much larger Radius is much larger distally than ulna distally than ulna

• Scapula & humerus serve Scapula & humerus serve as proximal attachments as proximal attachments for muscles that flex & for muscles that flex & extend the elbowextend the elbow

• Ulna & radius serve as Ulna & radius serve as distal attachments for distal attachments for these same musclesthese same muscles


JointsJoints

• Ginglymus or hinge-type jointGinglymus or hinge-type joint• Allows only flexion & extensionAllows only flexion & extension• 2 interrelated joints2 interrelated joints

– humeroulnar jointhumeroulnar joint– radiohumeral jointsradiohumeral joints


JointsJoints

• Elbow motionsElbow motions– primarily involve movement between primarily involve movement between

articular surfaces of humerus & ulnaarticular surfaces of humerus & ulna– specifically humeral trochlear fitting into specifically humeral trochlear fitting into

ulna trochlear notchulna trochlear notch– radial head has a relatively small amount radial head has a relatively small amount

of contact with capitulum of humerusof contact with capitulum of humerus– As elbow reaches full extension, As elbow reaches full extension,

olecranon process is received by olecranon process is received by olecranon fossa olecranon fossa • increased joint stability when fully extendedincreased joint stability when fully extended


JointsJoints

• As elbow flexes 20 As elbow flexes 20 degrees or more, its bony degrees or more, its bony stability is unlocked, stability is unlocked, allowing for more side-to-allowing for more side-to-side laxityside laxity

• Stability in flexion is more Stability in flexion is more dependent on the lateral dependent on the lateral (radial collateral (radial collateral ligament) & the medial or ligament) & the medial or (ulnar collateral ligament)(ulnar collateral ligament)


JointsJoints

• Ulnar collateral Ulnar collateral ligament is critical in ligament is critical in providing medial providing medial support to prevent support to prevent elbow from abducting elbow from abducting when stressed in when stressed in physical activityphysical activity– Many contact sports & Many contact sports &

throwing activities place throwing activities place stress on medial aspect stress on medial aspect of joint, resulting in of joint, resulting in injuryinjury


JointsJoints

• Radial collateral Radial collateral ligament provides ligament provides lateral stability & is lateral stability & is rarely injuredrarely injured

• Annular ligament Annular ligament provides a sling provides a sling effect around radial effect around radial head for stabilityhead for stability


JointsJoints

• Elbow moves from 0 degrees of Elbow moves from 0 degrees of extension to 145 to 150 degrees of extension to 145 to 150 degrees of flexionflexion


JointsJoints

• Radioulnar joint Radioulnar joint – Trochoid or pivot-type Trochoid or pivot-type

jointjoint– Radial head rotates Radial head rotates

around at proximal ulnaaround at proximal ulna– Distal radius rotates Distal radius rotates

around distal ulnaaround distal ulna– Annular ligament Annular ligament

maintains radial head in maintains radial head in its jointits joint

From Seeley RR, Stephens TD, Tate P: Anatomy & physiology, ed 7, New York, 2006, McGraw-Hill; Shier D, Butler J, Lewis R: hole’s human anatomy & physiology, ed 9, New York, 2002, McGraw-Hill.


JointsJoints

• Radioulnar joint Radioulnar joint – Supinate 80 to 90 degrees from Supinate 80 to 90 degrees from

neutralneutral– Pronate 70 to 90 degrees from Pronate 70 to 90 degrees from

neutralneutral


JointsJoints

• Radioulnar joint Radioulnar joint – Joint between shafts of radius & ulna Joint between shafts of radius & ulna

held tightly together between held tightly together between proximal & distal articulations by an proximal & distal articulations by an interosseus membrane (syndesmosis)interosseus membrane (syndesmosis)•substantial rotary motion between substantial rotary motion between

the bonesthe bones


MovementsMovements

• FlexionFlexion– movement of forearm to movement of forearm to

shoulder by bending the shoulder by bending the elbow to decrease its angleelbow to decrease its angle

• ExtensionExtension– movement of forearm away movement of forearm away

from shoulder by from shoulder by straightening the elbow to straightening the elbow to increase its angleincrease its angle


MovementsMovements

• PronationPronation– internal rotary movement internal rotary movement

of radius on ulna that of radius on ulna that results in hand moving results in hand moving from palm-up to palm-from palm-up to palm-down positiondown position

• SupinationSupination– external rotary movement external rotary movement

of radius on ulna that of radius on ulna that results in hand moving results in hand moving from palm-down to palm-from palm-down to palm-up positionup position


