Chapter 2 - Bones and Fascia of Lower Limb

Describe the divisions of the skeleton

• Axial skeleton - forms central axis of body

• Appendicular skeleton - bones of the limbs and girdles

What comprises the Axial skeleton

Axial skeleton - forms central axis of body

–Skull

–Rib cage - 12 pairs of ribs + sternum

–Vertebral column

• Cervical vertebrae (7)

• Thoracic vertebrae (12)

• Lumbar vertebrae (5)

• Sacrum - formed by fusion of 5 embryonic vertebrae

• Coccyx - formed by fusion of 4 embryonic vertebrae

• Intervertebral discs – fibrocartilage discs that unite adjacent vertebrae

What comprises the Appendicular skeleton

Appendicular skeleton - bones of the limbs and the girdle bones that unite limbs to axial skeleton

Lower limb:

• Hipbone - single bone that forms pelvic girdle; attaches lower limb to sacrum (part of axial skeleton)

• Femur - bone of the thigh

• Tibia and fibula - bones of the leg

• Tarsal, metatarsal, and phalanx bones - bones of the foot

Upper limb:

• Scapula and clavicle - form pectoral girdle; attach upper limb to sternum (part of the axial skeleton)

List and describe the regional names of the lower limb

Gluteal region - buttocks (posterior to hip joint)

• Covered by gluteal fascia (deep investing fascia)

Thigh - from hip to knee

• Surrounded by fascia lata (deep investing fascia of the thigh)

• Contains femur

• Popliteal fossa - diamond-shaped depression of posterior knee joint

*fossa = depression

Leg - from knee to ankle

• Contains tibia (medial side) and fibula (lateral side)

• Surrounded by crural fascia (deep investing fascia of leg)

Foot

• Dorsum = top of foot; covered by thin dorsal fascia (deep investing fascia on top of foot)

• Plantar = bottom of foot; covered by thick plantar fascia (deep investing fascia of plantar foot)

• Digits are numbered: big toe = #1; little toe = #5

List and describe the bones of the lower limb

Pelvis - consists of 2 hipbones + sacrum

• Hipbone - single bone in adult; formed by fusion of 3 bony parts (ilium, ischium, and pubis)

• Right and left hipbones united to each other anteriorly

• Posteriorly each hipbone is attached to the sacrum

Femur - single bone of the thigh

• Knee joint - articulation between femur of thigh and tibia and fibula of leg; also includes patella

• Patella - a sesamoid bone (‘floating’ bone located within a muscle tendon) (knee cap)

Tibia - weight bearing bone on medial side of leg (triangular bone)

• Medial malleolus - at distal end of tibia

Fibula - thin bone on lateral side of leg

• Lateral malleolus - at distal end of fibula

• Ankle joint - articulation between tibia and fibula of leg and talus bone (tarsals) of foot

Tibia and fibula strongly united along their length by interosseous membrane (layer of dense connective tissue) (in between bone)

• No movement between tibia and fibula (provides stability for weight-bearing support

Foot

• Tarsal bones - 7 irregular-shaped bones that form posterior ½ of foot

—» Talus bone - contributes to ankle joint

—» Calcaneus bone - forms heel

• Metatarsal bones - 5 elongated bones that form anterior ½ of foot

—» Metatarsal bones numbered 1-5, starting on medial side of foot

• Phalanx bones (phalanges) - bones that form the digits

—» Big toe (toe #1): has proximal and distal phalanx bones

—» Digits #2-5: have proximal, middle, and distal phalanx bones

List and describe the bony landmarks of the Pelvis

• Pelvis consists of 2 hipbones and the sacrum

• Hipbone formed by fusion of pubis, ischium, and ilium

Pubis - anterior, inferior portion of hipbone

• Pubic tubercle

• Pubic symphysis - joint that unites right & left hipbones

Ischium - posterior, inferior portion of hipbone

• Ischial tuberosity

• Ischial spine

Ilium - superior portion of hipbone

• Iliac crest

• Iliac fossa

• Anterior superior iliac spine

• Anterior inferior iliac spine

• Posterior superior iliac spine

Describe what consists of the hip bone

Pelvis

• Acetabulum - socket portion of hip joint

• Ischiopubic ramus (bare of bone)

• Greater sciatic notch; Lesser sciatic notch

—» Notches are separated by ischial spine

• Obturator foramen

• Sacroiliac joints - join sacrum to ilium portion of hipbone

Pelvic ligaments

• Sacrospinous ligament - sacrum to ischial spine

• Sacrotuberous ligament - sacrum to ischial tuberosity

• Addition of these ligaments converts greater and lesser sciatic notches into greater sciatic foramen and lesser sciatic foramen

Describe the pelvic brim

• Bony line formed by superior margin of pubis, inferior margin of iliac fossa, and superior margin of sacrum

• Greater (false) pelvic cavity - broad space located above level of pelvic brim (between iliac fossae)

• Lesser (true) pelvic cavity - narrow space located below level of pelvic brim

Describe the pelvic outlet. What is it defined by?

Pelvic outlet - inferior opening of pelvis

• Defined by pubic symphysis, ischiopubic rami, ischial tuberosities, sacrotuberous ligaments, and coccyx

• Outlet is wider and rounder in females; narrow in males

Describe the Subpubic angle

Describe the Inguinal Ligament

Inguinal ligament - dividing line between trunk of body and lower limb

Bony attachments:

• Anterior superior iliac spine - lateral attachment

• Pubic tubercle - medial attachment

List the Bony Landmarks of Proximal Femur

• Head - forms ball portion of ball & socket hip joint

• Neck

• Greater trochanter

• Lesser trochanter

• Gluteal tuberosity

• Shaft

• Linea aspera - bony ridge on posterior side of shaft

Describe the Deep Investing Fascia of Thigh

Fascia lata

• Surrounds entire thigh

• Anchored to linea aspera of femur by three intermuscular septa (lateral septum most important)

—» Intermuscular septa divide thigh into 3 compartments

Iliotibial tract - much thicker, lateral portion of fascia lata

• Runs down lateral side of thigh - anchored to femur by lateral intermuscular septum

• Attached superiorly to iliac crest of pelvis

• Attached inferiorly to proximal, lateral tibia