Leg muscle activation patterns during walking and leg lean mass are different in children with and without developmental coordination disorder

Abstract

Background Previous studies have shown that children with developmental coordination disorder (DCD) have a higher body fat and greater gait variability. Little research has investigated the gait muscle activity and lean mass measures in children with DCD. Aims To compare the leg muscle activation patterns of the gait cycle and leg lean mass between children with and without DCD. Methods Fifty-one children were in the DCD group (38 males and 13 females; 7.95 ± 1.04 years) and fifty-two in the control group (34 males and 18 females; 8.02 ± 1.00 years). Peak muscle activation patterns of treadmill walking in the right leg for the eight-gait phases were measured by means of surface electromyography, an electrogoniometer, and foot contact switches. Leg lean mass measures were evaluated using a whole-body dual energy X-ray absorptiometry scan. Results Children with DCD had a lower leg lean mass and appendicular lean mass index compared to the control group. Furthermore, they exhibited a less-pronounced peak muscle activation during the heel strike (gastrocnemius medialis), early swing (biceps femoris) and late swing phases (gastrocnemius medialis) of gait. Conclusions and implications Although lower limb total mass was similar between groups, the DCD group displayed lower lean mass measures than controls. Furthermore, children with DCD illustrated a lower leg peak muscle activation during the heel strike, early swing and late swing phases of gait when walking on a treadmill. Our results emphasize the need to incorporate lower limb phasic muscle strengthening components into gait rehabilitation programs for children with DCD.