Try to keep your arm from tensing. You should be able to lift the front leg ad remain balanced. Then develop this feeling in the rubbing. Take your time with this motion. 20-25 on each side is usual.
Partners bow, face each other in mirror image fighting stances.
Each cycle, the three strikes are directed either closer to the wrist, the middle, or the elbow end of the forearm, and the target is switched each cycle to work the whole forearm and prevent over pounding of certain sites. Always hit muscle to muscle, maintain a strong stance, keep tension in your arm whether striking or being struck, and in the wauke motion, keep your shoulder down and elbow in. Instead, take your time and deliver it accurately. This is an essential skill for sparring. Lastly, remember the pressure point response often elicted in the first and third strikes-tingling and pain.