College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Which muscles make up the deep posterior compartment of the leg?

1. Gastrocnemius, soleus, plantaris

2. Tibialis anterior, peroneus longus, flexor hallucis longus

3. Tibialis posterior, flexor digitorum longus, flexor hallucis longus, popliteus

4. Quadratus plantae, flexor digitorum brevis

The correct answer is: Tibialis posterior, flexor digitorum longus, flexor hallucis longus, popliteus

The deep posterior compartment of the leg is primarily composed of muscles that play crucial roles in movements such as flexing the toes and plantar flexion of the foot. The correct group of muscles identified includes the tibialis posterior, which is important for foot inversion and supports the arch of the foot; the flexor digitorum longus, which flexes the lateral four toes; the flexor hallucis longus, which flexes the big toe and assists in plantar flexion; and the popliteus, which functions as a stabilizer of the knee and assists in initiating knee flexion. This anatomical grouping is consistent with the established understanding of lower leg anatomy and contributes significantly to the functional mechanics of the lower extremity. The other groups listed contain muscles that belong to different compartments: the gastrocnemius, soleus, and plantaris are part of the superficial posterior compartment, while tibialis anterior and peroneus longus are found in the anterior and lateral compartments, respectively. Quadratus plantae and flexor digitorum brevis are intrinsic foot muscles rather than part of the leg compartments. Understanding the specific location and function of these muscles is essential for effective assessment and treatment in the practice of massage therapy.