The overwhelming majority of small babies with damaged brains have perfectly normal posture during sleep. When they are awake and attentive, looking at you, but not moving, they are similarly normal. The abnormal signaling from their brains is only evident when you move them or later when they try to move spontaneously. A normal child gains head control first, then neck control and later trunk control. All normal movement patterns of the limbs depends upon the baby first developing core strength and control.
Having examined literally thousands of babies with documented brain injury in the NICU and in the Neonatal Follow-up clinic at the Hospital for Sick Children in Toronto, I can confidently state that the first presenting abnormal neurologic sign, in the majority of babies, is low tone, muscle weakness. This persists into infancy. The babies develop neck control late and often arch their head backwards. However, if the trunk is well supported by parent or therapist, the abnormal arching decreases. The developmental sequence of normal and abnormal movement patterns is brilliantly documented in the new version of Lois Bly’s classic book.
I strongly advise all parents of young children with neurologic problems and the therapists that treat them to purchase this book and study it. It shows you the normal patterns that you are trying to achieve and allows you to recognize the abnormal patterns as they develop.
In the bad old days before we realized that baby brains can recover, the goal was to teach the child compensatory strategies… ways to inhibit abnormal movements… with the ultimate goal of functional independence. Normal movement patterns were often sacrificed for functional gains. To this date, many children with mild impairments are discharged from therapy as “good enough”. They are functionally independent, even though they walk with a limp and may have only one hand that works normally. To the gatekeepers of therapy services, they have reached the goal of independent walking or writing. In my view “Good Enough is not Enough”. If full recovery is not expected, it can never be achieved.
I believe that the 2013 goal should now be normal or better function for all these children with mild to moderate injury. For those with a more severe injury, the bar also has to be set much higher than it has been in the past. In my medical training, I was taught that you could confidently predict the outcome of a child with cerebral palsy by the age of 3 to 4 years. I now understand that accepting a lifetime prognosis at this early age was completely wrong. Neuroplasticity is possible even in old deteriorating brains. Surely our young deserve a better outcome than “good enough”.
Here is the problem. NDT therapy and every other early intervention therapy teaches parents ways to inhibit abnormal movements and the good ones teach techniques to strengthen the core muscles. A terrific idea in the abstract, but rarely achieved in real life. Parents cannot support a child’s developing trunk muscles during all the waking hours and therapists are only available for 1-3 hours a week.
Core muscle strength is a prerequisite for the postural control and balance that underlies all movement skills. I think it is useful to examine the importance of the core in Athletics. When I was young tennis player, my pro encouraged strength training and cardiovascular fitness off the court, but no direct exercises for the core. Sports related injuries were a big problem, largely caused by unbalanced muscle pull and a comparatively weak trunk. Over the last 20 years or so people have gradually realized the importance of these basic stabilizing muscles. This is an easy to read abstract.
Obviously a baby cannot do the exercises to increase core muscles that are used by athletes. However, the underlying principle of “proximal stability for distal mobility” is it universal rule of movement.
A strong core is also of great significance in the aging adult. This is a good summary that also provides you information of specific exercises for the muscles involved in developing core strength.
If you read through this link, you will understand that strengthening these muscles is a complicated process. Learning to control and sequence the action of all these different types of muscle is hard for the baby and this difficulty explains why it takes the baby a good 6 to 9 months, in the normal situation, to sit steadily and start to consider other movement options.
How do you assess core weakness? Clinically it is dead easy. You put the baby or child into a sitting position, providing pelvic support. Look at their back. If it curves down in a “C”, they have trunk weakness. When I ran the Magee Clinic, I realized that we needed an objective measure of change in core weakness. Anne White, an occupational therapist and I developed a method to easily assess the degree of core weakness in children with various neurologic disorders. The Slump Test was published in the American Journal of Occupational Therapy 20 years ago.
