<< Chapter < Page Chapter >> Page >

The lateral compartment of the leg    includes two muscles: the fibularis longus    (peroneus longus) and the fibularis brevis    (peroneus brevis). The superficial muscles in the posterior compartment of the leg    all insert onto the calcaneal tendon    (Achilles tendon), a strong tendon that inserts into the calcaneal bone of the ankle. The muscles in this compartment are large and strong and keep humans upright. The most superficial and visible muscle of the calf is the gastrocnemius    . Deep to the gastrocnemius is the wide, flat soleus    . The plantaris    runs obliquely between the two; some people may have two of these muscles, whereas no plantaris is observed in about seven percent of other cadaver dissections. The plantaris tendon is a desirable substitute for the fascia lata in hernia repair, tendon transplants, and repair of ligaments. There are four deep muscles in the posterior compartment of the leg as well: the popliteus    , flexor digitorum longus    , flexor hallucis longus    , and tibialis posterior    .

The foot also has intrinsic muscles, which originate and insert within it (similar to the intrinsic muscles of the hand). These muscles primarily provide support for the foot and its arch, and contribute to movements of the toes ( [link] and [link] ). The principal support for the longitudinal arch of the foot is a deep fascia called plantar aponeurosis    , which runs from the calcaneus bone to the toes (inflammation of this tissue is the cause of “plantar fasciitis,” which can affect runners. The intrinsic muscles of the foot consist of two groups. The dorsal group    includes only one muscle, the extensor digitorum brevis    . The second group is the plantar group    , which consists of four layers, starting with the most superficial.

Intrinsic muscles of the foot

This figure shows the muscles of the foot. The top panel shows the lateral view of the dorsal muscles. The bottom left panel shows the superficial muscles of the left sole, the center panel shows the intermediate muscles of the left sole, and the right panel shows the deep muscles of the left sole.
The muscles along the dorsal side of the foot (a) generally extend the toes while the muscles of the plantar side of the foot (b, c, d) generally flex the toes. The plantar muscles exist in three layers, providing the foot the strength to counterbalance the weight of the body. In this diagram, these three layers are shown from a plantar view beginning with the bottom-most layer just under the plantar skin of the foot (b) and ending with the top-most layer (d) located just inferior to the foot and toe bones.

Intrinsic muscles in the foot

This table describes intrinsic muscles in the foot. The dorsal group consists of the extensor digitorum brevis, which extends toes 2 through 5. It originates in the calcaneus and the extensor retinaculum. These muscles make up layer 1 of the plantar group. The abductor hallucis abducts and flexes the big toe. It originates in the calcaneal tuberosity and flexor retinaculum. The flexor digitorum brevis flexes toes 2 through 4. It originates in the calcaneal tuberosity. The abductor digiti minimi abducts and flexes the small toe. It originates in the calcaneal tuberosity. These muscles make up layer 2 of the plantar group. The quadratus plantae assists in flexing toes 2 through 5. It originates in the medial and lateral sides of the calcaneus. The lumbricals extend toes 2 through 5 at the interphalangeal joints; they also flex the small toes at the metatarsophalangeal joints. They originate in the tendons of the flexor digitorum longus. These muscles make up layer 3 of the plantar group. The flexor hallucis brevis flexes the big toe. It originates in the lateral cuneiform and in the cuboid bones. The adductor hallucis adducts and flexes the big toe. It originates in the bases of metatarsals 2 through 4, in the fibularis longus tendon sheath, and in the ligament across the metatarsophalangeal joints. The flexor digiti minimi brevis flexes the small toe. It originates in the base of metatarsal 5 and in the tendon sheath of the fibularis longus. These muscles make up layer 4 of the plantar group. The dorsal interossei abducts and flexes the middle toes at the metatarsophalangeal joints; it also extends the middle toes at the interphalangeal joints. It originates in the sides of the metatarsals. The plantar interossei abducts toes 3 through 5; it also flexes the proximal phalanges and extends the distal phalanges. It originates in the side of each metatarsal that faces metatarsal 2 (absent from metatarsal 2).

Chapter review

The pelvic girdle attaches the legs to the axial skeleton. The hip joint is where the pelvic girdle and the leg come together. The hip is joined to the pelvic girdle by many muscles. In the gluteal region, the psoas major and iliacus form the iliopsoas. The large and strong gluteus maximus, gluteus medius, and gluteus minimus extend and abduct the femur. Along with the gluteus maximus, the tensor fascia lata muscle forms the iliotibial tract. The lateral rotators of the femur at the hip are the piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus, and quadratus femoris. On the medial part of the thigh, the adductor longus, adductor brevis, and adductor magnus adduct the thigh and medially rotate it. The pectineus muscle adducts and flexes the femur at the hip.

