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NEUROMUSCULAR DISORDERS: Sports & Occupations

Sports/Occupation
Abattoir
Backpacking
Baseball
Bicycle
Bodybuilding
Bowling
Cold exposure
Football
Mountain climbing
Musicians
Running
Surfing
Volleyball
Occupations
Abattoir: Immune
Batteries: Lead
Cabinet maker: Hexacarbon
Copper smelting: Arsenic
Demolition: Lead
Dentist: Nitrous oxide
Dry cleaner: Trichloroethylene
Epoxy resin: Allyl chloride
Farmers: Organophosphates
Glass & Ceramics: Tellurium
Mining: Arsenic
Painter: Hexacarbon
Plastic industry: Acrylamide
Rayon industry: Carbon disulfide
Rubber industry: Trichloroethylene
Tool use: Vibration syndrome

BASEBALL

Local Nerve Lesions Other Disorders

BODYBUILDERS 1

Local Nerve Lesions Muscle Joint disorders


BOWLING

Neuroma of digital nerve to thumb ("Bowler's thumb")
Acute sensory neuropathy of thumb

SURFING

Saphenous nerve lesion at knee

Myelopathy 9

BICYCLING 6


FOOTBALL


MOUNTAIN CLIMBING & BACKPACKING


TENNIS


RUNNING


SKIING

Ski Boot neuropathies

HOCKEY 7

Neuropathies

MUSICIANS, INSTRUMENTAL 4

Playing-related disorders: General Musculoskeletal disorders: 64% Peripheral nerve disorders: 20% Focal dystonia: 8%


Hand-Arm Vibration Syndrome (HAVS) 3

  • Exposure
    • Regular use of vibratory tools: Risk proportional to
      • Magnitude & duration of vibration exposure
      • Vibration frequency: Harmful frequencies 8 to 1,000 Hz
    • Professions
      • Lumberjacks: Chainsaw
      • Drilling
      • Metal working: Fettling tools
    • Association with: Tobacco use (7x risk); Cold
  • Clinical
    • Onset
      • Paresthesias, continuous or relapsing
      • Latency: Mean 6 years; Range 1 to 17 years
    • Sensory loss
      • Onset: Often initial feature with pain
      • Panmodal
      • Arms
      • Distribution: Distal; More diffuse than single nerve
      • During & after exposure: Especially during night-time
    • Pain: Wrist, Palm, or Fingers; Often worse at night
    • Motor: Weakness; Reduced manual dexterity
    • Vascular
      • Raynaud's like symptoms
      • Vibration white finger
      • Local autonomic neuropathy
      • Onset: Later than neurologic features
      • Prognosis: Worse with age & smoking
    • Joint: Dupytron's contracture (Ring finger)
    • Associated disorders
    • Course
      • Neurosensory symptoms: Continued
      • More severity & white finger syndrome with continued vibration exposure
  • Laboratory
    • NCV
      • Abnormal motor & sensory potentials in arms
      • Multifocal pattern: Ulnar, Median, Radial, or Digital
        • Multiple-site lesions in segments of nerves
        • Lesions especially common distal to wrist
    • Vascular pathology: Thickened walls of digital vessels; Occlusions

SUPRASCAPULAR NEUROPATHY

  • Anatomy
    • Roots: C5-6
    • Brachial plexus: Upper trunk
    • Muscles innervated: Supraspinatus; Infraspinatus
    • Sensory cutaneous innervation: None
  • Entrapment & Lesions
    • Weakness: Arm abduction & External rotation
    • Locations
      • Suprascapular notch
        • Weakness: Supraspinatus & Infraspinatus
      • Spinoglenoid notch
        • Ligament over notch: Male > Female
        • Weakness: Isolated infraspinatus
    • Causes
      • Ganglion
        • Diagnosis: MRI or Ultrasound
        • Location
          • Spinoglenoid notch 75%
          • Suprascapular notch 20%
      • Nerve stretch: Overhead sports
      • Repeated trauma in notch
      • Shoulder trauma or damage
      • Surgery
        • Arthroscopy
        • Posterior shoulder approach
      • Familial calcification of superior transverse scapular ligament
  • Differential diagnosis
  • Sports
  • Clinical
    • Pain
      • Shoulder (Posterior & Lateral)
      • Less & more inferior with spinoglenoid lesions
      • Exacerbated by: Adduction of extended arm
    • Tenderness: Suprascapular notch; Over infraspinatus fossa
    • Weakness & wasting
      • Infraspinatus > Supraspinatus
      • Reduced arm abduction & external rotation
  • Laboratory
    • Electrodiagnostic
    • MRI or ultrasound: May localize ganglion
  • Treatment
    • Modalities
      • Rest
      • Nerve decompression
    • Outcomes
      • Reduces pain
      • ± Improvement in strength
Suprascapular nerve
Spinoglenoid
notch
Suprascapular notch


AXILLARY NERVE

Gowers
Deltoid weakness
Shoulder is elevated by trapezius.
Slight abduction by supraspinatus.

Quadrilateral (Quadrangular) Space Syndrome

  • Pathology: Nerve & vessel damaged or occluded in quadrangular space
    • Distal branch of axillary nerve
    • ± Posterior humeral circumflex artery
  • Clinical
    • Age: Young adults; 22 to 35 years
    • Pain
      • Shoulder; Poorly localized
      • Increased by: Abduction & external rotation of arm
    • Tenderness
      • Quadrilateral space
      • Near insertion of teres minor muscle
    • Paresthesias: Lateral shoulder; Upper posterior arm
    • Weakness
      • Muscles: Teres minor ± Deltoid
      • External rotation ± Abduction of arm
      • Dominant extremity
  • Sports
    • Baseball
  • Differential diagnosis
    • Other axillary nerve change
      • Anterior shoulder dislocation
      • Humeral neck fracture
      • Brachial plexus stretch injury
    • Shoulder injury
    • Subclavian artery stenosis
  • Lab
    • EMG: Denervation of teres minor
    • MRI
      • Selective atrophy: Teres minor ± Deltoid muscle
      • Tendon: Normal
    • Subclavian arteriography
      • Posterior humeral circumflex artery
        • Occluded with abduction & external rotation of arm
        • ? Non-specific: Occlusion may also occur in normals



MUSCULOCUTANEOUS NERVE


Long Thoracic Nerve


MEDIAL PECTORAL NERVE 2


HAMSTRING STRAIN 5


NOTALGIA PARESTHETICA 8


ENVIRONMENT: COLD EXPOSURE & PAINFUL SENSORY NEUROPATHY 10


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References
1. Muscle & Nerve 1998;21:809-812
2. Muscle & Nerve 1999;22:1597-1599
3. Clin Neurophysiol 1999;110:1276-1283, Int Arch Occup Environ Health 2006;79:665–671
4. Muscle & Nerve 2003;27:549-561, Neurologist 2002;8:163-174
5. Clinical Experimental Pharmacol Physiol 2004;31:546–550, Med Sci Sports Exerc 2004;36:756-759.
6. Sports Med 2006;36:7-18
7. J Sports Med Phys Fitness 2009;49:224-231
8. SKINmed 2011;9:353-358, Acta Clin Croat 2018;57:721-725
9. Neurosurgery 2016;78:602-611
10. Brain 2017; Online August

9/5/2019