Flashcards in Muscles of the thigh Deck (74)
What bones is the pelvic girdle composed of?
Hip bone - ischium, ilium, pubis
What are the bones that fuse to make up the hip bone and what are the points where the hip bones articulate?
Ilium, ischium, pubis
- articulates with the sacrum at the sacro-iliac joints
- articulates with each other at the pubic symphysis
What is the orientation of the axis of the acetabulum? (which direction is it facing)
Lateral, downwards, and slightly posterior
What are the important landmarks of the top of the ilium?
- moving round to back from front
ASIS (anterior superior iliac spine)
Iliac tubercle (just posterior to ASIS)
PSIS (posterior superior iliac spine)
What are the other important landmarks of the ilium?
Ala (wing of ilium, just the big wing of bone, not the name of the surfaces)
Iliac fossa (internal surface of ala
Posterior inferior iliac spine
Anterior inferior iliac spine
Greater sciatic notch (lesser SN is part of the ischium)
Arcuate line (just inferior to iliac fossa
What kind of joints are the sacro-iliac joints?
Synovial joints combined with fibrous joints
What kind of joint is the pubic symphysis?
Secondary cartilaginous joint
- ossifies with age, may expand in parturition (childbirth)
What are the important landmarks of the ischium?
Lesser sciatic notch
Body of ischium
Ramus of ischium
What are important proximal attachment points for muscles on the external surface of the ilium?
Gluteus medius, minimus and part of gluteus maximus
What are important proximal attachment points for muscles on the external surface of the ilium?
Gluteus minimus - between anterior and inferior gluteal lines
Gluteus medius - between anterior and posterior gluteal lines
Gluteus maximus - posterior to the posterior gluteal line
Iliacus - from internal surface of the ilium
Sartorius - from ASIS
Rectus femoris - from AIIS (inferior spine)
What are important muscle attachments to the ischiopubic ramus and body of the pubis?
Adductor part of adductor magnus
What are important muscle attachments to the ischial tuberosity?
Long head of biceps femoris
Part of adductor magnus
What are the two parts of the acetabulum?
Acetabular fossa (non-articular)
Lunate surface (articular)
What is the function of the acetabular fossa?
Doesn't articulate with anything but provides attachment point for the ligament of the head of the femur
Acetabular notch is continuous with the fossa and blood vessels/nerves pass through here
What does the lunate surface surround and what is its function?
Surrounds the anterior, superior and posterior margins of the acetabular fossa (not inferior - transverse acetabular ligament)
- articulates with head of the femur
What are the landmarks of the proximal end of the femur?
Greater and lesser trochanters
Intertrochanteric crest (posteriorly)
Intertrochanteric line (anteriorly)
What are the features of the shaft of the femur?
Smooth anterior surface
Gluteal tuberosity (posterior surface, superior to linea aspera)
Linea aspera (medial and lateral lip)
What is the orientation of the head of the femur and why is this?
Directed superiorly, medially and slightly anteriorly (needs to fit into the acetabulum)
What is the anteversion of the femoral neck, what are the normal values for adults and children and what does a higher/abnormal anteversion angle cause?
Difference in angle between the axis of the femoral neck and the transcondylar axis of the knee
- adults = around 12 degrees
- birth = around 30-40, decreases with age up to 20 yrs old
A higher anteversion angle results in intoed feet (feet turned towards the midline)
What are the two layers of fascia over the thigh and what does one of the layers become?
Superficial - subcutaneous tissue
Deep - fascia lata, extends like a stocking beneath the skin from the pelvis down the leg
- this forms the iliotibial tract which is a lateral thickened stretch of fascia from the ischial tuberosity down to the lateral tibial condyle
What kind of joint is the hip joint?
Synovial ball-and-socket joint between head of femur and acetabulum
What is the rim of tissue around the acetabulum called and what ligament is found within the acetabulum?
Transverse acetabular ligament on inferior border of acetabular fossa
Where does the capsule of the hip joint extend and does it extend further anteriorly or posteriorly?
