Erratum to: The influence of long distance running on sonographic joint and tendon pathology: results from a prospective study with marathon runners. Issue 1 (December 2016) - Proft, Fabian; Grunke, Mathias; Reindl, Christiane; Schramm, Markus; Mueller, Felix; Kriegmair, Maximilian; Leipe, Jan; Weinert, Peter; Schulze-Koops, Hendrik; Witt, Matthias