What is hypotonia? ‘Low Muscle Tone’

Hypo – Low
Tonia – Muscle tone

As Paediatric Physiotherapists at Ocean Kids Health we see a wide range of different conditions. One condition we commonly observe in children is hypotonia (which is also referred to as low muscle tone). Hypotonia is a common finding in babies and children with delays in motor milestones, gross motor and fine motor skill development, those struggling with fatigue and being unable to keep up with peers in physical activity. Hypotonia can occur idiopathically (meaning unknown cause) or may be a feature of an underlying neurological or genetic condition.

There is NO specific assessment tool to diagnose Hypotonia. It is a clinical observation of skin, movement, muscles, activity and postures by a trained allied health professional.

What is Muscle Tone?

Muscle Tone is level of resting muscle tension in our muscles. It is the ability of our muscles to hold up our body when sitting or standing. Even when our muscles are at rest, there is always a level of a passive activity in our muscles. Muscle tone assists in providing joint and postural stability, and provides our brains with feedback (proprioceptive information) on where our joints and extremities are located. All children’s bodies are different. Children will either have higher or lower resting tone whilst others fall in the ‘typical’ muscle tone range.

Children with hypotonia will often have more difficulty maintaining an upright posture for long periods and may tend to slouch or prop on things as they are more easily fatigued. Their bigger muscles have to do more work to keep them upright against gravity which drives fatigue.

Child with low muscle tone:

Child with ‘normal’ muscle tone

 

 

 

 

 

 

 

 

 

An easy way to think about muscle tone is like a spring! Typical or ‘normal’ muscle tone is a spring wound just tight enough to stay upright and keep an ideal shape, whereas in hypotonia the spring (our muscles) are less taught and floppy as demonstrated below.

How are muscle tone and strength different?

Muscle tone is the level of passive resting tension in our muscles. The ability to actively contract and use our muscles voluntarily is known as muscle strength. Strength is the ability of our muscles to produce force for a given task. For example when kids are running or jumping, they need more muscle contraction/s than when resting.

Thus meaning, kids with hypotonia need to use more energy and more muscle strength as their ‘springs’ or resting tension in their muscles is lower than other children. Using their strength to compensate for low muscle tone requires more energy for all activities, which leads to children appearing tired or fatigued earlier than those within the typical muscle tone range.

Signs of Hypotonia in children:

Below are some the common signs of hypotonia that you may see in your child:

  • Babies may be ‘Floppy’ or limp when you pick them up
  • Tired easily or quicker than other children their age – wanting to lay, sit or be carried more frequently
  • Poor postural endurance – may be able to sit up straight or still for shorter periods than their peers
  • Increased joint flexibility or hypermobility
  • ‘W’ sits frequently – this increases their base of support, which makes sitting less fatiguing for them
  • Flat feet – Some children with very flat or ‘pronated’ feet may need to see a podiatrist for orthotics
  • Uses arms for support when sitting or lays on couch/seat.
  • Unable to sit or stand in the same spot for long periods – needs to move
  • May struggles with eating (chewing, swallowing or may have speech delays.
  • May or may not have delays in meeting age matched milestones such as crawling, walking, running or jumping.
  • Often wanting to be carried or less tolerant of walking / running long distances

Physiotherapy strategies to help your child:

Some strategies you can try at home to manage your child’s hypotonia include:

    • Structured rest.
      It is important that our children’s bodies have time to recover, just like if you were to go to the gym. Having structured breaks incorporated in your child’s routine is important to ensure they have the energy they need for activities. Children with hypotonia will need MORE REST than their peers with ‘normal’ muscle tone. We recommend full body rest after school e.g. in a bean bag. Allow your child to sit down and have rest breaks when going for long distance walks / bike rides.
    • Focus on strength.

Strength based training is great in building a child’s global or overall strength. Animal walks are a fun and easy way to target multiple muscle groups and can easily be built into your daily routine. E.g. bear walks down your hallway. Building your child’s strength will help to improve their physical capacity, posture, participation and reduce fatigue. Another fantastic strengthening activity is swimming, which is low impact, but fantastic for building strength and cardiovascular endurance! Check out our blog on core strength for more info.

  • Supported seating options.
    Providing children with an appropriate seating option such as high back chairs or arm rests will allow their bodies to use less energy when sitting which can increase their participation during the day.
  • Proprioceptive input.
    Many children with hypotonia have reduced awareness of their body position and struggle with balance or coordination, completing heavy work exercises can help increase your child’s body awareness and built their strength. Some ideas include:

Heavy work activities can include:

  • Pulling – Along a heavy cart
  • Lifting – carrying a heavy basket or shopping bags or building a pillow fort
  • Carrying – a basket with wet clothes
  • Pushing – A weighted pram
  • Jumping – On the trampoline
  • Chewing – crunchy foods
  • Squeezing – Using theraputty
  • Climbing – On anything!

Hypotonia is a very common condition that can affect children in different ways. Our team of Paediatric Physiotherapists and Exercise Physiologists here at Ocean Kids Health can help to assess and diagnose your child, then work with you and your child to formulate an appropriate treatment plan. It is important to seek professional advice on the cause of your child’s hypotonia and ensure they have the best plan to help them thrive!

Thanks for reading

Emily de Groot
Paediatric Physiotherapist
Ocean Kids Health

Our Ocean Kids Health team are here to help you and your child thrive!