First, the representative training methods to improve the flexibility of hip joint.

Turn hips in situ and cross-walk:

Practice method: Hold the ribs, stand in place, with feet about one meter apart, left leg swinging to the right, heel driving the ground, right leg swinging to the left, and feet alternately following the ground.

Practice requirements: when the legs swing, the feet are close to the ground; Minimize the rotation of the upper body; The waist and hips cooperate to make a large rotation.

Second, develop the representative training methods of hip muscle strength.

1, supine leg pull fitness ball.

Practice method: Lie on your back on the ground, put your heels on the ball, and extend your two policemen to your side to keep balance. Lift your hips and lift them off the ground. When the hips, knees and ankles are in a straight line, bend your knees to close your legs, extend your knees to lower the height of your hips, and repeat the exercise. Practice requirements: If the difficulty increases, you can put your arm close to your body, use a bigger ball, tighten your ankle with a rubber band, or try to do something with one leg.

2. Lie on your side and lift your legs.

Exercise method: The body stretches and lies on the inclined plate, and the upper ankle joint is fixed on the rubber belt. The direction of pulling force is close to the oblique lower part of the body, and the legs are lifted up at the fastest speed. Repeat the exercise. Exercise requirements: the knee joint is straight, and only the muscles on both sides of the hip and trunk are used to complete the action.

Brief introduction of hip delivery technique in sprint;

The technique of hip delivery in sprint refers to the technical action that the thigh of the supporting leg fully extends backward at the hip joint at the last moment when the supporting leg is pushed to the ground, and the swinging leg fully flexes to drive the longitudinal axis of the ipsilateral hip joint to rotate, so that the two thighs present the maximum included angle. The situation of pelvic movement in sprint technology directly affects the hip sending action.

Therefore, in order to understand the correct hip delivery technique, we must first understand the structure and movement law of pelvis. The pelvis is a dome-shaped structure formed by connecting the hip and coccyx on both sides through ligaments, and its upper end is connected with the sacrum to form the trunk. It plays the role of a connecting link and a bridge. The hip joint is a clubfoot joint, which is a triaxial joint with high flexibility and wide range of motion.

Therefore, the thigh has three ranges of motion relative to the pelvis, namely, flexion and extension of the hip joint around the frontal axis, adduction and abduction around the sagittal axis, and pronation and supination around the vertical axis. In sprint technique, the action of hip joint is also very complicated. When the support leg is pushed backward, because the back kick is fixed, the pelvis can extend the hip joint around the frontal axis on one side of the hip joint relative to the back kick.