Lower limb notes PDF

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29.LOWER LIMB - BONES1. BONES OF THE LOWER LIMB33 bones per limb from pelvis through to toes.2. FEMURA. Long bone with the following features: i. Head ii. Neck iii. Greater trochanter iv. Lesser trochanter v. Linea aspera vi. Med. And lat. Condyles4. TIBIA AND FIBULAi. The tibia is the only one of t...

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29.10.2018

LOWER LIMB - BONES 1. BONES OF THE LOWER LIMB 33 bones per limb from pelvis through to toes.

2. FEMUR A. Long bone with the following features: i.

Head

ii.

Neck

iii.

Greater trochanter

iv.

Lesser trochanter

v.

Linea aspera

vi.

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Med. And lat. Condyles

3. PATELLA

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i.

Largest sesamoid bone in the body

ii.

Forms in the quadriceps tendon

iii.

Functions as an anatomical pulley increasing level arm of extensor mechanism allowing more effective flexion and extension of the knee joint

4. TIBIA AND FIBULA

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i.

The tibia is the only one of the two bones that articulates with the femur.

ii.

Some bony features – medial and lateral condyles, tibial tuberosity and medial malleolus

iii.

The fibula, lateral to the tibia, is less involved in weight bearing and articulates with the tibia and not the femur.

iv.

Some bony features – head, neck and lateral malleolus

5. KNEE JOINT

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i.

Synovial hinge joint

ii.

Bones – distal femur, proximal tibia and patella fibula provides attachment for stabilizing ligaments

iii.

Main ligaments – Lat. Collateral, Med. Collateral, Ant. Cruciate, Post. Cruciate ligaments (LCL, MCL, ACL, PCL) and patellar ligament

iv.

Crescent shaped cartilages called menisci sit on the tibial plateau

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LOWER LIMB - MUSCLES 6. THIGH The thigh can be split into compartments, each containing a different group of functional muscles. i.

Anterior: quadriceps – straightening at knee

ii.

Posterior: hamstrings – bending at knee and extending hip

iii.

Medial: adductors – moving limb closer to midline

iv.

Lateral: iliotibial band and fascia lata – stabilization

7. ANTERIOR THIGH Quadriceps group – quad = 4, therefore, 4 quadriceps muscles: A. Rectus femoris i. B.

Proximally - anterior superior iliac space Vastus lateralis

i. C.

Proximally – intertrochanteric line and lateral linea aspera Vastus medialis

i. D.

Proximally – intertrochanteric line and medial linea aspera Vastus intermedius

i.

Proximally – anterior/lateral surface of upper two thirds of femoral shaft

E.

Distally they all attach via the quadriceps tendon.

F.

As well as quadriceps group, there is another anterior muscle.

G. Sartorius

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i.

Proximally – anterior superior iliac spine

ii.

Distally – medial surface of the proximal tibia (contributes to pes anserinus)

8. POSTERIOR THIGH A. Hamstring group – 3 muscles which all cross both the hip and knee socket B.

Biceps femoris, occupies the posterolateral position and has 2 heads. i.

Proximally – long head from ischial tuberosity (shares a tendon with semitendinosus)

ii.

Proximally – short head from linea aspera

iii.

Distally – head of fibula

C.

Semitendinosus and semi-membranous occupy the posteromedial position.

D. Semitendinosus, named because of the length of its tendon. i.

Proximally – ischial tuberosity (shared with biceps femoris)

ii.

Distally – upper medial surface of tibia

E.

Semimembranosus, names due to its flattened form proximally. i.

Proximally – ischial tuberosity

ii.

Distally – posterior aspect of medial tibial condyle

9. MEDIAL THIGH A. Adductor group of muscles – 5 muscles in medial compartment, which all cross the hip joint but only one passes beyond the knee. B. Gracilis, most superficial muscle of the medial thigh i.

Proximally – body of pubis, ramus of pubis and ischium

ii.

Distally – medial tibia with sartorius and semitendinosus

C.

Adductor longus, most anterior of three adductor muscles. i.

Proximally – superior pubic ramus, below tubercle

ii.

Distally – by aponeurosis to linea aspera (middle third of femur)

D.

Adductor brevis lies posterior to pectineus and adductor longus. i.

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Proximally – body and inferior ramus of pubis

ii. E.

Distally – by aponeurosis of femur from lesser trochanter to linea aspera Adductor magnus, largest of the medial muscles.

i.

Proximally – ischiopubic ramus and ischial tuberosity

ii.

Distally – linea aspera and medial supracondylar line

iii.

Distally – medial condyle of the femur

F.

10.

