Upper Extremity Risk Factors & Injuries

• General Injury Categories

  • Vibration
  • Epicondylitis
  • Bursitis
  • Tenosynovitis
  • Tendonitis
• Occupational Risk Factors

  • Posture = tissue overload, asymmetrical & static loading
  • Force = weakens tissue overtime, excessive overload
  • Repetition = not enough recovery between reps, muscle mechanics
  • Duration = accumulated fatigue & tissue damage
• Inflammation

  • Protective response of tissue to damage & irritation
  • Limits motion & bacterial invasion, & initiates repair
• Repeated episodes of acute inflammation can lead to formation of fibrous tissue & development of chronic conditions, resulting in increased risk of injury
• Thoracic Outlet Syndrome

  • Symptoms: pain & numbness in neck/arm
  • Mechanisms: extreme rotations, compression of nerves & blood vessels, ischemia (slowed recovery)
  • Reduced blood flow worsens condition
• Rotator Cuff Bursitis & Tendonitis

  • Extreme abduction/flexion leads to pinching of bursa & tendons
  • Inflammation & swelling in acute phase
  • Frayed bursa & tendons if chronic phase is reached
  • General pain/swelling in shoulder area
• Elbow Epicondylitis

  • Loss of grip strength
  • Pain in lateral/medial elbow
  • Unsheathed tendons = less protection
  • Large muscle groups with small insertion structures
  • Irritated tendons that radiate pain from elbow to forearm
  • Micro-rupture of fibre origin
• Lateral epicondylitis is the most common occupational tendonitis of the elbow; increased strain on lateral epicondyle from repeated use of forearm muscles
• • Medial epicondylitis = wrist flexors
  • Lateral epicondylitis = wrist extensors
• Risk Factors of Elbow Epicondylitis

  • Grasping, twisting, vibration
  • Repeated pronation/supination & forceful wrist extension
  • Unaccustomed movements
• Cubital Tunnel Syndrome

  • Symptoms: radiating pain to hands & fingers
  • Mechanisms: compressed radial nerve, repeated/prolonged elbow flexion with wrist extension, repeated trauma & leaning on workstation
  • Common with repeated typing & talking on the phone
• Pronator Teres Syndrome

  • Repeated pronation, grasping with the middle finger to the thumb/palm
  • Tight gripping, turning of tools
  • Forced pronation with elbow extension
• Reynaud's Phenomena

  • aka Vibration White Finger
  • Symptoms: numbness & tingling of fingers, pale/cold skin, decreased sensation & control
  • Mechanisms: forceful gripping, vibrating hand tools, complete closure of digital arteries, cold vasospasm in fingers, changes in microvasculature (arterial wall cell hypertrophy, blood vessel fibrosis)
• Tenosynovitis in Hand/Wrist

  • Occurs in palm or wrist from excessive use of fingers/thumb that irritate tendon sheath
  • Force & rotations (flexion/extension, ulnar/radial)
  • Tendon moves up to 5cm
  • Difficult to treat (10-30 wks) due to how compressed or "busy" the area is
• de Quaervain's Disease

  • 1st dorsal compartment on radial side of wrist
  • Symptoms: tenosynovitis & peritendonitis crepitans of abductor & extensor pollicus tendons, & radial styloid
  • Mechanisms: hand twisting with forceful gripping, friction between 2 thumb tendons & common sheath
• Trigger Finger

  • Symptoms: chronic tenosynovitis, localized finger pain, obstructed finger flexion/extension
  • Mechanisms: tendon locked in sheath on palm side, tools with hard/sharp edges, flexion/extension of digits against resistance, pistol air tool
• Wrist/Hand Tendonitis

  • Symptoms: wrist/hand compartments (flexor tendons most common)
  • Mechanisms: repeated wrist flexion/extension with force, flexor carpi ulnaris tendon (chopping/wringing motions), gripping, jolting, vibration, sudden loading, peritendonitis
• Carpal Tunnel Syndrome Symptoms

  • Peripheral compression neuropathy (most common),
  • Localized in areas affected by median nerve: pain & numbness, tingling & coldness of hands, tense & shiny skin
  • Most acute when sleeping
  • Thenar muscle atrophy (pain prevents muscle use)
• Carpal Tunnel Syndrome Levels of Impairment

  1. Dynamic (Acute)
  2. Intermediate (Chronic)
  3. Advanced (Chronic)
• Carpal Tunnel Syndrome Mechanisms

  Multifactorial & Diverse
• Carpal Tunnel Syndrome Anatomic Peculiarities

  • Size of carpal tunnel
  • Contents of canal
• Carpal Tunnel Syndrome Physiologic Factors

  Neuropathic & inflammatory conditions, alterations of fluid balance
• Carpal Tunnel Syndrome Mechanical Factors

  • Repetitive loading
  • Flexion/extension: forceful squeezing & releasing
  • Torsion of a tool
  • Friction of tendon on flexor/extensor retinaculum: inflammation = pressure on median nerve, dynamic & repetitive
  • Hand vibration
  • Repeated forces on base of palm or hand
• Conservative Care for Carpal Tunnel Syndrome

  • Remove person from mechanical source (trial basis)
  • Job modifications
  • Splinting
  • Steroid Injection
  • Only temporary in all but 20% after 18 months
• Controversial Issues in Operative Release of Flexor Retinaculum

  • Endoscopic procedure= postoperative pain & scarring, loss of pinch & grip strength, recovery
  • Open procedure = visibility & ability to control bleeding, risk due to variable anatomy of median nerve
  • Synovectomy = synovitis may be cause or result, recommended only with arthritis
  • Retinacular Reconstruction = most proximal pulley of finger flexor tendons, may permit a palmar displacement, altered biomechanics, ligament lengthening
• Ulnar Arterial Thrombrosis or Clotting

  • aka Hypothenar Hammer Syndrome
  • Recurrent blunt trauma
  • Repetitive hand hammering when use of an actual hammer would damage the work being done
  • Repeated impact of catching
• Tendons & ligaments of the shoulder responsible for stability but joint is hyper-mobile, which leads to increased risk of injury
• Bursa meant to cushion & aid in shock absorption
• Carpal tunnel has many nerves & tendons passing through from muscles of the forearm to the hand