1. Chapter 6 The Elbow and Radioulnar Joints 6-1

2. The Elbow & Radioulnar Joints Most upper extremity movements involve the elbow(humeroulnar joint) & radioulnar jointsMost upper extremity movements involve the elbow(humeroulnar joint) & radioulnar joints Usually grouped together due to close anatomical relationshipUsually grouped together due to close anatomical relationship Elbow joint movements may be clearly distinguished from those of the radioulnar jointsElbow joint movements may be clearly distinguished from those of the radioulnar joints Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-2

3. Bones Ulna is much larger proximally than radiusUlna is much larger proximally than radius Radius is much larger distally than ulnaRadius is much larger distally than ulna Scapula & humerus serve as proximal attachments for muscles that flex & extend the elbowScapula & humerus serve as proximal attachments for muscles that flex & extend the elbow Ulna & radius serve as distal attachments for these same musclesUlna & radius serve as distal attachments for these same muscles Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-3

4. Bones Scapula, humerus, & ulna serve as proximal attachments for muscles that pronate & supinate the radioulnar jointsScapula, humerus, & ulna serve as proximal attachments for muscles that pronate & supinate the radioulnar joints Distal attachments of radioulnar joint muscles are located on radiusDistal attachments of radioulnar joint muscles are located on radius Manual of Structural Kinesiology6-4

5. Joints Ginglymus or hinge-type jointGinglymus or hinge-type joint Allows only flexion & extensionAllows only flexion & extension 2 interrelated joints2 interrelated joints –humeroulnar joint –radiohumeral joints Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-5

6. Joints Elbow motionsElbow motions –primarily involve movement between articular surfaces of humerus & ulna –specifically humeral trochlear fitting into ulna trochlear notch –radial head has a relatively small amount of contact with capitulum of humerus –As elbow reaches full extension, olecranon process is received by olecranon fossa increased joint stability when fully extendedincreased joint stability when fully extended Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-6

7. Joints Ulnar collateral ligament is critical in providing medial support to prevent elbow from abducting when stressed in physical activityUlnar collateral ligament is critical in providing medial support to prevent elbow from abducting when stressed in physical activity –Many contact sports & throwing activities place stress on medial aspect of joint, resulting in injury Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-7

8. Joints Ulnar collateral ligament (UCL)Ulnar collateral ligament (UCL) – –particularly crucial to high-velocity sporting activities requiring optimal medial elbow stability like baseball pitching – –compromise of this structure often requires surgery – –“Tommy John procedure” UCL surgical reconstruction using a tendon graft such as palmaris longus tendon Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-8

9. Joints Radial collateral ligament provides lateral stability & is rarely injuredRadial collateral ligament provides lateral stability & is rarely injured Annular ligament provides a sling effect around radial head for stabilityAnnular ligament provides a sling effect around radial head for stability Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-9

10. Joints Elbow moves from 0 degrees of extension to 145 to 150 degrees of flexionElbow moves from 0 degrees of extension to 145 to 150 degrees of flexion Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-10

11. Joints Radioulnar jointRadioulnar joint –Trochoid or pivot-type joint –Radial head rotates around at proximal ulna –Distal radius rotates around distal ulna –Annular ligament maintains radial head in its joint Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-11

12. Joints Radioulnar jointRadioulnar joint –Supinate 80 to 90 degrees from neutral –Pronate 70 to 90 degrees from neutral Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-12

13. Muscles Elbow flexorsElbow flexors –Biceps brachii –Brachialis –Brachioradialis –Weak assistance from Pronator teres Elbow extensorElbow extensor –Triceps brachii –Anconeus provides assistance Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-13

14. Muscles Radioulnar pronatorsRadioulnar pronators –Pronator teres –Pronator quadratus –Brachioradialis Radioulnar supinatorsRadioulnar supinators –Biceps brachii –Supinator muscle –Brachioradialis Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-14

