Resistance training alters the sensorimotor control of vasti muscles

The present study examined and compared two modes of weight training (bodybuilding and power-lifting) on the surface EMG of vasti muscles, knee joint position sense and isometric knee extension force in 48 able-bodied subjects. Subjects were randomly allocated into either a moderate loading and repetitions (bodybuilding) training or a high loading and low repetitions (power-lifting) training, or a no training control group. Training was conducted on alternate days with individual supervision. After 8 weeks of training, subjects from both training groups showed significantly earlier EMG onset timing and higher amplitude of vastus medialis obliquus relative to vastus lateralis (p = 0.005 or <0.001), and improved knee joint position sense (p < 0.001), but no such changes were found in the control group. However, the changes were not significantly different (p > 0.05) between the two training groups. The findings suggested that the neuromotor control of the vasti muscles could be altered by regular weight training.