Although this test has been fairly widely used as an objective measurement of change in research programs, it has not been used widely in clinical practice. I believe strongly in the value of measurement, both to document change and to diagnose early the problem of “no change”. The almost uniform reluctance by therapists to measure the degree of trunk weakness may be interpreted several ways. Some surely think it is a waste of time. But there is another more difficult explanation, that some do not want to document lack of progress. After all, many of the insurance reimbursement policies are based on documenting positive change. When we measured change in trunk strength routinely, we found that many of the time honored techniques to strengthen the trunk actually had little, if any, measurable effect. More on the fear of “No Change” later.
The assessment that is used for the majority of children is a subjective clinical assessment. The infant is held as described above and the therapist or physician judges how “slumped” the child is on that day. No record is kept for future comparison. The older child is examined for sitting balance on a bench. The therapist looks for compensatory movements such as tightening of the hands or legs. I also like to look at the child’s hand use while lying on the back or in side lying versus hand use in the sitting position. A record may be kept, but it is subjective. In my experience, photographs and/or measurements are rarely done.
For parents, if the child demonstrates fisting in the sitting position, check again with the child in supported sitting, between your legs, leaning back on you. In older children, look at what happens to the hand when they are up and moving. A child with a mild hemiplegia may demonstrate relatively good hand function in supported sitting, but has a fisted hand and retracted arm when running.
In all cases, the improved function with support demonstrates that there has been some degree of brain recovery. Poor balance and postural control is the underlying problem that creates the increased in tone and deteriorating function in less supported positions.
Recently I was speaking to a young father about the concept of Habit Hides Recovery. He obviously understood the concept because he asked me about a specific therapy technique that they were trying with their daughter. During the therapy sessions, his daughter frequently retracted her affected arm and fisted her hand. He was worried that this was creating a maladaptive habit. He was Right! Each and every time the child increases tone, the body learns how to do “increased tone” better. Mrs. Bobath, cofounder of the NDT program, was one of the first understand that you have to stop the child going into abnormal movement patterns. In her day, therapists were limited to hands-on techniques. Here is a wake-up call. We are in the 21st century. There are methods to support the trunk of the infant and toddler that serve the same function as the therapist guiding hands.
This is the “Catch 22” of developmental plasticity. For those who are too young to have read the terrific book of the same title by Joseph Heller, a Catch-22 is “a paradoxical situation in which an individual cannot or is incapable of avoiding a problem because of contradictory constraints or rules”. (Random House Dictionary (Random House), 2012)
You cannot adequately strengthen trunk or core muscles until the baby has had some brain recovery, which takes time. During the period of brain recovery, all the NDT based exercises are great and parents of young babies should learn them and integrate them into daily use. Here’s the catch… Who has the time or ability to keep their hands supporting the baby’s trunk throughout the waking hours? Depending solely on positioning and therapeutic exercise to improve your child’s trunk control is a set up for failure.
For the older child, even when they have enough brain recovery and developmental maturity to take part in active strengthening exercises, they still have problems for all the other hours of the day when they are not in active therapy. Even if they are able to maintain a good trunk when fresh at the start of the day, they will slump as they fatigue. Until the core muscles are strong and functioning in a coordinated fashion, all the waking hours, the child will revert into abnormal postural control and fall into maladaptive body habits.
The bad news is that in any situation of muscle weakness working against gravity, Habit Always Wins. The good news is that there are ways to support the child’s trunk while teaching them more normal movement patterns. For the older child, there are some exercises that will work better than others in the presence of established abnormal habits. A small “best possible step” that you can take right now, is to evaluate your child or your patient for residual trunk weakness and poor postural control in both sitting and standing. For adult readers of this blog with cerebral palsy, you have the advantage of being able to assess for yourself when your body tightens up. I suggest you assess this from the perspective of poor trunk control as described above. The simplest test is to sit unsupported and assess your hand function compared to sitting with good support. Assess your leg tone standing versus leg movements while lying on your back on the floor or bed. In many cases you’ll find better movement range and function when the trunk is supported.
If you do the assessments as I have outlined above, over 90% of affected children and adults will demonstrate evidence of significant trunk weakness. Do not despair. The first step to solving a problem is to recognize that a problem exists. The next post will focus on the types of exercises that can be used to strengthen the core “out of gravity” and the compressive garments that can provide needed trunk support during daily activities and therapeutic exercise sessions.