Kinesiology 201 Questions
Muscle Mechanics
Tony Leyland
School of Kinesiology
Simon Fraser University
1.
Briefly explain what is meant by the stabilizing component of a muscle force. [2]
2.
Draw the total force (tension)-length curve for human skeletal muscle. Be sure to
include passive and active components. [4] Briefly mention what structures the
active and passive components represent in human muscle? [4]
3.
a) Draw a typical force-velocity curve for human skeletal muscle. [2]
b) Draw a typical power-velocity curve for human skeletal muscle. [2]
c) Explain what is happening if someone was working in the “negative power”
portion of the power-velocity curve. [3]
4. The diagram below show the final phase of a javelin throw. The next two questions
refer to the "throwing phase" of the movements: this phase starts at left leg touch
down (LTD) and ends at the release.
a)
Which muscle groups are undergoing a "stretch-shortening cycle"? How do the
movements depicted initiate this cycle? [5]
b)
Explain (with the aid of diagrams and equations if needed) the benefits of this
"stretch-shortening cycle". [8]
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5. A unipennate muscle produces 60 N/cm of force, where the area in question is its
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physiological cross-sectional area (PCSA). The total PCSA of the muscle is 15 cm
o
and the angle on pennation is 15 . How much tension is produced in the muscle
tendon that runs longitudinally (i.e. at 15o to the fibres in this case)? [4]
6. List (do not discuss) six factors (other than the one given in the example) that affect
the force generating capacity of a muscle. For example, the cross-sectional area of
the muscle would affect its maximum force generating capability. [6]
7. A slightly different question; what factors affect the torque generating capacity of a
human muscle and joint system? [8]
8. Two individuals both curl 20 kg when performing a biceps
curl weight-training exercise (shown above). However,
the forces exerted by their elbow flexors (biceps,
brachialis & brachioradialis) are not necessarily the same.
Explain biomechanically why not. Note that there are
many factors that you could discuss, try to mention as
many as possible. [12: one mark for factor and one
mark for a satisfactory explanation of how it affects
muscle force]
9. Define isotonic weight training. Does this mean that the muscle force is constant
throughout the entire exercise, explain? Explain from a biomechanical perspective
the benefits and disadvantages of free weights. [10]
10. Explain in detail, the biomechanical rationale for plyometric training. [10]
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