DHZ muab cov kev cob qhia tshiab rau cov neeg uas tsis xav txi qhov chaw hauv pem teb tab sis nyiam cov tsoos jammer xovxwm txav. Cov khoom siv caj npab tuaj yeem txuas tau sai thiab tshem tawm ntawm lub hwj chim khib nyiab, nws cov qauv tsim siv siv qhov chaw txuag txav los hloov cov qib cumbersome. Ob leeg ob tog thiab unilateral txav tau tso cai, koj tuaj yeem sawv lossis zaum. Push, rub, squat lossis kab, tsim yuav luag tsis muaj kev cob qhia kev xaiv.