While it can happen to anyone who is active, you're more susceptible as you get older because muscles tighten as you age, says Jordan Metzl, MD, a sports medicine physician at the Hospital for Special Surgery in New York City. (health.com)
The variable - geometry turbo quickly spools, muscles tighten in the drivetrain and the Diesel Cayenne surges ahead as if it was pulled by some giant unseen tractor beam. (automobilemag.com)
Mark felt his stomach muscles tighten into a knot as speaker number five finished and the judges» cards came up. (sciencemag.org)