WINDSOR UNIVERSITY SCHOOL OF MEDICINE DEPARTMENT OF ANATOMY Lower limb Dr. SREEKANTH THOTA

Muscle compartments in the thigh In the thigh, there are medial (adductor), anterior (extensor), and posterior (flexor) compartments.

Anterior Compartment of the Thigh Muscles: Sartorius, iliacus, psoas, pectineus, and quadriceps femoris Blood supply: Femoral artery Nerve supply: Femoral nerve

Anterior Thigh Muscles Anterior thigh muscles are the flexors of the hip and extensors of the knee.

SARTORIUS shaft of tibia N. supply: Femoral nerve Origin : A.S.I.S. Insertion : Upper medial surface of shaft of tibia N. supply: Femoral nerve Action :1.Flexion, abduction and Lateral rotation of thigh at hip joint. 2. Flexion leg at knee joint

ILIACUS lesser trochanter of femur N. supply: Femoral nerve Origin : Iliac fossa of hip bone Insertion : Along with psoas into lesser trochanter of femur N. supply: Femoral nerve Action :Flexes thigh on trunk Eg.: Sitting up from lying down

PSOAS I.V.D.’S of T12 & L 1-L5 vertebrae trochanter of femur Origin : Transverse process, bodies & I.V.D.’S of T12 & L 1-L5 vertebrae Insertion : Along with Iliacus into lesser trochanter of femur N. supply: Lumbar plexus Action : Flexes thigh on trunk Eg.: Sitting up from lying down T12 12345

PECTINEUS Upper end of linea aspera of shaft of femur Origin : Superior ramus of Pubis Insertion : Upper end of linea aspera of shaft of femur N. supply: Femoral nerve Action :Flexion, adduction of thigh at hip joint

QUADRICEPS FEMORIS RECTUS FEMORIS : Quadriceps tendon in to patella Origin : Straight Head: A.I.I.S Reflected Head: Ilium (Above Acetabulum) Insertion : Quadriceps tendon in to patella Via lig.patellae in to tibial tubercle N. supply: Femoral nerve Action : Flexion of thigh at hip joint Extension of Leg at Knee joint

Patellar ligament The patellar ligament  is the central portion of the common tendon of the Quadriceps femoris, which is continued from the patella to the tuberosity of the tibia.

VASTUS LATERALIS patella via Lig.patellae in to tubercle of tibia Origin : Upper end & shaft of femur Insertion : Quadriceps tendon in to patella via Lig.patellae in to tubercle of tibia N. supply: Femoral nerve Action : Extension of Leg at Knee joint

VASTUS MEDIALIS patella Via Lig.patellae in to tubercle of tibia Origin : Upper end & shaft of femur Insertion : Quadriceps tendon in to patella Via Lig.patellae in to tubercle of tibia N. supply: Femoral nerve Action : Extension of Leg at Knee & Stabilizes Patella

VASTUS INTERMEDIUS of shaft of femur patella Via Lig.patellae Origin : Anterior & lateral surface of shaft of femur Insertion : Quadriceps tendon in to patella Via Lig.patellae in to tubercle of tibia N. supply: Femoral nerve Action : Extension of Leg at Knee joint

Summary of Ant compt of thigh Muscle Movements Anterior compartment Flexors of hip Sartorius (also abducts and laterally rotates hip and flexes and medially rotates knee) Iliopsoas Pectineus (also adducts hip) Extensor of knee Quadriceps femoris Rectus femoris (also flexes hip) Vastus lateralis Vastus intermedius Vastus medialis (also stabilizes patella)

Patellar tendon reflex Tapping the patellar ligament with a hammer elicits the patellar tendon reflex (knee jerk) Tests the L2-L4 nerves Diminution or absence—result from interruption of innervation of quadriceps .

Medial compartment of thigh Muscles: Gracilis, adductor longus, adductor brevis, adductor magnus, and obturator externus. Blood supply: Profunda femoris artery and obturator artery. Nerve supply: Obturator nerve

GRACILIS ramus of Ischium part of shaft of tibia Origin : Inferior ramus of Pubis & ramus of Ischium Insertion :Medial aspect of upper part of shaft of tibia N. supply: Obturator nerve Action : Adduction of thigh at hip joint Flexion of Leg at Knee joint

ADDUCTOR LONGUS to pubic tubercle shaft of femur Origin : Body of Pubis, medial to pubic tubercle Insertion : Posterior surface of shaft of femur N. supply: Obturator nerve Action : Adduction of thigh at hip joint Assists Lateral rotation

ADDUCTOR BREVIS shaft of femur N. supply: Obturator nerve hip joint Origin : Inferior ramus of pubis Insertion : Posterior surface of shaft of femur N. supply: Obturator nerve Action : Adduction of thigh at hip joint Assists Lateral rotation

ADDUCTOR MAGNUS Ramus of ischium Ischial tuberosity shaft of femur Origin : Inferior ramus of pubis Ramus of ischium Ischial tuberosity (HAMSTRING PORTION) Insertion :Posterior surface of shaft of femur Adductor tubercle of femur N. supply: Obturator + Sciatic nerves Action : Adduction of thigh at hip Assists Lateral rotation & Extension of thigh at hip joint

Adductor Hiatus The adductor hiatus is an opening or gap between the aponeurotic distal attachment of the adductor part of the adductor magnus and the tendinous distal attachment of the hamstring part. The adductor hiatus transmits the femoral artery and vein from the adductor canal in the thigh to the popliteal fossa posterior to the knee.

