Your hips are the central meeting point of the muscles in your torso and legs, they are interconnected to most parts of your body, so when they become restricted or weak it can effect other areas of your body such as your legs and back.
If you find you can’t squat easily, your hamstrings start to feel tight, maybe you compensate with certain movements when you walk which causes your back to start tightening up—and so on and so forth.
Improving your hip mobility eases strain in your lower back and knees, making walking, stair climbing, and running gait more efficient. This in turn makes daily activities such as getting in/out of car, on/off the floor, and driving more pleasurable and easy.
Here is one of my favourite hip flexor stretches.
How to do it:
Kneel on your left knee. Place your right foot flat on the floor in front of you, knee bent.
Lean forward, stretching your left hip toward the floor.
Squeeze your butt; this will allow you to stretch your hip flexor even more.
Make sure your knee stays behind your toes, it should be roughly over your ankle joint
keep your chest up and focus on pushing your hips forward