THE EFFECT OF JUVENILE IDIOPATHIC ARTHRITIS ON LOWER LIMB MUSCLE ACTIVITY IN THE PROPULSION PHASE OF THE COUNTER MOVEMENT JUMP

Abstract

The purpose of this study was to investigate the effect of Juvenile Idiopathic Arthritis (JIA) on lower limb muscle activity during a countermovement jump (CMJ). Two groups of patient data were collected; 6 patients had unilateral arthritis, and 8 patients had bilateral arthritis. Activity of lower limb muscles was assessed using integrated EMG (iEMG) and peak EMG (pEMG) of the propulsion phase of the CMJ. Analysis of the unilateral patients compared the iEMG and pEMG differences of each muscle for the limb affected with arthritis versus the same muscles in the unaffected lower limb. Analysis for the bilateral group compared the left versus right side. No significance was found between sides when comparing lower limb iEMG and pEMG. It still needs to be determined if children who suffer from JIA have adverse muscle deficiencies as a result of the disease.