The correct Jam Sau position has the palm open, the four fingers together and straight, with the thumb bent. The forearm is horizontal and the fingers point forwards and upwards at an angle of about 45 degrees. The elbow should be slightly in (not in the Centre), but it should still be two fists distance away from the body. We must not confuse this position with the Wu Sau護手. In Jam Sau the fingers point forwards at an angle and the elbow is in. In the Wu Sau, the fingers point upwards and the elbow is out.
In Daan Chi Sau, the opponent attacks us changing from a Taan Sau 攤手 to a palm strike. Initially we are using Fuk Sau 伏手 and when the palm strike comes we change to Jam Sau to block the attack. It means that Jam Sau is good to use when we have contact. Remember we must keep the forearm level, no lower and no higher. If we press down too much so the forearm is lower, then the opponent’s hand can come back up to hit us, and if too low he can just come through the centre. We must also maintain our elbow distance of two fists from our body. After Jam Sau we can punch or palm strike. The Jam Sau can also be used against the Cup Zaang 扱踭(Elbow Down Attack).