MusclesMuscles

• Elbow flexorsElbow flexors– Biceps brachiiBiceps brachii– BrachialisBrachialis– BrachioradialisBrachioradialis– Weak assistance from Pronator teresWeak assistance from Pronator teres

• Elbow extensorElbow extensor– Triceps brachiiTriceps brachii– Anconeus provides assistanceAnconeus provides assistance


MusclesMuscles

• Radioulnar pronators Radioulnar pronators – Pronator teresPronator teres– Pronator quadratusPronator quadratus– BrachioradialisBrachioradialis

• Radioulnar supinatorsRadioulnar supinators– Biceps brachiiBiceps brachii– Supinator muscleSupinator muscle– BrachioradialisBrachioradialis


MusclesMuscles

• ““Tennis elbow" - common problem usually Tennis elbow" - common problem usually involving extensor digitorum muscle near involving extensor digitorum muscle near its origin on lateral epicondyleits origin on lateral epicondyle– known lateral epicondylitisknown lateral epicondylitis– associated with gripping & lifting activitiesassociated with gripping & lifting activities

• Medial epicondylitisMedial epicondylitis– somewhat less commonsomewhat less common– known as golfer's elbowknown as golfer's elbow– associated with medial wrist flexor & pronator associated with medial wrist flexor & pronator

group near their origin on medial epicondylegroup near their origin on medial epicondyle– Both conditions involve muscles which cross Both conditions involve muscles which cross

elbow but act primarily on wrist & hand elbow but act primarily on wrist & hand


MusclesMuscles

• AnteriorAnterior– Primarily flexion Primarily flexion

& pronation& pronation• Biceps brachiiBiceps brachii• BrachialisBrachialis• BrachioradialisBrachioradialis• Pronator teresPronator teres• Pronator Pronator

quadratusquadratus


MusclesMuscles

• PosteriorPosterior– Primarily Primarily

extension & extension & supinationsupination• Triceps brachiiTriceps brachii• AnconeusAnconeus• SupinatorSupinator


NervesNerves• All elbow & radioulnar joints muscles are innervated All elbow & radioulnar joints muscles are innervated

from median, musculotaneous, & radial nerves of from median, musculotaneous, & radial nerves of brachial plexusbrachial plexus


NervesNerves

• Radial nerve - originates Radial nerve - originates from C5, C6, C7, & C8from C5, C6, C7, & C8– Triceps brachiiTriceps brachii– BrachioradialisBrachioradialis– Supinator (posterior Supinator (posterior

interosseous nerve)interosseous nerve)– Anconeus Anconeus – Sensation to Sensation to

posterolateral arm, posterolateral arm, forearm, & handforearm, & hand


NervesNerves

• Median nerve - derived from Median nerve - derived from C6 & C7C6 & C7– Pronator teresPronator teres– Pronator quadratus (anterior Pronator quadratus (anterior

interosseus nerve) interosseus nerve) – Sensation to palmar aspect of Sensation to palmar aspect of

hand & first three phalanges, hand & first three phalanges, palmar aspect of radial side of palmar aspect of radial side of fourth finger, dorsal aspect of fourth finger, dorsal aspect of index & long fingersindex & long fingers


NervesNerves

• Musculotaneous nerve - Musculotaneous nerve - branches from C5 & C6 branches from C5 & C6 – Biceps brachiiBiceps brachii– BrachialisBrachialis


