Improving stride length reduces the peak impact load on any single joint, thereby significantly lowering the risk of common running injuries such as Runner's Knee (Patellofemoral Pain Syndrome, Shin Splints, Achilles Tendinopathy, Plantar Fasciitis, IT Band Syndrome and even neck pain and lower back pain. 

Lower back pain in runner is all to common and often fixed once proper core strength is developed and hip mobility is improved.