Tarsal extensors Flashcards
M. gastrocnemius
o Origin: medial and lateral supracondylar tuberosities of femur (inside their heads – caput mediale and laterale – there are sesamoid /Vesalius/ bones, former: fabellae)
o Insertion: on tuber calcanei (as a part of common calcaneal tendon)
o Action: flexes stifle, extends tarsus
M. tibialis caudalis
o Origin: caudally on head of fibula
o Insertion: medially at tarsus it radiates into tarsal fascia
o Action: extends tarsus
M. flexor digitorum superficialis
o Origin: fossa supracondylaris of femur, partly fused with m. gastrocnemius caput lateralis
o Insertion: its plantar tendon (tendo plantaris) turns from medial to lateral direction around common calcaneal tendon, on the surface of tuber calcanei it makes a cap (galea calcanea), then finally attaches to middle phalanx of digits II-V. on plantar surface (in eq: tuberositas flexoria)
o Action: flexes stifle, extends hock, flexes joints of digits II-V
M. flexor digitorum profundus
o Origin: m. flexor digitorum lateralis (former: m. flexor hallucis longus) from proximal caudal half of fibula, proximal caudolateral border of tibia and from interosseous membrane; m. flexor digitorum medialis (former: m. flexor digitorum longus) starts caudo-proximally from tibia. Below tarsus the two parts unite.
o Insertion: plantar surface of distal phalanx of digits II-V. (on tuberculum flexorium, in eq: facies flexoria)
o Action: extends tarsus, flexes joint if digits II-V.
m. flexor digitorum profundus (Eq)
Receives lig. accessorium (fibrous
continuation of plantar tarsal ligament)
m. flexor digitorum superficialis (Eq)
Is mostly tendinous, doesn’t receive lig. accessorium (instead it’s tendon, the tendo plantaris forms galea calcanea on the calcaneus)
TENDO CALCANEUS COMMUNIS (ca)
o It comprise three main tendons:
- tendo m. gastrocnemii [Achilli] (tendon of m. gastrocnemius) - tendo plantaris (tendon of m. flexor dig. superficialis)
- tendo accessorius, from the following parts:
- lateral: m. biceps femoris (9a)
- medial: m. gracilis (18a) and m. semitendinosus (11a)
o As tendo plantaris widens, it forms galea calcanea
o Action: strongest extensor of tarsus
Between skin and tendo plantaris there is a protecting
bursa subcutanea calcanea
Between tendo plantaris and tendo m. gastrocnemii
bursa subtendinea calcanea (bursa calcanea subtendinea musculi flexoris digitorum superficialis)
Between tendo accessorius and tendo m. gastrocnemii
bursa tendinis calcanea
m. tibialis caudalis (in Eq)
– is a part of the m. flexor digitorum profundus
m. triceps surae
Eq. m. gastrocnemius+ m. soleus (from fibula to
join caput laterale m. gastrocnemii)
