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==Muscles of the Hindlimb==
 
==Muscles of the Hindlimb==
*'''[[Girdle Musculature - Anatomy & Physiology|Girdle Musculature]]'''
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===Girdle Musculature===
*'''[[Rump Muscles - Anatomy & Physiology|Rump Muscles]]'''
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*These muscles arise from the ventral aspect of the lumbar vertebrae and will insert on either the pelvis or femur. They are also known as the '''sublumbar muscles'''.
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* Their main function is to:
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** Stabilise the vertebral column and pelvis during locomotion.
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** Control dorsiflexion and ventriflexion of the spine.
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* The '''Psoas Minor'''
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** Function: flexion of the vertebral column during the stance phase. Stabilisation of the vertebral column.
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** Origin: 2nd-3rd caudal thoracic vertebrae on their ventral aspect and the 4th/5th cranial lumbar vertebrae
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** Insertion: via a strong tendon to the psoas tubercle of the femoral shaft.
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* The '''Iliopsoas''' - the strongest muscle of the girdle
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** Function: Flexion of the hip and outward rotation of the stifle. ie. draws hindlimb forward
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** In all animals, except carnivores were they are fused, the muscle can be divided into two distinct parts.
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** The '''Greater Psoas''' - the lumbar portion.
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*** Origin: last thoracic vertebrae and ribs and the bodies and transverse processes of the lumbar vertebrae.
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*** Insertion: Incorporates with iliac muscle and inserts on the lesser trochanter.
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*** It is positioned dorsally to the psoas minor and ventral to the quadrate lumbar muscle.
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** The '''iliac muscle'''
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*** Origin: wing and shaft of ilium
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*** Insertion: via the common iliopsoas tendon to the lesser trochanter of the femur.
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*** The muscle passes through the '''muscular lacuna'''; an opening between the os coxae laterally and caudally, the rectus abdominus medially and the iliac fascia cranially.
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* The '''quadrate lumbar''' muscle
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** Function: stabilisation of the lumbar vertebral column
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** Origin: Ventral aspect of the transverse processes of the lumbar vertebrae and the proximal ends of the ribs
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** Insertion: Ventral aspect of the wings of the ilium and sacrum.
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===Rump Muscles===
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The rump muscles main function is to extend the hip and some also extend the stifle and tarsus. They can be grouped into four distinct groups; the gluteals, the hamstrings, the medial muscles of the thigh and the inner pelvic muscles.
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===='''The Gluteals'''====
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They lie over the lateral and caudal aspect of the pelvic wall and extend between the thigh and ilium.
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'''''Superficial Gluteal Muscle'''''
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* This muscle shows great species variance and will be explained on their respective homepages.
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* Function - Extension of the hip, also retraction of the limb and supports outward rotation.
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'''''Gluteofemoral Muscle'''''
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* This muscle only exists in the cat.
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* Function - Retraction and abduction of the limb and hip extension
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* Origin - 2nd-4th caudal vertebrae
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* Insertion - Lateral aspect of patella and fascia lata via a aponeurosis
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* Location - Between the superficial gluteal muscle and biceps muscle of the thigh.
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'''''Middle Gluteal Muscle'''''
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* This muscle also shows great species variance. Though all species have a superficial and deep portion that a seperated by a tendinous sheet. Both tendons on their site of insertion are protected by a synovial bursa.
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* Function - most powerful extensor of the hip, also abducts and retracts the limb.
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'''''Piriform Muscle'''''
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* This is fused to the middle gluteal muscle except in carnivores.
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* Function - Extensor of hip and abducter of the limb.
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* Origin - last sacral vertebrae and sacrotuberous ligament.
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* Insertion - just distal to the greater trochanter on the lateral aspect of the femur.
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* Location - caudal and medial to the middle gluteal and is covered by the superficial gluteal.
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'''Deep Gluteal Muscle'''
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* Function - abduction of the limb.
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* Origin - lateral aspect of the ilial shaft
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* Insertion - via a short tendon to the greater trochanter.
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'''''Tensor Muscle of the Fascia Lata'''''
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* This muscle shows great species variance.
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* Function - flexion of the hip and extension of the stifle.
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===='''The Hamstrings'''====
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These muscles cover the caudal aspect of the thigh and are multi-articular. They originate near the ischium and extend to the tibia and have some tendinous components that will make up the '''common calcanean tendon'''.
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'''''Biceps Muscle of the thigh'''''
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* The largest and most lateral of the muscles, it is superficial and covered only by fascia and skin.
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* It consists of cranial part arising from the sacrum and sacrotuberous ligament and a small caudal part arising from the ischium.
