Final answer:
The hamstring muscle gets tight and needs to be stretched frequently for walking and running.
Step-by-step explanation:
The muscle that gets tight and needs to be stretched frequently for walking and running is the hamstring muscle. The hamstrings are a group of muscles located on the back of the thigh, and they play a major role in bending the knee and extending the hip. When these muscles become tight, it can limit the range of motion, increase the risk of injury, and affect the ability to walk or run comfortably.
To stretch the hamstring muscle, you can perform exercises such as standing hamstring stretches, seated hamstring stretches, or lying hamstring stretches. These stretches help elongate the muscle fibers and improve flexibility.