Cerebral Palsy (CP) is an umbrella term that encompasses permanent and non-progressive disorders that develop during the prenatal, perinatal, or postnatal period following various effects on the brain that has not yet fully developed 
The location and timing of the damage to the brain leads to 4 categories of CP; Spastic, Athetoid, Ataxic and Mixed . This then causes disturbances in the neuromuscular, musculoskeletal and sensory systems leading to inadequate posture and motility,  which affects body movement, muscle control, muscle coordination, muscle tone, reflex, posture and balance. It can also impact fine motor skills, gross motor skills and oral motor functioning.
These issues are then classified into Monoplegia (one limb) Diplegia (2 limbs) Hemiplegia (one side of body) Triplegia (3 limbs) quadriplegia (4 limbs possible facial muscles as well). Then combined with the categories i.e. spastic diplegia. Due to the varied and complicated nature of CP, there maybe many issues that need to be addressed. The major physical issues can be Dystonia (Hypotonia/weakness/lack of tone) or Spasticity (Hypertonia/tightness/Muscle weakness) these issues may be neurologic or muscular.
The neural factors that cause muscle weakness in children with CP are decreased motor management, stronger abnormal neural networks, disturbed firing pattern, reciprocal inhibition, and disturbance in the adjustment within the muscle spindle. The neurophysiological abnormalities in children with CP cause persistent and permanent problems when passing into adulthood. These abnormalities limit the ability of children with CP to grow so that they can become stronger in the normal manner.
The muscular issues such as predominant type 1 fibres, abnormal sarcomere length leading to 40% less power, shorter muscles containing less sarcomeres and therefore have less cross-bridges to produce power, longer tendons decreasing any biomechanical benefit .. A muscle in the rest position has a biomechanical disadvantage as it cannot shorten adequately to produce the necessary functional movement and create effective power, the disturbance in myosin production, structural abnormalities in the perinatal period, decreased muscle fascicle length, increased sarcomere length, decreased muscle volume, and decreased physiological section area.
Selective Dorsal Rhizotomy and muscle weakness
One way in which the spasticity can be reduced is via Selective dorsal rhizotomy (SDR). This is an operation used to reduce spasticity (muscle stiffness) in cerebral palsy. Once this has been completed and the spasticity has decreased there will now be less issues with reciprocal inhibition and issues of co contraction. However there will be a lack of strength and control in both the agonist and antagonist. The agonist being generally short (but now with less spasticity) and weak and the antagonist being long and weak. This muscle weakness becomes the major issue, optimal muscle strength comes from normal muscle and fascicle lengths. This lack of normal length will decrease the ability to produce force, which will influence motor performance which affects activity in daily life and the ability to develop functional activities.
Strength interventions for both agonist and antagonist include isokinetic training, progressive resistance exercise, bicycle and treadmill exercises, weight training, upper extremity strengthening, weight training, aquatic training, sports and electrotherapy. These can all be beneficial to increase muscle power, flexibility, posture, and balance. The muscle weakness in the trunk and lower extremity is especially important for ambulation and requires strength training [5 & 6]. Studies have revealed the positive effects of strength training and the relationship of muscle power with activity in children which then can be related to a general increase in the activity level during daily living in functional activities such as walking and running. This then has beneficial effects on body structure and function, activity limitation, and participation problems according to ICF in children with CP. 
So back to the initial question, Why use a strength and conditioning coach for pre or post SDR work?
There are plenty of different approaches or therapy for CP pre and post SDR these can include but not be an exhaustive list of the following:
I feel this is a loaded question as it implies that one person on their own can provide a full solution to the issues that can occur with CP pre or post SDR. But until you know what the issues you need to deal with, you won’t know which approach will work best. Most of the time it will be a combination of approaches, as this will lead to more variation which leads to more adaptation in neural and muscular systems. However, strengthening of the muscular system is imperative after SDR due to the inherent weakness after decrease of spasticity.
This is where a strength and conditioning coach can help by identifying with the help of a paediatric physiotherapy the muscles that are weak. They do this by manual muscle testing each muscle in certain ranges. Then using fundamental strength concepts develop the strength of the muscles via increased recruitment or size to increase force and power.
To ensure the development of these concepts there is a need to manipulate many of the variables of the program along the way, such as tempo, exercise selection/ order, rest, reps/sets, load, volume and frequency. But all changes should be monitored and be used to effect a change against a monitored system such as GFMS88. This allows an objective longer-term measure to be used to see if what may seem like a relatively unstructured child led, discovery session for a young client, is effective in its planning and application.
This type of session is also upheld by research that suggest that maintaining motivation and target activities for daily living produce the most effective sessions. Its not all about reps and sets when it comes to working with CP children. The most motivating sessions can be simplest sit to stands, assisted stair climbing etc. It’s about achieving everyday movements to facilitate activity in daily life. Don’t wait for them to be perfect, if they are effective and safe then the child will gain confidence which is one of the most important factors. Also, a parent needs to remember that they are not the physio or trainer they still need to be Mum and Dad. There will be lows and the highs as this type of development is not linear in nature so the parent must be there as an emotional support which will be difficult if they are trying to drive a training program as well. However, a little homework never goes a miss.
These types of session do not only need good knowledge of strength and conditioning principles but also good coaching/ interacting skills to allow application.
If you are looking for a strength and conditioning coach, you should be looking for someone who has experience of working with children and has some specific paediatric coaching experience. Children’s bodies are not the same as adult bodies and react differently to certain interventions. Strength is still at the core of what is needed for the child however due to growth generally and through puberty, understanding the growth issues especially when dealing with cp is essential. Just the fact that the bones tend to grow faster than the muscles, increasing the tension and lack of coordination so compounding the issues of CP means that sometimes progress is not linear. The allowance of changes both positive and negative have to be taken into account. The relationship does not just extend to the child and coach but also to the child coach and parent. Yes independence is great to work on but work with the parent and practitioner in the session develops everyone’s understanding of levels and exercises.
The coach should be accredited or certified by either UKSCA, NSCA , ASCA. and insured. Also ask for testimonials or references, if they have worked with CP before and been successful parents will be happy to speak about or recommend them.
Gareth Shelbourne MSc, ASCC, CSCS, CES.
Who is Gareth Shelbourne?
He is owner of Move4Sport, Head of Strength & Conditioning for Bromley Tennis Centre and Bromley Swimming Club. He has over 15 years’ experience in coaching children from 3 -18 year olds, elite youth athletes, CP pre and post SDR, LD children and general youth population. He has worked with many CP kids pre and post SDR. He has a Masters in strength and conditioning and is accredited with UKSCA and NSCA. He is also a sports massage therapist.
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