Lower limb: muscle groups (THIGH) Flashcards
What is deep fascia and what is its especially important role in the limbs?
It is a thick fibrous tissue that covers the entirety of the body
- It is particularly important in the limbs as it helps enclose different parts of the limb into COMPARTMENTS
What is the name of the deep fascia within the thigh?
Fascia lata
Fascia lata is a continuation of what?
The inguinal ligament and Scarpa’s fascia
The fasciae latae encloses two muscles as it runs down to the knee, what are they?
The tensor fasciae latae and the gluteus maximus
What is the name of the most superior opening of the fasciae latae? What drains into this opening?
Cribriform fascia
The great saphenous vein
What is the longest vein in the body and where does it drain into?
Great saphenous vein
- Drains into the femoral vein at the point of the cribriform fascia
The fasciae latae thickens to form what?
The iliotibial tract
What is the name of the fasciae latae as it travels distal to the knee?
The crural fascia
What is compartment syndrome?
It can happen in any part of the limb that has clearly defined compartments that are held by deep fascia
- Since deep fascia is a FIBROUS tissue, it does not stretch much, so anything that causes increased pressure within the compartment is going to have a negative impact, this is compartment syndrome
What can cause increased pressure within a compartment AKA compartment syndrome?
- Something within the compartment itself which is causing more volume to be placed within it (so if it cant stretch, it will begin to compress things within the compartment, this can be done by increased fluid content)
- examples include: a closed fracture which has resulted in a haemorrhage within the compartment and direct trauma to a blood vessel - Constriction of the compartment
- Can be caused by surgery (where the surgery over the top of a compartment has been closed too tightly)
- Scarring & contraction of skin or fascia, or both, due to burns can also cause constriction - External compression of the compartment
- A splint or cast that is too tight and doesn’t allow proper venous drainage from a compartment
What are the signs of compartment syndrome? (6 Ps)
- Pain on stretch
- Paraesthesia
- Pulse present
- Paresis (foot drop)
- Pink colour
- Pressure (palpable, painful tenseness of compartment)
What is the treatment for compartment syndrome?
Fasciotamy
- This is where the skin and superficial fascia are opened up to relieve the pressure therein, a mesh is placed over the wound to allow the wound to stay open whilst healing begins
The anterior muscles of the leg act as…
Ankle extensors & dorsiflexors
The lateral muscles of the leg act as…
Ankle everters
The posterior muscles of the leg act as…
Ankle flexors / plantar flexors
The anterior muscles of the thigh act as…
Hip flexors and knee extensors
The medial muscles of the thigh act as…
Hip adductors
The posterior muscles of the thigh act as…
Hip extensors and knee flexors
The anterior muscles of the foot act as…
Extensors
The posterior muscles of the foot act as…
Flexors
The muscles of the gluteal region act as…
Abductors, rotators and extensor but ONLY ACT ON THE HIP
The muscles of the iliac region act as…
Hip flexors
The muscles in the anterior compartment of the thigh are innervated by which nerve?
Femoral nerve
The femoral nerve has which roots?
L2-L4
The anterior muscles of the thigh act to…
Extend the knee and flex the hip
What are the muscles which make up the anterior compartment of the thigh?
- Quadriceps femoris
- Rectus femoris
- Vastus medialis, intermedius and lateralis - Sartorius
- Pectineus
- Iliopsoas*
- The end of the iliopsoas muscle passes into the anterior compartment
Which muscles make up the iliopsoas?
Psoas major
Iliacus
What is the origin & attachment, action and innervation of the iliopsoas muscle?
Attachment:
- Psoas major originates from the lumbar vertebrae whilst the iliacus originates from the iliac fossa, and they both insert onto the lesser trochanter
Action: Flexes the thigh at the hip joint
Innervation:
- Psoas major: anterior rami of L1-L3
- Iliacus: Femoral nerve
What is the origin & attachment, action and innervation of the vastus lateralis?
Origin & attachment: originates from the greater trochanter and inserts onto the lateral lip of the linea aspera
Action: Extends the knee joint and stabilises the patella
Innervation: Femoral nerve
What is the origin & attachment, action and innervation of the vastus intermedius?
Proximal attachment: Anterior and lateral surfaces of the femoral shaft
Actions: Extend the knee joint and stabilise the patella
Innervation: Femoral nerve
What is the origin & attachment, action and innervation of the vastus medialis?
Proximal attachment: intertrochanteric line and medial lip of the linea aspera
Actions: Extends the knee joint and stabilises the patella
Innervation: Femoral nerve
What is the origin & attachment, action and innervation of the rectus femoris?
Attachments: Originates from the ASIS and attaches to the patella via the quadriceps femoris tendon
Actions: Flexes the thigh at the hip joint and extends the knee joint
Innervation: Femoral nerve
What is the only muscle of the quadriceps to cross both the hip and knee joints?
