2.8 Muscles of the Pelvic Limb: Caudal Muscles of the Leg/ Crus

Caudal Muscles of the Leg/ Crus

Gastrocnemius

Superficial digital flexor

Deep digital flexor

Caudal tibial muscle

Popliteus

name the Caudal Muscles of the Leg/ Crus (5)

Gastrocnemius

• large two-bellied muscle arising from the distocaudal surface of the femur;

• its heads enclose the proximal end of the superficial digital flexor;

• distally it inserts on the calcaneal tuberosity.

•  the two heads (lateral head and medial head) springs from the caudal aspect of the femur proximal to the condyle

• the principal component of the common calcaneal tendon/ tendon of achilles

• Origin: lateral head - Lateral supracondylar tuberosities; Medial head - medial supracondylar tuberosities

• Insertion: proximal dorsal surface of the tuber calcanei

• Action: It extends the tarsal joint and flexes the stifle joint.

• Innervation: Tibial nerve

Superficial digital flexor

• thin muscle arising from the caudal aspect of the distal femur deep to the heads of the gastrocnemius muscle;

• extending distally, its tendon wrap medially around the gastrocnemius tendon and attaches superficially to the calcanean tendon.

• Origin: lateral supracondylar tuberosities

• Insertion: tuber calcanei

• Action: to flex the 2 digital joints of the 4 principal digits

• Innervation: Tibial nerve

Deep digital flexor

• large muscle composed of two or three bellies (Lateral digital flexor and Medial digital flexor) extending from the caudal surface of the tibia and fibula to the distal phalanx

• Origin: proximal aspect of tibia

• Insertion: plantar surface of the base of each phalanges

• Action: It flexes the digits and extends the tarsus

• Innervation: Tibial nerve

Caudal tibial muscle

• Origin: arises from the medial part of the proximal end of fibula

• Insertion: inserts on the medial ligament of the tarsus

• Action: to extend the tarsus

• Innervation: Tibial nerve

Popliteus

• small muscle lies directly over the caudal aspect of the joint.

• Origin: It arises from the lateral condyle of the femur

• Insertion: inserts on the proximal third of the caudal surface of the tibia.

• Action: It flexes the stifle and rotates the distal part of the limb.

• Innervation: Tibial nerve

Soleus

absent in dogs but present in cats; origin is on the fibula and it joins the lateral head of the gastrocnemius

Triceps surae

collective term for gastrocnemius and soleus