Sunday, September 15, 2013

Muscle Tone vs Muscle Strength

So What Is The Big Difference?

The Difference Between Muscle Tone and Muscle Strength Explained By Diane E Gagnon, M.Ed., PT (Physiotherapist) Biddeford, Maine

Many people don't understand the difference between muscle tone and muscle strength. True muscle tone is the inherent ability of the muscle to respond to a stretch. For example, if you quickly straighten the flexed elbow of an unsuspecting child with normal tone, the biceps will quickly contract in response (automatic protection against possible injury). When the perceived danger has passed, which the brain figures out really quickly once the stimulus is removed, the muscle then relaxes, and returns to its normal resting state.

The child with high tone or "spasticity" has over-reactive response to the same stimulus. When his arm is stretched, the biceps tightens at an even more rapid rate, and the rate of recovery is much slower, even after the stimulus is removed. Full relaxation is difficult to achieve, so the muscle stays taut for an extended period of time. If another stimulus is added before the muscle has a chance to recover (which happens often during normal movement in the everyday world), the muscle contracts again, becoming tighter. Because this child's muscles never truly rest unless he is asleep, the long term result is tighter, shorter muscles with reduced joint range. This is typically seen in the child with spastic CP.

The child with low tone has muscles that are slow to initiate a muscle contraction, contract very slowly in response to a stimulus, and cannot maintain a contraction for as long as his "normal "peers. Because these low-toned muscles do not fully contract before they again relax (muscle accommodates to the stimulus and so shuts down again), they remain loose and very stretchy, never realizing their full potential of maintaining a muscle contraction over time. These are the "floppy" children who have difficulty maintaining any posture without external support. A child's unique neurological wiring determines whether he will be low, high, or normal toned.

Most people have "Normal Tone". In those who do not, a number of factors are involved. Somewhere deep in the muscle are receptors responsible for detecting changes in muscle length. These receptors then tell the brain there is a stimulus, and the brain tells the muscle to contract in response. There are numerous feedback loops to tell the brain whether the muscle has responded appropriately, needs to contract again, relax or whatever... In addition, there are receptors that tell where each joint is located in relation to all the other body parts that help to determine position in space, etc. A delay in perception, decoding, or transmission anywhere along the neural pathways will result in a change from an optimal response, or "normal" tone.

People often refer to having a "toned" body when they are in "good physical condition" and exercise regularly. Their muscles are taut, and they look lean. An out of shape person is referred to as having "poor tone", with fleshy muscles and an abundance of "fat".  Neurologically these people actually have the same "tone", and the fat person is inherently capable of looking as "toned" as the other (with some allowances made for genetic make-up of course), and just needs to exercise regularly. Fitness experts and health clubs will tell you they are "improving muscle tone", when they are actually reducing the amount of fat to lean body mass ratio.

You can improve your fat to lean body mass ratio, and you can become stronger too. These are under your voluntary control. Muscle tone occurs at an involuntary level. We can effect changes in muscle responses with sensory integration treatment techniques that increase the "alert state of the muscle" by bombarding it with sensory stimuli and improve the brains ability to perceive changes in muscle length, preventing it from accommodating to stimuli.

With ongoing treatment and practice throughout the day, the more "normal" response elicited, the stronger and more efficient even low toned muscles become. "That" is the basis of our classroom program for children with low tone. Sensory bombardment can effect changes in perception that then lead to changes in efficiency along the neural pathways. But it goes way beyond a couple of hours a week in the gym.

© 1999 Diane E. Gagnon, M.Ed., PT Biddeford, Maine 04005, USA

My little Emmalin and a fine example of low tone.  So hard to believe this was comfortable.


Tone by Loren Shlaes-Pediatric Occupational Therapist

As a therapist, I sometimes forget that civilians don't understand all of the professional jargon that my colleagues and I use to communicate with each other. I try, when I write an evaluation of a child, to explain what each thing I assess means, and most important, how it affects the way the child functions. But when I hand over a 12 page report to a parent, I have to remember that not everything is sinking in all at once, and that the information I'm conveying has to be absorbed, bit by bit, as the parent can integrate it.

"Low tone" is something we occupational therapists talk about quite often. But parents complain to me that they have no idea what that means. Sometimes it's quite obvious -- the mother of one of the children that I treat just had a baby, and she called me to tell me that the baby is so weak and floppy that it can't tighten its fist around an index finger placed in its palm. Other times it's not nearly as apparent, and a child can appear to be quite athletic and still be plagued by all kinds of problems associated with low tone.

Tone is the amount of electricity that courses through the muscles and allows them to do the jobs of extending the body against gravity, contract themselves around joints for balance and stability, and work for long periods of time without undue fatigue. An example of someone with plenty of tone is a professional athlete or dancer. I'll never forget the time I met my favorite baseball player, Dennis Eckersley. He practically crackled, he had so much juice and electricity flowing through his body! As far as I know, there is no one definitive reason for low tone.