The rectus femoris
What is the origin & attachment, action and innervation of the sartorius?
Attachment: originates at the ASIS and attaches to the superomedial surface of the tibia
Actions: At the hip joint it is a flexor, abductor and lateral rotator. At the knee joint, it is a flexor
Innervation: Femoral nerve
What is the origin & attachment, action and innervation of the pectineus?
Attachment: Originates from the pectineal line on the anterior surface of the pelvis and attaches to the pectineal line on the posterior side of the femur, just inferior to the lesser trochanter
Action: Adduction and flexion at the hip joint
Innervation: Femoral nerve but may also receive a branch from the obturator nerve
The muscles in the medial compartment of the thigh are collectively known as?
Hip adductors
What are the different muscles of the medical thigh compartment?
- Gracilis
- Obturator externus
- Adductor brevis
- Adductor longus
- Adductor magnus
All the medial thigh muscles are innervated by which nerve and artery?
Obturator nerve
Obturator artery
What is the origin & attachment, action and innervation of the adductor magnus?
O&A: originates from inferior rami of the pubis and attaches to the linea aspera of the femur
Action: Split into the adductor part and the hamstring part, both adduct the thigh but the adductor component also flexes the thing with the hamstring portion extending the thigh
Innervation: Adductor part is obturator nerve (L2-L4) and the hamstring part is by the tibial component of the sciatic nerve (L4-S3)
What is the origin & attachment, action and innervation of the adductor longus?
O&A: originates from the pubis, and expands into a fan shape, broadly attaching to the linea aspera of the femur
Action: Adduction of the thigh
Innervation: Obturator nerve (L2-L4)
What is the origin & attachment, action and innervation of adductor brevis?
O&A: originates from the body of the pubis and attaches to the linea aspera on the posterior surface of the femur, proximal to the adductor longus
Actions: Adduction of the thigh
Innervation: Obturator nerve (L2-L4)
What is the origin & attachment, action and innervation of the obturator externus?
O&A: originates from the membrane of the obturator foramen and passes under the neck of femur to attack to the posterior aspect of the greater trochanter
Actions: Adduction and lateral rotation of the thigh
Innervation: Obturator nerve (L2-L4)
What is the origin & attachment, action and innervation of the gracilis?
O&A: originates from the inferior rami of the pubis and descends vertically down the leg to attach to the medial surface of the tibia, between the tendons of the sartorius (anteriorly) and the semitendinosus (posteriorly)
Actions: Adduction of the thigh at the hip and flexion of the leg at the knee
Innervation: Obturator nerve (L2-L4)
Groin strain is injury to which group of muscles?
The adductor muscles
The muscles in the posterior compartment of the thigh are collectively known as the…
hamstrings
What are the different muscles of the posterior thigh compartment?
Biceps femoris, semitendinosus, semimembranosus
As a group, the muscles of the posterior thigh compartment act to…
Extend at the hip and flex at the knee
The muscles of the posterior thigh compartment are innervated by which nerve?
Sciatic (L4-S3)
What is the origin & attachment, action and innervation of the biceps femoris?
O&A: long head origin = ischial tuberosity and short head origin = linea aspera on post. surface of femur and both heads form a tendon which inserts onto the head of the fibula
Action: main action is flexion at the knee. It also extends the thigh at the hip and laterally rotates at the hip and knee
Innervation: long head = tibial part of sciatic nerve & short head = common fibular part of sciatic nerve
What is the origin & attachment, action and innervation of the semitendinosus?
O&A: originates from ischial tuberosity of pelvis and attaches to the medial surface of the tibia
Action: flexion of the leg at the knee joint. Extension of thigh at the hip. Medially rotates the thigh at the hip joint and the leg at the knee joint
Innervation: tibial part of sciatic nerve
What is the origin & attachment, action and innervation of the semimebranosus?
O&A: originates from ischial tuberosity but does so more superiorly than semitendinosus and biceps femoris. Attaches to the medial tibial condyle
Actions: Flexion of the leg at the knee joint. Extension of thigh at the hip. Medially rotates the thigh at the hip joint and the leg at the knee joint
Innervation: tibial part of the sciatic nerve
What is the femoral triangle and what does it act as?
It is a wedge-shaped area located within the superomedial aspect of the anterior thigh
- It acts as a conduit for structures entering and leaving the anterior thigh.
What are the borders of the femoral triangle?
- Roof – fascia lata.
- Floor – pectineus, iliopsoas, and adductor longus muscles.
- Superior border – inguinal ligament (a ligament that runs from the anterior superior iliac spine to the pubic tubercle).
- Lateral border – medial border of the sartorius muscle.
