The most common musculoskeletal injuries of horses in work include tendon and ligament injuries, stress fractures, chip fractures, joint sprain/strain and foot soreness. The severity of the injury a horse may have depends on the type of training. Harness racing horses rarely develop bucked shins, while most flat racing horses are expected to have some shin soreness during their early training period. A horse in dressage training is unlikely to develop a chip fracture, but may be expected to develop back soreness as it strengthens its back and neck muscles as it learns collection. Some injuries, such as joint swelling due to osteochondrosis (OCD), occur because of an abnormality in joint development.