UMN signs(pattern of weakness)

Last reviewed 01/2018

The distribution of weakness after upper motor neurone lesions is:

In the upper limb:

  • shoulder abduction
  • wrist and finger extension and finger abduction are weaker than antagonist responses

In the lower limb:

  • hip flexion, knee flexion, dorsiflexion and eversion of the foot are weaker than their antagonists' action
  • patient may be unable to lift the leg off the bed and can have a foot drop at a time when hip extension and quadriceps function are normal and it is possible to stand on 'tiptoe'.