LCRS Anatomy of the Limbs Lower Limb Alexandra Burke-‐Smith LIGAMENTS OF THE PELVIS Ligament From To Head of the femur Acetabular fossa of pelvis Fovea capitis of humerus Iliofemoral (anterior) Between acetabulum and Intertrochanteric line of femur anterior inferior iliac spine Pubofemoral (lateral) Iliopubic eminence Lateral fibrous membrane Ischiofemoral (posterior) Ischium Greater trochanter Anterior sacroiliac Lateral sacral border Auricular surface of ilium Posterior sacroiliac Lateral sacral border Tuberosity of the ilium + PSIS Iliolumbar Transverse processes of L5 Posterior iliac crest Lumbosacral Transverse processes of L5 Sacral border Sacrospinous Lateral sacral border Ischial spine Sacrotuberous Inferior sacral margin Tuberosity of the ischium These ligaments form important boundaries… Greater sciatic foramen Lesser sciatic foramen Anterior – tuberosity of the ischium Anterolateral – greater sciatic notch Posterior – sacrotuberous ligament Posteromedial – sacrotuberous ligament Superior – anterior sacroiliac ligament Superior – sacrospinous ligament Inferior -‐ sacrospinous ligament MUSCLES OF THE GLUTEAL REGION Deep external rotators Muscle Function Piriformis Obturator internus Externally rotate + abduct the Gamelli (superior + inferior – associated with obturator lower limb internus) Quadratus femoris Superficial Gluteal Muscles Muscle Origin Insertion Function Innervation Gluteus Between inferior + Linear facet on Abduct lower limb Superior gluteal minimus anterior gluteal line anterolateral Reduce pelvic drop nerve (fan-‐shaped) (on lateral ilium) aspect of (of swinging limb) greater during walking trochanter Gluteus Between anterior + Elongate facet Abduct lower limb Superior gluteal medius posterior gluteal line on lateral Reduce pelvic drop nerve (fan shaped) (on lateral ilium) surface of (of swinging limb) greater during walking trochanter Gluteus maximus (quadrangle-‐ shaped)
Broad: extends from behind posterior gluteal line, along dorsal sacrum to the sacrotuberous ligament
Posterior aspect Extend flexed thigh of iliotibial tract Stabilize knee + hip + gluteal joints tuberosity of femur
Inferior gluteal nerve
LCRS Anatomy of the Limbs Lower Limb ANTERIOR COMPARTMENT OF THE THIGH Function: Hip flexors + Knee Extensors Innervation: Femoral Nerve Hip Flexors Muscle Origin Insertion Pectineus (flat, Superior ramus of Pectineal line of quadrangular) pubis femur, just inferior to lesser trochanter
Sartorius (long, ribbon-‐like)
ASIS + superior part of Superior medial notch inferior surface of tibia (acts on both hip + knee joint)
Alexandra Burke-‐Smith
Function Flexes thigh Adducts + medially rotates hip (transition muscle of medial compartment – often partially innervated by Obturator Nerve) Flexes thigh Extends knee (Weakly abducts + lateral rotates hip)
Additional Muscles of the hip (counted by Imperial as anterior compartment, but weird innervation) Muscle Origin Insertion Function Innervation Ilio-‐psoas Psoas – on Lesser trochanter Flexes thigh Psoas – posterior of femur ventral rami abdominal wall of L1-‐L3 Iliacus – iliac fossa Iliacus – Femoral nerve Tensor Fasciae Iliac crest Anterior iliotibial Stabilizes knee Superior latae tract during extension Gluteal Nerve Knee Extensors = Quadriceps femoris (converge to form quadriceps tendon, which continues as patellar tendon in which the patella is embedded) Muscle Origin Insertion Function Rectus femoris Anterior inferior iliac Tibial tuberosity (patellar Flex thigh spine (crosses hip) tendon) Extend knee Vastus lateralis Greater trochanter + Tibial tuberosity (patellar Extend knee (lateral) lateral lip of linea tendon) aspera Anterior border of tibial plateau (lateral patellar retinacula) Vastus Medialis Intertrochanteric line + Tibial tuberosity (patellar Extend knee (medial) medial lip of linea tendon) aspera Anterior border of tibial plateau (medial patellar retinacula) Vastus Intermedius Anterolateral femur Tibial tuberosity (patellar Extend knee (deep to rectus tendon) femoris)
