Name:
Biomechanics
Exam I
Choose the best answer for each
1.
The physiological cross sectional area of skeletal muscle is:
A. linearly and inversely related to maximum force output
B. linearly and directly related to maximum force output
C. non-linearly related to maximum force output
D. none of the above
2.
Strain can be calculated as:
A. original length * final length
B. change in length / original length
C. original length / final length
D. original length / change in length
E. none of the above
3.
The increase in muscle strength as a result of resistance training is most commonly attributed to:
A. hypertrophy
D. all of the above
B. hyperplasia
E. A and B only
C. atrophy
4.
Sarcomere length is generally:
A. longer in longer fiber muscles
B. longer in shorter fiber muscles
C. about the same regardless of fiber
length
D. there is no general rule
5.
The most common type of lever system in the body (during concentric contractions) is the:
A. first class
D. both B and C
B. second class
E. none of the above
C. third class
6.
The biceps brachii acting concentrically on the radius is an example of what class of lever?
A. first class
D. both B and C
B. second class
E. none of the above
C. third class
7.
The center of gravity of the whole body is approximately at the level of:
A. T-12
D. S-4
B. L-2
E. None of the above
C. L-5
8.
Two externally applied forces that are equal, parallel, and applied in opposite directions but are
not in line with each other are known as:
A. shear forces
D. both A and B
B. compressive forces
E. none of the above
C. tensile forces
9.
The mechanical behavior of bone is affected by:
A. rate of loading
B. the loading mode
C. geometric characteristics
D. all of the above
E. only A and B
10. An elderly woman with a history of osteoporosis suffers a fracture to the T-12 vertebrae. This
fracture is most like due to which mode of loading:
A. tensile
D. bending
B. compressive
E. none of the above
C. shear
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11. Hyaline cartilage:
A. covers the ends of long bones
B. has an extracellular matrix
composed of mainly elastin
C. is highly organized
D. all of the above
E. A and C only
Figure 1
2
3
Stress
1
Strain
12. Referring to the graph in Figure 1, which point most closely represents the yield point or elastic
limit of this material?
A. 1
D. between 2 and 3
B. 2
E. between 1 and 2
C. 3
13. Referring to the graph in Figure 1, which point most closely represents the plastic region?
A. 1
D. 3
B. between 1 and 2
E. none of the above
C. between 2 and 3
14. Which of the following is true regarding the plastic region of a stress/strain curve?
A. once a material reaches this region permanent deformation occurs
B. once a material reaches this region it undergoes ultimate failure
C. once a material reaches this region it can return to its original shape and size upon removal of
the load
D. none of the above are true
E. both A and B are true
15. Young’s modulus refers to:
A. the slope of the stress/strain curve in the elastic region
B. the slope of the stress/strain curve in the plastic region
C. the overall slope of the stress/strain curve
D. both A and C
E. none of the above
16. A viscoelastic material:
A. has elastic properties
B. has viscous properties
C. has time dependent properties
D. all of the above
E. only A and B
17. The ability of hyaline cartilage to resist compressive forces is mainly the result of:
A. its low water content
B. its high elastin content
C. the interaction between collagen and proteoglycans
D. both B and C
E. none of the above
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18. Viscosity refers to the ability of a material to resist loads that produce which of the following
forces:
A. tensile
D. shear
B. compressive
E. all of the above
C. bending
19. What factor is critical to all the theories for the lubrication of articular cartilage?
A. movement
D. all of the above
B. availability of elastin
E. both A and C
C. loading
20. Which connective tissue has the most similar material properties to tendons?
A. muscle
D. articular cartilage
B. bone
E. all of the above
C. ligaments
21. What factors affect the mechanical properties of tendons?
A. strength training
D. all of the above
B. immobilization
E. A and B only
C. aging
22. As presented in class, which of the following is not a common mode of peripheral nerve injuries?
A. shear forces
B. compressive forces
C. tensile forces
D. all of these are common modes of peripheral nerve injuries
E. both A and C
23. Following a peripheral nerve injury, which of the following statements is true regarding the
regeneration of the nerve?
