Thus silk reeling movements are continuous, cyclic, twisting and untwisting actions. The exercise involves grasping a rubber bar, twisting it, then slowly untwisting it. By natural untwisting the resulting knot tightens and stops without further aids. Treatment is by physically untwisting the testicle, if possible, followed by surgery. Another characteristic feature is the untwisting (deconvolution) of the cotton hair. The toggle hits the stretcher, which keeps the cord from untwisting. One property of laid rope is partial untwisting when used. An outer jacket is still required to prevent the cores untwisting.