The effect of a six-week core stability exercise training on the EMG activity, static and dynamic balance in mentally retarded teenage girls

Mental retardation is one of the most common mental disabilities that accounts for about 3% of the world population. The aim of the present study was to investigate the effects of a core stability exercise program on the electromyography activity, static and dynamic balance of mentally retarded adolescent girls. 24 mentally retarded female students (age range 15-17 yr) were divided into two groups: experimental (n=12) and control (n=12). The experimental group performed core stability exercises for 6 weeks. The selected exercises consisted of half sit-up, side plank and four lower abdominal strengthening exercises. The Stork (one-leg standing) and Y tests were respectively used to measure static and dynamic balance. The EMG system was used to evaluate the electromyography activities induced by maximum voluntary isometric contraction of the rectus abdominis and external abdominal oblique muscles. Dependent and independent t tests were used to analyze the data. The results indicated that the core stability exercises significantly improved the static and dynamic balance, and also EMG activity in experimental group compared with the control group (all P<0.001). Therefore, the practical application of this protocol along with other training is suggested to rehabilitate and enhance performance in mentally retarded adolescent girls.