Week 4 (EXAM 1) Flashcards
Where would the internal, tensile, bodyweight/gravity, compression, ground reaction, shear, friction forces, and the joint axis be during the heel strike portion of gait
Someone is flexing their neck excessively playing video games. What muscle type is most prevalent? How is COM affected?
Someone is in a semi squat position (sport). What muscle type is most prevalent? How is COM affected?
Someone dunking, ballet split jump, and snowboard jump. What muscle type is most prevalent? How is COM affected?
What happens to the angle of pennation as tension increases in a muscle?
Define muscle reverse action
Define muscle performance
What are the components of muscle performance?
How can you manipulate muscle performance to optimize patient function?
Do muscles overcome mechanical disadvantage?
What type of tissue is each?
T/F Compressive features of human bone are stronger than wood and concrete
true
Consider walking vs. running. How does the speed of running affect the stiffness of the ankle ligaments?
Makes the ligaments stiffer or tighter
Consider walking vs. running. How does greater load created by the weight of the runner and the resultant ground reaction force, affect the stiffness of the ankle ligaments?
Makes the ligaments stiffer or tighter
T/F Human compact bone is as strong as cast iron.
true
The compressive strength of compact bone is about 250 megapascals (MPa), greater than that of concrete (approximately 4 MPa) or wood (100), but less than that of steel (400 to 1500 MPa). Bone is about as strong as cast iron (140 to 300 MPa) but weighs much less.(Levangie et al., 2019)
What are the effects of immobilization in a shortened position?
What are the effects of immobilization in a lengthened position?
1) 2nd class lever
2) mechanical advantage 16/12 =1.33
3) If the force in the Achilles tending (FA) = 20N, what is the Torque provided by
the Achilles tendon in relation to the fulcrum point?
T = 20 x 0.16 = 3.2 Nm
4) What is the length of the moment arm of the force vector of the Achilles tendon from the fulcrum at the forefoot?
16 cm
5) this system has mechanical advantage
Where is reverse action?
Where is reverse action?
Where is reverse action?
Explain isometric contraction
Define a Concentric Contraction in terms of the filament actions relationship to one another.
Define a Eccentric Contraction in terms of the filament actions relationship
Label the forces
List the equations for COM, torque, force, and mechanical advantage
COM (for X or Y):
X = ((m1)(x1)+(m2)(x2)…) / m1+m2+…
T = F (force) x MA (moment arm)
F = M (mass) x 9.81 (gravity)
Mechanical advantage/disadvantage = effort or resistance arm / load arm
(Both arms are perpendicular from the axis/fulcrum)
Explain the lever classes
What is the parallel force system?
A) The distance from the hip joint is 0.52 m, and the distance from the knee joint is 0.50 m
B) The distance from the hip joint is 1.3 m, and the distance from the knee joint is 0.19 m
C) Based on your math calculations, what can you conclude from your comparisons of the 2 squat positions?
A 75-kg man stands on his toes by exerting an upward force through the Achilles tendon, as in the figure below. The fulcrum is shown with a blue triangle.
A) lever class?
B) calculate mechanical advantage/disadvantage
C) is it mechanical advantage or disadvantage?
A 75-kg man stands on his toes by exerting an upward force through the Achilles tendon, as in the figure below. The fulcrum is shown with a blue triangle.
D) what is the length of the moment arm of the force vector of the Achilles tendon from the fulcrum at the forefoot?
E) if the force in the Achilles tending (FA) = 20N, what is the Torque provided by the Achilles tendon in relation to the fulcrum point?
Part 1
Part 2
Part 3
Solve for Fm
Part 1
Part 2
Part 3
