Abstract 175

Aims To produce an objective means for measuring the grip strength of infants with cerebral palsy (CP). Subjects 55 infants with CP and 5 normal controls aged two years. Method. Grip strength was measured by an oil-filled bulb which the children squeezed. This was connected to a pressure transducer to output an analogue voltage proportional to the pressure exerted by the infant. The output was converted to a digital signal. 10 grip profiles, 5 for each hand, were recorded for all infants. A Fast Fourier Transform (FFT) was used to analyse quantitatively the pressure-time grip profiles. Maximum power and the length of time to achieve it was recorded. Results 23 children with CP and 5 controls completed 5 trials with each hand. The remaining 32 produced sufficient grip profiles for analysis. The median peak pressure for the infants with CP was 156 mm Hg (range 1 - 306), compared to 568 mm Hg (range 265 - 854) for the controls (p<0.05). The FFT plots generated a clear differential between right and left grip profiles for infants with CP. Normal controls gained 80% of full power at 10 Hz. Only 1 child with CP reached 80% of full power by 10 Hz. Infants with CP demonstrated lateral differences in the FFT plots, although this was not always evident at physical examination. Conclusion This dynamometer assessed grip strength reliably and objectively.