Introduction to Biomechanics

1. Introduction to Biomechanics ISE789 Dr. R. A. Wysk Spring 2010

2. Musculoskeletal System • Bones • Passive soft tissue • Muscles • Nerves

3. Functions of the skeleton • Support and motion • Protect vital organs • Mineral storage • Hematopoiesis

4. A little bit of anatomy • Major mechanical functions of the body • Purpose(s) • Medical related issues • Injuries • Treatments • Engineering issues • Replacement

5. Anatomy terms • Superior - toward the head • Inferior - away from the head • Anterior - the front of the body or body part • Posterior - the back of the body or body part • Medial - toward the midline that divides left and right • Lateral - to the side away from the midline • Proximal - closer to the torso • Distal - farther away from the torso • Anatomical position - standing erect, facing the observer, arms are at the sides with palms facing forward.

6. Sectioning • Read Medical Terms doc

7. Basic types of bone tissue • Cortical bone • Compact bone • Central shaft of long bone • Cancellous/trabecular bone • Spongy bone • Found inside ends of long bone and inside vertebral bodies Trabecular or spongy metal

8. The Human skeleton • There are 206 bones in the human body that make up our skeleton • 80 bones in the axial skeleton • 126 bones - appendicular skeleton • 60 bones – upper limbs • 60 bones – lower limbs • 4 bones – pectoral girdle • 2 bones – pelvic girdle

9. Groups of bones • Long bones • Long in one direction • Ends are expanded and covered • Femurs, tibias, fibulas, humeri, radii, ulnas, metacarpals, metatarsals, phalanges, and clavicles • Short bones • Same dimensions in all directions • Thin cordices; filled with trabecular bone • The entire vertebral column, carpal bones, and tarsal bones. • Flat bones • Skull • Pelvis • The ribs, scapula, sternum, and ilium

10. The human skeleton

13. Bone components

14. Cortical Bone

15. Osteonal Bone

17. Joints of the Body • Synovial Joints • Large range of motion joint • Cartilaginous joints • Between the ribs and sternum • Fibrocartilage pad Between adjacent vertebral bodies

18. Joints • Fibrous • Fibrous joints connect bones without allowing any movement. The bones of your skull and pelvis are held together by fibrous joints. The union of the spinous processes and vertebrae are fibrous joints. • Cartilaginous • Cartilaginous joints are joints in which the bones are attached by cartilage. These joints allow for only a little movment, such as in the spine or ribs. • Synovial • Synovial joints allow for much more movement than cartilaginous joints. Cavaties between bones in synovial joints are filled with synovial fluid. This fluid helps lubricate and protect the bones. Bursa sacks contain* the synovial fluid.

20. Synovial Joints • Synovial joints allow for much more movement than cartilaginous joints. Cavaties between bones in synovial joints are filled with synovial fluid. This fluid helps lubricate and protect the bones. Bursa sacks contain* the synovial fluid.

22. Ball and socket Joints • A ball and socket joint allows for radial movment in almost any direction. They are found in the hips and shoulders.

23. Ellipsoid Joints • Similar to a ball and socket joint -- allow the same type of movement to a lesser magnitude. The wrist is an ellipsoid joint.

24. Saddle Joints • A saddle joint allows movement back and forth and up and down, but does not allow for rotation like a ball and socket joint.

25. Pivot Joints • Pivot joints allow rotation around an axis. The neck and forearms have pivot joints. In the neck the occipital bone spins over the top of the axis. In the forearms the radius and ulna twist around each other.

26. Gliding • In a gliding or plane joint bones slide past each other. Metacarpal and metatarsal joints are gliding joints

27. The knee

28. A bad joint?!? • 30-50% of all sports injuries • 0.2% of the general population per year for knee ligament problems • ACL and MCL are 90% of all sport injuries • Women are 2-8 times greater risk

29. Long bone

30. Long bone cont’d

31. Coefficients of Friction J. Charnley 1960 A. Unsworth 1975

32. Synovial Joints • Ball and socket Joints • Hip and shoulder • Bicondylar Joints • Knee joints • Multiple bone joints • Wrist and ankle joints