• 1. Medial Elbow Injuries – The Ulnar 1. Medial Elbow Injuries – The Ulnar Collateral Ligament. Collateral Ligament. From the cocked From the cocked position shown in the picture below, the position shown in the picture below, the ulnar collateral ligament –or "UCL" - pulls ulnar collateral ligament –or "UCL" - pulls the forearm forward with the rotating upper the forearm forward with the rotating upper arm. The tremendous tension produced in arm. The tremendous tension produced in the relatively small UCL is close to its limit. the relatively small UCL is close to its limit. When improper mechanics are used or arm When improper mechanics are used or arm muscles become fatigued, the load placed muscles become fatigued, the load placed on the UCL may be increased to more than on the UCL may be increased to more than it can withstand, causing small "micro"-tears it can withstand, causing small "micro"-tears in the UCL. Microtears in muscles or in the UCL. Microtears in muscles or ligaments can heal when given enough ligaments can heal when given enough recovery time. In fact, microtears during recovery time. In fact, microtears during exercise followed by healing is how exercise followed by healing is how muscles become bigger and stronger. muscles become bigger and stronger. However, when a pitcher continues to tear However, when a pitcher continues to tear his UCL without allowing enough time for it his UCL without allowing enough time for it to heal, the microtears add up to be one to heal, the microtears add up to be one large tear in the ligament. Pitchers with UCL large tear in the ligament. Pitchers with UCL injuries often describe feeling or hearing a injuries often describe feeling or hearing a "pop" in the elbow on one particular pitch. "pop" in the elbow on one particular pitch. These types of stories lead many people to These types of stories lead many people to believe that a pitcher blows out his UCL on believe that a pitcher blows out his UCL on one bad pitch – such as the first pitch on a one bad pitch – such as the first pitch on a cold day or a poorly thrown breaking pitch. cold day or a poorly thrown breaking pitch. Really, this is usually not the case. Quite Really, this is usually not the case. Quite frequently the one bad pitch was really just frequently the one bad pitch was really just "the straw that broke the camel’s back" and "the straw that broke the camel’s back" and was the final microtear that led a series of was the final microtear that led a series of microtears to become a large tearmicrotears to become a large tear

From asmi.org


• Lateral Elbow Injuries- Lateral Elbow Injuries- A A pitcher rotates his arm back to pitcher rotates his arm back to the cocked position shown in the cocked position shown in the picture, and then rotates it the picture, and then rotates it forward to throw the ball. forward to throw the ball. Compression between the Compression between the forearm’s bone (the radius) and forearm’s bone (the radius) and the upper arm’s bone (the the upper arm’s bone (the humerus) helps the forearm humerus) helps the forearm stop cocking back and start stop cocking back and start rotating forward. This large rotating forward. This large crushing force on tiny bone crushing force on tiny bone surfaces sometimes results in surfaces sometimes results in small bone chips breaking off. small bone chips breaking off. These bone chips float in the These bone chips float in the elbow joint and may result in elbow joint and may result in pain, loss of elbow motion, and pain, loss of elbow motion, and diminished pitching diminished pitching performance.performance.

From asmi.org


• Posterior Elbow Injuries – Posterior Elbow Injuries – "Valgus Extension Overload""Valgus Extension Overload"

From the arm-cocked position From the arm-cocked position shown in the picture, the arm shown in the picture, the arm rapidly rotates forward at the rapidly rotates forward at the shoulder and straightens out at shoulder and straightens out at the elbow. The elbow straightens the elbow. The elbow straightens out in less than a tenth of a out in less than a tenth of a second (0.1 sec). The second (0.1 sec). The combination of this rapid elbow combination of this rapid elbow extension and the forceful extension and the forceful forward rotation of the upper arm forward rotation of the upper arm and humerus can cause a and humerus can cause a grinding injury in the posterior-grinding injury in the posterior-medial elbow (the "funny bone" medial elbow (the "funny bone" area of the elbow). Small bone area of the elbow). Small bone chips can break off and float in chips can break off and float in the elbow joint, which may result the elbow joint, which may result in pain, loss of motion, and in pain, loss of motion, and diminished pitching diminished pitching performance.performance.

From asmi.org




Biceps Brachii Biceps Brachii MuscleMuscleFlexion of elbowFlexion of elbow

Supination of Supination of forearmforearm

Weak flexion of Weak flexion of shoulder joint shoulder joint

Weak abduction of Weak abduction of shoulder joint shoulder joint when externally when externally rotatedrotated


Brachialis MuscleBrachialis Muscle

True True flexion flexion of elbow of elbow


Brachioradialis MuscleBrachioradialis MuscleFlexion of elbowFlexion of elbow

Pronation from supinated Pronation from supinated position to neutralposition to neutral

Supination from pronated Supination from pronated position to neutralposition to neutral


Triceps BrachiiTriceps Brachii MuscleMuscle

Long head:Long head:extension extension of shoulder of shoulder joint; joint; adduction adduction of shoulder of shoulder joint;joint;horizontal horizontal abductionabduction

All heads: All heads: extension extension of elbowof elbow


AnconeusAnconeus Muscle Muscle

Extension of elbowExtension of elbow


Pronator Teres MusclePronator Teres Muscle

Pronation of Pronation of forearm forearm

Weak flexion Weak flexion of elbow of elbow


Pronator Quadratus MusclePronator Quadratus Muscle

Pronation Pronation of of forearm forearm


Supinator MuscleSupinator Muscle

Supination of Supination of forearmforearm


Elbow FlexionElbow Flexion• Ex. Biceps curlEx. Biceps curl• AgonistsAgonists

– Biceps brachiiBiceps brachii– BrachialisBrachialis– BrachioradialisBrachioradialis


