In this study, our goal was to test for conservation of energy across a number of different insoles and foot orthoses. An increase in energy conservation between the foot and the ground means an increase in ground force and improved performance efficiency. Three different insoles and foot orthoses were tested and compared.
A stock insole found in the Hoka One One Clifton 8’s was used as the control. A ball weighing 0.046 kg was dropped from a height of 0.5956 m from a static position for each drop. The potential energy of the ball was calculated using the well knowen gravitational energy equation (seen in image 1) at 0.2694 J.
Image 1: Gravitational Energy Equation
The ball was dropped, bounced off the forefoot of the insole, and the apex of the rebound (bounce height) was measured. A slow-motion camera was used to record the bounce and aided in determining the height of the rebound.
Data was collected and recorded for each tested insole and compared to the stock insole that came in the Hoka One One Clifton 8’s.
See below for the resultant data collection.
Table Showing Summary of Collected Data
Conserved Energy by Insole
The control conserved 31.91% of the originally measured energy (a 0.00% increase because this is the control). Superfeet Blue conserved 34.06% of the originally measured energy (a 2.14% increase compared to the control). inStryde conserved 38.30% of the originally measured energy (a 6.38% increase compared to the control).
All tested insoles improved the efficiency of energy conservation compared to the control. inStrydes showed the biggest improvement by conserving 6.38% more energy - 4.24% better than the nearest tested competitor.