LCRS Anatomy of the Limbs Lower Limb Alexandra Burke-‐Smith MEDIAL COMPARTMENT OF THE THIGH Function: Adduction of Thigh Innervation: Obturator Nerve (except hamstring portion of adductor magnus = tibial part of sciatic nerve) Muscle Origin Insertion Additional Function Adductor longus Anterior aspect of Middle third of linea aspera (most anterior) pubis just inferior to pubic tubercle Adductor brevis Body + inferior Pectineal line + proximal linea (deep; anterior + ramus of pubis aspera posterior branches of obturator nerve) Adductor magnus Adductor part – Adductor part – fan aponeurotic (most posterior) inferior ramus insertion from gluteal tuberosity, entire linea aspera + medial supracondylar ridge Hamstring part – Hamstring part – tendinous Hamstring part – ischial tuberosity insertion onto adductor tubercle extends thigh of femur Gracilis Body + inferior Superior medial surface of tibia Flex knee + (most medial + ramus of pubis internally rotate superficial – only thigh one to cross knee + hip joint) Obturator Externus Margins of Trochanteric fossa of the (deep + obturator foramen femur superomedial) + membrane POSTERIOR COMPARTMENT OF THE THIGH Function: hip extensors + knee flexors (hamstrings) Innervation: tibial part of sciatic nerve (except short head of biceps femoris, which is common peroneal/fibular part of sciatic nerve) Muscle Origin Insertion Semitendinosus (Fusiform Ischial tuberosity Medial surface of superior tibia belly interrupted by tendinous intersection that begins 2/3rd down thigh) Semimembranosus (flattened Ischial tuberosity 1. posterior aspect of medial membranous proximal tibial condyle attachment. Tendon forms in 2. blends with popliteal fascia the middle of the thigh and 3. reflection with joint capsule divides distally into 3 parts) (oblique popliteal ligament) Biceps femoris (fusiform Long head – ischial tuberosity Lateral side of head of the fibula muscle with long + short head) Short head – lateral lip of (split by fibular collateral inferior linea aspera + ligament) supracondylar ridge
LCRS Anatomy of the Limbs
Lower Limb
Alexandra Burke-‐Smith
Neurovascular intermuscular passage from femoral triangle to popliteal fossa = The Adductor Canal/Hunter’s Canal. The boundaries of the canal are: • Vastus medialis = anterolateral • Adductor longus + magnus = posterior • Sartorius = medial + roof THE KNEE Hinge joint that consists of articulation between the femur and the tibia + articulation between the patella and femur • Articular surfaces = femoral + tibial condyles o Femoral condyles separated by an intercondylar fossa o The tibial condyles are separated by the intercondylar eminence, formed by 2 tibial spines; between these are 6 attachment sites for ligaments • The 2 C-‐shaped menisci are attached at each end to facets in the intercondular region of the tibial plateau. These accommodate the change from curved to flat surface of the femoral condyles during flexion > extension o The medial meniscus is also attached to the capsule of the joint and tibial collateral ligament Bursae The synovial membrane forms pouches of synovial fluid which provide low friction surfaces for the movement of tendons associated with the joint: Bursa Location Infrapatellar bursa (+ fat pad) Anterior, inferior to the patella Subpopliteal recess Lateral, between the tendon of the popliteal muscle and lateral condyle of the femur Suprapatellar bursa Between the anterior surface of the distal femur and the deep surface of the quadriceps femoris
