Poor Muscle Tone/hypotonia is a condition of abnormally low muscle tone; the amount of tension or resistance to the movement of a muscle.

Low muscle tone occurs when the length of the resting muscle is slightly longer than typical. As a result, the person’s muscle needs to go through a greater range of motion which consumes more energy.

Hypotonia, or poor muscle tone, is usually detected at birth or during infancy. Depending on the underlying cause, hypotonia can appear at any age.


Signs of hypotonia in infants and children include:

  • poor or no head control

  • delay in gross motor skills development, such as crawling

  • delay in fine motor skills development, such as grasping a crayon

Signs of hypotonia at any age include:

  • the decrease in muscle tone

  • decrease in strength

  • poor reflexes

  • hyper flexibility

  • speech difficulties

  • the decrease in activity endurance

  • weakened posture

Causes include:

  • Problem with the nervous system or muscular system

  • genetics including down syndrome and Prader-Willi syndrome

  • Injury or illness

  • Inherited disorder