My child has been diagnosed with low muscle tone. What does this mean?

Who gets a diagnosis of low muscle tone?

An infant or child will get a diagnosis of low muscle tone when:

  • The muscles appear to be less firm than usual
  • The child appears to be floppy and to have loose joints
  • The child appears to be less alert and have poor posture and attention

For a more technical discussion please see Rethinking Low Muscle Tone



FAQ'w.jpgThe difficulties experienced by children that lead to diagnosis of low muscle tone 

  • May be late learning to sit and walk - but not always
  • Have trouble sitting erect and working at a table - tend to sit with back rounded, may lean on one hand when drawing and writing
  • Have difficulty sitting still, tend to fidget, not complete school tasks
  • Have difficulties with handwriting and drawing 
  • May tire very quickly, not like walking far, have trouble going up stairs
  • May be good at games that involve short bursts of running, but have difficulty with posture in sitting, drawing and handwriting - these tasks require sustained activity in the postural muscles
  • Sit between legs on floor (w-sitting), do not like cross legged sitting
  • Appear to have poor attention span or concentration, give up easily
  • Cannot hang on the monkey bars, do not like climbing on the jungle gym, are fearful


    It is important to note that all these difficulties are in fact related to a mixture of coordination problems, muscle tightness, weakness and poor endurance, generalised joint hypermobility, attention difficulties, a very cautious nature and avoidance of tasks that require effort and persistence.  

Help your child overcome these difficulties - implement a training program to improve strength, flexibility, stamina and coordination and courage.


What causes these difficulties? 

The most common cause of these difficulties is joint hypermobility  associated with a cautious temperament.

In individuals with hypermobile joints (loose or lax joints) the connective tissue structures that hold the body together have more give (are more easily stretched) than usual. This means that the muscles must work harder than usual to hold the keep a good posture and move. 

Joint hypermobility is probably the main  (and often unrecognized)  reason a child get a a diagnosis of low muscle tone. 

Children with a cautious temperament  are often quite anxious  which leads to avoidance of tasks that require effort and a tendency to give up very quickly. This in turn leads to low levels of activity, weakness and poor endurance. 

Read more here about the link between joint hypermobility and low tone 

Recognizing joint hypermobility

finger extension_0.jpg

Fingers that bend back to 90 degrees

wrist flexion_1.jpg

Wrist can be bent so that thumb touches the forearm 

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Knees and elbows  bend backwards 

Hypermobile joints and tight muscles as a cause of movement difficulties

Sometimes joint hypermobility is missed because the child appears to have tight muscles. It is important to understand tight muscles is a common feature of joint hypermobility, especially in the muscles crossing the back and sides of the hips.  It is also important to understand that this muscle tightness if often an important underlying cause of some of the difficulties experienced by children with a diagnosis of low muscle tone. 

ben longsitting slumped.jpg w sitting.jpg sitting slumped hips abducted.jpg
Tight back and hip muscles affect sitting posture in children with joint hypermobility

What exactly is muscle tone?

The term muscle tone refers to two aspects of muscles structure and function.

  1. The inherent stiffness of a muscle - its resistance to being stretched and firmness when palpated (squeezed).
  2. A muscle's (or groups of muscles') readiness for action - the muscle's responsiveness to signals from the brain and to sensory feedback.

    The term low muscle tone is used when the muscles' stiffness is less than usual (ie it is low) and the readiness for action is also low (muscles respond slowly).

​How is a muscle's firmness (tone) tested?

The clinician makes a judgment about a muscles firmness and inherent stiffness by:

  • Squeezing the muscle to feel the resistance to compression
  • Lifting up and moving the limbs and feeling the resistance to this movement 

What determines a muscle's firmness? 

The firmness of a muscle is determined by its inherent stiffness and this in turn depends on the stiffness in the connective tissue sheaths that encase each muscle fiber, hold the bundles of muscle fibers together and connects the muscle to the tendons.

In children with hypermobile joints  the connective tissue is less stiff than usual. (It has more give and is more easily stretched).

This tendency for less stiff connective tissue which results in hypermobile (lax)  muscles and joints is genetically determined. About 10-15% of people are hypermobile.

The other very important structure that that determines a muscle's firmness and resistance to being stretched is the giant molecule titin. 