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* The muscle is composed of multiple parts and has different points of insertion in different species.
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* Function - Extension and abduction of the limb. The cranial part extends the hip and stifle, though the caudal part extends the hip but flexes the stifle. It also causes tarsal extension.
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* See species pages as is very species specific.
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'''''Abductor muscle of the thigh'''''
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* Only present in carnivores
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* Function - abduction of the limb
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* Origin - sacrotuberous ligament
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* Insertion - crural fascia
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'''''Semitendinous'''''
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* Function - extends the hip, stifle and tarsus when the foot makes contact with the ground, therefore propulsing the animal. On a non-weightbearing leg it flexes the stifle and rotates the leg back and out.
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* Origin - the ischial tuberosity ('''pelvic head''')
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* Insertion - cranial margin of the tibia and a tendinous insertion on the calcaneal tuberosity.
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'''''Semimembranous'''''
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* The most medial of the hamstrings.
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* Function - Extension of the hip and stifle in a weightbearing stance. On a non-weightbearing limb it adducts and retracts the limb.
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* Origin - can be from either just the pelvic head or from the pelvic head and '''vertebral head'''. This is dependent on species.
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* Insertion - onto the medial condyle of the femur and the medial condyle of the tibia.
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===='''Medial Muscles of the Thigh'''====
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This muscle groups main functions are to adduct the limb and to prevent unwanted abduction. They lie between the pelvic floor and the medial aspect of the femur.
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'''''Sartorius'''''
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* Function - flexion of the hip, advancement and abduction of the limb. It can also extend the hip via its attachments to the crural fascia and stifle fascia.
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* Origin - Coxal tuberosity; ilial shaft or tendon of psoas minor
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* Insertion - Deep fascia of the leg
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* Location - superficially on the craniomedial border of the thigh as a strap like muscle.
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'''''Gracilis'''''
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* Function - adductor of the limb, extends the stifle.
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* Origin - from an aponeurosis of the pelvic symphysis, the insertional tendons of the straight muscle of the abdomen. A tendinous plate is formed between the two aponeurosi of the gracilis' on which the adductor muscles originate.
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* Insertion - An aponeurotic insertion with the crural fascia that attaches to the tibial crest.
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* Location - broad muscular sheet on the caudal aspect of the medial part of the thigh.
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'''''Pectineal Muscle'''''
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* Function - flexor of the hip, adductor and supinator of the limb.
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* Origin - iliopubic eminence of pelvic floor
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* Insertion - medial border of the femur
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* Location - a fusiform muscle extending between the pecten of the pubis, the pelvic floor and the femur.
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'''''Adductor Muscles'''''
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* Function - adduction of the limb, can also retract the limb
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* Origin - the tendinous plate of the gracilis muscles.
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* Insertion - medial aspect of the femur, fascia and ligaments of the medial aspect of the stifle.
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===='''Inner Pelvic Muscles'''====
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This set of muscles are a rather mixed group of small muscles lieing close to the hip joint. They lie between the pelvis and trochantic fossa of the femur.
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'''''Internal Obturator'''''
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* Only exists in carnivores and horses.
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* Function - extension of the hip and rotation of the femur laterally.
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* Origin and insertion - are both dependent on species involved.
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'''''External Obturator'''''
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* Function - supinator of the femur and adductor of the limb
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* Origin - the ventral pelvic surface close to the obturator foramen
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* Insertion - trochantic fossa
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'''''Gemellus'''''
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* Function - rotation of the limb laterally
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* Origin - ischiatic spine
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* Insertion - unites partially with the internal obturator  and so inserts on the trochantic fossa.
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'''''Quadrate Muscle'''''
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* Function - extension of the hip and retraction of the limb
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* Origin - ventral aspect of ischium
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* Insertion - trochantic fossa
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'''''Articular muscle of the hip joint'''''
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* Only in carnivores and horses
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* Function - causes tension of the joint capsule and thus helps prevent damage to the peri-articular structures.
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* Origin - Hip joint capsule
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*'''[[Muscles of the Stifle - Anatomy & Physiology|Muscles of the Stifle]]'''
 
*'''[[Muscles of the Stifle - Anatomy & Physiology|Muscles of the Stifle]]'''
  
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