Biomechanics of wrist joint

Integral university physiotherapy Development 2015-2016 Batch

1. Presentation on Biomechanics of Wrist Joint MADE BY - ADARSH PATHAK BPT 3 rd year

2. CONTENTS INTRODUCTION BASIC ANATOMY LIGAMENTS MUSCLES KINESIOLOGY

3. INTRODUCTION The wrist (carpus) consists of two compound joints : the radiocarpal and the midcarpal joints , referred to collectively as the wrist complex. The major contribution of the wrist complex seems to be to control length-tension relationships in multiarticular hand muscles and to allow fine adjustment of grip. The wrist muscles appears to be designed for balance and control rather than for maximising torque production.

4. BASIC ANATOMY OF WRIST JOINT Wrist joint is a synovial joint of ellipsoid variety between lower end of radius and three lateral bones of proximal row of carpus. Articular Surface: Upper - inferior surface of the lower end of the radius . - articular disc of the inferior radioulnar joint. Lower – scaphoid ; lunate ; triquetral bones.

5. LIGAMENTS The ligaments of the wrist complex are designated either – extrinsic or intrinsic. Extrinsic ligaments are those that connect the carpals to the radius or ulna proximally or to the metacarpals distally . Intrinsic ligaments are those that interconnect the carpals themselves & also known as intercarpal / interosseous ligaments. VOLVAR CARPAL LIGAMENTS – it has three distinct bands Radiocapitate ; short & long radioulnate ; & radioscapholunate . RADIAL COLLATERAL LIGAMENT to maintain the stability ULNAR COLLATERAL LIGAMENT at radioulnar deviation

6. On the palmar aspect there are two carpal ligaments : PALMAR RADIOCARPAL LIGAMENT PALMAR ULNOCARPAL LIGAMENT On the dorsal aspect of the joint there is one ligament : DORSAL RADIOCARPAL LIGAMENT

7. MUSCLES OF THE WRIST COMPLEX Six muscles have tendons crossing the volar aspect of the wrist & therefore are capable of creating a wrist flexion movement. Flexor Compartment Palmaris longus Flexor carpi radialis Flexor digitorum profundus Flexor digitorum superficialis Flexor policis longus Flexor carpi ulnaris

8. EXTENSOR COMPARTMENT The dorsum of the wrist complex is crossed by tendons of nine muscles. Extensor carpi radialis longus . Extensor carpi radialis brevis . Extensor carpi ulnaris . Extensor digitorum communis . Extensor indicis proprius . Extensor digiti minimi . Extensor pollicis longus . Extensor pollicis brevis . Abductor pollicis longus .

9. KINESIOLOGY OSTEOKINEMATICS Flexion / Extension Axis - Coronal axis Plane - Sagittal plane ROM – (0 - 65 - 85 ) degree of flexion (0 -55 - 80 ) degree of extension Flexion is not pure , it is with ulnar deviation due to oblique axis. Ulnar / Radial Deviation Axis - anteroposterior Plane - coronal plane

10. ROM - (0 - 30 ) degree of ulnar deviation ( 0 - 15 - 20 ) degree of radial deviation

11. ARTHROKINEMATICS Wrist Flexion / Extension : It follows CONVEX - CONCAVE rule. Roll & Slide will be in opposite direction. Dorsal Roll - during extension Ventral Slide - lunate moves on styloid process of radius. Extension at RadioCarpal joint: The convex surface of lunate rolls dorsally on radius & slides ventrally. Flexion at RadioCarpal joint : The convex surface of lunate rolls ventrally & slides dorsally.

12. Extension at MidCarpal joint : The convex capitate moves on concave lunate. Dorsal roll & Ventral slide. Flexion at MidCarpal joint : Ventral roll & Dorsal slide . Ulnar Deviation : Convex - concave rule. Scaphoid , lunate , triquetrum rolls on ulnar side while slightly slide away radially in radial carpal joint.

13. Radial Deviation : The amount of radial deviation is limited into impingment against styloid process . Therefore , most of the radial deviation occurs at midcarpal joint & hamate , triquetrum separate at the end of radial deviation.

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