Vertical Jump Lab
Due: Friday, January 26th
Open Hu-m-an and select a jump trial from the list
Select Options: Instant Calculation
Follow directions to determine aspect ratio and scaling factors
Measure vertical jump height _____
*Explain how you measured vertical jump height
Relative Angles
Select Help: Hu-m-an Manual
Scroll down to Chapter 3 and click on “Natural Relative Angles”
Observe how relative angles are determined for the hip, knee, ankle, shoulder, and elbow
joints.
Keep that window available for reference and determine relative angles at those joints for
the:
First Frame
Maximum flexion of the hip, knee, and ankle joints (lowest point)
Take-off
Digitizing sequence (click-on the joint centers or axes of rotation for each joint):
Shoulder: shoulder-hip-shoulder-elbow _____ _____ _____
Elbow: elbow-wrist-elbow-shoulder _____ _____ _____
Hip: hip-knee-hip-shoulder _____ _____ _____
Knee: knee-hip-knee-ankle _____ _____ _____
Ankle: heel-ball-heel-ankle _____ _____ _____
Digitizing (click-on the joint centers or axes of rotation for each joint)
Selection Options: Digitize from the first frame until subject lands from their jump
Calculations
Exit the digitizing window
Calculate: System C. of G. (center of gravity) for Y
Display the graph and smooth
Click-on the graph to display the C. of G. values at take-off and at the peak of the vertical
jump
Determine the difference in C. of G. at take-off and the peak of the vertical jump _____
*How does this compare with the vertical jump height you calculated earlier?
Calculate relative angles at the hip, knee, and ankle
Calculate velocity at the hip, knee, and ankle
Display the angular velocity graphs for each of these joints and smooth
Observe the angular velocity graphs for the hip, knee, and ankle and compare when peak
angular velocity occurs at each joint. Describe the temporal relationship between these
three joints and how it functions to maximize vertical jump height.
Graphs
Display each graph one at a time. Then select Utilities, Copy, Graph Window, and paste
into a Word document.
Additional Questions
Vertical jump height is decreased if subjects perform the jumps with their hands placed
on their hips. Which of Newton’s laws best explains the positive effect that the upward
swing of the arms has on vertical jump height?
The vertical jump you observed for this lab is classified as a countermovement jump
because the subject flexed their hip, knee, and ankle joints before immediately and
powerfully extending those same joints. Vertical jump height is decreased if no or
minimal countermovements are performed. Explain how countermovements increase
vertical jump height. Please do some research before answering this question.