Elbow ExtensionElbow Extension

• EX. Push-upEX. Push-up

• AgonistsAgonists– Triceps brachiiTriceps brachii

• AnconeusAnconeus


Radioulnar PronationRadioulnar Pronation

• AgonistsAgonists– Pronator teresPronator teres– Pronator Pronator

quadratusquadratus– BrachioradialisBrachioradialis


Radioulnar SupinationRadioulnar Supination

• Ex. Tightening a Ex. Tightening a screwscrew

• AgonistsAgonists– Biceps brachiiBiceps brachii– Supinator Supinator

musclemuscle– BrachioradialisBrachioradialis


Web SitesWeb SitesAmerican Family Physician

http://www.aafp.org/afp/20000201/691.html– Evaluation of Overuse Elbow Injuries

Medical Multimedia Groupwww.healthpages.org/AHP/LIBRARY/HLTHTOP/CTD/– A Patient's Guide to Cumulative Trauma Disorder(CTD)

Lecture Topics in Kinesiologyhttp://moon.ouhsc.edu/dthompso/namics/elbow.htm– Describes motions caused by the muscles.

Huei Ming Chaiwww.pt.ntu.edu.tw/hmchai/Kines04/KINupper/Elbow.htm– Functions, stability and joint structure of elbow complex;

kinematics, muscle action and common injuries of the elbow.Southern California Orthopedic Institute

www.scoi.com/teniselb.htm– Tennis elbow information


Web SitesWeb SitesNational Aeronautics and Space Administration

http://rehabworks.ksc.nasa.gov/education/protocols/basicwristelbow.php

– Basic Wrist and Elbow RehabilitationUpToDate

http://patients.uptodate.com/topic.asp?file=bone_joi/7086– Physical Therapy for Elbow Tendinitis

American Sports Medicine Institutewww.asmi.org/asmiweb/mpresentations/mmp.htm– Biomechanics of the Elbow during Throwing

American Academy of Orthopaedic Surgeonshttp://orthoinfo.aaos.org/category.cfm?topcategory=Hand– Patient Education Library on the Elbow


Web SitesWeb SitesAmerican Physical Therapy Association

http://www.apta.org/AM/Template.cfm?Section=Home&CONTENTID=20403&TEMPLATE=/CM/HTMLDisplay.cfm

– Taking Care of Your Hand, Wrist, and ElbowThe Physician and Sportsmedicine

http://www.physsportsmed.com/issues/1996/05_96/nirschl.htm– Assessment and Treatment Guidelines for Elbow Injuries

The Physician and Sportsmedicinehttp://www.physsportsmed.com/issues/1999/06_99/

whiteside.htm– Elbow Injuries in Young Baseball Players

Radiologic Anatomy Browserhttp://radlinux1.usuf1.usuhs.mil/rad/iong/index.html – This site has numerous radiological views of the

musculoskeletal system.


Web SitesWeb SitesUniversity of Arkansas Medical School Gross Anatomy for Medical

Studentshttp://anatomy.uams.edu/anatomyhtml/grossresources.html– Dissections, anatomy tables, atlas images, links, etc.

Loyola University Medical Center: Structure of the Human Bodywww.meddean.luc.edu/lumen/MedEd/GrossAnatomy/GA.html– An excellent site with many slides, dissections, tutorials, etc., for the

study of human anatomyWheeless’ Textbook of Orthopaedics

www.wheelessonline.com/– This site has an extensive index of links to the fractures, joints,

muscles, nerves, trauma, medications, medical topics, lab tests, and links to orthopedic journals and other orthopedic and medical news.

Arthroscopy.Comwww.arthroscopy.com/sports.htm – Patient information on various musculoskeletal problems of the

upper and lower extremity


Web SitesWeb SitesPremiere Medical Search Engine

http://www.medsite.com/Default.asp?bhcp=1– This site allows the reader to enter any medical condition and

it will search the net to find relevant articles.Virtual Hospital

www.vh.org– Numerous slides, patient information, etc.

Documents

© 2007 McGraw-Hill Higher Education. All rights reserved. 6-1 Chapter 6 The Elbow and Radioulnar Joints