MedSchool: Ace Your OSCEsThe Medical Company
GET - On the App Store
Hand & Wrist Exam

Muscle Inspection

August 21st, 2017

Muscle Wasting

  • Look For

  • Decreased mass of the thenar and/or hypothenar eminence.
  • Causes of Localised Wasting

  • Forearm flexor wasting - median nerve lesion, e.g. entrapment at or above the cubital fossa
  • Thenar wasting - median nerve lesion, e.g. entrapment at or above the carpal tunnel
  • Hypothenar wasting (ulnar nerve) - ulnar nerve lesion e.g. entrapment at or above the cubital fossa
  • Causes of Generalised Wasting

  • Normal aging
  • Disuse
  • Malnutrition - poor diet, malabsorption, cancer
  • Denervation - trauma, ALS, Guillain-Barre Syndrome, neuropathy
  • Muscular disorders - inflammatory myopathy, muscular dystrophies
  • Chronic disease - cancer, heart failure, COPD, infection, cirrhosis, kidney disease
  • Tip

  • Muscle wasting and shiny skin with reddish discolouration is a very specific for reflex sympathetic dystrophy.

Muscle Spasms

  • Look For

  • Spontaneous, uncontrollable contraction(s) of muscle. Note whether the spasm affects a single region, is generalised or affects the ipsilateral arm and leg.
  • Causes of Muscle Spasms

  • Exercise-induced spasm (cramping)
  • Dehydration
  • Electrolyte abnormalities - hyper/hyponatraemia
  • Hereditary dystonia - idiopathic, Huntington's, Wilson's
  • Acquired dystonia - brain damage, encephalitis, parkinsonism, brain tumour, stroke, drug-induced
  • Factitious dystonia


  • Look For

  • Visible, spontaneous localised muscle contraction and relaxation.
  • Causes of Fasciculations

  • Benign / normal
  • Lower motor neuron disorders - ALS, radiculopathy, peripheral neuropathy, entrapment, syringomyelia, Creutzfeldt-Jakob disease
  • Metabolic disorders - thyrotoxicosis, tetanus, anticholinesterase medications
Next Page
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now

Snapshot: Initialising...