OBTURATOR EXTERNUS Obturator membrane Pubic & Ischial rami Origin : Outer surface of Obturator membrane Pubic & Ischial rami Insertion :Medial surface of greater trochanter N. supply: Obturator nerve Action : Lateral rotation of thigh at hip joint

Obturator nerve As the obturator nerve enters the thigh, it divides into two branches, an anterior branch and a posterior branch, which are separated by the adductor brevis muscle: Anterior branch: adductor longus, gracilis, and adductor brevis muscles, and often contributes to the supply of the pectineus muscle, and cutaneous branches innervate the skin on the medial side of the thigh. Posterior branch: obturator externus and adductor brevis muscles and the part of adductor magnus that attaches to the linea aspera

Obturator nerve

Obturator nerve

Deep artery of thigh (Profunda femoris artery) Branches :lateral and medial circumflex femoral branches and four perforating branches. Lateral circumflex femoral artery: 3 branches 1. Ascending branch 2. Descending branch 3. Transverse branch Medial femoral circumflex artery: It takes part in the formation of the cruciate anastomosis.

Obturator Artery The obturator artery is a branch of the internal iliac artery. It gives off muscular branches and an articular branch to the hip joint.

Gluteal Region The gluteal region lies posterolateral to the bony pelvis and proximal end of the femur. Muscles in the region mainly abduct, extend, and laterally rotate the femur relative to the pelvic bone.

Ligaments of the Gluteal Region Sacrotuberous Ligament: sacrotuberous ligament connects the back of the sacrum to the ischial tuberosity Sacrospinous Ligament: sacrospinous ligament connects the back of the sacrum to the spine of the ischium.

Foramina of the Gluteal Region Greater Sciatic Foramen:The greater sciatic foramen is formed by the greater sciatic notch of the hip bone and the sacrotuberous and sacrospinous ligaments. It provides an exit from the pelvis into the gluteal region.

Lesser Sciatic Foramen: Formed by the lesser sciatic notch of the hip bone and the sacrotuberous and sacrospinous ligaments. It provides an entrance into the perineum from the gluteal region.

Nerves of the Gluteal Region Sacral Plexus: The sacral plexus lies on the posterior pelvic wall in front of the piriformis muscle . It is formed from the anterior rami of the lumbar nerves and the anterior rami of the sacral nerves.

Posterior wall of the pelvis

Branches Branches to the lower limb that leave the pelvis through the greater sciatic foramen . 1. Sciatic (L4, L5, S1, S2, S3): Articular branches to hip joint and muscular branches. It is the largest nerve in the body and consists of the tibial and common peroneal nerves bound together with fascia. Innervates all muscles in the posterior compartment of the thigh that flex the knee and all muscles that work the ankle and foot. llmusclein leg and foot

2. Superior gluteal (L4, L5, S1) : Gluteus medius and gluteus minimus muscles 3. Inferior gluteal (L5, S1, S2): Gluteus maximus

4. Nerve to obturator internus ( L5, S1, S2) : Obturator internus and superior gemellus muscles 5. Nerve to quadratus femoris (L4, L5, S1) : Quadratus femoris and inferior gemellus muscles 6. Posterior cutaneous nerve of the thigh(S2, S3) : Cutaneous branches to buttock and uppermost medial and posterior surfaces of thigh.

Branches to the pelvic muscles, pelvic viscera, and perineum: 1. Pudendal (S2, S3, S4) : Structures in perineum: sensory to genitalia; muscular branches to perineal muscles, external urethral sphincter, and external anal sphincter 2. Nerve to piriformis (S1, S2) : Piriformis muscle

Muscles of the Gluteal Region Muscles of the gluteal region are mainly in two groups: Superficial group of larger muscles: Gluteus minimus, gluteus medius, and gluteus maximus-and tensor fasciae latae. 2. Deep group of small muscles: Piriformis, obturator internus, gemellus superior, gemellus inferior, and quadratus femoris.

