An explanation for the handwriting difficulties experienced by children with spina bifida myelomeningocele was sought within theframework of a closedloop theory of motor skill acquisition. The handwritingperformance of 34 children (16 boys and 18 girls) aged6.16 to 13.42 years was detailed with aoailable norms, Regression analyses were then performed for thefive handwriting components of speed, alignment, letter formation, spacing, and size. The regressions for speed, alignment, and letter formation reached statistical significance. For speed, age provided thegreatest explanation of performance (R2 = .62, P = .008). Alignment was explained substantially by age, handedness, scholastic aptitude, and kinesthesia (RZ = .55, P = .03). utter formation was detennined primarily by age and kinesthesia (R2 . 71, P = .001,). Theoverallregressionwasnotsignificantforspacing(RZ = .39, P = .30), or size (RZ = .35, P = .43), although a significant single degree of freedom was detectedfor theeffect of age. These findings are discussed in terms of skill acquisition theory.