Las manifestaciones óseas de la inserción humeral del pectoral mayor: desde la patología hasta la actividad física

Abstract

Pectoralis major stands out as one of the strongest muscles in the human body. Located in the anterior area of the ribs, it is inserted in the greater tubercle of the humerus. Its insertion has occasionally been related to osseous morphologies corresponding to an osteolysis, also known as ‘fossa’ insertion. The aim sought in this study is to examine the morphologies and causes linked to this osseous marker in order to assess the most probable factors. Examples of archaeological bone remains are presented: a humerus from the ossuary of Wamba (Valladolid) dating back to the 12th-17th centuries; and two humeri from the chalcolithic site of Camino de las Yeseras (San Fernando de Henares, Madrid). Despite the importance of physical activity for the presence of this marker, other factors can explain its appearance too. When it comes to subadults, bone immaturity itself can cause this ‘fossa’ appearance; as for adults, this morphology may be due to several causes, ranging from calcifying tendinitis to biomechanical stresses. In short, pectoralis major insertion illustrates the problems that arise when analysing entheseal changes on past populations; hence why such a study can highlight the need to be cautious when proposing functional demands and specifc work-related activities based on enthesopathy assessments.