Adjustable folding shoulder holder for violin or viola

The utility model discloses an adjustable folding shoulder holder for a violin or a viola, a shoulder holder for a bowed stringed instrument, and a shoulder holder for the violin or the viola. The shoulder holder comprises a shoulder joint main body which is provided with a first end part and a second end part, and is also provided with a shoulder joint side and an instrument facing side. The shoulder holder also comprises a first folding fork-shaped clamping member which is disposed at the first end part so as to clamp the violin or the viola and to enable the violin or the viola to be folded to a folding position from an unfolding position; a second folding fork-shaped clamping member which is disposed at the second end part so as to clamp the violin or the viola and to enable the violin or the viola to be folded to the unfolding position from the folding position; a first sliding end part member which is used for storing a threaded rod for bearing the first folding fork-shaped clamping member, can slide between a withdrawing position and an extension position, and is provided with a bow-shaped channel; and a second sliding end part member which is used for bearing the second folding fork-shaped clamping member, can slide between the withdrawing position and the extension position, and is provided with a bow-shaped channel.