The thigh muscles that move the femur, tibia, and fibula are divided into medial, anterior, and posterior compartments. The medial compartment includes the adductors, pectineus, and the gracilis. The anterior compartment comprises the quadriceps femoris, quadriceps tendon, patellar ligament, and the sartorius. The quadriceps femoris is made of four muscles: the rectus femoris, the vastus lateralis, the vastus medius, and the vastus intermedius, which together extend the knee. The posterior compartment of the thigh includes the hamstrings: the biceps femoris, semitendinosus, and the semimembranosus, which all flex the knee.

The muscles of the leg that move the foot and toes are divided into anterior, lateral, superficial- and deep-posterior compartments. The anterior compartment includes the tibialis anterior, the extensor hallucis longus, the extensor digitorum longus, and the fibularis (peroneus) tertius. The lateral compartment houses the fibularis (peroneus) longus and the fibularis (peroneus) brevis. The superficial posterior compartment has the gastrocnemius, soleus, and plantaris; and the deep posterior compartment has the popliteus, tibialis posterior, flexor digitorum longus, and flexor hallucis longus.

Questions & Answers

what are diseases in the bood
Azoyenime Reply
Haemophilia
Aliyu
right hypochondriac rision how meain word
Ganesh Reply
Diabetes insipidus or diabetes mellitus would most likely be indicated by ________.
Ganesh
oral cavity how miean
Ganesh Reply
oral cavity how mean what
Suresh
seems to me every one is here a doctor and worse part is that even they donot know what to ask.
Muhammad
they know what to ask the problem is how to ask it.too much broken english.
George
dear George ongeche I think if they ask these kind questions and telling themselves as HCPs or medical student's .these are the basic ones go ask something more interesting .
Muhammad
what is blood red
Ahmad Reply
what is human anatomy?
Arpita Reply
tell me what is human anatomy?
Arpita
what is Openstax?
Arpita
arpita jana I think it's not the forum to ask such basic question...
Muhammad
study of structure of an object in this case human body.
Suresh
what are deferent between trasemicacid and vitamin k
Ubah Reply
This medication is used to treat heavy bleeding during your menstrual period. Tranexamic acid works by slowing the breakdown of blood clots, which helps to prevent prolonged bleeding. It belongs to a class of drugs known as antifibrinolytics
Muhammad
jj
John
In the body, vitamin K plays a major role in blood clotting. So it is used to reverse the effects of “blood thinning” medications when too much is given; to prevent clotting problems in newborns who don’t have enough vitamin K; and to treat bleeding caused by medications including salicylates, sulfo
Muhammad
Vitamin K plays a key role in helping the blood clot, preventing excessive bleeding. Unlike many other vitamins, vitamin K is not typically used as a dietary supplement. Vitamin K is actually a group of compounds. The most important of these compounds appears to be vitamin K1 and vitamin K2. Vitami
Muhammad
how much tha total vertebrea bone
Muhammad
26 vertebrea bone
Bhumi
wathe is blood function
dhena Reply
Blood, fluid that transports oxygen and nutrients to the cells and carries away carbon dioxide and other waste products. ... It is a tissue because it is a collection of similar specialized cells that serve particular functions. These cells are suspended in a liquid matrix (plasma), which makes the 
Ashiish
how tissue carries waste matrial
Nadeem
how many bone in human body?
Islam Reply
what is endocrin? plese help many people.
Islam
206
Nadeem
heart layers
Suresh
endoceime is the inner layer of heart
pandit
What is buffer?
Peer Reply
a buffer is a solution that resists a chemical change.
George
Yup it also balances the solutions
Peer
most common side effect reported by users emergency contraceptive pill
Shivvir Reply
spotting .breakbrough bleeding .weightgain.breast tenderness.mood alteration. headache
Ubah
How many systems are in the body?
Irvin Reply
11
AJ
names the systems pls
Joyce
name the systems pls
Joyce
integumentary system, lymphatic system, skeletal system, digestive system, cardiovascular system, reproductive system, respiratory system, urinary system, endocrine system
Irvin
approximately 11 system
Nadeem
what's the meaning of Acidphosphacidic
Tiwa Reply
most common source of phosphoric acid is an 85% aqueous solution; such solutions are colourless, odourless, and non-volatile. The 85% solution is a syrupy liquid, but still pourable. Although phosphoric aciddoes not meet the strict definition of a strongacid, the 85% solution is acidic 
Rose
What is osteoblast and what is osteoclast?
Irvin
osteoblast is the bone forming cells osteoclast is the bone dissolving cells
Juliet
Which of the following is most likely to be found evenly distributed in water in a homogeneous solution? a. sodium ions and chloride ions b. NaCl molecules c. salt crystals d. red blood cells
Ashley Reply
NaCl
Muhammad
b
Shivvir
what are the bases of classifying epithelium
Boahen Reply
What iz anti-cubical-fosa?
Peer Reply
Deep portion above the brachial artery Where we put stathescope while checking blood pressure
Peer

Get the best Anatomy & Physiology course in your pocket!





Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Anatomy & Physiology' conversation and receive update notifications?

Ask