There is still controversy on best treatment of proximal humeral fractures. While some authors propose surgical treatment other advocate for conservative treatment. Traditionally, fractures treated non-operatively undergo a 3-week period of immobilization followed by progressive rehabilitation program. Nevertheless, there is little evidence to support a 3-week immobilization period. The purpose of this study is to bring evidence to support either a 1-week immobilization or 3-week immobilization period in non-operatively treated proximal humeral fractures.