15. Muscles AnteriorAnterior –Primarily flexion & pronation Biceps brachiiBiceps brachii BrachialisBrachialis BrachioradialisBrachioradialis Pronator teresPronator teres Pronator quadratusPronator quadratus Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-15

16. Muscles PosteriorPosterior –Primarily extension & supination Triceps brachiiTriceps brachii AnconeusAnconeus SupinatorSupinator Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-16

17. Biceps Brachii Muscle Flexion of elbow Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-17 Supination of forearm Weak flexion of shoulder joint Weak adduction of shoulder joint when abducted

18. Brachialis Muscle True flexion of elbow Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-18

19. Brachioradialis Muscle Flexion of elbow Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-19 Pronation from supinated position to neutral Supination from pronated position to neutral

20. Triceps Brachii Muscle All heads: extension of elbow Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-20 Long head: extension of shoulder joint; adduction of shoulder joint; horizontal abduction

21. Anconeus Muscle Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-21 Extension of elbow

22. Pronator Teres Muscle Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-22 Pronation of forearm Weak flexion of elbow

23. Pronator Quadratus Muscle Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-23 Pronation of forearm

24. Supinator Muscle Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-24 Supination of forearm

25. Elbow Flexion Ex. Biceps curlEx. Biceps curl AgonistsAgonists –Biceps brachii –Brachialis –Brachioradialis Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-25

26. Elbow Extension EX. Push-upEX. Push-up AgonistsAgonists –Triceps brachii AnconeusAnconeus Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-26

27. Radioulnar Pronation AgonistsAgonists –Pronator teres –Pronator quadratus –Brachioradialis Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-27

28. Radioulnar Supination Ex. Tightening a screwEx. Tightening a screw AgonistsAgonists –Biceps brachii –Supinator muscle –Brachioradialis Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-28

29. Muscles “Tennis elbow" - common problem usually involving extensor digitorum muscle near its origin on lateral epicondyle“Tennis elbow" - common problem usually involving extensor digitorum muscle near its origin on lateral epicondyle –known lateral epicondylitis –associated with gripping & lifting activities Medial epicondylitisMedial epicondylitis –somewhat less common –known as golfer's elbow –associated with medial wrist flexor & pronator group near their origin on medial epicondyle –Both conditions involve muscles which cross elbow but act primarily on wrist & hand Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-29

30. Web Sites American Sports Medicine Institute www.asmi.org/asmiweb/mpresentations/mmp.htm – –Biomechanics of the Elbow during Throwing University of Washington School of Medicine www.orthop.washington.edu/PatientCare/OurServices/Shoulder Elbow.aspx – –Information on various upper extremity conditions Medical Multimedia Group www.eorthopod.com/adult-elbow-patient-guides – –Elbow Patient Guides Huei Ming Chai www.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. Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-30

31. Web Sites The Physician and Sportsmedicine www.physsportsmed.com/index.php?article=886 – –Elbow injuries in young baseball players. American Family Physician www.aafp.org/afp/20000201/691.html – –Evaluation of overuse elbow injuries. Loyola University Medical Center: Structure of the Human Body www.meddean.luc.edu/lumen/meded/grossanatomy/index.html – –An excellent site with many slides, dissections, tutorials, etc., for the study of human anatomy. Wheeless’ Textbook of Orthopaedics www.wheelessonline.com – –An extensive index of links to the fractures, joints, muscles, nerves, trauma, medications, medical topics, lab tests, and links to orthopaedic journals and other orthopaedic and medical news. Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-31

32. Web Sites Arthroscopy.com www.arthroscopy.com/sports.htm – –Patient information on various musculoskeletal problems of the upper and lower extremities. The Physician and Sportsmedicine www.physsportsmed.com/index.php?article=1340 – –Assessment and treatment guidelines for elbow injuries. National Aeronautics and Space Administration http://ihamedical.com/mesc/rehabworks/basicwristelbow.html – –Basic Wrist and Elbow Rehabilitation Manual of Structural Kinesiology The Elbow and Radioulnar Joints 6-32