The tibial nerve runs medially at the knee joint.
The plantaris muscle is a small muscle located in the back of the lower leg that forms part of the calf. As the muscle crosses both the knee and ankle joints, it weakly assists with knee and plantar flexion. Edinburgh: Churchill Livingstone. Deeply: superior lateral genicular artery.
This article will cover the anatomy and functions of the plantaris muscle. Reading time: 4 minutes. Ankle flexion may also be painful.[7]. The plantaris muscle is a fine rope-like tendon running next to the larger Achilles Tendon.
According to autopsy studies, the muscle can vary in size, thickness, and length, and is thought to be entirely absent in about ten percent of the population. When the tibial nerve receives an action potential, the plantaris muscle contracts, providing weak plantar flexion of the foot and weak flexion of the knee. Grounded on academic literature and research, validated by experts, and trusted by more than 1 million users.
Decussation of the lateral corticospinal tract occurs in the medullary pyramids, then the fibers continue down the contralateral side of the spinal cord.
and grab your free ultimate anatomy study guide! The attachment often extends onto the oblique popliteal ligament. Our engaging videos, interactive quizzes, in-depth articles and HD atlas are here to get you top results faster. The lower motor neuron fibers continue down the sciatic nerve and then diverge into the tibial and common fibular nerves. Last reviewed: October 29, 2020 Plantaris tendon runs between soleus and gastrocnemius. The tibial nerve arises from the S1 and S2 spinal nerves. Print. Adrian Rad BSc (Hons) Functions. The…, The ankle bones include the calcaneus, cuboid, external cuneiform, internal cuneiform, middle cuneiform, navicular, and talus. The plantaris tendon inserts onto the posterior surface of the calcaneus, medial to the calcaneal tendon (common tendon of the soleus and gastrocnemius muscles, also known as Achilles’ tendon). Saladin, Kenneth S. Anatomy and Physiology The Unity of Form and Function. Last medically reviewed on January 19, 2018, The adductor hallucis is a two-headed muscle that is responsible for flexing and contracting the big toe, and reinforcing the arch of the foot. (Tendon of Plantaris labeled at bottom right.). If it is tense or carries trigger points, it can trigger pain in the area of the hollow of the knee and in the calf. Superficially it receives blood from the lateral sural artery, a branch of the popliteal artery. Superficial layer. The muscle belly is variable both in thickness and length.
There is also an ongoing debate about its function. This means its role is most likely limited to being a pretty weak and pretty insignificant assistant to the functions of the gastrocnemius. However, in humans, the plantaris comes nowhere near it. It is considered a vestigial muscle, and can be used as a tendon graft in reconstructive orthopedic surgery.
Reviewer: Plantaris is innervated by the tibial nerve, which is a branch of the sciatic nerve. Sometimes the muscle has two bellies separated by a tendon, and in around 10% of the population, plantaris is absent altogether. However, since neither proprioceptive or flexor functions are affected when removed or absent, some studies argue that plantaris might be almost vestigial in humans. Plantaris has a dual blood supply.
Gielen, Johannes (Hans) Zwerver (2015). Register now The zygomaticus major muscle…, The semitendinosus muscle is one of three hamstring muscles that are located at the back of the thigh. It is composed of a thin muscle belly and a long thin tendon.
2020 The extensor…. In one clinical study, 94 out of 141 patients (66.7%) diagnosed with tennis leg were found with a partial rupture of the gastrocnemius muscle, while rupture of the plantaris tendon was only seen in 2 patients (1.4%). … As a result, it has acquired the nickname ‘freshman’s nerve’. Innervation. Its deep surface is supplied by the superior lateral genicular artery, which also stems from the popliteal artery. The plantaris acts to weakly plantar flex the ankle joint and flex the knee joint. This muscle is the largest of the quadriceps group (often called quads) which also…, The adductor pollicis is a large triangular muscle located in the hand. “I would honestly say that Kenhub cut my study time in half.” The plantaris descends between the gastrocnemius and soleus, the latter being located deep to the plantaris. Philadelphia, PA: Lippincott Williams & Wilkins. Read more. Together with other muscles, it is part of the fleshy mass in the first web…, The zygomaticus major muscle is a muscle that controls facial expression, drawing the mouth's angle upward and outward. Muscles of the back of the leg.