Muscles of Gluteal Region (Superficial group) Extensor of hip Gluteus maximus (also helps in lateral rotation) Abductors of hip (help in Medial rotation) Gluteus medius Gluteus minimus Tensor Fascia lata (also stabilizes knee in extension) Function of all 3 Contract to prevent sagging of unsupported side of hip during locomotion, enabling opposite foot to swing through (e.g., Trendelenburg test)

Gluteus maximus Origin : Outer surface of ilium, sacrum, coccyx, sacrotuberous ligament Insertion :Iliotibial tract and gluteal tuberosity of femur N. supply:Inferior gluteal nerve Action :Extends and laterally rotates hip joint

Gluteus medius Origin : Outer surface of ilium Insertion :Lateral surface of greater trochanter of femur N. supply: Superior gluteal nerve Action :Abducts thigh at hip joint; tilts pelvis when walking to permit opposite leg to clear ground

Gluteus minimus Origin : Outer surface of ilium Insertion :Anterior surface of greater trochanter of femur N. supply: Superior gluteal nerve Action :Abducts thigh at hip joint; tilts pelvis when walking to permit opposite leg to clear ground

Positive Trendelenburg's sign If right gluteus medius and minimus muscles are paralyzed, the unsupported left side of the pelvis falls (sags) instead of rising; normally, the pelvis rises.

Tensor fasciae latae Origin : Iliac crest Insertion :Iliotibial tract N. supply: Superior gluteal nerve Action :Assists gluteus maximus in extending the knee joint

Deep group of small muscles Lateral Rotators of the Hip. Small Muscles Mostly attach near or on greater trochanter All but one innervated by named nerves specific to one or two of them The exception is the obturator externus – innervated by posterior branch of obturator n.

PYRIFORMIS N. supply: 1st & 2nd Sacral nerves Origin : Anterior surface of sacrum; sacrotuberous ligament Insertion : Upper border of Greater trochanter of femur N. supply: 1st & 2nd Sacral nerves Action : Lateral rotation of thigh at hip joint

OBTURATOR INTERNUS Obturator membrane Greater trochanter of femur Origin : Inner surface of Obturator membrane Insertion : Upper border of Greater trochanter of femur N. supply: Nerve to obturator internus Action : Lateral rotation of thigh at hip joint

SUPERIOR GEMELLUS N. supply: Nerve to obturator internus Origin : Spine of ischium Insertion : Upper border of Greater trochanter of femur N. supply: Nerve to obturator internus Action : Lateral rotation of thigh at hip joint

INFERIOR GEMELLUS Greater trochanter of femur Origin : Ischial tuberosity Insertion : Upper border of Greater trochanter of femur N. supply: Nerve to quadratus femoris (L5, S1) Action : Lateral rotation of thigh at hip joint

QUADRATUS FEMORIS ischial tuberosity femur Origin : Lateral border of ischial tuberosity Insertion : Quadrate tubercle of femur N. supply: Nerve to quadratus femoris (L5, S1) Action : Lateral rotation of thigh at hip joint

Nerves of the Gluteal Region 1. Sciatic Nerve: L4 to S3 2. Posterior Cutaneous Nerve of the Thigh 3. Superior Gluteal Nerve: L4 to S1 4. Inferior Gluteal Nerve: L5 to S2 5. Nerve to the Quadratus Femoris 6. Pudendal Nerve:S2 to S4 7. Nerve to Obturator Internus

Intramuscular injections The safest place to inject is the upper outer quadrant of either gluteal region.

Arteries of the Gluteal Region 1. Superior Gluteal Artery 2. Inferior Gluteal Artery

Posterior compartment of thigh Muscles: Biceps femoris, semitendinosus, semimembranosus, and a small part of the adductor magnus (hamstring muscles) Blood supply: Branches of the profunda femoris artery Nerve supply: Sciatic Nerve

Biceps femoris Origin : Long head: Ischial tuberosity Short head: linea aspera, lateral supracondylar ridge of shaft of femur Insertion : Head of fibula N. supply: Long head: tibial portion of sciatic nerve Short head: common peroneal portion of sciatic nerve Action : Flexes and laterally rotates leg at knee joint; long head also extends thigh at hip joint

Semitendinosus N. supply: Tibial portion of sciatic nerve Origin : Ischial tuberosity Insertion : Upper part of medial surface of shaft of tibia N. supply: Tibial portion of sciatic nerve Action : Flexes and medially rotates leg at knee joint; extends thigh at hip joint

Semimembranosus N. supply: Tibial portion of sciatic nerve Origin : Ischial tuberosity Insertion : Medial condyle of tibia N. supply: Tibial portion of sciatic nerve Action : Flexes and medially rotates leg at knee joint; extends thigh at hip joint

Adductor magnus (hamstring portion) Origin : Ischial tuberosity Insertion : Adductor tubercle of femur N. supply: Tibial portion of sciatic nerve Action : Extends thigh at hip joint

Posterior compartment Hamstrings Together extend hip (except short head of biceps femoris) and flex knee (except add mag) Biceps femoris- (laterally rotates knee) Semitendinosus- (medially rotates knee) Semimembranosus- (medially rotates knee)

Blood Supply of the Posterior Compartment of the Thigh The four perforating branches of the profunda femoris artery provide a rich blood supply to this compartment