Titin is a very large elastic molecule found within the muscle cell.  The size and strength of the titin molecules is determined by the  amount of work a muscle is made to do on a regular basis. Strong muscles have larger and stiffer titin molecules - and this makes the muscle firmer and stiffer.  The muscle has better tone.

Generally speaking, strong muscles are firmer and have better tone.


Muscle tone, alertness and readiness for action

The term muscle tone is also used to describe the a muscle's readiness for actionThis is set by the child's alertness,  general level of arousal and readiness for action.  

The brain primes the muscles for action by sending signals to the muscles’ sensory receptors.  In effect the sensory receptors become more alert and provide more effective sensory feedback and respond more quickly. This allows for the rapid adjustments needed for maintaining balance and postural stability.

  • When a child is alert and engaged,  the muscles are primed for action.  The muscle tone is good and the posture is erect.
  • When a child is over-aroused, the muscles may become twitchy and overactive.  This makes the child less able to focus attention on a task.
  • If a child is anxious, finds a task difficult and is having trouble focusing his attention, the normal alertness for action signals do not reach the muscles. They become less responsive and provide less sensory feedback.  Muscle tone is lowered and the child's posture becomes less erect and alert..

Can low muscle tone be cured? Yes - by addressing the underlying causes 

The behaviors associated with a diagnosis of low muscle tone can be improved with a training program that addresses the underlying difficulties

Weak muscles can be strengthened to improve posture, sitting posture and endurance, jumping,running and other outdoor activities.

Tight muscles can be stretched to improve sitting posture.

General fitness and stamina can be improved with training.

Sitting posture and endurance can be improved with a combination of exercises for strength, flexibility and coordination.

Poor coordination can be improved with task based training.

Task avoidance can be improved by addressing anxiety issues, training courage and improving confidence.


How you can help your child - starting today

Start by identifying the things that your child cannot do and then implement a training routine to address the things that are causing the difficulties. Read more

 

More about babies with joint hypermobility and associated low muscle tone

How low muscle tone affects an infant's development and what you can do to help your infant. Read more

 

Comments

Question

I have a 2 year old boy who trips over a lot when walking & has poor posture he arches his back a lot.. How do I help him I've been so worried since he was 18mths and it really hasn't improved. I went to my local physiotherapist and she said he had mild peripheral joint hypermobility & decreased central tone. I have took up swimming with my son & also purchased a little play gym for him to use at home but still he keeps falling over. He isn't able to balance either like on a trampoline he can walk slowly but not jump. Is there anything else I can do. He is very active and can climb no problem it just seems to be walking & running he also walks a lot on tip toes or with knees locked & won't walk down steps but will walk up holding onto a rail..

Several causes for frequent falls and toe walking

Hello

Thank you for your interesting question. 

Your child's tendency to frequent falls and toe walking may be caused by a number of conditions. It may be due to a condition called idiopathic toe walking.  I find that this is usually associated with generalized joint hypermobility with associated tightness in the hip and calf muscles. 

Did you see a physiotherapist with pediatric experience and did she rule out any other reasons for your child's walking difficulties? If not I would suggest that you see a developmental pediatrician to rule out any other possible explanations for the frequent falls and toe walking. 

Whatever the underlying cause your child will need physiotherapy for loosening tight muscles, strengthening weak ones and improving balance when walking.  This is important so you need to find a developmental physiotherapist who recognises and deals with the problems effectively.

Pam

Bike riding

My 9 yr old autistic son learned how to ride a bike at 8 yrs of age. We live on a main road so it was difficult to take him out as the traffic is so distracting. I heard form a local person at the park about an indoor bike park. We arranged for him to have lessons two nights in a row and it was amazing as this place had ostacle courses and beams and it looked really interesting and fun. The instructor was fairly young himself and he took the training wheels and the pedals of immediately and set the seat lower so that my son could put his feet on the floor. The lesson was an hour long on both nights but you could stay and ride after the lesson was over. After the second lesson my son was doing just fine riding quite well. It was also good that they taught him proper positioning of the bike and manoeuvering around things. After that experience he was confident at riding his bike. It was a great experience and well worth the money. Hope this helps

Bike park

Hello

Thank you for telling us about the bike park - sounds like a really fabulous place. 

