Prelab Images - Anterior Leg & Foot

Prelab should consist of reading the lab manual and dissector answers and viewing the dissection video. To begin your study, you may find it useful to look over the Netter's or LWW Atlas images listed below.

Step 1. Review the bony landmarks. (Play movie)

The tibia (condyles, tuberosity, soleal line, anterior border, and medial malleolus) and the fibula (head and lateral malleolus) are shown in plate N513 or TG3-08 and TG3-09. The tarsals (calcaneus, talus, navicular, cuboid, and three cuneiform bones), metatarsal, and phalanges are shown in plates N523 or TG3-40 and N524 or TG3-41. Plate N524 or TG3-41 shows that the tarsals are arched both medially and laterally. If you view a foot as it is shown in the bottom picture of plate N523 or TG3-41 you will see that the foot also has a transverse arch (arched in the medial-lateral direction). The tuberosity of the calcaneus and the sustentaculum tali are labeled in plate N525 or TG3-40. The tarsal sinus is shown in plates N523 or TG3-41 and 524. The subtalar joint (joint between the talus and calcaneus) is shown in plates 524 or TG3-60 and N525. The transverse tarsal joint is shown in plates N523 or TG3-41A and 524 or TG3-41B.

Step 2. Open the lateral compartment of the leg and identify its muscles. (Play movie)

Remove any remaining skin and subcutaneous tissue from the leg and foot. Be careful while skinning the foot because it is easy to damage the neurovasculature there. Plates N529 or TG3-35 and N530 or TG3-36 show the extensor, flexor, and fibular (peroneal) retinacula. Plate N522 or TG3-32 examines the compartments you will be dissecting.

Plate N521 or TG3-36 shows the fibularis longus and brevis. Plate N535 or TG3-52 shows the tendons of the two muscles in the foot, which you will see later.

Step 3. Open the anterior compartment of the leg and identify the muscles within it; follow their tendons into the foot. (Play movie)

Plate N519 or TG3-37 shows the muscles of the anterior compartment (fibularis tertius is a small muscle that is closely associated with extensor digitorum longus - its tendon is labeled in plate N519 or TG3-37 and N521 or TG3-36 attaching to the fifth metatarsal). Plate N530 or TG3-45 shows the tendons of these muscles in the foot, synovial sheaths, and extensor expansions

Step 4. Trace the vessels and nerves into the lateral and anterior compartments of the leg. (Play movie)

Plate N518 or TG3-35 (and N512 or TG3-38) shows the division of the popliteal artery into anterior and posterior tibial arteries. Plate N518 or TG3-38 also shows the inferior lateral and medial genicular arteries. Plate N518 or TG3-38 shows the anterior tibial artery giving off the posterior tibial recurrent artery and then entering the anterior compartment. Plate N520 or TG3-38 shows the artery in the anterior compartment and giving off the anterior tibial recurrent artery (also see plate N512 or TG3-62). Plate N520 or TG3-62 also shows the anterior medial and lateral malleolar branches of the anterior tibial artery at the ankle (the lateral communicates with the perforating branch of the fibular artery, which will be dissected next). Plate N531 or TG3-47 shows the anterior tibial artery continuing as the dorsalis pedis artery and giving off the arcuate artery (has digital branches) and the deep plantar artery, which dives to the plantar side of the foot to help form the plantar arch (plate N536 or TG3-53). Plate N518 or TG3-38 shows the posterior tibial artery giving off the fibular (peroneal) artery, which has a perforating branch at the ankle that continues into the anterior leg (N520 or TG3-38). Later, you will follow the posterior tibial artery into the foot where it divides into medial and lateral plantar arteries (N534 or TG3-50). The lateral plantar artery and deep plantar artery form the plantar arch that gives off plantar metatarsal branches (N536 or TG3-53). Plate N520 or TG3-39 shows the origin of fibularis longus cut to trace the common fibular (peroneal) nerve. Plate N542 or TG3-65 traces the superficial and deep fibular nerves into the foot and shows their motor and cutaneous distribution (TG3-65C). Plate N518 or TG3-35 shows the tibial nerve in the leg, plate N529 or TG3-39 at the medial malleolus, and plate N535 or TG3-51 shows it dividing into medial and lateral plantar nerves in the foot. Plate N541 or TG3-66AB, TG3-67A, TG3-67B, and TG3-67C shows all the muscle and skin innervated by the tibial nerve in the leg and foot. Once again, plate N522 or TG3-32 shows the leg compartments and plate N512 or TG3-62 shows the collateral blood supply to the knee.

