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KNES 373 (1)
Final

# Lab Exam Study Guide.docx

6 Pages
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School
University of Calgary
Department
Kinesiology
Course
KNES 373
Professor
Aaron Tubman
Semester
Fall

Description
Lab Exam Study Guide Lab #2 Mass: The weight of an object, measure in (kg) Acceleration: Pull of earth’s gravity on a kilogram of mass (9.81ms ) -2 Force: That what changes or tends to change the state of rest or motion in matter. (Also expressed as…) that which changes or tends to change the velocity of an object -2 Force (Newtons)= Mass (kg) X acceleration (9.81ms ) Radian: One rad is 57 degrees. Radss measured to two decimal places Work: Force expressed through displacement with no limitation of time Work (Joules)= Force(N) X Distance (m) Power: The rate of performing work or the rate of transformation of metabolic potential to work/ and or heat. Power (Watts)= Work (J) / Time (s) Velocity: When both speed and direction are specified velocity is being defined Velocity (V)= Distance (m)/ Time (s) Measurements for velocity: -1 Linear: ms Angular: rads -1 Torque: ftlbsto Nm… ftlbs X 1.356! Nm is the effectiveness of a force to produce rotation of an object about an axis, and depends on both the force applied and the distance from the axis of rotation.  Muscle Actions: review via cue cards  Know how to do calculations!!!!! POWER-VELOCITY RELATIONSHIP The information that we have collected in lab regarding the power-velocity characteristics shown in figure 2 tends to follow the correct general trend suggested in today’s literature. Studies suggest that a person that has a higher percentage of type-2 (fast twitch) fibers can produce a larger power output compared to someone who has a greater abundance of slow twitch fibers (Suter, E, Herzog, Sokolosk, Wiley, MacIntosh, 1993). This difference in power is seen due to the fast twitch fibers ability to contract at a quicker rate, hence peak tension is reached faster than in slow twitch fibers and a higher power output is possible when experiencing higher velocities (Tihanyi, Apor, Fekete, 1982). Due to their slower contraction time, slow twitch fibers are unable to reach peak tension before the contraction ends/ in time for optimal joint angle when experiencing high velocities and therefore will produce a lower power output (Tihanyi et al. 1982). As the velocity increases the dependence or correlation of power output relying on percent of fast twitch fibers present increases (Suter et al. 1993). There are many different reasons for fast twitch fibers being able to produce higher outputs of power. Fast twitch fibers tend to transmit action potentials more frequently and at a faster rate (McArdle, Katch F., Katch V., 2010). Due to more action potentials being produced there is a higher crossbridge cycle turnover, higher amounts of myosin ATPase activity, and a greater release an re uptake of calcium causing contractions to occur at a faster rate (McArdle et al., 2010). Another factor that plays a role in power output is the cross sectional area (Tihanyi et al. 1982). A larger fast twitch fiber cross sectional area was also found in correlation to higher power outputs (Tihanyi et al. 1982). There are individual differences seen in figure 2. Subject 3 produced an exceptionally high power output increasing with angular velocity, while figure 1 was significantly lower and subject 2 fell in between (figure 2.). The difference could be from: number of fibers, cross sectional area, fiber type, neural factors, etc. PEAK TORQUE (Nm) AND ANGULAR VELOCITY RELATIONSHIP Figure 1 shows the general relationship between peak torque at various angular velocities. Our data shows that with increasing angular velocity less peak torque or force is being produced, This follows the general suggestions of the literature. TA any given angular velocity the amount of torque that is being produced will vary greatly depending on the fibre type distribution in the person. Type 2 fibres have a quicker and more powerful contraction hence if someone yield more type two fibres a greater torque will
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