Emg Study On Stable And Unstable Exercise Under Different Load

Since"unstable"is one of the differences between core strength and traditional strength training, 13 male juniors from the department of Physical Education, Beijing Sport University, are chosen as the subjects and experimented with surface EMG under 3 kinds of load (bodyweight, 30%RM, 60%RM) and 2 kinds of surface conditions (solid floor and unstable balance board) to get the activation difference of 8 muscles of lower limb and lower back. It is concluded that the influence made by unstable surface when squatting depends on the load. The unstable surface with bodyweight is the best condition for increasing the recruitment of muscles around ankle. The unstable surface with 30%RM can not only increase the recruitment of muscles around ankle and knee, but might also increase the recruitment of deeper local muscles of core area. However, the unstable surface brings about the shaking of body in squatting when the load goes higher than 30%RM, even if the antagonist of knee extension increase at the same time. The shaking brought about by unstable surface under >30%RM might increase the danger of technical deformation, as well as injuries. It is recommended that <30%RM be chosen when using the unstable surface in consideration of training effectiveness and safety. A complete strength training plan should include training both on stable and unstable surface.