A. axonal growth is approximately 5 mm per day
B. the preservation of Schwann cell columns guides regeneration
C. efferent nerves regenerate faster than afferent nerves
D. all of the above are true
E. only A and B are true
24. The epimysium and perimysium are part of the:
A. series elastic component
B. parallel elastic component
C. contractile component
D. all of the above
E. none of the above
25. The energy that is lost after a viscoelastic material is deformed is known as:
A. hysteresis
D. equilibrium
B. conservation of energy
E. none of the above
C. creep
26. During a fast eccentric muscle contraction, energy is best stored in the:
A. contractile component
D. both A and C
B. parallel elastic component
E. none of the above
C. series elastic component
27. Which muscle fiber type appears to be the most susceptible to atrophy?
A. I
D. All of the above
B. IIA
E. A and B only
C. IIB
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28. A man suffers an above knee amputation of his right lower extremity. What will happen to his
center of gravity?
A. It will move slightly to the right
D. Both A and C
B. It will move slightly to the left
E. Both B and C
C. It will move slightly downward
29. A man performs the concentric phase of a bench press in 3 seconds, he then performs the same lift
in 1 second. In which lift is more work being done?
A. no work is done in either lift
B. more work is done in the 1 second lift
C. more work is done in the 3 second lift
D. the same amount of work is done in both lifts
30. Referring to the previous question, which lift is considered more powerful?
A. the power is the same for both lifts
B. the 1 second lift is more powerful
C. the 3 second lift is more powerful
D. no power is generated in either lift
31. In the “stress fracture model” presented in class, which of the following is true?
A. fatigue reduces the muscles ability to absorb forces
B. fatigue alters the gait pattern
C. direct compressive loading from strenuous exercise causes traumatic fractures
D. all of the above
E. A and B only
32. When opening a heavy, spring-loaded door that you must pull toward your body to open, which of
the following combinations is correct?
A. eccentric – posterior deltoid
D. both A and B
B. eccentric – triceps
E. none of the above
C. concentric – biceps
33. Which of the following is an effect of early mobilization following an injury?
A. more rapid vascularization
C. increase in muscle atrophy
B. generation of parallel fiber
D. all of the above
orientation
E. A and B only
34. Muscles composed of relatively long muscle fibers usually have:
A. a greater ability to produce force
D. all of the above
B. a greater number of sarcomeres
E. B and C only
C. a greater range of excursion
35. An axial stress is a force that is:
A. parallel to the suface acted upon
B. perpendicular to the surface acted
upon
C. is often consider a shear force
D. both B and C
E. none of the above
36. Plyometrics utilizes which of the following structures:
A. muscle spindles
B. golgi tendon organs
C. both A and B
D. neither A nor B
37. When reaching above your head to obtain a cup from the cupboard, which of the following
combinations is true?
A. biceps – concentric
D. both A and B
B. posterior deltoid – eccentric
E. all of the above
C. triceps – eccentric
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38. In general, which of the following is NOT considered a theory behind plyometrics?
A. golgi tendon organs cause agonist inhibition
B. the muscle utilizes the effects of a quick stretch of muscle spindles
C. it is the ability of a muscle to utilize stored elastic energy
D. both B and C
E. all of the above
39. Figure 2
C
Load
D
B
A
Joint Displacement
In figure 2 representing the response of the ACL to loading, which of the points represents “tissue
microfailure”?
A. A
D. D
B. B
E. None of the above
C. C
40. When using one arm to lower a heavy object that is above your head to the level of your waist,
which of the following is a correct combination?
A. posterior deltoid – concentric
D. both B and C
B. anterior deltoid - eccentric
E. none of the above
C. triceps – eccentric
41. When pulling closed a light-weight door with no spring, which of the following muscles is
working eccentrically?