Steps 5. Remove the subcutaneous tissue from the posterior surface of the leg and dissect the superficial posterior compartment. (Play movie) and 6. Reflect the soleus and dissect the deep posterior compartment. (Play movie)

See plate N515 or TG3-30 for the origins and insertions of the muscles of the leg. After removing the fascia of the posterior leg your cadaver should look similar to plate N516 or TG3-33, which shows the gastrocnemius. The flexor retinaculum is shown in plates N516 or TG3-33 and N518 or TG3-35. Separate the gastrocnemius from the underlying soleus and plantaris muscles then cut through its midpoint and reflect it to reveal the soleus, popliteus, and plantaris muscles (plate N517 or TG3-34). The triceps surae is composed of the soleus muscle and the two heads of the gastrocnemius. After cleaning the popliteus muscle remove the soleus muscle from its fibular (lateral) attachment and reflect it medially. Now you will need to cut through the intermuscular septum (plate N522 or TG3-32) to expose the deeper posterior leg muscles. Plate N518 or TG3-35 shows the flexor digitorum longus, tibialis posterior, and flexor hallucis longus muscles that you need to identify. Plate N529 or TG3-35 shows the tendons rearranged at the medial malleolus [remember Tom (Tibialis posterior), Dick (flexor Digitorum longus), And (posterior tibial Artery), Very (posterior tibial Vein), Nervous (tibial Nerve), Harry (flexor Hallucis longus) for how these tendons cross the ankle superior to inferior]. Plate N518 or TG3-35 (and N512 or TG3-62) shows the division of the popliteal artery into anterior and posterior tibial arteries. Plate N518 or TG3-35 also shows the inferior lateral and medial genicular arteries. Plate N518 or TG3-35 shows the anterior tibial artery giving off the posterior tibial recurrent artery and then entering the anterior compartment. Plate N520 shows the artery in the anterior compartment and giving off the anterior tibial recurrent artery (also see plate N512 or TG3-62). Plate N520 also shows the anterior medial and lateral malleolar branches of the anterior tibial artery at the ankle (the lateral communicates with the perforating branch of the fibular artery, which will be dissected next). Plate N531 or TG3-36 shows the anterior tibial artery continuing as the dorsalis pedis artery and giving off the arcuate artery (has digital branches) and the deep plantar artery, which dives to the plantar side of the foot to help form the plantar arch (plate N536) Plate N518 or TG3-35 shows the posterior tibial artery giving off the fibular (peroneal) artery, which has a perforating branch at the ankle that continues into the anterior leg (N520 or TG3-38). Later, you will follow the posterior tibial artery into the foot where it divides into medial and lateral plantar arteries (N534 or TG3-50). The lateral plantar artery and deep plantar artery form the plantar arch that gives off digital branches (N536 or TG3-53). Plate N520 or TG3-39 shows the origin of fibularis longus cut to trace the common fibular nerve. Plate N542 or TG3-65 traces both of these nerves into the foot and shows their motor and cutaneous distribution. Plate N518 or TG3-35 shows the tibial nerve in the leg, plate N529 at the medial malleolus, and plate N535 or TG3-51 shows it dividing into medial and lateral plantar nerves in the foot. Plate N541 or TG3-66 and TG3-67A show all the muscle and skin innervated by the tibial nerve in the leg and foot. Once again, plate N522 or TG3-32 shows the leg compartments and plate N512 or TG3-62 shows the collateral blood supply to the knee.

 

Updated 9 Nov 2011