vendex and Down-Syndrome

This study compared isokinetic leg strength of aged individuals with mental retardation (MR) with and without Down's syndrome (DS). Nine subjects with MR and DS (mean age = 61) and 16 subjects with MR but without DS (mean age = 63) performed a leg strength test on a Biodex dynamometer. Parameters measured were peak torque, peak torque percent body weight (ratio displayed as a percentage of the maximum torque production to the subject's body weight), and average power percent body weight. In addition, anthropometric measurements (height, weight, skinfolds, and body mass index) and intelligence quotient (IQ) were also analyzed and compared. The results indicate a significant increase of scores for isokinetic knee extension and flexion in the group with MR but without DS over the subjects in the group with MR and DS. As a group, the individuals with MR and DS tended to be smaller and fatter. No significant difference in IQ was observed between the 2 groups with MR. It was concluded that the strength of individuals with MR but without DS is greater than the group of subjects with MR and DS. When comparing their results to aged individuals without MR, a significant decline in muscle strength can be observed among people with MR.

Topics: Age Factors; Aged; Body Composition; Down Syndrome; Female; Foster Home Care; Humans; Institutionalization; Leg; Male; Middle Aged; Muscle, Skeletal; Persons with Mental Disabilities; Prospective Studies; Torque

We examined the systematic variation in shoulder and elbow torque, as well as movement kinematics, for horizontal-plane arm movements with direction reversals performed by normal individuals and individuals with Down syndrome. Eight neurologically normal individuals and eight individuals with Down syndrome performed horizontal, planar reversal movements to four different target locations. The four locations of the targets were chosen such that there is a systematic increase in elbow interaction torque for each of the four different target locations. This systematic increase in interaction torque has previously been shown to lead to progressively larger movement reversal errors, and trajectories that do not show a sharp reversal of direction, for movements to and from the target in patients who have proprioceptive abnormalities. We computed joint torques at the elbow and shoulder and found a high correlation between elbow and shoulder torque for the neurologically normal subjects. The ratio of joint torques varied systematically with target location. These findings extend previously reported findings of a linear synergy between shoulder and elbow joints for a variety of point-to-point movements. There was also a correlation between elbow and shoulder torque in individuals with Down syndrome, but the magnitude of the correlation was less. The ratio of joint torques changed systematically with target direction in individuals with Down syndrome but was slightly different from the ratio observed for neurologically normal individuals. The difference in the ratio was caused by the generation of proportionately more elbow torque than shoulder torque. The fingertip path of individuals with Down syndrome showed a sharp reversal in moving toward and then away from the target. In this respect, they were similar to neurologically normal individuals but dissimilar to individuals with proprioceptive deficits. Finally, we observed that individuals with Down syndrome spend proportionately more time in the vicinity of the target than normal individuals. Collectively these results show that there is a systematic relationship between joint torques at the elbow and shoulder. This relationship is present for reversal movements and is also present in individuals with Down syndrome.

Topics: Adolescent; Adult; Arm; Down Syndrome; Elbow; Female; Humans; Kinetics; Male; Movement; Reference Values; Shoulder; Time Factors; Torque