A. triceps
D. anterior deltoid
d
B. biceps
E. none of the above
C. posterior deltoid
42. When pushing open a light-weight door with no spring, identify the correct muscle and type of
contraction?
A. triceps – concentrically
D. anterior deltoid – eccentrically
B. biceps – eccentrically
E. none of the above
C. posterior deltoid – concentrically
43. When moving from a standing position to a sitting position, which of the following muscle actions
is correct?
A. hamstrings – concentric
D. tibialis anterior – concentric
B. iliopsoas – eccentric
E. none of the above
C. quadriceps – eccentric
44. You are attempting to gently resist a heavy, spring-loaded door that closes toward you. Which of
the muscle actions is correct?
A. concentric – biceps
D. concentric – posterior deltoids
B. eccentric – anterior deltoids
E. none of the above
C. eccentric – posterior deltoids
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Figure 3
3
Stress
1
2
Strain
45. Figure 3 represents the stress – strain curve of a connective tissue under tensile loading. Which
region represents the alignment of collagen fibers?
A. region between points 1 and 2
D. point 3 only
B. region between points 2 and 3
E. none of the above
C. region between points 1 and 3
Figure 4
2
Load
3
1
0
Velocity
46. In the load-velocity curve in figure 4, which of the following statements is true?
A. the greatest force production during a concentric contraction is found in the region between
points 2 and 3 and closest to point 2
B. the greatest force production during a eccentric contraction is found in the region between
points 2 and 3 and closest to point 2
C. the greatest force production during a eccentric contraction is found in the region between
points 1 and 2 and closest to point 2
D. all of the above are true
E. only A and C are true
47. In muscle, passive tension is developed during which type of contraction:
A. isometric
D. both A and C
B. concentric
E. none of the above
C. eccentric
48. When descending a single step, once the lead limb (lower extremity first stepping off the step)
makes contact with the floor below, which of the following muscle actions is correct regarding
that lead limb?
A. quadriceps – eccentric
D. both A and B
B. gluteus maximus - concentric
E. all of the above
C. hamstrings concentric
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49. Refer to the graph and question below:
C
B
Stress
A
Strain
Referring to the above graph, which material will demonstrate the greatest stiffness?
A. A
B. B
C. C
D. you cannot determine relative stiffness from this graph
E. stiffness for all 3 is identical
50. Collagen fibers are designed best to resist:
A. shear forces
B. compressive forces
C. tensile forces
D. both B and C
E. none of the above
51. Which of the following statements best describes Boundry lubrication in articular cartilage?
A. a wedge of fluid is formed between articular surfaces when non-parallel surfaces slide over each other
B. pressure is created in the fluid film by bearing surfaces that are perpendicular
C. a layer of lubricant molecules binds to each articular surface
D. pools of lubricant are trapped in undulations that result from elastic deformation
52. Which of the following describes a difference between ligaments and tendons?
A. in general the collagen fiber alignment in ligaments is more parallel than in tendons
B. tendons are better designed to resist multi-directional tension forces
C. tendons have a twice the water content when compared to ligaments
D. all of the above are true
E. none of the above are true
53. When slowly lowering a heavy object from a height above the shoulder with one upper extremity, which of the
following muscle actions acts on the scapula?
A. rhomboids work concentrically
D. serratus anterior eccentrically
B. rhomboids work eccentrically
E. both B and D
C. serratus anterior concentrically
54. Following eight weeks of immobilization, the “maximum load to failure” strength of ligaments is reduced by
approximately?
A. 5%
D. 80%
B. 10%
E. 100%
C. 40%
55. The increase in temperature associated with “warming-up” prior to competing in an athletic event
prepares skeletal muscle by:
A. increasing the metabolism within muscle
B. increasing the frequency of stimulation with muscle
C. increasing elasticity of collagen fibers in muscle
D. all of the above
E. A and C only
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