Effects of specifically sequenced massage on spastic muscle properties and motor skills in adolescents with cerebral palsy.
PhD thesis, University of Glasgow.
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Cerebral Palsy (CP) is the most common childhood disability, with an incidence around 2-2.5 in every 1,000 live births in Europe. It results from damage to the developing brain and adversely affects motor control. The limitations in motor control range from an inability to even hold the head erect and an inability to self-feed, to cases where for example walking is hampered by spasticity in one limb.
The cornerstone of current treatment is physiotherapy in which the aims are to maintain and improve mobility and to prevent limitation of the range of joint movement. Specific forms of physical therapy include Conductive Education and Bobath treatment. Other interventions include botulinum toxin injections, intrathecal baclofen, selective dorsal rhizotomy and multi-level orthopaedic surgery. Despite these varied and concerted inputs, improvements in motor skills are very limited – motor skills tend to plateau around the age of seven and in fact deteriorate in adolescence.
Of the four classifications of CP (Spastic, Athetoid or Dyskinetic, Ataxic and Mixed), the spastic type is the most common. Around 75% of all cases are spastic and around 60% of these are diplegic (meaning it affects both limbs, usually the legs). Spastic diplegia results from periventricular leucomalacia, where oligodendrocytes are damaged by hypo-perfusion of the periventriucular areas predominantly affecting the corticospinal tracts supplying the legs. This results in a deficit in the development of the white matter forming the insulation around those nerves and consequently compromises the signal transduction to the legs. As spastic diplegia is the most common type of CP, and the presenting symptoms are considered less complex than the other types, patients with spastic diplegia were chosen for participation in the current studies.
The main symptoms presenting in spastic diplegia are reduced gross motor function, increased reflex response to muscle stretch, reduced range of ankle movement and shortened calf muscle/tendon units, evident in equinus.
Whilst the main cause of spasticity in conditions other than CP is considered to be the neuropathology, altered muscle properties are considered to be the main problem in CP. Masseurs contend that they bring about a healthy response in damaged muscle by altering the resting state of the muscle, although this has not been scientifically proven until now.
The initial aim of the present series of studies was to test if a specific massage sequence could increase the range of movement at the ankle joint by altering the mechanical properties of the muscle in adolescents with spastic diplegia. However the investigations indicated that instead, this type of massage changed sensory feedback from the spastic muscles, which led to significant improvements in motor skills. The physical limitations of the 12 participants with CP range from habitual wheelchair users to one participant who is able to run. Their abilities classified by the Gross Motor Function Classification System (GMFCS) ranged from level I to IV. The investigation involved the use of goniometry to measure change in the active and passive range of movement at the ankle joint and EMGs to measure incidence of stretch reflex contractions. Motor skills were assessed by an independent physiotherapist, using the Gross Motor Function Measure-66 (GMFM-66).
In chapter 3, three passive ankle dorsiflexions at a controlled rate were carried out before and after massage which was given twice weekly for 5 weeks. The incidence of stretch reflex contractions during passive dorsiflexion was reduced from 40% in the first 5 massage sessions to 22% in the last 5 sessions, in the 5 participants tested. After massage the resistance of the calf muscle to stretch was not reduced as expected; in fact the muscles were stiffer (more force was needed to take the ankle through the same range of movement). However, the resting angles of the ankles often changed, indicating alteration of the resting length of the calf muscles. The change was not always in the one direction, although, on the whole, muscles lengthened after massage (shown by an average increase in dorsiflexion of 1.4º). It is argued that thixotropic properties of muscles were responsible and that the massage changed the mechanical properties of the calf muscles.
In chapter 4, Gross Motor Function Measure-66 scores for all 12 adolescent participants who received the specialised massage were shown to be improved by an average of 5.8. Five of the 7 participants showed improvements in their ability to descend stairs, which is recognised to be particularly difficult in spastic diplegia. The range of voluntary ankle movement improved in some participants in some tests.
Despite a lack of scientific evidence, masseurs also contend that their intervention brings about change by altering the blood flow. In the current studies, near infrared spectroscopy was used to measure oxygenation of the muscles and changes in the skin temperatures were also recorded. In chapter 5, temperature recorded from the skin over the calf muscle after massage was increased in both the CP group and the controls. Both finished with comparable temperatures although the CP group’s temperatures started 1-1.5°C below those of the control group. Contralateral effects of raised skin temperature were also observed. It was confirmed that the extent of change in skin temperature over the massaged muscles could be used to determine the effectiveness of a trainee using the massage technique. Additionally, the oxygenation of the tissue was altered significantly at some stage during massage for all participants. It is proposed that spastic muscles in CP may sometimes operate in oxygen debt, particularly in cold conditions.
The improvements in GMFM-66 with massage are at least as effective as other current therapies and the massage has none of the adverse side effects of surgery and drug interventions. The mean improvement in GMFM-66 score after massage was 5.8, whereas treatments using selective dorsal rhizotomy and baclofen showed improvements of only 2.7 and 3.8 respectively.
It is proposed that the mechanical properties and the feedback from spastic muscles are altered by the massage and that the CNS is able to accommodate the change in feedback to produce improved motor function.
It is recommended that the massage used here be incorporated into the physiotherapy regime for individuals with CP.
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