Progressive Supervised Home-based Strength Training in Children With Spastic Cerebral Palsy

A randomized controlled trail will be carried out to investigate the effect of a 12-week supervised home-based progressive strength intervention in children with spastic cerebral palsy aged 5-11 years. The results of this strength intervention aiming for increased strength and muscle hypertrophy will serve as input for a clinical decision making framework based on muscle and tendon architecture.

Background: The alterations of morphological muscle and tendon properties are a primary determinant of the pathological muscle behaviour in spastic cerebral palsy (SCP). As treatments aim to reduce the progressive secondary problems, they are mainly directed at the muscle level. Muscle morphology features like volume, fascicle architecture and tendon properties are all responsive to treatment, but these treatment responses seem to be both patient and muscle-specific. Therefore, objective tools and protocols are needed for the evaluation of morphological muscle and tendon (MMT) properties in routine clinical practice. These are required to guide the patient-specific selection of appropriate, rationalized treatment choices and to determine the impact of these treatments on the MMT properties, the muscular impairment and function in children with SCP.

This intervention study is one out of three intervention studies focused on defining the effects of conservative treatments (strengthening, stretching and botulinum toxin injections) on muscle and tendon architecture. In this phase of the Treatment Algorithms based on Muscle and Tendon Morphology (TAMTA) project, we aim to develop specific guidelines for these treatment options linked to the MMT evaluation protocol. To achieve this goal, prediction models based on baseline MMT parameters for the prognosis of specific treatment outcomes will be developed from the data of the three intervention studies.

Aim: (1) determine whether the 12-week program of targeted progressive strengthening of the plantar flexors, the knee flexors and extensors leads to changes in the MMT properties of medial gastrocnemius, semitendinosus and rectus femoris, in the muscle strength and in gross motor function; and (2) determine the correlation between baseline MMT properties and the changes in the outcome parameters.

Methods/Design: A randomized controlled trial will be conducted in 40 ambulatory children with a confirmed diagnosis of SCP between 5 and 11 years of age. Participants will be randomized to the intervention group (who will additionally receive the strengthening program while continuing their usual care) or to the waitlist-control group (who will continue their usual care without additional treatment) using the randomization by minimization method (with influencing characteristics age and GMFCS level). Participants in the control group will be able to participate in the intervention after the control period. The MMT parameters of the medial gastrocnemius, tibialis anterior, semitendinosus and rectus femoris and the isometric and functional strength for the 4 related lower limb muscle groups (plantar flexors, dorsiflexors, knee flexors and knee extensors) as well as the gross motor function will be assessed before and after the 12-week program. After 6 weeks a short evaluation of the MMT parameters, isometric and functional strength will take place.

The change in primary outcome parameters before and after training of the intervention group will be compared to the data behaviour of the control group. Secondly, to explore the predictive value of specific baseline MMT parameters on treatment effect, both univariate and multivariate linear regression analyses will be conducted to identify significant predictive variables for the primary outcome parameters.

Eligibility Criteria:
Inclusion Criteria:

* Confirmed diagnosis of SCP
* Aged 5-12 years
* GMFCS levels I-III (GMFCS = Gross Motor Function Classification Score, expressing the overall functional level of impairment)
* Sufficient cooperation to comprehend and complete the test procedure

Exclusion Criteria:

* Non-ambulatory
* Botulinum toxin A injections six months prior to enrollment
* Lower limb surgery two years prior to enrollment
* Presence of ataxia or dystonia
* Cognitive problems that impede measurements
* Severe co-morbidities (severe epilepsy, non-correctable visual impairment, autism spectrum disorders, mental problems that prevent comprehensiveness of the tasks)