Capsule of the hip joint extends down the neck of the femur and extends further anteriorly than posteriorly
Why is the capsule of the hip joint important and what medical terms have been derived from its importance?
Important blood supply to the head of the femur inside the capsule
- hip fractures are described as extracapsular or intracapsular to reflect whether the fracture disrupted this blood supply or not
What are the 4 important ligaments at the hip joint?
Ilio-femoral ligament (y-shaped, attaches at AIIS and femur)
Ligament of the head of the femur
What are the main arteries that supply the hip joint/head of the femur and what can happen in a hip fracture?
Medial and lateral circumflex arteries
- easily damaged in intracapsular fractures of the proximal femur which can lead to avascular necrosis of the femoral head
What structures pass through the greater sciatic foramen above the piriformis muscle?
Superior gluteal nerve, artery, vein
What structures pass through the greater sciatic foramen below the piriformis muscle?
Inferior gluteal nerve, artery, vein
Internal pudendal artery, vein
Nerve to obturator internus + superior gemellus
Nerve to quadratus femoris + inferior gemellus
(Posterior femoral cutaneous nerve)
What structures pass through the lesser sciatic foramen?
Obturator internus muscle tendon
Pudendal nerve and internal pudendal vessels pass into perineum from gluteal region (go through greater THEN lesser sciatic foramina)
What structures pass through the obturator canal (medial and inferior to greater sciatic foramen)?
What structures pass through the gap between the inguinal ligament and pelvic bone into the leg?
Psoas major, iliac, pectineus muscles
Femoral artery, vein, nerve
Femoral branch of genitofemoral nerve
Lateral cutaneous nerve of the thigh
What are the 4 muscle compartments of the thigh and which nerves supply them?
Gluteal - superior gluteal nerve (gluteus medius + minimus) and inferior gluteal nerve (gluteus maximus)
Anterior - femoral nerve, includes pectineus
Medial - obturator nerve, excludes pectineus
Posterior - sciatic nerve for most, common peroneal innervates short head of biceps femoris
What are the muscles of the gluteal region?
- gluteus maximus, medius, minimus
Short external rotators of the hip
- piriformis, obturator internus, superior/inferior gemellus, quadratus femoris, tensor fascia latae
What nerves innervate the short external hip rotator muscles?
Nerve to obturator internus = obturator internus + superior gemellus
Nerve to quadratus femoris = quadratus femoris + inferior gemellus
Superior gluteal nerve = tensor fascia latae
Branches from L5, S1, S2 = piriformis
What actions do the gluteal region muscles have?
Extension, abduction and external rotation of the hip
What are the muscles of the anterior compartment of the thigh and what nerve innervates this compartment?
Quadriceps femoris divisions
- FEMORAL nerve
What are the 4 quadriceps femoris divisions?
What are the actions of the thigh's anterior compartment muscles?
What bony structures do the patellar tendon and quadriceps tendon attach to?
Patellar tendon = Tibial tuberosity
Quadriceps tendon = Superior aspect of patella
What are the muscles in the medial compartment of the thigh?
What is the action of the thigh's medial compartment muscles and what nerve innervates them?
Adduction of the hip
- OBTURATOR nerve
What structures stabilise the lateral and medial aspects of the extended knee?
Medial aspect - Gracilis, sartorius and semitendinosus
Lateral aspect - tensor fascia latae and iliotibial tract
What are the muscles of the posterior compartment of the thigh?
Laterally to medially
- Biceps femoris (long + short head)
What are the actions of the muscles of the posterior compartment of the thigh and what nerve innervates them?
- tibial division of SCIATIC nerve
- short head of biceps femoris by common peroneal nerve
What are the borders of the femoral triangle?
Superiorly - inguinal ligament
Medially - medial border of adductor longus
Laterally - medial border of sartorius
(Inferior apex leads into adductor canal
Floor - medially adductor longus then pectineus)
What does the femoral triangle contain?
Lateral to medial
- femoral nerve
- femoral artery
- femoral vein
What is the name of the fascia that surrounds the contents of the femoral triangle and which contents does it surround?
