Joint lesions are a major cause of euthanasia and culling of sows in Denmark and are of importance both economically and in relation to animal welfare . Joint lesions of sows are frequent causes of leg weakness, and non-inflammatory joint diseases as arthrosis and osteochondrosis are main causes of lameness [2-4]. Osteochondrosis developes in growing animal and is due to a failure in the endochondrale ossification of the articular cartilage and the growth plate . The lesions caused by osteochondrosis can heal completely  or progress into secondary arthrosis in the adolescent animal . The aetiology of osteochondrosis is thought to be multifactorial, and trauma, heredity, rapid growth, nutrition, and anatomical conformation are factors associated with this disease [5-7]. Non-osteochondrosis-related arthrosis (i.e. primary arthrosis) is characterized by fibrillation and ulceration of the articular cartilage and of eburnation of the subchondral bone . The pathogenesis of primary arthrosis of sows is not well understood, but the confinement of sows and the subsequent limitations of exercise have been suggested as a possible aetiology . Osteochondrosis and arthrosis in sows are often bilateral and symmetrical and are frequently observed in the distal humerus and femur .
Focus on the association between clinical observations and lesions of the locomotive system has been the objective in only a few porcine studies [3,4]. Therefore, it is uncertain which specific joint lesions actually are associated with the different types of abnormal gait and posture in pigs. The clinical examination of sows has until now been of limited use when trying to asses the cause of lameness, and a post-mortem examination of the animal has been preferred to differentiate the various causes of lameness .
The present study was performed in order to examine the correlations between certain joint lesions and defined gait and posture variables in sows.