Farrowing sows spend the majority of their time laying on their side, and as a result can develop lesions on their shoulders. The sows on an Ontario farm were monitored on the development of lesions on different floor types. Lesions were scored on a scale of 0-4 on size and severity, and if lesions were 3 or 4 sows were assigned to a treatment group. The treatment involved including a steel plate or a rubber mat on the flooring , or leaving it as a control. There was an increase in risk of lesion formation in sows with a body condition score below 3 by 3.7 times (P<0.05), a flank-to-flank measurement of 94-104cm by 2.8 times (P<0.05), and an increase of 1kg to weaning weight  by 1.1 times (P<0.05). As well, Landrace or Duroc sows were more likely to develop lesions than Yorkshire sows, as were first or fifth and above parity sows. The sows with the stainless steel plate treatment had an average healing time of 39 days, the control group had 32 days, and the rubber mat group had 25 days. The cost for rubber mats with multiple uses becomes $0.09, and the benefit to sow welfare is significant enough to consider implementing.