- Medial border – medial border of the adductor longus muscle. The rest of this muscle forms part of the floor of the triangle.
- The inguinal ligament acts as a flexor retinaculum, supporting the contents of the femoral triangle during flexion at the hip.
What are the contents of the femoral triangle?
Its contents (lateral to medial) are: - Femoral nerve – innervates the anterior compartment of the thigh, and provides sensory branches for the leg and foot.
- Femoral artery – responsible for the majority of the arterial supply to the lower limb.
- Femoral vein – the great saphenous vein drains into the femoral vein within the triangle.
- Femoral canal – contains deep lymph nodes and vessels.
- Acronym for the contents of the femoral triangle (lateral to medial) – NAVEL: Nerve, Artery, Vein, Empty space (allows the veins and lymph vessels to distend to accommodate different levels of flow), Lymph nodes.
The femoral artery, vein and canal are contained within…
a fascial compartment – known as the femoral sheath.
What is the adductor canal and what is it role?
- It is a narrow conical tunnel located in the thigh.
- It is approximately 15cm long, extending from the apex of the femoral triangle to the adductor hiatus of the adductor magnus.
- The canal serves as a passageway from structures moving between the anterior thigh and posterior leg.
What are the borders of the adductor canal?
- Anteromedial: Sartorius.
- Lateral: Vastus medialis.
- Posterior: Adductor longus and adductor magnus.
What are the contents of the adductor canal?
- It transmits the femoral artery, femoral vein (posterior to the artery), nerve to the vastus medialis and the saphenous nerve – the largest cutaneous branch of the femoral nerve.
- As the femoral artery and vein exit the canal, they are called the popliteal artery and vein respectively.
What is the lumbar plexus and where is it located?
It is a network of nerve fibres that supplies the skin and musculature of the lower limb.
It is located in the lumbar region, within the substance of the psoas major muscle and anterior to the transverse processes of the lumbar vertebrae
The lumbar plexus is formed by anterior rami of which spinal nerves?
the lumbar spinal nerves L1, L2, L3 and L4.
It also receives contributions from thoracic spinal nerve 12 (T12)
What are the different branches of the lumbar plexus?
I, I Get Leftovers On Fridays
- Iliohypogastric n.
- Ilioinguinal n.
- Genitofemoral n.
- Lateral cutaneous n.
- Obturator n.
- Femoral n.
What are the roots of the iliohypogastric nerve?
T12 and L1
- H comes before I, so ilioHypogastric comes before the ilioInguinal
What are the roots of the ilioinguinal nerve? Incl. sensory function
L1
Sensory function: : Innervates the skin on the superior antero-medial thigh. In males, it also supplies the skin over the root of the penis and anterior scrotum. In females, it supplies the skin over mons pubis and labia majora.
What are the roots of the genitofemoral nerve? Incl. motor and sensory functions
L1, L2
- Motor Functions: The genital branch innervates the cremasteric muscle
- Sensory Functions: The genital branch innervates the skin of the anterior scrotum (in males) or the skin over mons pubis and labia majora (in females). The femoral branch innervates the skin on the upper anterior thigh.
What are the roots of the lateral cutaneous nerve of the thigh?
L2, L3
What are the roots of the obturator nerve?
L2, L3, L4
What are the roots of the femoral nerve?
L2, L3, L4
What is the sacral plexus and where is it located?
It is network of nerve fibres that supplies the skin and muscles of the pelvis and lower limb.
It is located on the surface of the posterior pelvic wall, anterior to the piriformis muscle.
What is the sacral plexus formed by?
The anterior rami of the sacral spinal nerves S1-S4 but also receives contributions from L4 and L5
- So L4-S4
What are the roots of the superior gluteal nerve?
L4, L5, S1
What are the roots of the inferior gluteal nerve?
L5, S1, S2
What are the roots of the sciatic nerve?
L4, L5, S1, S2, S3
The sciatic nerve has 2 portions, what are they?
Tibial and common fibular portions
What are the roots of the posterior femoral cutaneous nerve?
S1, S2, S3
What are the roots of the pudendal nerve?
S2, S3, S4 keeps poo off the floor
What are the motor and sensory functions of the pudendal nerve?
- Motor Functions: Innervates the skeletal muscles in the perineum, the external urethral sphincter, the external anal sphincter, levator ani.
- Sensory Functions: Innervates the penis and the clitoris and most of the skin of the perineum.
What is the mneumonic for the major branches of the sacral plexus?
Some Irish Sailor Pesters Polly
- Superior gluteal
- Inferior gluteal
- Sciatic
- Posterior cutaneous
- Pudendal
What are the smaller branches, in addition to the five major nerves, of the sacral plexus?
- Nerve to piriformis
- Nerve to obturator internus
- Nerve to quadratus femoris