Some people believe that it is a nutritional issue, and that for some reason the body is not delivering, {perhaps because of dietary issues or metabolic difficulties} or the muscles are not utilizing, the raw materials needed for maintenance and sustained use. The child's muscles don't develop well, and so they tire easily.

An under responsive vestibular system can be a possible reason for low tone. The vestibular nerve is responsible for many things. It tells us, along with our eyes and muscles, where we are in space. It also responds to how much and what kind of movement we get, and communicates directly with the muscles that extend us against gravity and allow us to be upright. It also talks to the part of the brain that is responsible for alertness, attention, and arousal. If the vestibular nerve is not picking up and processing this information correctly, the result will be insufficient muscle tone and chronic low arousal.

Another issue that interferes with the child's ability to function is delays in the maturation of spinal reflexes. When a child is born, its nervous system is immature, unlike a horse's -- a pony can get up and walk shortly after birth. Humans start out instead with nervous systems that respond by increasing or decreasing muscle tone in response to certain stimulation, and then go on to refine themselves through movement and play until voluntary control is established. Then the reflexes disappear. If they don't disappear and are dominating the nervous system, the child will have difficulty working his body against gravity.

If your child tires easily, complains that he doesn't have any energy, can't sit up while he's writing, is a chronic slumper, or has a hard time sitting still or sitting on the floor, chances are his tone is low, even if he appears to be athletic. I've seen plenty of boys who could pitch a ball like Roger Clemens -- but their core strength was so weak that they couldn't do a single sit up or lift their chests and thighs up off the floor when lying on their bellies. Children with low muscle tone have an especially difficult time of it in school, because their bodies don't have the effortless uprightness against gravity that allows them to sit still. If they are struggling to stay upright, they're using the mental and physical energy to sit that they should be applying towards attending to the lesson.

I once went to school to observe a little boy who acted out a lot, especially during circle time, when all the children had to sit cross legged on the floor. The day I saw him, during circle time, he sat with his legs straight in front of him and his hands behind his back on the floor, using his arms to brace himself. He simply was not able to sit in the traditional "criss cross applesauce" position, and needed the additional support from his arms, and wide base from his extended legs, just to stay upright. I saw immediately that he was so uncomfortable sitting this way, and that it was so much effort, that he couldn't sit on the floor and attend to what was going on at the same time. He didn't have enough sophistication in his language to tell anyone what the problem was. His only recourse was to refuse to stay there for very long, and this was viewed as disruptive behavior. I suggested to his teacher that he either be allowed to sit in a chair or that he be assigned a place against the wall so that he could sit with his back supported. He was much happier after that, and he was much more able to attend. Low tone affects many aspects of function, which I will address in future posts.  Meanwhile, if your child has low tone, no amount of yelling at him to sit up straight will help. Try incorporating activities to strengthen the trunk, like sitting on a therapy ball while doing homework or watching TV, doing sit ups and pushups, wheelbarrow walking, wrestling matches, and playing with whistles, bubbles, and blow toys to your child's daily routine. Spinning is good for vestibular activation, if your child likes to spin. Or take your child outside and play tag or ball, or organize a game of statues or red rover with other children in the neighborhood.

So Now What?


Your child’s doctor will run a series of tests to determine the extent of the condition. He may use x-rays and other tests to check muscle and nerve function. He will also assess your child’s balance, coordination, and motor skills. Whenever possible, your child’s underlying medical condition will be treated.


Hypotonia may sometimes gradually improve with treatment. A physical therapist might use a sensory stimulation program, which involves facilitating muscle contractions by stretching and tapping the muscles. Physical therapy may help improve fine motor control. Your child will also likely be treated by an occupational therapist. The occupational therapist will also work to improve fine motor control.

Speech Therapy

Low tone does not stop with physical and occupational therapy.  Low tone in fact plays are large role with our kids speech.  Children with hypotonia often have trouble breathing and vocalizing. Hypotonia can affect the ability to move oral structures like the jaw, lips, and tongue. It can also affect the quality and rate of speech, often resulting in slurred or slowed speech. A speech-language pathologist (SLP) can help your child improve his swallowing and feeding abilities, as well as address his speech delays. She may help him improve his oral motor skills, which means that he will have better control over his mouth muscles. 

See more at:

Emmalin started hippotherapy to help with the low tone.  The horse will be a great addition to our therapy program.

1 comment:

  1. I finally got around to reading this whole thing...I've been behind on my email for awhile now :-) Thanks so much for finally helping me understand what low tone was really about. I'll have to read it through another few times to really absorb this completely, but it's so interesting to read about how the whole body works together.