1. Metabolic and Mechanical Energy Saving Mechanisms in
Barefoot vs. Shod Human Running
Leslie Fischer
Honors Program and Division of Kinesiology and Health Advisor: Dr. Matthew W. Bundle
Spring 2010

2. Background

3. Metabolic energy use during running
Loaded
Metabolic Energy
Running Speed

4. Muscle Function During Running
No muscle length change during stance
Therefore muscles perform little, to no, work during the stance phase
The job of the active muscle is to provide force for weight support
Roberts et al., 1997

5. Muscle force production and metabolism
The force generation step in muscle requires ATP hydrolysis (the energy currency of the cell)
This provides for a link between rates of muscle force production and cellular energy release
Metabolic Energy α 1/tc
Kram & Taylor, 1990

6. Spring-like function of the human leg
During the stance phase of running the leg is under compression and is shortest at mid-stance
Since muscle is isometric, this length change occurs in the tendons, and connective tissue
This allows for the temporary storage and release of elastic energy within the large tendons of our legs

7. Foot strike patterns and collision forces in habitually barefoot versus shod runners
Foot can collide with the ground in three ways:
Rear-foot strike (RFS)
Mid-foot strike (MFS)
Fore-foot strike (FFS)
Evidence showing that barefoot runners and minimally shod runners avoid RFS
Barefoot or minimally shod runners are likely to be resistant to injury
Lieberman et al., 2010

8. Cost of transport on average is 1.41% less for barefoot running
Metabolic Energy
Cost of transport on average is 1.41% less for barefoot running
Squadrone & Gallozzi, 2009

9. Contact Time
Divert et al and
Squadrone & Gallozzi 2009

10. Electromyography
Speed was at 3.33 m/s
Divert et al., 2005

11. Variables During Running
Expectations
Results
Energy Expended
Same
Contact Time
EMG
Less in Barefoot
Less in Barefoot
Greater in Barefoot

12. Question:
Why is it in-expensive to run barefoot?

13. Hypotheses: 1.) Massiveness of Limb 2.) Leg Stiffness
3.) Effective Mechanical Advantage (EMA)

14. 1.) Massiveness of the limb
Constant Speed at 3.33m/s
Percent Differences:
0.50 kg thighs: 1.66% 1.00 kg thighs: 3.53%
0.50 kg feet: 3.34% 1.00 kg feet: 7.16%
Martin,1985

15. 1.) Massiveness of the limb
Frederick, 1985

16. Metabolic Energy

17. 2.) Leg Springs
The tendons, ligaments, and muscles in our legs function like springs
The stiffness of the leg spring
kleg = Force Δl
can change in response surface and shoe compliance

18. 2.) Stiffness
Lieberman et al., 2010

19. 3.) Effective mechanical advantage (EMA)

20. Conclusion

21. References
Burkett, L.N., Kohrt, W.M., & Buchbinder, R. (1985). Effects of shoes and foot orthotics on VO2 and selected frontal plane kinematics. Med Sci Sports Exerc, 17(1):
De Wit, B., De Clercq, D., & Aerts, P. (2000). Biomechanical analysis of the stance phase during barefoot and shoe running. J Biomech, 33(2):
Divert, C., Mornieux, G., Mayer F., & Belli, A. (2005) Mechanical comparison of barefoot and shod running. Int J Sports Med, 26(7):593-8.
Frederick, E.C. (1983). A model of the energy cost of load carriage on the feet during running. Nike Sport Research Laboratory, Exeter, New Hampshire, U.S.A.
Karm ,R. & Taylor, R. (1990). Energetics of running a new perspective. Nature, 346:
Martin, P.E. (1985). Mechanical and physiological responses to lower extremity loading during running. Med Sci Sports Exerc, 17(4):
Roberts, T.J., March, R.L., Weyand, P.G., Taylor, C.R. (1997). Muscular force in running turkey: the economy of minimizing work. Science, 275: ,
Squadrone, R. and Gallozzi, C. (2009). Biomechanical and physiological comparison of barefoot and two shod conditions in experienced barefoot runners. J Sports Med Phys Fitness, 49(1):6-13.