In today's lab we will be measuring the power output of a class member doing pushups. Yesterday we discussed how we could collect the data that would be needed to measure the power of a pushup. Review your notes from the brainstorming session, set up the motion detector and connect it to the ULI and computer. Open the MacMotion program from the Vernier software folder.

Construct a rough data table to record the appropriate data for 3 runs on each subject. You will be measuring the power output of three different subjects.

Call the instructor over to check off your set up and data table.

___________ Set up complete

___________ Data table complete

Proceed with the measurement of power output for your three subjects. Make three runs for each subject. Allow them only a 30 second break between runs. We want to see them fatique. After the first run, save the data as subject name/ your name with run number. After the second run use the save as command and change the run #. This will save it as a separate file. Same thing for third run.

Once you have completed all the runs set up a new folder with your name /pushup lab. Transfer the experiment files to this folder. Call the instructor over to check off your data file transfer and storage.

_____________ Files stored correctly

DATA ANALYSIS:

Once the data has been collected, you should export it into a spreadsheet, like Excel. Open the Data table from the window menu and copy the time, distance(corrected), velocity, and acceleration columns to paste into the spread sheet. When you have the data into the spread sheet, you need to collect the peak power for each cycle of the exercise. Enter peak power and time by hand into the spread sheet so you can produce an endurance curve for the exercise. In the spread sheet set up columns to calculate power, horsepower, and power to mass ratio.

Your data section should include the following graphs:

1) Power vs time for the whole exercise

2) A two graph display of distance corrected vs time and power vs time for a selected series of pushups.

3) Power vs distance corrected ( the performance envelope)

4) Peak power per cycle vs time ( the endurance curve)

ANALYSIS:

Performance analysis:

In this section of your report you should select the data from a series of four or five pushups the have similar power curves. Compare the power vs time curve to the distance corrected vs time curve using the "two graphs" selection from the display menu. Describe how the changes in the power curve relate to the distance curve through one cycle of a typical pushup. Focus on the shape, maximum, minimum, and slopes of the power curve. Set up a single graph of power vs distance(corrected). This graph produces what we could call a performance envelope for the subject for that exercise. Use what you learned from the previous analysis to interpret the information from this graph. Discuss the shape, maximum, minimum, and slopes of the peak power vs time curve from the spread sheet. Discuss the physical significance of these graphs.

Biomechanical Analysis:

Identify the major muscle groups and bones involved in the pushup. Draw a diagram of the basic positions involved in the movement. Determine when each muscle is at full extension and at full contraction. Describe how the leverage and mechanical advantage changes for each joint. Relate this analysis to the performance analysis above.

ASSIGNMENT:

1) Over the next 12 weeks of the football season we will perform weekly tests on the selected players. Your assignment as a class is to track the performance of the players for the pushup exercise. It would be great if this report was in the form of a set of hyperstudio stacks.

2) Your individual assignment is to design an experiment to analyze the power output and performance characteristics of subjects doing another different exercise. Identify the major muscle groups and bones involved and do a biomechanical analysis of that exercise.

3) Your individual assignment is to prepare an individual report analyzing the performance tests for your exercise on the selected players. You can get extra credit if you agree to track the players' performance over the training season.