When doing pike stretch you point your toes toward the floor as far as you can. Keep your legs and knees straight and tight throughout the pike stretch. As you lift your arms above your head your palms should be turned inward and your fingers toward the ceiling. Make sure that your back and legs are kept straight as you reach. As you repeat the pike stretch, flex your toes upward and hold onto your toes. Pull them toward your chest holding it for 15 to 20 seconds. As to the tingling sensation, I'm not sure about that. I think it would be better to just stretch your calfs another way.