Understand and develop knowledge based on functional disorders and structural injuries along with common presentations, aetiology, healing diagnosis and management.

Muscle structure and function

Muscle structure - Label

  • Epimysium
  • Perimysium
  • Tendon
  • Fascicle

Type 1 muscle fibre

  • Slow twitch
  • Fast twitch
  • High myoglobin (oxidative) content
  • Fast contraction times
  • High quantity in endurance athletes

Type 2a muscle fibre

  • Intermediate fast twitch fibre
  • Red muscle fibre
  • White muscle fibre
  • Capable with long duration activity or contracting with force before fatigue

Type 2b muscle fibre

  • White muscle fibre
  • Fatigues slowly
  • Produces rapid force but fatigues quickly
  • E.g. 10,000m run
  • E.g. Long Jump

Structural or Functional?

  • Structural muscle injuries
    Macroscopic evidence of fibre tear
  • Functional muscle disorders
    No macroscopic evidence of fibre tear
  • Structural example
    Partial Tear
  • Functional example

Fatigue induced muscle disorders

Fatigue = some loss of  and can predispose to injury


  • Psychological and protective reflexes - generated in the brain
  • Neuromatrix


  • Neurotransmitter depletion
  • Electrolyte depletion


Exercise Associated Muscle Cramps

Painful involuntary contraction of skeletal muscle or muscle group

2 hypotheses...

  • Dehydration and electrolyte loss 

Management =

  • Active  
  • STT


Delayed Onset Muscle Soreness

DOMS = low grade muscle damage and inflammation

Cellular damage - activation of inflammatory processes which chemically and mechanically stimulate nociceptors within the muscle

  • Eccentric contractions require the actin & myosin to separate forcefully creating high tension in the muscles causing muscle soreness
  • Eccentric contractions force the actin and myosin to force together creating a collision resulting in muscle soreness

Muscle tear grading