Working capacity of deaf, and visually and mentally handicapped children.

Using bicycle ergometers, physical working capacity was determined in 61 deaf, 22 visually handicapped, and 67 mentally retarded children 8 to 17 years of age. Compared to the normal population, the working capacities per kilogram body weight of the deaf children, particularly the girls, were superior to the other groups and to the normal population. The visually handicapped had lower working capacities, while those of the retarded children were similar to the normals. The work efficiency was similar in both groups. For the boys and younger girls, the maximum oxygen uptakes per kilogram body weight were similar in the deaf and visually handicapped, results that were contrary to the working capacity studies. The difference could be explained by postulating that the deaf children did not work to maximal values though lactic acid and respiratory quotient data suggested that they did. The maximum heart rates of the deaf children were lower than the visually handicapped.