Skip to content


There are 4 stages of startle response

  1. Investigative response
  2. Assertion and annoyance
  3. Anger or avoidance
  4. Submission and collapse


Investigation - stage 1 of startle response

  • There is a initial suprise which leads to a investigative repsonse
  • There is a shift of position to upright as in readiness for action
  • There is a straightening of the spine, which is paradoxical because reaction to fear is folding the body inward to protect internal organs
  • There is increased focus, and therefore the body braces
  • The increase in focus affects the eyes, ears and nose which are highly alert
  • A position where everything 'stops', a beginning of startle response
  • Body is in a state of alert
  • Territorial stance to protect one's ground is seen
  • There is a high degree of attention to the threat
  • The following responses from mild caution to severe shock or terror, the degree of rigidty increases until it anaesthetizes the organism (which also affects dysassociation)
  • In an extreme state of shock, there is total immobility of the muscles, spinal cord, and the lungs, a defocusing of the eyes, and a partial congealing of the fluids and the arterial blood supply

Function of investigation

  • Identifying potential threats as harmful or safe for the individual

Muscle reaction in investigation

  • Extension of erector spina muscles
  • Slight retraction of head
  • Stabilization of the head
  • Mouth closes
  • Nostrils flare
  • Eyes open
  • Hands are ready to open
  • Arms flex
  • Chest is raised by intercostals
  • Diaphragm descends
  • Legs stiffen slightly

Muscles which can be considered for treatment