As Sasuke had his hands on Kabutos right leg, he sees pressure and tension building up on kabuto's left leg and the bones in the leg extending. This indicated that Kabuto would be kicking Sasuke with the leg that is free. Without hesitation, Sasuke takes his right hand and pushes down on Kabuto's shin whole his right leg pushes up on the back of Kabuto's shin. This causes Kabuto's head to drive down to the ground and at the same time, making him miss the kick.