Elbow Biomechanics

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Elbow Biomechanics
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Anatomical Landmarks to Review

• Humerus
• Medial and lateral epicondyles, medial and
  lateral supracondylar ridge, trochlea, capitulum,
  coronoid fossa, radial fossa and olecranon fossa
• Radius
• Radial head and radial tuberosity
• Ulna
• Olecranon process, coronoid process and trochlear
  notch

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Elbow Articulations

• Humeroulnar Joint
• True elbow joint
• Strong bony configuration
• Hinge joint
• Humeroradial Joint
• Slides along capitulum
• Modified ball and socket joint
• Provides no ABD or ADD
• Proximal Radioulnar Joint
• Annular ligament
• Movements
• Interosseous membrane

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Elbow Articulations

• Humeroulnar Joint
• True elbow joint
• Strong bony configuration
• Hinge joint
• Humeroradial Joint
• Slides along capitulum
• Modified ball and socket joint
• Provides no ABD or ADD
• Proximal Radioulnar Joint
• Annular ligament
• Movements
• Interosseous membrane

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Joint Capsule

• Anterior
• Posterior
• Medial
• Lateral
• Large, loose and weak
• Reinforced by other ligaments

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Medial (Ulnar) Collateral Ligament

• Anterior Band
• Primary stabilizer against valgus force
• Three bands
• Anterior to medial epicondyle
• Below tip of medial epicondyle
• Inferior edge of medial epicondyle
• Posterior Band
• Limits elbow extension

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Lateral (Radial) Collateral Ligament

• Fan shaped
• Resists varus force

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Ligaments of the Elbow

• Annular Ligament

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Muscles of the Humeroulnar Joint as Stabilizers

• Anterior
• Brachialis

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Muscles of the Elbow

• Anterior
• Biceps brachii

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Muscles of the Elbow

• Anterior
• Brachioradialis

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Muscles of the Elbow

• Anterior
• Wrist flexors
• Flexor Carpi Radialis
• Flexor Carpi Ulnaris
• Pronator Teres
• Palmaris Longus

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Muscles of the Elbow

• Posterior
• Triceps

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Muscles of the Elbow

• Anconeus
• Locks out the elbow in extension

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Muscle of the Proximal Radioulnar Joint

• Pronation
• Pronator Teres
• Pronator Quadratus

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Muscle of the Proximal Radioulnar Joint

• Supination
• Supinator
• Biceps Brachii
• Brachioradialis

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Elbow (Humeroulnar Humeroradial) Joint Function

• Axis of Rotation
• Passes through capitulum and trochlea
• Carrying angle
• ROM
• Flexion
• Active 135-145
• Passive 150-160
• Depends on shoulder position
• Arthrokinematics
• Last 5-10 degrees of flexion
• Last 5-10 degrees of extension

.
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Proximal Radioulnar Joint Function

• Axis of Rotation
• ROM

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Kinesiological Concepts of the Wrist and Hand
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Wrist and Hand Bones

• Wrist
• Scaphoid
• Lunate
• Triquetrium
• Pisiform
• Trapezium
• Trapezoid
• Capitate
• Hamate

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Wrist and Hand Bones

• Hand
• Metacarpals
• Phalanges 2-5
• Proximal
• Middle
• Distal
• Phalange 1 (Thumb)
• Proximal
• Distal

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Wrist Musculature

• Primary Wrist Flexors
• Flexor Carpi Radialis
• Flaxor Carpi Ulnaris
• Secondary Wrist Flexors
• Palmaris Longus
• Flexor Digitorum Profundus
• Flexor Digitorum Profundus
• Flexor Pollicus Longus

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Wrist Musculature

• Primary Wrist Extensors
• Extensor Carpi Radialis Longus/Brevis
• Extensor Carpi Ulnaris
• Secondary Wrist Extensors
• Extensor Digitorum
• Extensor Indicis
• Extensor Digit Minimi

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Hand Musculature

• Hand Flexors
• Flexor Digitorum Profundus
• Flexor Digitorum Superficialis
• Flexor Pollicis Longus/Brevis
• Flexor Digit Minimi Brevis
• Lumbricales

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Hand Muscles

• Hand Extensors
• Extensor Pollicis Longus/Brevis
• Extensor Indicis
• Lumbricales

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Hand Musculature a Closer Look

• Flexor Digitorum Profundus vs Flexor Digitorum
  Superficialis

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Closer Look at the Carpal Tunnel

• Structures within Tunnel
• FDS
• FDP
• FPL
• Median Nerve