A device for applying pressure to a bone of a human arm. The device includes a flexible member having first and second ends, a linear member fixed to the first end and slidingly coupled to the second end, a cam coupled to one end of the linear member and contacting a surface of the second end, and a lever arm coupled to the cam. The lever arm being movable between: a first position in which the cam to apply a first pressure to the surface of the second end of the flexible member； and a second position in which cam applies a second, larger pressure to the surface of the second end of the flexible member causing the second end of the flexible member to move relative to one end of the linear member and reduce a distance between the first end and second ends of the flexible member.
