Minimizing Injection Site Bruising: No studies, to our knowledge, have assessed the characteristics or clinical importance of bruising in patients receiving subcutaneous LMWH or UFH. Thus, there is no evidence to support any association between bruising and discomfort. To bridge this gap in knowledge, we will document each injection site during the course of the study and measure the amount of bruising observed using a standardized photographic methodology. Injection site bruising has the potential to cause medical problems if an injection site hematoma develops, which can become infected or can cause long-term discomfort.