LCRS Anatomy of the Limbs Lower Limb Alexandra Burke-‐Smith Ligaments Ligament From To Patellar ligament Quadriceps femoris tendon Tibial tuberosity Fibular collateral ligament Lateral femoral epicondyle Lateral fibular head Tibial collateral ligament Medial femoral epicondyle Medial surface of tibia Anterior cruciate ligament Anterior part of tibial Posterolateral wall of (ACL) – prevents anterior intercondylar area intercondylar fossa of the displacement of tibia femur Posterior cruciate ligament Posterior aspect of tibial Anteromedial wall of (PCL) – prevents posterior intercondylar area intercondylar fossa of the displacement of the tibia femur The knee is also supported anterolaterally by a fibrous extension of the iliotibial tract, and posteromedially by the oblique popliteal ligament. METATARSALS • Clear = Calcaneus (heel) • Turns = talus (ankle) • Navigate = navicular (intermediate bone) • Clueless = cuboid (lateral distal metatarsal) • Couples = cuneiform bones (lateral, intermediate + medial) NB: talocalcaneonavicular joint is also known as the mid-‐tarsal joint. It is reinforced by calcaneonavicular and talocalcaneal ligaments. Movement at this joint contributes to inversion/eversion of the foot. MUSCULAR ANATOMY OF THE LEG + FOOT Compartment Function Muscles Innervation Vascular supply Anterior leg
Lateral leg
Dorsi-‐flexion Digit extension (aid eversion)
Tibialis anterior Extensor digitorum longus Extensor hallucis longus Fibularis tertius Peroneus longus Peroneus brevis
Deep peroneal/ fibular nerve (L4-‐L5)
Anterior tibial artery
Eversion Superficial Peroneal/fibular (aid dorsi-‐ peroneal/ artery flexion) fibular (L5-‐S2) Posterior leg Plantar-‐flexion Superficial: Tibial nerve (L4-‐ Posterior tibial Digit flexion Gastrocnemius S2) artery (aid inversion) Soleus Plantaris Deep: Popliteus Flexor digitorum longus Flexor hallucis longus Tibialis posterior NB: the Achilles tendon is the continuation of the gastrocnemius and soleus tendons which fuse. Testing this reflex tests the S1-‐S2 segmental supply specifically • The sole of the foot = 4 layers of intrinsic muscles supplied by branches of the tibial nerve • The dorsum consists of 2 layers supplied by branches of the deep + superficial peroneal/fibular nerve
LCRS Anatomy of the Limbs Nerve Origin Femoral Posterior nerve fibres of L2-‐ L4 (lumbar plexus)
Obturator nerve
Lower Limb
Innervation Anterior compartment of thigh Iliacus + pectineus Cutaneous to anterior aspect of thigh Anterior Enters thigh passing Medial fibres of L2-‐ through obturator compartment of L4 (lumbar canal thigh except plexus) hamstring part of adductor magnus (sciatic nerve) L4+L5 fibres Feeds sacral plexus
Lumbosacral plexus Sciatic nerve All fibres of L4-‐S3
Course Leaves abdomen passing inferior to inguinal ligament to enter femoral triangle
Leaves pelvis through greater sciatic foramen, passes through gluteal region + enters posterior compartment of thigh. Divides at apex of popliteal fossa
Superior Posterior gluteal nerve fibres of L4-‐ S1
Leaves pelvis through greater sciatic foramen
Inferior
Leaves pelvis
Posterior
Posterior compartment of thigh Hamstring part of adductor magnus
Alexandra Burke-‐Smith Branches Saphenous nerve = terminal cutaneous branch. Supplies anteromedial aspects of knee, leg + foot
Cutaneous branch supplies medial side of thigh
Tibial nerve (posterior fibres of L4-‐S2): runs medially supplies posterior compartment of leg, an divides into medial and lateral plantar nerves posteroinferior to medial malleolus. Plantar nerves supply intrinsic foot. Common fibular (peroneal): runs laterally, winding around neck of fibula. Superficial branch lies anterolateral to fibula and supplies lateral compartment of leg, distal anterior skin of leg, dorsum of foot + digits. Deep branch runs inferomedially, supplying anterior compartment and skin between 1st + 2nd toes Gluteus medius, minimus and tensor fasciae latae Gluteus
LCRS Anatomy of the Limbs Lower Limb gluteal nerve fibres of L5-‐ through lesser maximus S2 sciatic foramen Dermatomes • L2 – upper lateral thigh • L3 – front of thigh • L4 – front of leg + big toe • L5 – antero-‐lateral leg + dorsum of foot • S1 – lateral aspect of foot + sole • S2 – posterior leg + thigh • S3 – gluteal region
