Difference between revisions of "Muscles of the Crus - Horse Anatomy"

Revision as of 13:03, 31 October 2012

Introduction

These muscles can be divided into two groups. On the craniolateral aspect of the limb are the flexors of the tarsus and extensors of the digit. On the caudal aspect are the extensors of the tarsus and flexors of the digit.

Craniolateral Muscles of the Crus

These muscles arise from the distal femur or proximal tibia or fibula. Their tendinous insertions are often multiarticular and insert on the metatarsals or phalanges. They are innervated by the peroneal nerve.

Flexors of the tarsus

Cranial Tibial

Origin - the lateral condyle and tuberosity of the tibia.

Insertion - the metatarsal tuberosity and the combined first and second tarsal bones.

Its tendinous insertion has a synovial sheath, and a bursa is present between its medial branch and the medial ligament of the hock.

Peroneus tertius

Origin - extensor fossa of the femur.

Insertion - proximal extremity of the third metatarsal bone and third tarsal bone. Also the calcaneus and fourth tarsal bones.

An almost exclusive tendinous muscle that plays an important part in the stay apparatus.

Extensors of the Digits

Long digital extensor

Origin - extensor fossa of the femur.

Insertion - extensor process of the third phalanx, and the dorsal surfaces of the proximal extremities of the first and second phalanges.

Its tendon of insertion passes over the front of the hock, and is held in place by three annular ligaments and a synovial sheath. The tendon of the lateral digital extensor joins the tendon a hands breath distal of the tarsus.

Lateral digital extensor

Origin - lateral patella ligament, fibula, lateral border of the tibia and the interosseous ligament.

Insertion - the long digital extensor tendon.

It appears to have no function, apart from maybe to support the long digital extensor.

Caudal Muscles of the Crus

These are innervated by the tibial nerve.

Extensors of the Tarsus

Gastrocnemius

Origin - lateral head from the lateral supracondyloid crest of the femur. The medial head from the medial supracondyloid crest.

Insertion - Calcaneus.

The two bellies combine in the middle of the crus, which twists around to the dorsal aspect of the superficial digital flexor. A large bursa lies between these two tendons and a small bursa lies between the gastrocnemius and the its point of insertion on the calcaneus.

Soleus

Origin - the head of the fibula.

Insertion - the gastrocnemius tendon.

Its function is mainly to assist the gastrocnemius.

Flexors of the Digits

Superficial digital flexor

Origin - the supracondyloid fossa of the femur.

Insertion - the calcaneus, the eminences on the sides of the proximal extremity of the second phalanx, and the distal extremity of the first phalanx behind the collateral ligament of the pastern joint.

A large synovial bursa lies under the tendon from the distal fourth of the tibia to the middle of the tarsus. A subcutaneous bursa is sometimes present at the point of the hock.

Deep digital flexor

Origin - the lateral condyle of the tibia, the caudal and medial aspect of the tibia.

Insertion - the semilunar crest and adjacent surface of the cartilage of the third phalanx.

The tendon has a synovial sheath from the distal fourth of the tibia, to a third of the way down the metatarsus.

Muscles of the Crus - Horse Anatomy Learning Resources
Drag and Drop (Dragster) Test your knowledge using drag and drop boxes	Equine Crus and Pes Surface Anatomy Resources (I, II & III)

