The popular "weak hips" theory is weak: it’s super unlikely that weak hips are a cause of runners knee (IT band pain or patellofemoral pain).
Patellofemoral Pain Syndrome
How to Strengthen Your Hip Flexors and Exercises to Try
Exercises for Medial Tibial Stress Syndrome (AKA 'Shin Splints') - RunningPhysio
Hip Mobility Exercises for Runners
How to Fix Runner's Knee Permanently (Videos)
Training Tips to Prevent Knee Pain After Running
Is running bad for your knees? Research shows impact on marathoners
Gluteus Medius - evidence based rehab - RunningPhysio
Runners Knee Rehab Rationale: Exam and Initial Phase - [P]rehab