The immediate effect of different loads does not alter muscle co-activation of the upper limb in young adults with dyskinetic cerebral palsy.

Abstract

There is insufficient information on muscle co-activation in the upper limbs to help healthcare providers develop treatment programs for patients with dyskinetic cerebral palsy (DCP). Is the degree of muscle co-activation greater in adults with DCP than in healthy individuals? Does the use of different arm weights modify co-contraction in individuals with PCD? Fourteen healthy individuals (control group [CG]) and 14 individuals with DCP (dyskinetic group [DG]) participated in the study. The degree of muscle co-activation of the dominant limb during drinking from a mug was compared between the two groups. The task was divided into a going, adjusting, and returning phase. In the DG, an analysis was also performed on using an arm weight during the functional task. The loads corresponded to 10, 20, and 30 % of maximum isometric muscle strength measured in each participant. In comparing the two groups, the DG exhibited a greater muscle co-activation in the shoulder and elbow muscles during the going phase, the shoulder, elbow, and wrist during the adjusting phase; and the elbow during the returning phase. The DG also showed a greater mean index of curvature (MIC), time to perform the movement phases, and lesser mean velocity (Vm) to drinking. In analyzing the DG's arm weight, no effect on co-activation, MIC, time to perform the movement phases, and Vm to drinking were found with the loads tested (p > 0.05). Muscle co-activation is increased in adults with DCP in comparison to healthy individuals. Moreover, arm weight during the functional activity of drinking from a mug did not alter co-activation, although an immediate effect was expected.