Heel Pressure
Do you really know how to walk or run? PocketLab's tactile pressure sensor provides for an opportunity for your students to investigate foot pressure during these activities. Improper form can ultimately lead to unwanted visits to a podiatrist. Whenever you take a step, your body places pressure on muscles, joints and tendons in your legs, knees, ankles, feet and toes. Controlling heel pressure is a key factor to prevent injuries in this regard.
Although toddlers commonly walk on their toes, most humans tend to adapt to a pattern of walking known as heel-toe walking--striking the heel on the ground first. This pattern of walking is quite efficient for humans and also has the advantage of preventing injuries.
When running, things are kind of reversed. If you hit the ground with your heels first, the complete extension of your legs results in shock to your ankles, Achilles tendons, knees, hips, back, and neck. Instead, you need to land on the balls (between your big toes and arches) of your feet, with the knees bent. This allows the shock to be absorbed rather than sent to the rest of your body. This can be referred to as toe-heel running. People who want to correct their running technique by changing to toe-heel running need to do so gradually, as their calves can get quite sore. Some people find that a good way to change to toe-heel running is to run uphill. Doing so results in a shortened stride in which it is more natural to land on the balls of your feet.
PocketLab Voyager Setup and Typical Results
Figure 1 (left--bare foot) shows how the tactile sensor has been taped to the heel of the foot. Figure 1 (center--shoes and socks on) shows how Voyager and the tactile sensor wire have been taped to the leg. Figure 1 (right) shows a snapshot of the collected tactile pressure sensor data. The left portion of the graph captured heel-toe walking, while the right portion of the graph captured toe-heel running. It is clear that while running, there was a noticeable decrease in pressure on the heel.
A special thanks goes to Gregory Born, B.S. in Exercise Science from Iowa State University, for his help in the design of this lesson.
If the Shoe Squeaks, Wear It
Here is a quick related story from Robby at PocketLab:
"My son was walking on his toes a lot so my wife and I got him shoes that squeak only if he steps heel to toe. He gets encouraged by the squeaking and it positively reinforces heel to toe walking. It would be cool to use the pressure sensor with the squeaky shoes and with his other pair of shoes to see how well he carries over the heel to toe stepping when the shoes don't squeak."
Check out this link for details on these squeaky shoes: ikiki
Additional Voyager Tactile Pressure Sensor Activities
Links to three additional tactile pressure sensor investigations are:
