Forearm, Wrist and Hand

Functions of the Forearm, Wrist, and Hand Enables the hand to grip and hold objects Wrist Provides stability for hand movements Hand Perception (hot, cold, sharp…) Fine motor movements Manipulation Grasp Support or transfer of force Nonverbal communication (sign language)

Nerves of the Forearm, Wrist, and Hand Radial Nerve Innervates the triceps brachii and provides sensation to dorsal side of thumb, index, middle, and half of ring finger Ulnar Nerve Palmar side of the little finger and half of the ring finger Median Nerve Palmar side of thumb, index , and half of ring finger

Bones of the Forearm, Wrist and Hand 2 from the forearm-radius and ulna 8 carpals 5 metacarpals 14 phalanges Total: 2+8+5+14=29

Forearm Anatomy Bones Radius and Ulna Radioulnar Joint Formed by radius and ulna Joint Actions Pronation and Supination In supination the radius and ulna are parallel During pronation the radius crosses over the ulna Find and grip objects in different positions (vertical, horizontal and at an angle) and observe how the position of the forearm changes to allow the hand to grip

X-Ray

Pronators Supinators Biceps Brachii Supinator Brachioradialis Muscles of the Forearm Pronators Pronator Teres Pronator Quadratus Brachioradialis Supinators Biceps Brachii Supinator Brachioradialis

Pronator Teres Superficial Anterior Muscle O: Medial Epicondyle of Humerus I: Medial and Lateral Surface of Radius A: Pronation of Radioulnar Joint Integrated Function: Assists in deceleration of supination of radioulnar joint Assists in dynamic stabilization of radioulnar joint

Pronator Quadratus Deep Anterior Muscle O: Distal anterior ulna I: Distal anterior radius A: Forearm Pronation Integrated Function: Assists in deceleration of supination of radioulnar joint

Supinator Deep Posterior Muscle O: Lateral Epicondyle of Humerus I: Wraps around proximal radius A: Supination of Radioulnar Joint Integrated Function: Assists in deceleration of pronation of radioulnar joint Assists in dynamic stabilization of radioulnar joint

Wrist Anatomy Bones Distal radius and ulna and carpals Radiocarpal Joint Formed by distal radius and proximal row of carpal bones Ulna makes NO contact with carpals Joint Actions Flexion, extension, abduction, adduction and circumduction Carpal Bones Flat bones aligned in two rows of 4 (8 total) Proximal and Distal Row

Carpal Bones Beginning with the radial side Proximal Row Scaphoid-most commonly fractured Lunate-most commonly dislocated Triquetrum-triangular Pisiform Distal Row Trapezium-aligns with 1st metacarpal Trapezoid-aligns with 2nd metacarpal Capitate-aligns with 3rd metacarpal Hamate-aligns with 4th and 5th metacarpal

X-Ray

Carpals On the dorsal side, locate the third metacarpal bone . A depression can be found on the proximal end of the third metacarpal bone. This is the location of the Capitate bone. Flex the wrist and you may feel the Capitate bone. The Scaphoid bone is found below the anatomical snuff box (when snuff was popular, this compartment was used to hold tobacco for snorting)

Hand Anatomy Metacarpals Phalanges Numbered 1-5 Thumb =1 and pinky = 5 Actions: Flexion, extension, abduction, adduction, and circumduction Phalanges Proximal, intermediate and distal abduction, adduction, and thumb opposition

Muscles Causing Wrist Actions Superficial Wrist flexors Flexor Carpi Radialis Palmaris Longus Flexor Carpi Ulnaris Superficial Wrist extensors Extensor Carpi Radialis Longus Extensor Carpi Radialis Brevis Extensor Carpi Ulnaris These muscles do not cause finger movements

Attachments Wrist Flexors All originate from the medial epicondyle of the humerus Insertions: Anterior aspect of the wrist and hand Wrist Extensors All originate from the lateral epicondyle of the humerus Insertions: Posterior aspect of wrist and hand

Flexor Carpi Radialis O: Medial Epicondyle of Humerus I: Bases of 2nd and 3rd metacarpals A: Flexion and Abduction of wrist (radial deviation)

Palmaris Longus Absent in 15 - 20% of Population O: Medial Epicondyle of Humerus I: Palmar Aponeurosis A: Wrist flexion Q: How do you test for this muscle and why is it important?

