Stretching in Children and Adolescents With Spastic Cerebral Palsy

Background: Spastic cerebral palsy (SCP) is a non-progressive neuro-muscular disorder in children resulting from an injury in the central nervous system. Individuals with SCP present with impairments such as hyperreflexia, demonstrate impaired motor control and muscle growth. Manual stretching is an important approach in the physical therapy of individuals with SCP used to increase muscle extensibility and length, decrease muscle stiffness, and to improve functional abilities. However, there are only a few studies that have examined its acute and long-term effects in children with SCP and it is still not clear, if it may lead to the expected changes, and which method might be the most-effective one. Besides static stretching, proprioceptive neuromuscular facilitation (PNF) stretching has been used to aid the rehabilitation of, for example, stroke patients by either facilitating muscle elongation and/or improving muscle strength. Positive effects were found (e.g., increased dorsiflexion, improved gait function, altered tendon properties), which are also clinically relevant for individuals with SCP. However, there is no information about the impact of PNF in this population.

Aims: The primary aim of this study is to gain knowledge about both the effects of a single bout of static and PNF stretching and the effects of 8-week static and PNF stretching training on the calf muscle-tendon properties in children with SCP. Furthermore, the effects on joint and muscle function, stretch reflexes, gait, and self-reported gait function and functional performance are examined to receive a comprehensive picture of potential changes. Further aims of this study are to identify which stretching technique might be more efficient by comparing the effects of both stretching interventions, and to gain information about the influence of foot flexibility on the stretch achieved by the spastic gastrocnemius muscle-tendon unit.

Methods: A randomized controlled trial with a cross-over design will be performed. Prior to the measurements, a familiarization session takes place and both groups will further be examined in three separate measurement sessions. Based on a power calculation and in order to account for possible dropouts, 30 individuals with SCP (age range: 6 to 15 years) will be recruited. The participants will be randomly allocated to either the static stretching or PNF stretching intervention after the familiarization session. Passive muscle-tendon morphological properties will be examined. A manually controlled instrumented spasticity assessment will be performed to test for differences in the reflex responses. Information about the lengthening behavior of the tissues throughout the dorsiflexion rotations will also be collected by use of ultrasound. Isometric muscle strength and the active torque-angle relationship will be investigated using an isokinetic dynamometer. To assess the gait pattern of the children, a gait analysis will be performed by use of an 8-camera motion capture system. In addition, we will examine the participants' gait function and functional performance by use of the Gait Outcomes Assessment List questionnaire.

Inclusion criteria

• spastic cerebral palsy
• ambulatory children and adolescents
• ability to accept and follow verbal instructions
• no severe contracture of the calf muscles (max. ankle dorsiflexion >= 0°, with knees extended)
• classified as GMFCS level I, II, or III
• aged between 6 and 5 years
• willingness to participate

Exclusion criteria

• others than spastic forms of cerebral palsy
• severe mental retardation
• fixed muscle contractures (ankle equinus deformity = max. ankle dorsiflexion <= 0°, with knees extended)
• oral anti-spastic and/or muscle relaxation medication in the last 6 months
• orthopaedic surgery and/or Botulinum toxin type A application in the last 12 months