Mangel AW, Fehnel SE. End points in irritable bowel syndrome. Expert Rev Gastroenterol Hepatol. 2011 Jun 1;5(3):293-5.
Brodtkorb T, Kogler GF, Arndt A. The influence of metatarsal support height and longitudinal axis position on plantar foot loading. Clin Biomech (Bristol, Avon). 2008;23(5):640-7.