Introduction
Cerebral palsy (CP) is an umbrella term used to describe a group of disorders of movement which cause varying degrees of activity limitations.1 The most widely used means for classifying gross motor function in children with CP is the Gross Motor Function Classification System (GMFCS).2 Children classified GMFCS I are able to walk and run but have limitations with speed, balance and coordination while children classified GMFCS V are transported in a wheelchair in all settings. Although the focus of the GMFCS is on functional mobility, the realm of gross motor activities, that is skills involving movement of the large muscles of the limbs or whole body, undertaken by children is much broader.3 Development of gross motor skills underpins functional, play and social activities across childhood and complex movement skills required for sports in older children.3 In children with CP, limitations in gross motor function increase as GMFCS level increases, however, children at all GMFCS levels (I–V) participate, on average, less in physical activities than their typically developing peers.2 This is an issue because of the known poor health outcomes in adulthood due to inactivity in childhood.4 Effective interventions tailored to GMFCS levels and developmental stages are required to improve these outcomes in this population.
The International Classification of Functioning, Disability and Health (ICF) has become the common language for clinicians, researchers and families for understanding the effect of CP on the individual and for targeting interventions.5 6 Where interventions previously focused on remediating limitations in body structures and functions, there has been a more recent acknowledgement of the importance of the effect of interventions within the activity and participation domains.7 8 Clinicians working with children with CP need guidance from evidence synthesis to implement effective means of improving physical skills and improve the uptake of these skills in the child’s daily life. The historical bias towards impairment-focused motor interventions yielded few effective treatments,6 9 10 thus more functional approaches have emerged.
Task-specific training (TST) involves practice of context-specific tasks where the intervention focuses on the skills needed for a task(s)11—there is similarity between the training task and the goal of the intervention. Although level I evidence exists for TST to improve gross motor activities in adults after stroke,12 the majority of high-level evidence for interventions involving task specificity in children with CP relates to training of upper limb or fine motor activities6 13 with limited evidence for gross motor skills training. TST inherently involves principles of motor learning with components including context, practice and dosage.11 Other motor learning strategies, such as feedback and task modification, have the potential to optimise TST, however, this has not been systematically studied.14 TST should involve varied components depending on the requirements of the skill, the environment and the function of the child.15 Moreover, training for a child of higher-level motor function (eg, GMFCS I–III) should be targeted towards different skills compared with training with a child of lower-level motor function (eg, GMFCS IV–V). Similarly, children of different ages and developmental stages have varying learning capabilities, and physical demands placed on them by their context.16
Previous systematic reviews of motor interventions in children with CP have been broad in terms of ages (including infants and children) and motor function (all GMFCS levels), and included interventions have been heterogeneous.17 18 TST may be a promising approach for ambulant children who have specific gross motor skills goals, however, there has been no systematic review to examine the effectiveness of this approach in this population. The primary aim of this study is to evaluate and synthesise the evidence for the effectiveness of task-specific gross motor skills training in ambulant children aged 4–18 years with CP for activity and participation outcomes. The secondary aim of this study is to identify motor learning strategies reported within TST and assess relationship to outcome.