Perturbation of a skilled action 1. The responses of neurologically normal and cerebral palsied individuals

A preliminary report on the effectiveness of trunk targeting in achieving independent sitting balance in children with cerebral palsy

OBJECTIVE

To assess the potential of Targeted Training in initiating or accelerating improved movement control of the trunk and hip joints in children with cerebral palsy so that independent sitting balance without specialized seating could be achieved.

DESIGN

Six single case studies.

SETTING

Assessment and review were undertaken in a specialized centre with intervention in the subjects' home or school.

SUBJECTS

Children between the ages of two years five months and seven years five months (mean four years seven months) with an established diagnosis of cerebral palsy. None had independent sitting balance at the start of the study.

INTERVENTION

Targeted Training using specialized equipment was directed at the appropriate few joints of the trunk as determined by initial testing and progressed when control at those joints had become automatic. The equipment provided support and challenged control learning. Periods of no intervention and placebo intervention, when the equipment was inappropriately set up, were also used. Two of the children ceased their traditional physiotherapy input while Targeted Training or placebo training took place.

MAIN OUTCOME MEASURE

A new test was devised and validated to determine the most caudal extent of control of the vertical posture. In addition, a functional test of independent sitting balance was defined.

RESULTS

All six children showed an increase in movement control and all gained independent sitting balance within 12-25 weeks (mean 16 weeks). This was irrespective of the continuation or cessation of traditional physiotherapy.

CONCLUSION

These preliminary findings suggest that Targeted Training may be an effective means of promoting movement control and functional ability. Confirmation of these findings by other investigators would be of value.

Improvement in walking performance of children with cerebral palsy: preliminary results

The effect of four to six months use of ankle-foot orthoses (AFOs) and balance training was determined for six children with cerebral palsy. The six consecutively referred patients had spastic diplegia or hemiplegia, with hyperextension of the knee, and had accurate voluntary control of the trunk and hips. Fixed AFOs were adjusted to control the position of the ground reaction force in relation to the knees. Balance training was targeted to the knees. All children showed a decrease in the magnitude of the knee-extending moment arm toward normal when barefoot. Improvement was noted in foot-ground contact for three children and of stance-phase posture for three. These improvements were not related to range of motion or speed, and a motor learning effect is proposed. The value of monitoring the moment arm is emphasised.

Spastic cerebral palsy: possible spinal interneuronal contributions

The author explores the possibility that abnormal and immature spinal interneuronal circuits play a rôle in spastic cerebral palsy. Interneuronal abnormalities could account for a number of characteristic signs: sensitivity to normally innocuous stimuli, hyperreflexia, abnormal and inappropriate co-ordination patterns, and limitations in acquiring, planning, executing and correcting skillful actions. The precise pattern of interneuronal anomalies present will depend on the original site of the lesion, age at onset, and on how central and segmental development were affected. Although the number of relevant studies is very small, there are indications that long-term training can produce changes in segmental response, both by altering descending inhibition and by producing lasting changes in spinal neuronal organisation and responsiveness. Modern recording techniques have introduced the prospect of tracing immature and abnormal segmental components and of establishing their impacts on movement control.