Isokinetic knee muscle strength of individuals with mental retardation, a comparative study.

The purpose of this study was to assess differences in isokinetic muscle torque in the knee among mentally retarded individuals with Down syndrome, mentally retarded individuals without Down syndrome, and sedentary subjects without mental retardation (ns of 7, 8, and 12, respectively). Subjects performed strength tests to knee extension and flexion on a Cybex II isokinetic dynamometer. The measure was peak torque at angular velocities of 60, 120, and 300 degrees/sec. For the Mentally Retarded subjects with and without Down syndrome, the test was performed on two separate days 24 hr. apart. For Sedentary subjects, testing was performed on one day. Their scores indicated significantly higher values of torque than the two other groups. Also, subjects with Down syndrome had inferior muscle torque of lower extremities than peers in the Mentally Retarded Group.