Question

At approximately 50% competition of the gait cycle, what extensor and flexor muscles are active?

A. Iliopsoas, Rectus Femoris, and Medial Gastrocnemius
B. Iliopsoas, Biceps Femoris, and Medial Gastrocnemius
C. Gluteus Maximus, Rectus Femoris, and Tibialis Anterior
D. Iliopsoas, Rectus Femoris, and Tibialis Anterior
E. Gluteus Maximus, Biceps Femoris, and Medial Gastrocnemius

Answer 1

Option E, which includes the Gluteus Maximus, Biceps Femoris, and Medial Gastrocnemius, best represents the muscles active at 50% completion of the gait cycle, assisting in thigh extension, knee flexion, and plantar flexion of the foot.

Step-by-step explanation:

At approximately 50% completion of the gait cycle, the active extensor and flexor muscles are the Gluteus Maximus, Biceps Femoris, and Medial Gastrocnemius. This corresponds to the option E. The Gluteus Maximus is one of the primary muscles for thigh extension at the hip, the Biceps Femoris, part of the hamstring group, aids in knee flexion, and the Medial Gastrocnemius, part of the superficial posterior compartment of the leg, assists in plantar flexion of the foot. These muscles work in concert to create the push-off phase that propels the body forward during walking.