Erratum to: Is entheses ultrasound reliable? A reading Latin American exercise

1 Rheumatology Unit, La Paz University Hospital, P° de la Castellana 261, 28046 Madrid, Spain 2 Musculoskeletal Ultrasound Laboratory, Instituto Nacional de Rehabilitacion, Mexico City, Mexico 3 Rheumatology Unit, CentroMedico Clinica Santa Maria La Dehesa, Santiago, Chile 4 Rheumatology Unit, Hospital Edgardo Rebagliati Martins, Lima, Peru 5 Rheumatology Unit, Hospital Felix Bulnes Cerda-Universidad Mayor, Santiago, Chile 6 Rheumatology Unit, Facultad de Ciencias Medicas, Hospital Nacional de Clinicas, Cordoba, Argentina 7 Rheumatology Unit, Instituto Reumatologico Strusberg, Cordoba, Argentina 8 Rheumatology Unit, Instituto de Rehabilitacion Psicofisica, Buenos Aires, Argentina 9 Reumatoligya SA, Rheumatology Medellin, Medellin, Colombia 10 Rheumatology Unit, Hospital Universitario Fundacion Santa Fe de Bogota, Bogota, Colombia