Palmaris Longus Tested: With wrist slightly flexed Oppose thumb and little finger Importance: Used in tendon transfers (autografts)

Flexor Carpi Ulnaris O:Medial Epicondyle of Humerus I: Pisiform (carpal bone proximal row) A: Flexion and Adduction of Wrist (ulnar deviation)

Wrist Flexor Palpation Video http://www.youtube.com/watch?v=ykB4YFPJ2ek&feature=related

Integrated Function of Wrist Flexors Assists in deceleration of wrist extensors Assists in dynamic stabilization of the wrist and hand Flexor Carpi Radialis and Flexor Carpi Ulnaris Assists in deceleration of wrist abduction Flexor Digitorum Superficialis Assists in deceleration of finger extension

Extensor Carpi Radialis Longus O: Lateral Epicondyle of Humerus I: Base of 2nd metacarpal A: Extension of wrist Abduction of wrist (radial deviation)

Extensor Carpi Radialis Brevis O: Lateral Epicondyle of Humerus I: Base of 3rd metacarpal on dorsal surface A: Extension of wrist Abduction of Wrist

Extensor Carpi Ulnaris O: Lateral Epicondyle of Humerus I: Base of 5th metacarpal on dorsal surface A: Extension of Wrist Adduction of Wrist (ulnar deviation)

Integrated Function of Wrist Extensors Assists in deceleration of wrist flexion Assists in dynamic stabilization of the wrist and hand Extensor Carpi Radialis Brevis and Longus Assists in deceleration of wrist adduction Extensor Carpi Ulnaris Assists in deceleration of wrist abduction

Phalange Muscles These muscles assist in wrist actions Finger flexors Flexor Digitorum Superficialis Flexor Digitorum Profundus Thumb flexor Flexor Pollicis Longus Finger extensors Extensor Digitorum Extensor Indicis Extensor Digiti Minimi Thumb extensor Extensor Pollicis Longus Extensor Pollicis Brevis These muscles assist in wrist actions

Carpal Tunnel Syndrome Impingement or compression of the median nerve Occurs from chronic swelling of the wrist flexor tendons The median nerve, which innervates the first three fingers and the thumb, can become impaired from pressure in the carpal tunnel in the wrist

Carpal Tunnel Syndrome Causes Awkward hand postures Long hours of repetitive typing Repeated use of hand tools Smoking-it may reduce blood flow to median nerve Wrist injuries Development of a cyst or tumor in the carpal tunnel Common in assembly line workers, nail technicians, data entry personnel, musicians

Carpal Tunnel Syndrome Signs and Symptoms Pain, numbness, or tingling in the first three fingers and the thumb Increased pain with increased use of your hand, such as typing Night pain Weak grip and tendency to drop objects

Carpal Tunnel Syndrome Tests Tinel’s Sign: Tapping over the median nerve at the wrist may cause pain to shoot from the wrist to the hand Phalen’s Test: Pushing the back of your hands together for 60 seconds compresses the carpal tunnel and may cause pain

Carpal Tunnel Syndrome Treatments Ergonomic aids: Split keyboards, keyboard trays, typing pads, cushioned mouse pads and wrist braces, may be used to improve wrist posture during typing Take frequent breaks when typing and always stop if there is tingling or pain Avoid sleeping on wrists NSAID’s Physical or Occupational Therapy Carpal tunnel release surgery

Carpal Tunnel Syndrome Exercises Contraindicated Heavy resistance training Excessive wrist flexion and extension What to do: Focus on flexibility!

Carpal Tunnel Syndrome Stretch the following muscle groups Elbow Flexors Wrist Flexors Finger Flexors Extension exercises are key to recovery! It will help hold the carpal tunnel open Strengthen the following muscle groups Elbow Extensors Wrist Extensors Finger Extensors Finger Abductors