Most scabbards were worn in such a way that the sword was held firmly against the body so it didn't swing around. Exactly how this was done differs with different styles and whether the wearer was on foot or mounted, however whatever the style, the sword and scabbard must be attached to the belt in at least 2 places. Generally one strap will pass around the back of the body and one around the front. There is usually a way to adjust the strap length slightly to fine tune the position to the wearer.
During some periods a single suspension point was sometimes used, notably in the 14thC. Scabbards suspended from a single point will always be prone to swinging around.
Below are links to videos on Tod's Youtube Channel, demonstrating how to tie sword belts.