Often used describing sports activity, particularly in context of stretching or injury. She can't play in today's soccer game because she has a hamstring problem.
Pro Tip 2/3
Physical Exercise
Essential for people who exercise, to indicate caution during workouts to prevent injury. Always warm up your hamstrings to avoid strains.
Pro Tip 3/3
Not Actual Strings
Though 'string-like,' it's not literally strings; refers to muscles and tendons. Hamstring strains occur when the muscle fibers get overloaded.