Fundamentally, the main reason why runners get knee pain (they get ankle, hip, and other joint pains) is because they either lack strength or flexibility in their muscles. Muscles play a huge role in our running. The more strengthened and flexible they are, one can keep running without worrying about any injury or pain.
Strength and flexibility in our muscles absorb all the shock that is generated as we pound our legs on the ground during our runs. The moment you do not have enough strength and elasticity in your muscles, you tend to carry those shocks to your joints (knee, hip, ankle, lower back), causing injuries.
Please read this article to get more insights to prevent knee and other joint pains as you continue to run.
Be Strong. Run Forever.