@@ Line 1: / Line 1: @@
+{{unfinished}}
 {{OpenPagesTop}}
@@ Line 7: / Line 8: @@
 =='''Craniolateral Muscles of the Crus'''==
-These muscles arise from the distal [[Limb Bones and Cartilages - Horse Anatomy#Femur|femur]] or proximal [[Limb Bones and Cartilages - Horse Anatomy#Tibia and Fibula|tibia]] tibia or [[Limb Bones and Cartilages - Horse Anatomy#Tibia and Fibula|fibula]]. Their tendinous insertions are often multiarticular and insert on the [[Limb Bones and Cartilages - Horse Anatomy#Metacarpals and Metatarsals|metatarsals]] or [[Phalanges - Horse Anatomy|phalanges]]. They are innervated by the '''peroneal nerve'''.
+These muscles arise from the distal femur or proximal tibia or fibula. Their tendinous insertions are often multiarticular and insert on the metatarsals or phalanges. They are innervated by the '''peroneal nerve'''.
 ==='''Flexors of the tarsus'''===
-'''''Cranial Tibial (Tibialis Cranialis)'''''
+'''''Cranial Tibial'''''
-:'''Origin''': Lateral condyle and tuberosity of the [[Limb Bones and Cartilages - Horse Anatomy#Tibia and Fibula|tibia]]
+:Origin - the lateral condyle and tuberosity of the tibia.
-:'''Insertion''': Bifurcates into a medial and lateral branch. The lateral branch inserts on the [[Limb Bones and Cartilages - Horse Anatomy#Metacarpals and Metatarsals|metatarsal tuberosity]].  The medial branch inserts on the combined first and second [[Limb Bones and Cartilages - Horse Anatomy#Tarsal Bones|tarsal bones]]. The medial branch is also known as the '''cunean tendon'''.
+:Insertion - the metatarsal tuberosity and the combined first and second tarsal bones.
-:'''Action''': Flexes the [[Joints and Ligaments - Horse Anatomy#Tarsal Joint|tarsus]] (hock)
+:Its tendinous insertion has a synovial sheath, and a bursa is present between its medial branch and the medial ligament of the hock.
-:Its tendinous insertion has a synovial sheath, and a bursa is present between its medial branch and the medial ligament of the [[Joints and Ligaments - Horse Anatomy#Tarsal Joint|tarsus]] (hock).
-:In the horse, its fibres join with the ''third fibular muscle'' proximal to the [[Joints and Ligaments - Horse Anatomy#Tarsal Joint|tarsus]].
 '''''Peroneus tertius'''''
-:'''Origin''': Extensor fossa of the [[Limb Bones and Cartilages - Horse Anatomy#Femur|femur]]
+:Origin - extensor fossa of the femur.
-:'''Insertion''': Proximal extremity of the [[Limb Bones and Cartilages - Horse Anatomy#Metacarpals and Metatarsals|third metatarsal]] and [[Limb Bones and Cartilages - Horse Anatomy#Tarsal Bones|third tarsal]] bone. Also the [[Limb Bones and Cartilages - Horse Anatomy#Tarsal Bones|calcaneus]] and [[Limb Bones and Cartilages - Horse Anatomy#Tarsal Bones|fourth tarsal]] bones.
+:Insertion - proximal extremity of the third metatarsal bone and third tarsal bone. Also the calcaneus and fourth tarsal bones.
-:'''Action''': An almost exclusively tendinous muscle that plays an important part in the [[Stay Apparatus - Horse Anatomy|Stay Apparatus]]
+:An almost exclusive tendinous muscle that plays an important part in the stay apparatus.
 ==='''Extensors of the Digits'''===
 '''''Long digital extensor'''''
-:'''Origin''': Extensor fossa of the [[Limb Bones and Cartilages - Horse Anatomy#Femur|femur]], shared tendon of origin with the third fibular muscle
+:Origin - extensor fossa of the femur.
-:'''Insertion''': Extensor process of the [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]], and the dorsal surfaces of the proximal extremities of the [[Phalanges - Horse Anatomy#Proximal Phalanx|proximal]] and [[Phalanges - Horse Anatomy#Middle Phalanx|middle]] phalanges
+:Insertion - extensor process of the third phalanx, and the dorsal surfaces of the proximal extremities of the first and second phalanges.
-:'''Action''': Extends the digits, assists in flexing the [[Joints and Ligaments - Horse Anatomy#Tarsal Joint|tarsus]] (hock)
+:Its tendon of insertion passes over the front of the hock, and is held in place by three annular ligaments and a synovial sheath. The tendon of the lateral digital extensor joins the tendon a hands breath distal of the tarsus.
-:Its tendon of insertion passes over the front of the [[Joints and Ligaments - Horse Anatomy#Tarsal Joint|hock]] , and is held in place by three annular ligaments (proximal, middle and distal) and a synovial sheath. The [[Tendons - Horse Anatomy#Extensors|tendon]] of the lateral digital extensor joins the tendon in the approximately the middle of the[[Limb Bones and Cartilages - Horse Anatomy#Metacarpals and Metatarsals|third metatarsal]] (cannon) bone. It is also joined by two branches of the [[Tendons - Horse Anatomy#Flexors|suspensory ligament]] before its insertion.
 '''''Lateral digital extensor'''''
-:'''Origin''': Lateral patella ligament,  proximal [[Limb Bones and Cartilages - Horse Anatomy#Tibia and Fibula|fibula]], lateral border of the [[Limb Bones and Cartilages - Horse Anatomy#Tibia and Fibula|tibia]] and the interosseous ligament. It lies between the ''long digital extensor'' muscle and the ''long flexor muscle of the first digit''.
+:Origin - lateral patella ligament, fibula, lateral border of the tibia and the interosseous ligament.
-:'''Insertion''': [[Tendons - Horse Anatomy#Extensors|Long digital extensor tendon]]
+:Insertion - the long digital extensor tendon.
