Do you like running and jogging? But keep getting leg injuries? Do you often feel tired on your feet after running? Scientific studies have linked how you run to these problems at the lower limbs.
The weight of the body falls on the legs
It is true, the act of running moves your whole body, but the distribution of energy differs. Indeed, the average frequency of a runner is between 150 and 170 steps a minute, that is to say that his feet will strike the ground around 5000 times, during 30 minutes of running. For Dr. John Mercer at the University of Nevada in Las Vegas, “Every time your foot touches the ground, your body absorbs the impact”.
To show the effects of these movements (vibrations) on the body, Delphine Chadefaux at Aix-Marseille University in France and her colleagues had an experiment. They used high-speed cameras, leg sensors and force sensing plates to track movement, acceleration, muscle activity and the strength of hitting the ground in 10 recreational riders. Participants ran both barefoot and with shoes and at two different speeds.
Based on these technics, the researchers were able to position themselves where the leg absorbs the impact of the energy supplied in running. Thus, they noticed, that the legs absorbed most of the energy. Then, come to the top of the leg starting with the tibia and the knee. During exercise barefoot, the observation was clear: the absorption of the impact of the shock was four times more than when the runner was wearing shoes.
Protect the upper body to the detriment of the legs
The results of these experiments showed that the shocks suffered at the end of a stroke disappear entirely when one reaches the hip, that is to say that the upper part of the body does not undergo any energy impact. For Delphine Chadefaux, it is the way we run that protects the upper body against these vibrations. They are working to understand how to reduce leg impact to prevent common injuries such as fractures and articular problems.
These frequent injuries are the result of constant and repetitive shocks that affect the bones and articulars. “If your legs suffered too many shocks, and the bone couldn’t recover, it can lead to a fracture or other problem,” said John Mercer.