What do the footprints at Laetoli tell us about the prehistoric hominins that left them behind? YOU can measure and assess the correlation between foot length and stride length versus body height and then use these data along with those from other students to estimate the height of the Laetoli hominins. You can then use these data to better understand the fossil record. Check out the Trackways Video!
After you have printed out the worksheet, record your name, age, location (city, state, country, and/or latitude and longitude), and date on the form. Circle if you are male or female. Next, take off your shoes and trace the outline of your bare foot (no shoes or socks) on the worksheet. Stand barefoot on the data sheet with your heel lined up against the fold and direct your foot so that it points out along the length of the ruler. Draw a line across the tip of your big toe perpendicular to the ruler and read the value for the length of your foot from the ruler. Record your foot measurement in the space marked "Foot Length (cm)".
Use a ruler to measure your height in cm while standing barefoot (no shoes and socks) from the bottom of your feet to the top of your head. Record this measurement in the space marked "Height (cm)".
Prepare your work area by rolling out about 10 feet of butcher paper on the ground. Fill a basin with a small amount of fingerpaints, mix with water to dilute, and place this basin at one end of the butcher paper. Fill a second basin with water and place it at the opposite end of the butcher paper along with a towel. Step into the basin of fingerpaints (or here, toepaints!).
Walk carefully and normally for several steps across the butcher paper. Try to take normal length strides (not baby steps and not giant strides). When you reach the end of the butcher paper, step into the basin of water and wash and dry your feet.
Use a ruler to measure the length of your stride using your footprints. Your stride is the distance between the back of your heel on one step to the back of your heel on the second step taken with the same foot. The easiest way to find your stride length is to single out three consecutive steps that you made in your trackway. It is usually best to start the measurement several strides into the trackway that you made so that the measurement is taken once you have achieved your usual walking gait. Record this measurement in the space marked "Stride Length (cm)". (Of course, you can also measure several stride lengths and then calculate an average for your stride length and record this mean value on the data sheet).
Enter your measurements into the data form by following the directions on the website. After you contribute your data, you can view the results of your experiment. If y choose to create your own graphs offline, be sure to create two plots: one for foot length versus height, and one for stride length versus height. Use a red marker or pen to represent females, and a blue marker or pen to present males. You can download files for these graphs from the website.