The Wrist Complex PDF

The wrist complex Principles of kinesitherapy Prof. Olga Hoyos López MSc PT The wrist complex Functions -Control de multi-articular muscles of the hand -Fine adjustment of the gr...

The wrist complex Principles of kinesitherapy Prof. Olga Hoyos López MSc PT The wrist complex Functions -Control de multi-articular muscles of the hand -Fine adjustment of the grip 2dg of freedom -Radial/ulnar deviation -Flexión/extension 2 The wrist complex Distal radio-ulnar joint Radiocarpal joint Midcarpal / intercarpal articulations 3  1.The distal radioulnar joint Pivot joint Concave rule: Radius (concave) moves Function: Forearm pronosupination Arthrokinematic gliding component: -Pronation: Palmar Rolling and Gliding -Supination: Dorsal Rolling and Gliding 4  2.The radiocarpal joint Proximally: radius & radioulnar disk (distal radius is concave) Distally: 3 bones in the proximal carpal row: scaphoid, lunate, and triquetrum (convex) Ellipsoid joint. 2 axis. Convex rule 5  3.Intercarpal-midcarpal joints Plane synovial joints that interconnect each carpal bone 6  3.Intercarpal/Midcarpal Joint Compound joint: three or more articulation surfaces. Two single functional units: – Proximal row: scaphoid-lunate-triquetrum (relatively mobile) *Pisiform: sesamoid bone that serves to enhance the power of the flexor carpi ulnaris – Distal row: trapezium-trapezoid-capitate-hamate. (relatively immobile) 7  3.Intercarpal/Midcarpal Joint Bicondylar: 1. Medial compartment: Capitate-hamate / Triquetrum-Lunate 2. Lateral comparment: Trapezium-trapezoid / Scaphoid 8 9  Wrist osteokinematics MOVEMENT AXIS PLANE ROM PALMAR FLEXION TRANSVERSAL SAGITTAL 85º DORSAL FLEXION TRANSVERSAL SAGITTAL 85º ULNAR/CUBITAL ANT-POST FRONTAL 35-40º DEV RADIAL DEV ANT-POST FRONTAL 15º 10 Wrist arthrokinematics: OPEN KINEMATIC CHAIN (Flexion/extension) -Movement of the carpal bones on top of the radius (distal radius: convex) -Proximal and distal rows move Convex rule (roll & glide occur in opposite directions!) Radiocarpal (red arrows) Midcarpal / intercarpal (white arrows) FLEXION: Roll anterior/glide posterior EXTENSION: Roll posterior/glide anterior 11 Wrist arthrokinematics: OPEN KINEMATIC CHAIN (radial/ulnar deviation) -Movement of the carpal bones on top of the radius -Proximal and distal rows move Convex rule (roll & glide occur in opposite directions!) Radiocarpal (red arrows) Midcarpal / intercarpal (white arrows) Convex proximal & distal rows of carpals… -RADIAL DEVIATION: Roll radial /glide ulnar -ULNAR DEVIATION: Roll ulnar/ glide radial 12 Wrist arthrokinematics ARTHROKINEMATIC ATHROKINEMATIC OSTEOKINEMATIC (GLIDE) (ROLL) Convex rule PALMAR FLEXION DORSAL PALMAR Radiocarpal DORSAL FLEXION PALMAR DORSAL Midcarpal / intercarpal ULNAR DEVIATION RADIAL ULNAR RADIAL DEVIATION ULNAR RADIAL 13  Wrist stability Static: Capsule attaches to the radius, ulna and the proximal row of the carpal bones. It is lined internally by a synovial membrane, which produces synovial fluid to reduce friction between the articulating structures. Ligaments (A notable feature of the ligaments of the wrist is that none of them are truly extracapsular; most of them are defined as thickenings of the joint capsule, providing it with additional support). -- Radiocarpal: Palmar and dorsal Radial and ulnar colateral – Intercarpal: Palmar and dorsal – Triangular fibrocartilage complex Dynamic: – Palmar & dorsal musculature of the wrist 14 15 16 Passive ligament limits to osteokinematics 17  The triangular fibrocartilage complex (TFCC) Load-bearing structure located on the medial aspect of the wrist region between lunate, triquetrum, and ulnar head The TFCC functions as a major stabilizer of both radiocarpal and ulnocarpal joints. It prevents ulnocarpal abutment by transmitting and distributing the axial load from the carpus to the ulna. It also facilitates the complex movements at the wrist joint. 18  Passive ligament limits to osteokinematics SCAPHOLUNATE LIGAMENT Connects the scaphoid bone to the lunate bone in the wrist and helps to stabilize these two bones, maintaining the alignment of the carpal bones and contributing to the overall stability of the wrist joint. Injuries to the scapholunate ligament can occur due to: falls onto an outstretched hand, sudden impacts, or repetitive stress over time. It can lead to instability of the wrist joint, which may result in pain, weakness, and limited range of motion. Over time, untreated can lead to chronic wrist problems such as arthritis or carpal instability. 19 Kinetics 20 Kinetics Movement arm: Maximal muscle force: distance to the axis Cross-sectional area Levers: third class Torque: combination of movement arm and maximal force (Cross- sectional área) 21 Kinetics Why does your extensor muscle group also activates while producing a strong grip (fist)? What are the wrist positions with highest / lowest gripping torques?? Why?? 22