Femoral sheath - surrounds femoral artery/vein but NOT the nerve
- a portion of this sheath forms the femoral canal medially
What is the purpose of the saphenous opening and where is it?
Allows great (long) saphenous vein to drain into femoral vein (superficial to deep venous system transition)
- found superficial to the femoral vein so medial part of the femoral triangle
Where does the adductor canal extend and what is its purpose?
Extends along the medial aspect of the thigh from the apex of the femoral triangle to the adductor hiatus
- allows femoral vessels to pass into the popliteal fossa
What are the borders of the adductor canal?
Anteriorly + laterally = vastus medialis
Posteriorly = adductor longus + add. magnus
Medially = sartorius
What are the contents of the adductor canal and what does the nerve innervate?
Femoral artery + vein
- cutaneous innervation to medial knee, medial leg, and medial foot
How are the greater and lesser sciatic foramina formed and where to where do they each transmit structures?
Greater sciatic foramen = formed by sacrotuberous and sacrospinous ligaments and greater sciatic notch
- transmits structures from pelvis to thigh, connects pelvis to gluteal region
Lesser sciatic foramen = formed by sacrotuberous and sacrospinous ligaments and lesser sciatic notch
- transmits structures from pelvis to the perineum and connects perineum to gluteal region
Where does the sciatic nerve enter the buttock, what does it divide into and what does it supply itself?
Passes through greater sciatic notch inferior to piriformis to move from pelvis to buttock
- divides into tibial and common peroneal (fibular) nerves, these innervate all the muscle below the knee
- sciatic nerve itself (sciatic nerve 'proper') innervates most of the posterior compartment of the thigh
Why must care be taken with intramuscular injections made in the gluteal region and where is the safe zone for these injections?
Buttock area divided into quadrants
- sciatic nerve lies in the inferior + medial quadrant
- so IM injections are to be made in the safe zone of the superior + lateral quadrant to minimise the risk of damage to the sciatic nerve
What are the two arteries from which the arteries of the lower limb arise?
External and internal iliac arteries
What is the progression of the arteries in the thigh, starting with the two originator arteries?
External iliac becomes femoral artery at mid-inguinal point at the level of the inguinal ligament
- femoral artery then gives off the profunda femoris (deep artery of the thigh)
- at this level, both the femoral artery and profunda femoris give off the circumflex arteries
- the femoral artery continues as the superficial femoral artery in the adductor canal
- at the level of the knee, the femoral artery becomes the popliteal artery
Internal iliac gives off the superior/inferior gluteal arteries and the obturator artery
Where is the mid-inguinal point?
Half-way between the ASIS and the pubic symphysis
What two vessels pass from the anterior thigh compartment to the posterior of the knee, what do they pass through to do this, and what are they named after doing so?
Femoral artery + vein
- pass into popliteal fossa via the hiatus of the adductor magnus muscle
- become popliteal artery + vein after passing posteriorly
How are veins in the lower limb organised and how are the different systems connected?
Superficial and deep venous systems
In the thigh, the main superficial vein is the long (great) saphenous vein (short saph is only in the leg)
Long saphenous vein joins the deep venous system by joining the femoral vein at the femoral triangle
The main deep vein is the femoral vein. The popliteal vein runs alongside the popliteal artery and becomes the femoral vein at around the same point that the femoral artery becomes the popliteal artery (going the other way if that makes sense)
Proximal to the sapheno-femoral junction (closer to the hip), the femoral vein receives the venae comitantes of the profound femoris artery
What structure is present at the sapheno-femoral junction, what is its function and what pathology is caused if the structure is faulty?
- prevents back flow of blood from deep to superficial veins
- often faulty or incompetent in varicose veins
How is lymphatic drainage organised in the thigh?
Lymph flows with the superficial and deep venous systems
- superficial system runs with the long+short saphenous veins and has lymph nodes in the groin = superficial inguinal nodes
- the deep system of lymphatic drainage drains alongside the deep veins to the deep inguinal lymph nodes
The superficial inguinal nodes drain to the deep inguinal nodes which then drain into the external iliac nodes (final destination of lymph regardless of superficial or deep system originally carrying it)
How is the segmental motor supply distributed amongst the compartments of the thigh?
