Forensic Anthropology Bones of the Leg. Skeletal anatomy of the leg Comprised of 4 bones Femur Femur...

Forensic Anthropology

Bones of the Leg

Skeletal anatomy of the legComprised of 4

bones Femur Tibia Fibula Patella

Useful for age/growth Sex determination stature

determination

THE FEMUR Largest, heaviest bone of the body

Ball shaped head

Articulates with innominate, tibia (does NOT form a straight line with tibia in anatomical position), patella

Shaft has circular cross section

THE FEMUR – what to know

Proximally Head Fovea capitus Anatomical neck Greater and lesser

trochanter Intertrochanteric crest Linea aspera

Distally Lateral condyle Lateral epicondyle Medial epicondyle Medial condyle Intercondylar fossa Patellar articular surface

THE FEMUR – L from R

Orient head medially, greater trochanter

Intercondylar fossa posterior

Larger condyle is medial

The tibia - description

Second largest bone in the body Hinge joint – greatest weight bearing Articulations:

• Proximal – femur at horizontal platform AND fibula• Distal – fibula AND talus• Note there is NO articulation with the patella

Shape = triangular shaft• Sharpest angle anterior• Malleolus at distal end

The tibia – What to know Proximal end:

Intercondylar eminence

Medial condyle Lateral condyle Tibial tuberosity Fibular facet of tibia

Popliteal line Interosseous crest Anterior crest

Distal end: Fibular notch of tibia Articular surface for

talus Medial malleolus

Tibia – Right from left Orient plateau superiorly

Make sure tibial tuberosity is anterior Medial malleolus is medial

Interosseous crest points toward fibula

Growth and the humerus

Fusion ages ♀14-16/ ♂15-18 distal epiphysis ♀13-17/ ♂15-19 proximal epiphysis

Also age related changes in bone density associated with elderly

The fibula - description

Lateral to the tibia, most slender long bone

Makes up the ‘outside’ of the ankle

The fibula Shaft – triangular X-section

Flat head at top Distal end composed largely of lateral malleolus

Articulations• Proximal – with tibia at fibular facet just below lateral

condyle • Distal – passes through fibular notch of tibia to

articulate with talus

The fibula – What to know

Proximal End: Head Styloid process Facet for tibia

Interosseous crest

Distal End: Lateral malleolus Malleolar facet for

talus Malleolar fossa

fibula – Right from left

Orient head superior

Lateral malleolus is lateral, tip points posteriorly (when looking at lateral side)

Styloid process and interosseous crest

Bones of the hand

Carpal bones

1. scaphoid

2. lunate

3. triquetrum

4. pisiform

5. trapezium

6. trapezoid

7. capitate

8. hamate

Metacarpal bones

9. I

10. II

11. III

12. IV

13. V

Phalanges

proximal 14

middle 15

distal 16

Sorting metatarsals

Longer, thinner, and more curved than MC MT1: thickest MT2: Longest, slight process

Triangular with off-set lateral facet MT3: triangular with continuous lateral facet MT4: base rectangular MT5: long, lateral process

Bones of the Foot

1. Calcaneus

2. Talus

3. Navicular

4. Medial cuneiform

5. Intermediate

cuneiform

6. Lateral cuneiform

7. Cuboid

8. First metatarsal

9. Second metatarsal

10. Third metatarsal

11. Fourth metatarsal

12. Fifth metatarsal

13. Proximal phalanx of

great toe

14. Distal phalanx of

great toe

15. Proximal phalanx of

second toe

16. Middle phalanx of

second toe

17. Distal phalanx of

second toe

Sorting metacarpals

MC1: shortest, thickest

MC2: longest, 2 processes at base M2 – M5 decrease in size successively

MC3: 1 processes at base MC4: no processes, facets on both sides

of base MC5: short, no processes, facet on only

1 side of base

Manual vs pedal phalanges Manual phalanges are longer Flattened in the middle (oval cross-

section) Narrower top to bottom

Pedal phalanges are ‘slim-waisted’ in the middle

Circular cross-section Narrower side to side

Sorting phalanges

Proximal phalanges: cup-shaped proximal end (art. w/ MC head)

Medial phalanges: double-faceted proximal end

Distal phalanges: flat, ‘fingernail shaped’ distal end