lecture 4 equine pelvic limb part 2

equine pelvic muscles- sparks

what do the gluteal muscles act to do

extend, abduct and medially rotate the limb at the coxal joint

what does the middle gluteal muscle have and what does this cause

a lumbar head which makes it an active participant in rearing

what types of headas does the caudal thigh have

vertebral heads

what do the caudal thigh muscles (hamstrings) act as

extension of coxal joint and flexion of stifle joint when non-weight bearing

what is A

middle gluteal

what is B

superficial gluteal

what is C

biceps femoris

what is D

semitendinosus

what is E

semimembranosus

origin of superficial gluteal m

tuber coxae and gluteal fascia

insertion of superficial gluteal m.

third trochanter

origin of middle gluteal m

Gluteal surface of ilium, tuber coxae, sacrosciatic ligament; Longissimus dorsi m. (vertebral head, as far cranially as cranial lumbar region

insertion of middle gluteal m.

Greater trochanter (caudal part); proximal femur between greater

and third trochanters

where tendon of middle gluteal m. insertion passes over cranial part of greater trochanter

trochanteric bursa

origin of deep gluteal m.

body of ilium, ischiatic spine

insertion of deep gluteal m.

greater trochanter (cranial part)

all parts of hamstring take partial origin from

tuber ischii but also have additional originswha

biceps femoris origin

sacrum and sacrosciatic ligament

origin of semitendinosus

sacrosciatic ligament and caudal vertebrae

origin of semimembranosus

caudal most edge of sacrosciatic ligament

biceps femoris has 3 parts what are their insertions

▪ Patella and lateral patellar ligament (1)

▪ Cranial border of the tibia (lateral aspect) (2)

▪ Crural fascia and tuber calcanei via common

calcanean tendon (3)

semitendinosus inserts on

cranial border of tibia (medial aspect) and tuber calcanei via common calcanean tendon

semimembranosus inserts on

medial epicondyle of femur and medial collateral ligament of stifle

what nerve innervates biceps femoris and semitendinosus

caudal gluteal

what are the pelvic heads of caudal thigh supplied by

sciatic n.

adductors of pelvic limb

sartorius

gracilis

adductor

pectineus

origin of sartorius

psoas fascia and tendon

insertion of sartorius

medial aspect of stifle

action of sartorius

flexes hip; flexes and extends (weight bearing)stifle joint

origin of gracilis

pelvic symphysis via symphyseal tendon

insertion of gracilis

medial aspect of stifle, cranial border of the tibia

origin of adductor

ventral surface of pubic and ischium, symphyseal tendon

insertion of adductor

caudal aspect of and medial epicondyle of femur

origin of pectineus

margin of pubis

insertion of pectineus

medial surface of femur

all adductor muslces provide motor innervation by obturator nerve except what

sartorius which is innervated by the saphenous nerve

the pectineus m. forms the caudal border of the

femoral triangle

what forms the cranial border of the femoral triangle

sartorius m.

where does the femoral nerve emerge from

ilioposoas m.

where does the obturator n. pass through

obturator foramen

lateral rotators of the hip

external obturator, internal obturator, gemelli, quadratus femoris

where do the lateral rotators of the hip insert

in trochanteric fossa and trochanteric crest of femur

where can be found as the pelvic floor muscle, dorsal to obturator foramen

internal obturator

what does the tendon of insertion of the internal obturator pass over

lesser ischiatic notch

gemelli origin

ischium ventral to lesser ishiatic notch

quadratus femoris origin

ventral aspect of ilium inserts on trochanteric crest of femur

quadriceps femoris group

rectus femoris

vastus lateralis

vastus medialis

vastus intermedius

where do quadriceps femoris insert

on the patella and tibial tuberosity via the patellar ligaments

where does rectus femoris originate

body of ilium craniodorsal to acetabulumwh

at is the only muscle of the quadriceps femoris to cross hip joint

rectus femoris

what does the rectus femoris do

flex the hip joint

what muscle of the crus is not present in horses

fibularis longus m.

what muscle of the crus is present in large animals and cat but not dogs and is a part of the common calcanean tendon

soleus m.

action of cranial muscles of the crus

flexion of hock

what is A

cranial tibial m

what is B

long digital extensor m.

what is C

peroneus tertius

origin of cranial tibial muscle

lateral condyle of tibia

insertions of cranial tibial muscles

▪ Dorsal tendon: Metatarsal tuberosity

▪ Medial tendon (a.k.a., cunean tendon): fused tarsal bones I & II

what is affiliated with the medial tendon of the cranial tibial m.

cunean bursa

origin of peroneus tertius

extensor fossa of femur in common with long digitala extensor m.

insertion of peroneus tertius

Dorsal tendon: Tarsal bone III, Metatarsal bone III

▪ Lateral tendon: Calcaneus, Tarsal bone IV

what does the peroneus tertius m. form

“tunnel” through which the tendon of the cranial tibial m. passes

origin of long digital extensor

extensor fossa of femur

origin of lateral digital extensor

lateral collateral ligament of stifel

where do the long and lateral digital extensors unite

at the level of the metatarsus, distal to the metatarsal (disatl) extensor retinaculum

where do the long and lateral digital extensors insert

extensor process of distal phalanx III

action of long and lateral digital extensor

flexes hock and extends digit

what makes up the extensor retinacula

crural extensor retinaculum

tarsal extensor retinaculum

metatarsal extensor retinaculum

collective a ction of the caudal muscles of the crus

extension of hock

triceps surae muscle group

gastrocnemius and soleus muscle

origin of triceps surae muscle group

Medial and lateral supracondylar tuberosities of femur (lateral and medial heads of gastrocnemius); head of fibula (soleus)

insertion of triceps surae group

calcaneal tuber

origin of superficial digital flexor m

supracondylar fossa of femur

insertion of superficial digital flexor muscle

Calcaneal tuber; eminences

(medial and lateral) on palmar and

distal aspect of proximal phalanx and

proximal aspect of middle phalanx

action of superficial digital flexor muscle

Extension of hock; flexion

of fetlock and pastern joints;

counteracts flexion (buckling

forward) of pastern joint when

weight bearing

origin of deep digital flexor m

Lateral condyle of tibia and caudal

proximal surface of tibia

insertion of deep digital flexor

flexor surface of distal phalanx

action of deep digital flexor

extension of hock and flexion of all digital joints

tell me about the calcanean bursae

Subcutaneous

between skin and SDF tendon;

subtendinous located deep to the

SDF tendon where it passes over

the point of the hock.

Surrounds the

lateral digital flexor tendon from

~2-3 inches proximal to the

medial malleolus to a quarter of

the way down the metatarsus.

tarsal sheath

digital sheath

surrounds the tendons of the SDF and DDF proximal and distal to the fetlock

major components of reciprocal apparatus

superficial digital flexor m

peroneus tertius m

what does the reciprocal apparatus do

turns the limb in a pantograph

femur and metatarsus move in parallel

the reciprocal apparatus links what

the action between the stifle and the hock

how to diagnose peroneus tertius rupture

ability to extend the hock when the stifle is flexed

animal is lame but can usually bear weight on the limb

if the stifle can be locked in extension what will this allow

lock the hock in extension as well

through patellar locking mechanism

explain the patellar locking mechanism

during patellar locking mechanism what maintains extension of tarsus

SDF

clinical condition in which the patella becomes locked in position on the trochlear resting surface commonly known as stifled horse

upward fixation of patella

how does upward fixation of patella most likely occur

by a neuromuscular disorder or spasm of the medial thigh muscles