Faulty alignment or movement patterns - The most common issues are feet that turn out and knees that move inward (knock knees). Your body is designed to optimally absorb the impact of running when your joints are properly aligned. If they aren’t, you will cause undue wear and damage over time. If you sit for long periods of time, I’ve got the corrective exercises and stretches to undo muscle imbalances that this causes at prehabpostrehab.com.
Bad shoes - shoes need to be replaced every 3-4 months or 300-400 miles because the midsole loses cushioning. If you buy last season’s shoes at a discount store or website, the clock has been running on them, the midsole has started to dry and lose cushioning. Another factor is whether the shoe provides the right level of stability for you. Do you need a neutral shoe, a stable shoe, a motion control shoe? A knowledgeable salesperson or trainer can help guide you to the right shoe.
Prior injuries - This includes impact injuries, sprains, strains, twists, and the cumulative impact of the above. If you’ve had physical therapy, you probably need to continue some version of the program to prevent reinjury.
Contact me if you need more help.