Pectineus, flat quadrangular muscle which can sometimes be thought of as part of anterior thigh. i.

Proximally – pectineal line on superior ramus of pubis

ii.

Distally – posterior surface of the femur, inferior to lesser trochanter

LATERAL THIGH A. Tensor fasciae latae muscle and iliotibial tract make up the lateral compartment. B. Function to maintain upright posture and extends the knee through lateral rotation.

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ANTERIOR LEG A. Can also be described as the extensor compartment and dorsiflex the ankle. B. Tibialis anterior also active during inversion i.

Proximally – lateral condyle and proximal tibia

ii.

Distally – medial cuneiform and base of 1st metatarsal

C.

Fibularis tertius also active during eversion i.

Proximally – distal third of fibula

ii.

Distally – base of 5th metatarsal

D.

Extensor hallucis longus is also active during extension of the big toe i.

Proximally – medial surface of the tibia

ii.

Distally – base of the distal phalanx of the hallux (big toe)

E.

Extensor digitorum longus is also active during extension of the toes. i.

Proximally 0 lateral condyle of the tibia and proximal fibula

ii.

Distally – divides into 4 slips and attach to metatarsophalangeal joints of digits 2-5

F.

The lateral compartment everts the foot and plantar flexes the ankle.

G. Fibularis longus is the more superficial of the two muscles. i.

Proximally – head and proximal fibula

ii.

Distally – medial cuneiform and base of 1st metatarsal

H.

Fibularis brevis i.

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Proximally – distal fibula

ii.

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Distally – base of 5th metatarsal

12.

POSTERIOR LEG (SUPERFICIAL) A. The posterior compartment contains superficial and deep groups of muscle. B.

Gastrocnemius arises from two heads and cross the knee and the ankle. i.

Proximally – medial head from medial condyle of femur

ii.

Proximally – lateral head from lateral condyle of femur

iii.

Distally – calcaneus via calcaneal tendon

C.

Plantaris is a small muscle belly with a long tendon, sometimes absent or double like palmaris longus in the upper limb. i.

Proximally – supracondylar line

ii.

Distally – merges with calcaneal tendon or flexor retinaculum

D.

Soleus, immediately deep to gastric i.

Proximally – head and proximal fibula, soleal line and medial tibia

ii.

Distally – forms the calcaneal tendon with gastrocnemius

13.

POSTERIOR LEG (DEEP) A. Popliteus arises within the capsule of the knee and rotates the tibia or femur and is described as ‘unlocking’ a fully extended knee i.

Proximally – lateral condyle of femur

ii.

Distally – head of fibula

B.

Flexor digitorum longus flexes the phalanges and are active especially during toe off and tip toe movements. i.

Proximally – posterior surface of the tibia

ii.

Distally – 4 tendons on distal phalanx of toes 2-5

C.

Flexor hallucis longus works with flexor digitorum longus i.

Proximally – posterior surface of fibula and interosseous membrane

ii.

Distally – base of the distal phalanx of hallux

D. Tibialis posterior is the deepest muscle of the flexor group and inverts the foot and raises the heel. i.

Proximally – posterolateral tibia, interosseous membrane and posteromedial fibula

ii.

Distally – tuberosity of navicular, intermediate cuneiform and base of 2nd, 3rd and 4th metatarsals

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MOVEMENTS OF THE LOWER LIMB i.

At knee – flexion, extension, crossing legs

ii.

Rotation – medial rotation of tibia, lateral rotation of femur

iii.

At ankle – dorsiflexion, plantar flexion

15.

ARTERIAL BLOOD SUPPLY

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AREAS OF THE LOWER LIMB 16.

FEMORAL TRIANGLE i.

Superior – inguinal ligament

ii.

Medial border- adductor longus

iii.

Lateral border – sartorius

iv.

Floor – iliopsoas, pectineus and adductor longus

v.

Roof – fascia lata

vi.

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Contents – femoral artery, vein and nerve

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ADDUCTOR HIATUS i.

Anterior border – sartorius

ii.

Lateral border – vastus medialis

iii.

Posterior border – adductor longus and magnus

iv.

Contents – femoral artery and vein, nerve to vastus medialis and saphenous nerve

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POPLITEAL FOSSA i.

Superomedial border – semimembranosus

ii.

Superolateral border – biceps femoris

iii.

Inferomedial border – medial head of gastrocnemius

iv.

Inferolateral border – lateral head of gastrocnemius and plantaris

v.

Floor – posterior surface of knee joint capsule

vi.

Roof – popliteal fascia

vii.

Contents – popliteal artery and vein, tibial nerve and common fibular nerve

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