Undergraduate Biomechanics Labs

[Troy Rand]

Hello,

I am a first year masters student and the graduate assistant for the undergraduate biomechanics lab. I am looking for ideas for lab activities.

I am currently teaching 3 sections that include linear kinematics, projectiles, and angular kinematics, this week we did all equations and my plan for next week is to go to a gym and use photocells to time some 40 yd sprints while having them use a stopwatch to compare the difference. I was also going to have them throw balls in the air and time how long they took to hit the ground and then figure out velocities, etc. I'm just curious if anyone has any other ideas for these sections.

This is my first semester teaching this lab and I am disappointed in the amount of actual activities that I am supposed to have them engage in, I do not want this to be another lecture but instead an actual lab, so I am looking for ideas for next year or the rest of this semester,

Thank you,

Troy

[Jos Vanrenterghem]

Re: Undergraduate Biomechanics Labs

Dear Roy,
In case you have computers available, you get them to obtain some kinematic or kinetic data, and process the data. For example, if you have kinematics and you can have them digitize the position of a ball thrown in the air, they could from the displacement data calculate velocity and acceleration data, and see how close they can get to -9.81 for acceleration signal. If the displacement data is noisy, they can explore the effect of filtering to obtain a better representation of g. To avoid having to use formulae or advanced software, the Biomechanics Toolbar and be used to do these processes easily in Excel: http://www.staff.ljmu.ac.uk/spsjvanr...csToolbar.html
Kind regards,
Jos

[Nicholas Murray]

Re: Undergraduate Biomechanics Labs

Hi Troy,

I am a PhD student at the Universty of Texas at El Paso. I currently teach the undergrad biomechanics lab and I have been redesigning the curriculum for the course.

I also previously taught biomechanics lecture and labs at San Diego State University.

What are you specifically looking for? What tools do you for use in your class? What is the main focus or demographics of students you are teaching (eg pre-PT, exercise science, etc).

I have designed labs ranging from linear kinetics/kinematics to angular kinetics/kinematics to motion analysis and EMG.

Please let me know how I can help? I have been in your shoes before so I am more than willing to help!

Regards,
Nic

[James Furmato]

Re: Undergraduate Biomechanics Labs

Hey Troy,

Seeing is believing and (as in the case of biomechanics) is understanding! There are several valuable software tools you could use, but the Java successor to NIH Image, ImageJ is free and powerful. Set a video recorder on a tripod and throw the ball thrown at different angles. When you convert the frames to a stack of images, you see the trajectory of the projectile as well as that of the thrower (especially if you have a contrasting marker to track movement).

You can write code to enhance features and extract points.

Use two cameras parallel to each other on a fixed base with 6-10 cm separation (6.5 cm is about the separation of human eyes viewing at about 3.5m; greater separation would be used for larger scale venues) and you should start to appreciate three dimensions in your calculations.

The visuals are great for report writing, research posters, and showing off to alumni and family during spring open house!

Jim Furmato

[Karine Jacon Sarro]

Re: Undergraduate Biomechanics Labs

Hello!

To the projectile class I use one video camera to record the students throwing a ball, simulating a shot put. I use a software to obtain the release angle and the distance of the ball and the students have to calculate the velocity. Then I put these data on the Shotput Program (http://www.florian-rappl.de/?i=forsc...hotput-program), this program shows the trajectory of the projectile and allows changing the initial parameters to simulate throws. With this program students can adjust the velocity and the angle of release to reach greater distances.

Cheers,

Karine Sarro
College of Physical Education and Sports
Federal University of Espírito Santo/Brazil

[Gannon White]

Re: Undergraduate Biomechanics Labs

Hello,

I start with a gait lab where they calculate their SL & SR for walking and running.
I also do a jumping and landing (on FPs) lab where they have to calculate heights, and velocities based on FP data.
You can also record these jumps and have them digitize (MaxTRAQ is really easy to teach them and my students have easily picked it up) their own jumps and calculate their joint angles. I find the students are more engaged when they have to analyze their movements. Have them do a box jump and measure Sag hip, knee, & ankle angles. Then they can measure hip displacement in lieu of COM to calculate other measures. This combines a data collection day that can be used for linear, angular, or a PM lab!

Note: I don't have an invested interest in MaxTRAQ. I just found it easy to only have to post a few directions and they quickly learned the 2D version....There's probably some free app by now with digitizing/motion analysis?

[Ted Andresen]

Re: Undergraduate Biomechanics Labs

Hi Troy,

I had a few ideas that might possibly be helpful as lab exercises. Because of my background they may emphasize a bit too much physics for a biomechanics lab, but maybe they will prompt some other ideas:

You could put the photocells a few meters apart and the students could examine the difference in transit times between starting from a standing posture and using starting blocks (pushing off from a crouching position at the base of the gym wall). Here, approximate acceleration is: a=2d/t^2. How much do starting blocks help a sprinter?

You could place the photocells at the bottom and top of a long stairway. If each student runs up the stairs and records their time-of-ascent, they could estimate their mass specific power (MSP) output (P/m = hg/t). They could compare their values with each other and the MSPs of elite stair racers, amateur and professional cyclists (3-6 watts/kg; continuous) or that required for human-powered aircraft.

They could practice unit conversions by converting ml of O2/(kg-min) to watts/kg. That might raise some interesting questions regarding metabolic input power versus mechanical output power.

If there is a treadmill in the lab, students could measure and graph the step frequency of each other as they run on the treadmill at a series of velocity steps. Some step-frequency-versus-velocity data is linear, others are not.

They can tie the above activity in with learning to use Excel. If they enter the speed-step frequency data in adjacent columns of an Excel spreadsheet they can display the data in a chart using the Chart Wizard icon. Students could fit the data using the Chart/Add Trendline/Type pull-down menu to fit the data with a Linear or Polynomial least-squares fit. If they click on the Options tab, they can direct Excel to “Display equation on chart”. Then they could connect what they learned in algebra with their lab data.

Hope this is of some assistance,

Ted Andresen