Association between limited dorsiflexion of the first metatarsophalangeal joint and Achilles tendinopathy in athletes: a case control study

Abstract

There were several recent studies about numerous risk factors in development of non-insertional Achilles tendinopathy (AT), however the exact etiology of AT is still unclear. High activity level is closely related to the development of AT since the lifetime incidence of AT in athletes is much greater than in non-athletic persons. METHODS: Setting of this case control study was Novi Sad Health Care Center, Sports Medicine Center. The participants were 44 athletes (ballet, basketball, soccer, and tennis) diagnosed with non-insertional AT and 44 healthy controls (88 all together). Seven persons had AT on both sides: there were 51 tendons with the symptoms of AT (cases) and 125 healthy tendons (controls). The scope of dorsiflexion of the first metatarsophalangeal joint was measured with a standard goniometer in all patients on both limbs. The data were analyzed using t-test for dependent and independent samples, Mann Whitney U Test, contingency coefficients and logistic regression. RESULTS: The average dorsiflexion of the first MTP joint on the sides with non-insertional AT is considerably smaller than on the sides of healthy tendons. Limited dorsiflexion of the first MTP joint is correlated with the occurrence of AT. These findings are modeled and explained by the mechanical principles of lever. CONCLUSIONS: A strong correlation is determined between AT and the limited dorsiflexion of the first MTP joint in athletes. It is possible that limited dorsiflexion of the first MTP joint can cause AT, which is explained by mechanical principles of lever.