Final answer:
When lifting the thigh parallel to the floor, the action at the hip is flexion, performed by the anterior group of muscles, particularly the quadriceps femoris group.
Step-by-step explanation:
The action at the hip when lifting the thigh parallel to the floor is flexion. The locational group of muscles responsible is the anterior group. Specifically, this action involves the quadriceps femoris group in the anterior compartment of the thigh, which assists in raising the knee. In contrast, the posterior compartment, which includes the hamstring group, is involved in extending the thigh and flexing the leg, but not in the lifting of the thigh to a parallel position to the floor.