© 2005-2020 Healthline Media a Red Ventures Company. Its tendon then travels inferomedially along the medial border of the gastrocnemius. The plantaris is one of the superficial muscles of the superficial posterior compartment of the leg, one of the fascial compartments of the leg. The plantaris muscle and tendon sit roughly in the center of the calf, between the two heads of the gastrocnemius. One of the superficial muscles of the superficial posterior compartment of the leg. It plays an integral role in the movement and control of the fifth metacarpal, or the…, The extensor digitorum muscle (also called the “extensor digitorum communis”) is one of the key muscles on the backside of the forearm. Standring, S. (2016). The plantaris muscle is a smaller component of the calf muscles. Cross-section through middle of leg. Often mistaken for a nerve by new medical students (and thus called the "freshman nerve"), the muscle was useful to other primates for grasping with their feet. Learn the plantaris and other muscles of the leg fast with these interactive quizzes and worksheets. It is one of the plantar flexors in the posterior compartment of the leg, along with the gastrocnemius and soleus muscles. • Upper motor neurons synapse with lower motor neurons at the anterior horn of the spinal cord in the sacral plexus (formed from the anterior rami of spinal nerves L4, L5, S1–4). Egle Pirie Kim Bengochea, Regis University, Denver, Author: This tendon is so thin that it often gets confused for a nerve by less experienced students during dissections. Signaling for contraction begins in the frontal lobe of the brain with the pre-central gyrus (primary motor cortex). Ventricles, meninges and blood vessels of the brain, Lateral supracondylar line of femur, oblique popliteal ligament of knee, Posterior surface of calcaneus (via calcaneal tendon). Dierckx, Jan L.M.A. Not including the tendon, the plantaris muscle is approximately 5–10 centimetres (2.0–3.9 in) long and is absent in 8-12% of the population. Isolated plantaris muscle strains are rare, and ruptures normally occur in conjunction with injury to other muscles in the posterior compartment of the lower leg. It occasionally separately inserts into the medial side of the calcaneus.
Together with its lateral belly, the plantaris muscle forms the inferolateral border of the popliteal fossa. The synovial sheaths of the tendons around the ankle. The plantaris acts to weakly plantar flex the ankle joint and flex the knee joint. Plantaris is one of the most superficial muscles within the posterior compartment of leg. Moore, Keith L; & Dalley Arthur R (2008). Plantaris muscle (musculus plantaris) - Liene Znotina. Due to its small size in relation to other muscles in the calf and knee, it has often been mistaken for a tendon or a large nerve. In reality, however, it weakly assists the gastrocnemius and soleus muscles to perform these two movements. More research is needed in order better understand its function and also to improve the diagnosis and treatment of injuries to the muscle; currently, accurate diagnosis can only be determined through MRI scans. The plantaris muscle contains a large number of muscle spindles (proprioceptive receptors), so it has been theorised that it acts as a proprioceptive organ for the larger flexors of the ankle joint. Read more. Actions of Plantaris Muscle: a. Plantar flexes foot.
Plantaris muscle: want to learn more about it? Sometimes, plantaris might join the calcaneal tendon, or merge with the flexor retinaculum of the ankle or leg fascia.
It originates from the inferior end of the lateral supracondylar line of femur, just superior to the lateral head of the gastrocnemius muscle. Superficially: lateral sural and popliteal arteries The plantaris muscle arises from the inferior part of the lateral supracondylar ridge of the femur at a position slightly superior to the origin of the lateral head of gastrocnemius. New York: McGraw-Hill Science Engineering, 2009. It passes posterior to the knee joint in an inferomedial direction and becomes tendinous distally to insert into the Achilles tendon. The plantaris muscle is innervated by the tibial nerve, a branch of the sciatic nerve in the sacral plexus. – Ease your learning and review the key facts efficiently using Kenhub's muscle anatomy and reference charts! Not having one in no way affects mobility, either in the long or short term. There is relatively little existing research on this muscle, and its role is not fully understood. It forms, together with gastrocnemius and soleus, the superficial group of the posterior compartment of the leg.
6th ed. Kenhub. Plantaris is a long, slender muscle that consists of a short, fusiform belly (7-10 cm) and a long, thin tendon extending ... Relations. Edinburgh: Elsevier Churchill Livingstone. Origin and insertion. While not as thick as the achilles tendon, the plantaris tendon (which tends to be between 30–45 centimetres (12–18 in) in length) is the longest tendon in the human body.
[4], A common injury that is normally attributed to the plantaris muscle is a condition called tennis leg. Moore, K. L., Dalley, A. F. & Agur, A. M. R. (2014). The unusually high density of proprioceptive receptor end organs supports this notion. Learning the origins, insertions, functions and innervation of every muscle can be daunting. [5], Injury may occur from running, jumping, or pushing off one leg in sports such as tennis, basketball and soccer, which require quick foot movement in a certain direction. Copyright © Plantaris is long, thin muscle extending behind the knee and into the sural region (calf) of the posterior leg. Interdigitations with the lateral head of the gastrocnemius and a fibrous extension of the muscle to the patella are not unusual.[2]. Plantaris gets its name because in many mammals it inserts into the plantar aponeurosis. Plantaris tendos is indicated by white arrow-heads. Medial aspect. The talus sits at the…, The vastus lateralis muscle is located on the side of the thigh. There is a level of disagreement about the function of the plantaris muscle. It is made of a muscle belly and a thin tendon, and ranges from seven centimeters to twelve centimeters in length. Gray's Anatomy (41tst ed.). Plantaris muscle. Upper motor neurons are stimulated and send a signal through the internal capsule and down the corticospinal tract. Function Plantaris acts weakly to plantar flex the foot and flex the knee. The plantaris is visible under the gastrocnemius.