Alexandra Burke-‐Smith
Anterior Compartment of the Arm Nerve supply: Musculocutaneous Nerve (C5-‐C7) Function: Flexion of the elbow (+ biceps brachii assists supination of forearm) Muscle Origin Insertion Biceps Brachii Long head = supraglenoid tubercle Radial tuberosity Short head = coracoid process Brachialis Anterior aspect of humerus Tuberosity of the ulna Coracobrachialis Coracoid process Linear roughening of midshaft of humerus on medial side Posterior Compartment of the Arm Nerve supply: Radial Nerve (C5-‐T1) Function: Extension of the elbow (+ aconeus stabilizes elbow during pronation/supination) Muscle Origin Insertion Triceps Brachii Long head = infraglenoid tubercle Olecranon process Medial head = posterior humerus Short head = posterior humerus Aconeus (insignificant) Lateral epicondyle of humerus Olecranon process Anterior Compartment of the Forearm Nerve supply: Median Nerve (C5-‐T1) except FCU + medial half of FDP = Ulnar nerve (C8-‐T1) Function: flexion of the wrist, pronation of forearm + flexion of digits (long flexors) – C7/C8 Superficial Muscles Origin Function Pronator teres Pronation of forearm Flexor Carpi Radialis Radial deviation of wrist Just distal to medial epicondyle Ulnar deviation of wrist Flexor Carpi Ulnaris Palmaris Longus Flexion of palm Flexor Digitorum Superficialis Flexes PIP joint NB: to remember these, supinate your left hand and place right hand on medial epicondyle + use fingers
Deep Muscles Flexor Digitorum Profundus Flexor Pollicis Longus Pronator quadratus
Origin Just distal to the medial epicondyle
Function Flexes DIP joint Flexes thumb Pronation of hand
LCRS Anatomy of the Limbs
Lower Limb
Alexandra Burke-‐Smith
Posterior Compartment of the Forearm Nerve Supply: Radial Nerve (C5-‐T1) Function: extension of the wrist, supination of forearm + extension of digits (long extensors) – C8/T1 Muscles Origin Function Muscles that move the wrist Wrist extension • Extensor carpi radialis longus • Extensor carpi radialis brevis • Extensor carpi ulnaris Muscles that move the digits Digit extension • Extensor digitorum • Extensor indicis Just distal to the lateral • Extensor digiti minimi epicondyle Muscles that move the thumb Thumb abduction • Abductor pollicis longus Thumb extension • Extensor pollicis brevis Thumb extension • Extensor pollicis longus Other muscles Supination/pronation during • Brachioradialis elbow flexion Supination of forearm • Supinator Intrinsic Hand Muscles Nerve Supply: Ulnar Nerve (C8-‐T1) except Thenar muscles + lateral 2 lumbricals = Median Nerve (C5-‐T1) Function: fine movements of the hand – C8/T1 Muscle Origin Insertion Function Palmaris brevis Flexor Medial dermis Improves grip retinaculum Adductor pollicis Middle MCP joint of thumb Adduction of thumb metacarpal + capitate Dorsal interossei Adjacent sides of Extensor hood and Abduction of fingers (4 bipennate muscles) metacarpals base of proximal phalange of middle, index + ring fingers Palmar interossei Medial sides of Extensor hoods of Adduction of fingers (4 unipennate muscles) metacarpals every digit except
LCRS Anatomy of the Limbs Lumbricals
Lower Limb
Flexor digitorum profundus
middle finger Extensor hoods of fingers
Thenar muscles (thumb) Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hypothenar muscles (little finger) Opponens digiti minimi Abductor digiti minimi Flexor digiti minimi brevis General Overview of Spinal supply of muscle action Compartment Action Shoulder Abduction Adduction External Rotation Internal Rotation Elbow Flexion Extension Forearm Supination Pronation Wrist Flexion Extension Long tendons to hand Flexion Extension Intrinsic Hand
Alexandra Burke-‐Smith
Pointing (flexion of MCP during IP extension) Opposition Abduction Flexion Opposition Abduction Flexion
Segmental supply C5 C6/C7/C8 C5 C6/C7/C8 C5/C6 C7/C8 C6 C7/C8 C6/C7 C7/C8 C7/C8 C8/T1 C8/T1