It might be a good idea to make a list of such places. If you know about such places please  post the location in the comment box below.  

 pam

My son, who will be 3 in

My son, who will be 3 in early October, has had some trouble we have been watching since February. He was diagnosed with very mild autism a year ago. We first noticed the issues with his walking when he would trip and fall over nothing 2-4 times in 30 minutes and also would collapse to the floor when put on his feet after being carried. We then noticed he walked "off balance" his steps can weave back and forth. He also is just learning to jump but very seldom tries and doesn't really run. He has limited to no reflexes in his knees and ankles according to a neurologist. We saw his old doctor about the issue (have since moved) and she referred us to neurology. Neurologist watched him walk 5 steps or less tested reflexes and order an Emg and nerve conduction study. Both returned normal results. After our follow up last month, I noticed my son's legs seem to fall in pretty far over his feet at his ankles. Is this a product of low muscle tone?

Autism, hypermobiity and DCD

HI

Lots of good news then from your neurologist then. Pity though that they do not recognize joint hypermobilty which is probably the reason for his ankles looking wobbly.

So you have three factors contributing to the falling - very flexible joint, muscle weakness which goes with the hypermobility and difficulties with balance and coordination which is related to the autism.   Along with all of this he possibly also has a  cautious nature

And here is more good news. Muscles can be strengthened and coordination can be improved with training.  And cautious children can learn courage and determination.

And here is a little bit of bad news.  I am in busy writing the toddler pages on the new developmental gym website  but the process has slowed down because I am nursing a bad break of my left hand and typing with one hand is a very slow process. But with practice it is speeding up!

But the one page that there is is a good place to start. See Lifting and carrying for walking balance, strength and endurance.

And also see if you can get to see a physical therapist - that is your very best option. 

Pam

Knee pain

Hi my daughter is a 18y/o with dx of NF1 at the age of 2. She was told she is low muscle tone. She received Early Intervention then moved into public schools SPED at 3y/o. She received PT,OT and speech. All of the symptom you listed in your information she plus she would vomit easily at birth till toddler age. My daughter last year was on spring track- field - between the exercises and spinning around to throw,I believe this made her complain of pain in her legs which eventually went away after her stopping practice and meets. When she was yelling out to me, grimacing face--that she was in pain it reminded me when she was young with growing pain. She on swimming team this fall and the dry land running --she now c/o knee pain- the trainer wrap the knees. Is this common what she is experiencing. Your list of symptoms was only explain to in dept by PT- (the MD explain some basic info. when dx at 2).
My daughter still receives speech now but no longer receives PT/OT. Also, what credentials is your staff- are you doctors or rehab?

Knee pain and NF1

Thank you for your question. It sounds like your daughter is doing very well. 

NF1 is sometimes associated with joint hypermobiliy - and hypermobile joints are more prone to injury. 

If your daughter has knee pain with sporting activities she really needs to see a PT for a popper assessment and advice on how to protect her joints as well as an appropriate strengthening program.  There is no substitute for this. 

This is a sports injury and should be managed as such. 

Pam 

 

Bike riding

If my child has low muscle tone does it realistic goal to tach him how yo ride a bike. It seems like he has difficult time with it. He is 11 yo.
Thank you

It all depends

Hello 

Thank you for your important question and my apologies for the slow response. I managed to sustain a spectacular fracture of my left arm last week - so my life has gone into slow motion!

Low muscle tone is such a vague and essentially meaningless term which means that I really cannot say anything about bike riding at all.

Riding a bike requires strength, balance and coordination. If your son is hypermobile with associated muscle weakness and a very cautious nature but  no coordination difficulties learning to ride a bike may take extra time and effort but should be possible.  It really all depends on how keen he is on being able to cycle. 

If your son has a coordination problem - he can also learn to ride a bike but it will require extra time and effort. 

It may help to start by riding an exercise bike. Then you can first get the peddling action sorted out and work on strength and endurance. Next try cycling on a smooth flat surface - maybe an empty car park to get peddling and balancing going. Be prepared to run along holding the saddle until he gets the idea.  A flat area of grass also works well. 

Lastly work on steering the bike. 

And remember this may take a great deal of hard work, persistence and practice but will be worth it once you see your kid whizzing down the road on his bike. 

Good luck and let us know how you get on. 

Pam

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