To test tibialis posterior, invert the foot against resistance in slight plantarflexion.
![3 compartments of leg 3 compartments of leg](https://www.proceduresconsult.jp/UploadedImages/pcj_0025_00001579_100000_large_03112010144615.jpg)
Whilst this muscle is involved with inversion and plantarflexion of the foot, its main function is to support the medial arch of the foot. Located between flexor digitorum longus and flexor hallucis longus, tibialis posterior is the deepest muscle in the posterior compartment. Insertion: posterior surface of the proximal tibiaĪction: unlocks the knee joint by laterally rotating the femur on the fixed tibia as well as stabilising the knee jointīlood supply: genicular branches from the popliteal artery Figure 4.
![3 compartments of leg 3 compartments of leg](https://sportsmobile.com/wp-content/uploads/2018/12/40-sprinter-4x4-van-conversion-06-512x740.jpg)
Origin: lateral femoral condyle and lateral meniscus It does this by rotating the femur laterally 5 o to release the knee from its locked position allowing flexion to occur. The main function of popliteus is to unlock the knee. Popliteus is a flat triangular-shaped muscle that forms part of the floor of the popliteal fossa. Popliteus is the only muscle to act on the knee whereas the others act on the foot and toes. There are four muscles which make up the deep group of the posterior compartment: popliteus, flexor digitorum longus, flexor hallucis longus and posterior tibialis. Origin: inferior part of the lateral supracondylar line of femur and oblique popliteal ligament of kneeīlood supply: sural arteries (branches from the popliteal artery) Figure 3. The muscle is also absent in approximately 10% of people. to perform a tendon repair in hand surgery) without causing disability. Its involvement in foot plantarflexion or knee flexion is insignificant and as a result, the plantaris tendon can be removed for grafting (e.g. Plantaris is a small muscle with a short belly and a long tendon which joins the calcaneal tendon distally. Origin: soleal line and medial border of tibia posterior fibular head and tendinous arch between tibial and fibular attachmentsīlood supply: posterior tibial, fibular and sural arteries (branches from the popliteal artery) Figure 2. This tendinous arch is where the popliteal artery exits the popliteal fossa to enter the deep region of the posterior compartment of the leg, immediately dividing into the anterior tibial and posterior tibial arteries. Soleus has three origin points, one of which being the tendinous arch of soleus which spans between the tibia and fibula. Soleus is a large flat muscle located underneath gastrocnemius that received its name for its resemblance to a Sole, a type of flatfish. Insertion: posterior surface of the calcaneus (via calcaneal tendon)Īction: plantarflexes foot and flexes kneeīlood supply: sural arteries (branches from the popliteal artery) Figure 1.
![3 compartments of leg 3 compartments of leg](https://image.slideserve.com/58812/lateral-compartment-of-the-leg-n.jpg)
The word gastrocnemius has Greek and Latin origin which translates as ‘stomach of the leg’. The heads of gastrocnemius combine to form the muscle belly of the characteristic calf shape and distally contribute to the formation of the calcaneal tendon. These heads form the borders of the lower section of the popliteal fossa, an important anatomical landmark for neurovascular structures. Gastrocnemius is the most superficial muscle within the posterior compartment and originates from its two heads, the medial and lateral head. These strong powerful muscles are able to propel the body forward when moving and elevate it upwards on to the toes.Īll three of the superficial muscles insert into the calcaneus (heel) via the calcaneal tendon, the most powerful tendon in the body. The large size of gastrocnemius and soleus form the typical ‘calf’ shape, which is a human trait due to our upright nature.
![3 compartments of leg 3 compartments of leg](https://s3-us-west-2.amazonaws.com/courses-images-archive-read-only/wp-content/uploads/sites/18/2014/07/19181808/1123_Muscles_of_the_Leg_that_Move_the_Foot_and_Toes.jpg)
The three muscles of the superficial group are gastrocnemius, soleus and plantaris. All muscles within the posterior compartment are innervated by the tibial nerve. These two groups are divided by a layer of deep fascia called the transverse intermuscular septum.Īs a group these muscles act to plantarflex and invert the foot, as well as flexing the toes. The muscles in the posterior compartment are arranged into two groups: the superficial group and the deep group. You might also be interested in our Anatomy Flashcard Collection which contains over 2000 anatomy flashcards in addition to advanced features such as spaced repetition.