INTRODUCTION

Poor motor performance, usually called clumsiness, has been found in about 5% of children when measured with a set of gross and fine motor tasks (Gubbay, 1975; Henderson & Hall, 1982). Mild neurological dysfunction, implying not only poor performance in motor tasks but also deviations in a thorough neurological examination, has been found in mild form at the age of 9 years in 15% of neonatally normal children (Hadders-Algra, Huisjes & Touwen, 1988a, b). Marked neurological dysfunction was found in 5% of these children.

Clumsiness is often not an isolated problem. It is associated with cognitive, psycholinguistic and learning disabilities (Henderson & Hall, 1982; Lyytinen & Ahonen, 1988; Lindahl, Michelsson & Donner, 1988a; Lindahl et al., 1988b). Abnormalities noted in neurological examinations have similarly been found to be linked with learning disabilities and with poor cognitive and psycholinguistic performance (Younes, Rosner & Webb, 1983; Wolff, Gunnoe & Cohen, 1983; Hadders-Algra et al., 1988a, b). Poor motor performance has been recorded as an essential part in diagnosing the syndrome of minimal brain dysfunction (MBD) (Dunn, 1986; Gillberg et al., 1982).

The aetiological background factors in poor motor function have been the subject of both epidemiological studies and studies concerning various risk groups. In Gothenburg an epidemiological study on the origin of MBD problems indicated that, compared with neonatal, hereditary and rearing factors, a more important part was played by non-optimal prenatal factors (Gillberg & Rasmussen, 1982b; Gillberg et al., 1982).