Forearm

Bones of the Forearm Ulna Radius Medial Extension of the humerus Lateral Extension of the hand

3 Joints of the Forearm Proximal Radioulnar Distal Radioulnar Pivot joint: radial head held in place by annular ligament Distal Radioulnar Pivot joint Head of ulna and ulnar notch on radius

Bones Carpal Metacarpals Phalanges 8 cube shaped bones Proximal row of 4 bones & distal row of 4 bones Metacarpals 5 bones 1st metacarpal – thumb side 5th metacarpal – little finger side Phalanges 14 bones Proximal, middle, distal 1st – thumb side; 5th little finger side

8 Carpal Bones Proximal Row starting on radial side Distal Row Scaphoid (navicular) Lunate Triquetral Pisiform Distal Row Trapezium Trapezoid Capitate Hamate

Some Linemen Try Positions That They Can’t Handle Carpals Some Linemen Try Positions That They Can’t Handle

Scaphoid (navicular) Lunate Inside “anatomical snuffbox” Avascular; fx don’t heal well Lunate Most commonly dislocated carpal

Trianglular Fibrocartilage Complex (TFCC) Triangular shaped disc that is between the ulna and the triquetrum and pisiform Main stabilizer and shock absorber Like the meniscus of the knee

Joints of the Wrist Radiocarpal Joint Carpal Joints Condyloid joint Radius and proximal row of carpal bones Carpal Joints Gliding joints Between carpal bones Metacarpalphalangeal (MCP) Joints Condyloid joints Metacarpal and phalanges Phalangeal Joints Hinge joints Proximal interphalangeal (PIP) & Distal interphalangeal (DIP)

Bony Anatomy

Wrist Ligaments

Wrist Collaterals Radial Collateral Ligament (RCL) Resists ulnar deviation Ulnar Collateral Ligament (UCL) Resists radial deviation

Wrist Nerves Median Nerve Ulnar Nerve Carpal Tunnel Thumb, Index & Middle (1st, 2nd, 3rd phalanges) Ulnar Nerve Tunnel of Guyon Ring & pinky (4th & 5th phalanges)

Terms Palmar = palm side/anterior side Dorsal = back of the hand/posterior side Pollicis= thumb (1st) Digitorium = 2st – 4th phalanges Digiti minimi = 5th phalange (little finger)

Muscles of the Forearm Anterior Posterior Flexors Pronators Extensors Supinators

Wrist Flexor Group Anterior/ Medial Epicondyle

WRIST / HAND Muscles: Flexor Group anterior forearm forearm & wrist muscles: flexor carpi ulnaris flexor carpi radialis palmaris longus finger muscles: flexor digitorum superficialis flexor digitorum profundus flexor digiti minimi (pinky) opponens digiti minimi (pinky) abductor digiti minimi (pinky)

Flexors continued Flexor digitorum superficialis Inserts on middle phalanx Flexor digitorum profundus Inserts on distal phalanx

Wrist Extensors Posterior/ Lateral Epicondyle

WRIST / HAND Muscles: Extensor Group posterior forearm forearm & wrist muscles: extensor carpi radials longus extensor carpi radials brevis extensor carpi ulnaris finger muscles: extensor digitorum extensor digiti minimi (pinky) extensor indicis (index)

WRIST / HAND Muscles: Thumb (Pollicis) anterior forearm flexor pollicis longus flexor pollicis brevis abductor pollicis brevis abductor pollicis opponens pollicis posterior forearm abductor pollicis longus extensor pollicis brevis extensor pollicis longus

WRIST / HAND Muscles: Many muscles make up the wrist & hands movement. Realize that the forearm flexor & extensor muscles insert into the hand. these muscles are responsible for moving the wrist & fingers

WRIST / HAND Movements: Wrist Fingers & Thumb flexion & extension radial deviation towards radius ulnar deviation towards ulna Fingers & Thumb flexion extension ABD / ADD

WRIST / HAND Ligaments: Tendons: We’re not going to study these. There are a lot of small ligaments that connect each carpal, metacarpal & each phalanx. Tendons: Each forearm muscle turns into a tendon as it enters the hand. We’re not going to study these.

Wrist Tendons Flexors Extensors Flexor carpi ulnaris Flexor Carpi radialis Palmaris Longus Extensors Extensor carpi ulnaris Extensor carpi radialis

Anatomical Snuffbox Extensor pollicus longus Extensor pollicus brevis Abductor pollicus longus

Fall On Out-Stretched Hand FOOSH Scaphoid fx Avascular; slow healing Forearm fx Common children; greenstick Colles ‘ fracture Elbow dislocation Assume fx Tx: ice, splint, x-rays

Scaphoid Fracture Most frequent wrist fx Pn in anatomical snuffbox Concern of avascular necrosis (poor blood supply) Non-surgical: brace Surgical: Pin and bone graft

Mallet Finger MOI: force to end of finger, that caused extensor tendon injury Avulsion of distal phalanx S&S: pn at DIP joint, swollen, DIP in flexion & unable to be extended TX: ice, splint, X-ray, must stay splinted for weeks

Mallet Finger MOI

Boutonniere Deformity aka Buttonhole deformity MOI: blow to end of finger that forces PIP into flexion and DIP into extenstion Split of central slip which allows the PIP to go through the hole S&S: PIP in flexion, DIP hyperextension, pn along to of finger Splint to allow healing of central slip

Gamekeeper’s Thumb MOI: Forceful abduction hyperextension of thumb Soccer goalies Linebackers/Lineman Skiers Sprain UCL of thumb Possible avulsion fx

Gamekeeper’s Thumb S&S: Pn, swelling, decreased ROM & strength, instability Limit ability to pinch Ice, splint, x-ray Named because the game (rabbits, birds…) keepers back in the day often injured this ligament when killing the animals to cook them

X-Ray Gamekeeper’s Thumb Rule out avulsion injury Assess

Subungual Hematoma Contusion or crushing to distal phalanx Accumulation of blood under fingernail Confined space = Increase of pressure Extreme pain Possible Nail Loss Tx: ice, possibly drill through nail to release pressure

Subungual Hematoma Release pressure Cauterized needle under sterile conditions Monitor for signs of infection

Finger Dislocation Blow to the tip of the finger Force directed upwards Displacement of joint Tearing of capsule R/O rupture of tendons

Finger Dislocation DO NOT REDUCE! Check for pulse distal to injury Capillary Refill Neurological symp. Tingling/Numbness Splint as found X-ray to r/o fracture

Volar Plate Injury MOI: Hyperextension injury Ligament avulsion injury to palmar aspect of phalanx R/O fx and splint