As subjects ran on a treadmill wearing the exosuit, the actuation unit pulled on the wires, which acted as a second pair of hip extensor muscles applying force to the legs with each stride. (sciencedaily.com)
While you do get some activation of the hip extensor muscle groups (hamstrings and glutes) the quads are taking the majority of the load. (fitnesscrest.com)
However, several studies have investigated the behavior of hip extensor moments in response to step length. (strengthandconditioningresearch.com)