During practice, Ai Miyazato places a potato chip between her teeth and swings without breaking it.
If you tense your jaw, the tension spreads to your neck and shoulders.

To make your swing faster, relaxation is essential — and loosening the jaw helps achieve that.

Kiichiro Sports Body Care NYC specializes in releasing jaw tension.

宮里藍選手は、練習でポテトチップを歯に挟む。スイングしてもポテチを割らないように。顎に力が入ると、首・肩に力が入ってしまうので。

スイングを速くしたいのなら、脱力が大事で、そのためには顎を緩めるといい。