The movement of the dorsal flexion of the first metatarsophalagic joint (MTPJ) is necessary for a correct gait. Its restriction generates an alteration in the establishment of the windlass mechanism, the Jack´s test allows to assess if there is alteration of movement. The use of compressive running socks is commonly used in the population, but we do not know how these socks influence the mechanism of windlass.Objectives: the aim of this study is to measure the amount of force needed to perform the dorsal flexion of the first MTPJ with the use of special compressive running socks.Methods: The sample size of this research was 30 subjects. Jack's test was measured with a new device, consisting of an algometer and a lever system. The necessary force was calculated with the use of two types of compressive running socks.Results: There were statistically significant differences with the use of special compressive running socks with orthopedic corrections during the Jack´s test measured with the new device(13.33N ±3.54, p<0.001).Conclusions: The use of special compressive running socks with orthopedic corrections decreases the force needed measured in Newtons to perform the dorsal flexion of the first MTPJ during the Jack´s test. The new device for measuring dorsal flexion of the first MTPJ is a valid and reliability tool.