The triceps surae consists of two
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
s located at the
calf
Calf most often refers to:
* Calf (animal), the young of domestic cattle.
* Calf (leg), in humans (and other primates), the back portion of the lower leg
Calf or calves may also refer to:
Biology and animal byproducts
* Veal, meat from calves
* ...
– the two-headed
gastrocnemius
The gastrocnemius muscle (plural ''gastrocnemii'') is a superficial two-headed muscle that is in the back part of the lower leg of humans. It runs from its two heads just above the knee to the heel, a three joint muscle (knee, ankle and subtalar ...
and the
soleus
In humans and some other mammals, the soleus is a powerful muscle in the back part of the lower leg (the calf). It runs from just below the knee to the heel, and is involved in standing and walking. It is closely connected to the gastrocnemius mu ...
. These muscles both insert into the
calcaneus
In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock.
S ...
, the bone of the heel of the human
foot
The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
, and form the major part of the muscle of the posterior leg, commonly known as the calf muscle.
Structure
The triceps surae is connected to the foot through the
Achilles tendon
The Achilles tendon or heel cord, also known as the calcaneal tendon, is a tendon at the back of the lower leg, and is the thickest in the human body. It serves to attach the plantaris, gastrocnemius (calf) and soleus muscles to the calcaneus (h ...
, and has 3 heads deriving from the 2 major masses of muscle.
* The superficial portion (the gastrocnemius) gives off 2 heads attaching to the base of the
femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...
directly above the
knee
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...
.
* The deep (profundus) mass of muscle (the soleus) forms the remaining head which attaches to the superior posterior area of the tibia.
The triceps surae is innervated by the
tibial nerve
The tibial nerve is a branch of the sciatic nerve. The tibial nerve passes through the popliteal fossa to pass below the arch of soleus.
Structure Popliteal fossa
The tibial nerve is the larger terminal branch of the sciatic nerve with root val ...
, specifically, nerve roots L5–S2.
Function
Contraction of the triceps surae induce
plantar flexion
Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ...
(sagittal plane) and stabilization of the ankle complex in the
transverse plane
The transverse plane (also known as the horizontal plane, axial plane and transaxial plane) is an anatomical plane that divides the body into Anatomical terms of location#Superior and inferior, superior and inferior sections. It is perpendicula ...
. Functional activities include primarily movement in the
sagittal plane
The sagittal plane (; also known as the longitudinal plane) is an anatomical plane that divides the body into right and left sections. It is perpendicular to the transverse and coronal planes. The plane may be in the center of the body and divid ...
, stabilization during locomotion (walking, running), restraining the body from falling and power
jumping
Jumping or leaping is a form of locomotion or movement in which an organism or non-living (e.g., robotic) mechanical system propels itself through the air along a ballistic trajectory. Jumping can be distinguished from running, galloping and o ...
. By controlling the disequilibrium torque, the triceps surae can affect force through the exchange of potential into
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its accele ...
.
Clinical significance
Calf strain (torn calf muscle)
A calf
strain
Strain may refer to:
Science and technology
* Strain (biology), variants of plants, viruses or bacteria; or an inbred animal used for experimental purposes
* Strain (chemistry), a chemical stress of a molecule
* Strain (injury), an injury to a mu ...
refers to damage to a muscle or its attaching tendons.
A premature return before recovery is achieved will result in a prolonged recovery or incomplete return to baseline prior to injury.
Stretches such as alternating calf raises can improve
flexibility
Stiffness is the extent to which an object resists deformation in response to an applied force.
The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is.
Calculations
The stiffness, k, of a bo ...
as well as mobilize legs before running.
Calf muscles are a common place for
fasciculation
A fasciculation, or muscle twitch, is a spontaneous, involuntary muscle contraction and relaxation, involving fine muscle fibers. They are common, with as many as 70% of people experiencing them. They can be benign, or associated with more serio ...
s.
Additional images
File:Triceps surae - animation.gif, Animation. Gastrocnemius and Soleus are shown in different colors.
File:Sobo 1909 303.png, Illustration of the gastrocnemius
The gastrocnemius muscle (plural ''gastrocnemii'') is a superficial two-headed muscle that is in the back part of the lower leg of humans. It runs from its two heads just above the knee to the heel, a three joint muscle (knee, ankle and subtalar ...
.
File:Sobo 1909 304.png, Illustration of soleus
In humans and some other mammals, the soleus is a powerful muscle in the back part of the lower leg (the calf). It runs from just below the knee to the heel, and is involved in standing and walking. It is closely connected to the gastrocnemius mu ...
.
File:Sobo 1909 579-580.png, Nerves, arteries and veins surround the gastrocnemius and soleus.
File:Braus 1921 293.png, Cross section of the lower leg, with triceps surae at back (soleus and gastrocnemius)
File:Sobo_1909_720.png, Nerves and blood-vessels overlying the triceps surae
File:Medial view of a cadaver dissection of the gastrocnemius–soleus junction - with text.png, Photograph of the gastrocnemius
The gastrocnemius muscle (plural ''gastrocnemii'') is a superficial two-headed muscle that is in the back part of the lower leg of humans. It runs from its two heads just above the knee to the heel, a three joint muscle (knee, ankle and subtalar ...
-soleus
In humans and some other mammals, the soleus is a powerful muscle in the back part of the lower leg (the calf). It runs from just below the knee to the heel, and is involved in standing and walking. It is closely connected to the gastrocnemius mu ...
junction.
Etymology and pronunciation
The term is pronounced . It is from Latin ''caput'' and ''sura'' meaning "three-headed
uscleof the calf".
References
Further reading
*
{{Authority control
Calf muscles
Muscles of the lower limb