-:'''Action''': It appears to have no function, apart from maybe to support the ''long digital extensor''.
+:It appears to have no function, apart from maybe to support the long digital extensor.
 =='''Caudal Muscles of the Crus'''==
@@ Line 43: / Line 41: @@
 '''''Gastrocnemius'''''
-:'''Origin''': Lateral head from the lateral supracondyloid crest of the [[Limb Bones and Cartilages - Horse Anatomy#Femur|femur]]. The medial head from the medial supracondyloid crest.
+:Origin - lateral head from the lateral supracondyloid crest of the femur. The medial head from the medial supracondyloid crest.
-:'''Insertion''': [[Limb Bones and Cartilages - Horse Anatomy#Tarsal Bones|calcaneus]] as part of the '''common calcaneal tendon'''
+:Insertion - Calcaneus.
-:'''Action''': Extends the [[Joints and Ligaments - Horse Anatomy#Tarsal Joint|tarsus]], assists in flexing the [[Joints and Ligaments - Horse Anatomy#Stifle Joint|stifle]]
+:The two bellies combine in the middle of the crus, which twists around to the dorsal aspect of the superficial digital flexor. A large bursa lies between these two tendons and a small bursa lies between the gastrocnemius and the its point of insertion on the calcaneus.
-:The two bellies combine in the middle of the crus, which twists around to the dorsal aspect of the ''superficial digital flexor''. A large bursa lies between these two tendons and a small bursa lies between the gastrocnemius and the its point of insertion on the [[Limb Bones and Cartilages - Horse Anatomy#Tarsal Bones|calcaneus]].
 '''''Soleus'''''
-:'''Origin''': Head of the [[Limb Bones and Cartilages - Horse Anatomy#Tibia and Fibula|fibula]]
+:Origin - the head of the fibula.
-:'''Insertion''': Joins the lateral head of the ''gastrocnemius'' to become part of the gastrocnemius tendon
+:Insertion - the gastrocnemius tendon.
-:'''Action''': Mainly to assist the ''gastrocnemius''
+:Its function is mainly to assist the gastrocnemius.
 ==='''Flexors of the Digits'''===
 '''''Superficial digital flexor'''''
-:'''Origin''': Supracondylar fossa on the caudal [[Limb Bones and Cartilages - Horse Anatomy#Femur|femur]], attached to the lateral head of the ''gastrocnemius''
+:Origin - the supracondyloid fossa of the femur.
-:'''Insertion''': [[Limb Bones and Cartilages - Horse Anatomy#Tarsal Bones|Calcaneus]], the eminences on the sides of the proximal extremity of the [[Phalanges - Horse Anatomy#Middle Phalanx|middle phalanx]], and the distal extremity of the [[Phalanges - Horse Anatomy#Proximal Phalanx|proximal phalanx]]  behind the collateral ligament of the [[Joints and Ligaments - Horse Anatomy#Proximal Interphalangeal (Pastern) Joint|proximal interphalangeal]] (pastern) joint .
+:Insertion - the calcaneus, the eminences on the sides of the proximal extremity of the second phalanx, and the distal extremity of the first phalanx behind the collateral ligament of the pastern joint.
-:'''Action''': Extends the digit, assists in extending the [[Joints and Ligaments - Horse Anatomy#Tarsal Joint|tarsus]] and flexing the [[Joints and Ligaments - Horse Anatomy#Stifle Joint|stifle]].
+:A large synovial bursa lies under the tendon from the distal fourth of the tibia to the middle of the tarsus. A subcutaneous bursa is sometimes present at the point of the hock.
-:Almost entirely tendinous, major component of the '''common cunean tendon''' which forms the caudal part of the [[Stay Apparatus - Horse Anatomy#Reciprocal Mechanism|reciprocal apparatus]].
-:Widens at the point of the [[Joints and Ligaments - Horse Anatomy#Tarsal Joint|hock]] to form a cap over the [[Limb Bones and Cartilages - Horse Anatomy#Tarsal Bones|calcaneal tuberosity]]. The calcaneal bursa lies between the [[Limb Bones and Cartilages - Horse Anatomy#Tarsal Bones|calcaneal tuberosity]] and the [[Tendons - Horse Anatomy#Flexors|superficial digital flexor tendon]].
 '''''Deep digital flexor'''''
-:'''Origin''': The deep digital flexor muscle has three heads, originating from the lateral condyle of the [[Limb Bones and Cartilages - Horse Anatomy#Tibia and Fibula|fibula]], the caudal and medial aspect of the [[Limb Bones and Cartilages - Horse Anatomy#Tibia and Fibula|tibia]].
+:Origin - the lateral condyle of the tibia, the caudal and medial aspect of the tibia.
-:'''Insertion''': Semilunar crest and adjacent surface of the cartilage of the [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]], continues as the [[Tendons - Horse Anatomy#Flexors|deep digital flexor tendon]] to insert on the [[Phalanges - Horse Anatomy#Distal Phalanx|distal phalanx]]
+:Insertion - the semilunar crest and adjacent surface of the cartilage of the third phalanx.
-:'''Action''': Flexes the digit
+:The tendon has a synovial sheath from the distal fourth of the tibia, to a third of the way down the metatarsus.
-:The tendon has a synovial sheath from the distal fourth of the [[Limb Bones and Cartilages - Horse Anatomy#Tibia and Fibula|tibia]], to a third of the way down the [[Limb Bones and Cartilages - Horse Anatomy#Metacarpals and Metatarsals|metatarsus]].
 <br>
 {{Template:Learning
 |dragster = [[Equine Crus and Pes Surface Anatomy Resources (I, II & III)]]
 }}
-{{review}}
-[[Category:Muscles
-==Webinars==
-<rss max="10" filter="equine" highlight="none">https://www.thewebinarvet.com/internal-medicine/webinars/feed</rss>
-- Horse Anatomy]]