Hip flexors - L2, L3
Hip extensors - L4, L5
Knee extensors - L3, L4
Knee flexors - L5, S1
What are the specific nerves that supply each muscle compartment?
Femoral nerve = anterior compartment (+ pectineus)
Obturator nerve = medial compartment (-pectineus)
Sciatic nerve = tibial branch (most muscles) and common peroneal branch (biceps femoris short head)
Superior/Inferior gluteal nerves = superior for gluteus medius/minimus, inferior for gluteus maximus
What are the 10 peripheral nerves that supply sensory innervation to the buttock and thigh? (accessory flashcard)
Subcostal nerve (T12)
Ilio-hypogastric nerve (L1)
Ilio-inguinal nerve (L1)
Genito-femoral nerve (L1, L2)
Lateral cutaneous nerve of the thigh (L2, L3)
Sensory branches of the femoral nerve (medial femoral cutaneous, intermediate femoral cutaneous, saphenous) (L2, L3, L4)
Sensory branches of the obturator nerve (L2, L3, L4)
Posterior cutaneous nerve of the thigh (S2, S3)
Saphenous nerve (L2, L3, L4)
Buttock nerves derived from sacral plexus (L1 to S3)
What are the vertebral levels of the iliac crest and iliac tubercle, what can this be used for?
Iliac crest - L4
Iliac tubercle - L5
- L4 can be used to find point for lumbar puncture
How would one test the gluteus maximus muscle?
Subject lies prone with knee flexed, extend thigh at the hip joint while applying resistance at the distal end of the thigh, palpate rounded contour of the buttock (WITH PERMISSION lol) for muscle contraction
How would one test the gluteus medius and minimus muscles?
Subject lies on their side with the lower limb fully extended. Abduct limb at the hip joint while applying resistance at the distal end of the thigh and palpate contraction of medius just inferior to iliac crest
How would one test the tensor fascia lata?
Subject rolled slightly toward supine, abduct lower limb at hip joint, resistance at distal end of thigh, place finger-tip on TFL and the ilio-tibial tract
How would one test the hamstrings?
Subject lies prone with knee flexed to 30 degrees, apply opposing force (trying to extend the knee) while subject attempts to further flex the knee, hamstring tendons are visible with contraction, palpable on posterior side of mid-thigh
How would one test the quadriceps?
Subject sits on couch with knees bent 90 degrees, apply pressure at distal part of the leg while subject attempts to extend the knee, contracting quads can be palpated on anterior mid-thigh
How does one conduct the Trendelenberg test and why is it done?
Subject asked to stand on both legs, right and left side of pelvis should be at the same level without any tilt
Ask subject to raise one leg off the ground, pelvis should remain horizontal on one leg only
If pelvis dips on unsupported side then the Trendelenberg test is positive
A positive Trendelenberg test indicates a loss of or weakness of the motor function of the abductor muscles (gluteus medius + minimus) on the supported side.
Patients with a positive T sign tend to waddle when they walk.
How are true and apparent leg length measured?
Start with subject lying supine on couch with legs fully extended and kept side by side with the hip squared (ASIS on each side should be at the same level)
True leg length - measure the distance between the medial malleolus of the ankle a FIXED bony part of the pelvis (usually ASIS) using a tape measure.
Apparent (functional) leg length - measure distance between the medial malleolus of the ankle and a NON-FIXED landmark, such as the xiphisternum, with a tape measure.
With both, measure both sides and note down the measurements.
If there is a difference of >1.5cm in either, then there is a discrepancy in the respective measurement (e.g. if true lengths differ >1.5cm there is a discrepancy in true leg length and vice versa)
What are the main causes of true leg length discrepancy?
- Idiopathic unilateral hyper/hypoplasia
- Growth plate injury (trauma or infection)
- Asymmetric paralysis due to poliomyelitis or cerebral palsy
- Mass induced growth due to tumour, juvenile rheumatoid arthritis and post-fracture hypervascularity