Continuum Phenomena in Biomedical Engineering

Eric A. Nauman, Ph.D. ME 3061A [email protected] “If I could make you purtier, I would.”

~ Adam Baldwin as Jayne to Nathan Fillion as Mal in Firefly Anatomy Basics • We will focus on bones, joints (ligaments), and muscles in this course. • Tissues: – Connective tissues (bone, cartilage, skin, fascia, tendons, ligaments) – Muscle tissues (skeletal, cardiac, smooth) – Nerve tissue (neurons, neuroglia) – Epithelial tissues – Blood • Edward Ulysses Cation Skeleton Bones • 206 of them - many in the hands and feet Joints • Diarthroidal (separation of bones, joint cavity) • Synarthroidal (no separation or joint cavity) Muscles • Attach to bones through tendons • Myofibrils - Look like wires in suspension bridges Lower Extremities • Hip – Acetabulum – Femoral head – Ligament at the head of the femur – Greater trochanter Lower Extremities • Hip – Acetabulum – Femoral head – Ligament at the head of the femur – Greater trochanter Post-cranial anatomy • Knowing the weight of the individual, calculate the force exerted by the gluteus medius and the joint contact force during the single-legged stance phase of gait.

Angle between Skeletons Distance to Muscle muscle force and center of moment arm, vertical gravity, b, (mm) c, (mm) (degrees)

Australopithecus 66 36 15

Homo sapiens (Amerindians, 79±5.2 50.6±1.7 12.9±2.2 male)

Homo sapiens (Amerindians, 82.9±4.5 45.4±3.8 13.3±2.8 female) Anatomy of the Knee

• ACL, PCL don’t heal • MCL, LCL usually heal Anatomy of the Knee

Stability Mechanisms 1. Contact/conformity 2. Ligament stretch 3. Muscle co-contraction Weightlifting

Initiation and progression of a patellar tendon rupture by a weightlifter in Olympic competition. From Sports Biomechanics by Roger Bartlett (E&FN Spon, New York, 1999).

Astroturf

Weights and rotation applied via the vertical shaft

Rotation of shaft measured using rotary potentiometer

Torque-thrust load cell Shoe 'forefoot' being tested

Frame of device, this is in contact with surface being tested

Figure 2 Astroturf

25 Turf Shoe on Astroturf

10 Grass Shoe on Grass Surface 5 Torque (ft*lbs) Torque

0 0 10 20 30 40 50 60 70 80 90 Rotation (degrees)

Figure 3 Upper Extremities

• Shoulder dislocations • Football players (biceps and triceps tears) • Ulna/radius fractures in patients with osteoporosis • Falls • Boxer breaks Upper Extremities - Injuries Upper Extremities - Injuries Basic Anatomy • Hand – Wrinkles on hands and feet – 1/3 of all acute injuires in the ER involve upper extremities – 27 bones in the hand Common Injuries

http://www.csmfoundation.org/Educational_Upper_Extremity.html Rock Climbing

- Rock climbing and indoor climbing are becoming popular recreational activities The Slope Grip: - As route difficulty increases, so do the demands on finger bones, joints, and tissues - Up to 90% of rock climbers are using the crimp grip to hold small grips - The second most used grip is the slope grip

The Crimp Grip:

Schweizer et al.

Schweizer et al. Notation Anatomy UL ulnar ligament of MCP joint RL radial ligament of MCP joint FDP flexor digitorum profundus FDS flexor digitorum EDC extensor digitorum communis LU lumbrical UI ulnar interosseus http://www.personal.psu.edu/Vigouroux et al. RI radial interosseus users/j/u/jus149/handfinger/ TE terminal extensor tendon handandfinermodel/ ES extensor slip handfingermodel.htm RB radial band UB ulnar band Head • The human head weighs ?? • Damage caused by – Assaults and Violence – Falls – Miscellaneous ? – MVC – Sports and Recreation Head

http://mywebpages.comcast.net/wnor/lesson1.htm Phineas Gage Spine • 7 Cervical • 12 Thoracic • 5 Lumbar • 5 Sacrum (fused) • 4 Coccyx (fused) Spine • Musculature – Rectus Abdominus – Obliques (internal and external) – Erector spinae – Latissimus dorsi Vertebral Bodies and Intervertebral Discs

Disc degeneration; Herniation; Osteoporosis; Burst fractures; Annular tears Vertebral Bodies and Intervertebral Discs

Disc degeneration; Herniation; Osteoporosis; Burst fractures; Annular tears Mechanical Properties of Vertebral Ligaments • Intraspinous and supraspinous ligaments – Ultimate load: 203 N +/- 102.9 N – Elastic Stiffness: 60.6 N/mm +/- 36.7 N/mm – Tensile Strength: 1.2 Mpa +/- 0.6 Mpa – Elastic Modulus: 3.3 Mpa +/- 2.1 Mpa

– Mechanical strength of human lumbar posterior spinal ligaments decrease with age and facet degeneration, although no correlation was found between disc-related parameters and tensile strength

Hukins, Dw. “Comparison of structure, mechanical properties, and functions of lumbar spinal ligaments”. Spine. August 1990, pp. 787-795.[2]

1. Pinter, FA. “Biomechanical properties of human lumbar spine ligaments”. J. Biomech. Eng., November 1992, pp. 1351-1356.[5]

Cirque du Solei