The technology of crawl should nod natant fitness

Old drought the crawl of 4 bid farewell

　　The head brushs surface, neck backbone is smooth long, issue mental astringent, take a breath not is held high. Connect body to want firm, lumbar stomach is nervous, log scroll, hilum looks at both sides. Make a long arm enters sleeve, turn the shoulder takes draw a frame round, close body delimits continuously, pull soft push firm. Ham is clipped, crus is like reed, sufficient ankle is loosened, have relax piece.

Behavioral structure and technology want a place


Crawl, its movement structure compares reasonable, save labour, obstruction small, it is a current rate is the rapiddest kind of natant pose.

　　 One, behavioral structure and technical point

　　(one) body poseFu of the body when crawl lies to be become in surface clipper-built, back and coxal muscle maintain proper tensity, the head holds in Youjin smooth, the nature that trunk has rhythm around body x-axis is rotational ゜ of 35 ゜ ~45. 　　 (2) leg department actionAlthough action of crawl leg department has certain drive, but basically have balance effect, stabilize and coordinate double arm what hold the body to do effectively thrash. Ask two legs are natural and approach, foot a bit inward turning, gambrel closes a pine, it is an axis with hip joint, drive crus and sole by ham, two legs do whip to move alternately, bipod needle fluctuates most make an appointment with 30~40 substantially centimeter, the biggest Qu Du makes an appointment with knee joint 160 ゜. 　　 (3) brachial department actionCrawl is brachial department action it is the main motive force that urges body advancement. With periodic cent is water, hold water, thrash in the arms, the arm moves in giving water and air not cannot intersected phase. 1. Enter water: After the arm moving in the sky that finish, the hand loosens water naturally below control. The dot entering water of the hand is commonly between body x-axis and the around extension line with joint shoulder. The hand when entering water points to natural unbend and approach, brachial inward turning makes ancon joint drive up is in apogee, palm hand is inclined outward lower part, make finger hits water above all, it is small arm next, finally is douse of big arm nature. 2. Hold water in the arms: After the arm enters water, in the process that inserts actively to lower part, the palm turns from the lower part outside syncline inside syncline rear begin to bend wrist, bend ancon, hand of ancon prep above, the thrash place with so that can transfer quickly,arrive better. Hold water end in the arms, the palm has approached pair of water, joint bends ancon to be controlled to 150 ゜, whole arm resembles be being held in the arms prepare for thrash like a big pellet. 3. Thrash: Thrash is play the biggest the main level that boosts action, its start course can be divided to pull water is mixed turn water two parts. The back-to-back phase that hold water in the arms is entered draw water, should maintain at this moment carry ancon, make big arm inward turning. Continue to bend ancon at the same time, make the movement of the hand catchs up with the progressive rate of the body quickly, can make water movement causes logical behavioral way to breathe out course, in the meantime, also make main muscle group the action that turn water is entered below good working requirement, draw water after the perpendicular plane to the shoulder, enter the share that turn water namely, at this moment the Qu Du of ancon makes an appointment with 100 ゜ to control. Big arm is in maintain inward turning pose, drive small arm, turn water backward forcibly. In the meantime, make move after humeral ministry, with the thrash line with significant lengthen. Have to pusher water from bend an arm to arrive of make a long arm accelerate a process, the palm go up from introversion, from below up behavioral course delimits quickly to ham by. Whole thrash movement, the contrail of the hand only then at the shoulder before, of afterwards fall to the abdomen, arrive finally by ham, submit S form. 4. Give water: When thrash ends, the centre of the palm turns to ham, the little finger when giving water up, the arm is loosened, small bend ancon. Drive by the upper arm, outward upper part carries elbow pull take antebrachium and hand to give water, the upper part after the centre of the palm changes direction. Movement giving water must pause rapid and ceaselessly, at the same time should downy, loosen. 5. The arm moves in sky: Back-to-back give water to keep be being entered suddenly the arm moves in sky, move when the arm, 　 of hand of ancon prep above 6. Two arms cooperate: The across before the alternate position that thrash of the two arms when crawl produces has, medium the across after across is mixed 3 sort. Across is before when showing one arm enters water, another arm already before place to humeral ahead and plane to become 30 ゜ left and right sides. Across is helpful for movement of abecedarian control crawl and breath before. Across is in when showing one arm enters water, another arm becomes 90 ゜ at inward thrash phase and horizontal. Across is after when showing one arm enters water, another arm delimits fall to the abdomen, hand and horizontal become 150 ゜ left and right sides.