Most injuries are the result of too much stress exerted on a specific body part (bone, cartilage, tendon, muscle, etc.). Let the body adapt to change by leaving enough time for it to become stronger. This video demonstrates how to assess mechanical stress quantification in order to prevent injuries.




What is mechanical stress?


The most important tool in the prevention and treatment of running injuries is mechanical stress quantification.

Indeed, the human body is made of living tissues, such as bones, muscles, tendons and cartilage. During a physical activity like running, which involves a series of jumps, various forces exert stress on these tissues. These forces consist of tension, compression and torsion.

Obviously, physical activity is not the only area of life where stress is exerted on tissues, which is also the case in one’s professional life and daily activities. However, the stress created when practicing sports is often much higher. Mechanical stress quantification consists in measuring the stress exerted on tissues in order to prevent injuries.

The level of stress and the tissues affected vary according to the sporting activity. For instance, the force exerted on the Achilles tendon during swimming is close to nil. At the other end of the spectrum, explosive jumps and plyometrics are extremely stressful while very low levels of stress are recorded for biking. Finally, running shows significant signs of stress that vary according to speed: the higher the speed, the stronger the force exerted on the tissues.


Don’t do it to the extreme


One way to illustrate the quantity of mechanical stress felt on a daily basis is to draw a curve with various stages representing the level of mechanical stress exerted on the body based on the activity performed.

Let’s look at a typical case where mechanical stress varies according to someone’s schedule. Sunday is a day off with no activity whatsoever. Monday does not include any sporting activity either apart from walking around the house and to work. Subsequently, some more days off are required due to pain. Although taking a few days off is preferable in order to avoid aggravating an acute injury, spending too much time in this “comfort zone” can be tricky in the long run. Interestingly, the body weakens in such an inactive state and becomes increasingly vulnerable to injury.

Let’s now take a look at the opposite scenario. On Sunday, the level of intensity is significant. In fact, the level of intensity is so high that the body’s maximum capacity is exceeded, which now poses a risk of injury. In the event of prolonged intense physical activity, there may be irritation or inflammation on tissues that already have low tolerance to mechanical stress. Since the body is so well designed, there will be many signs indicating that the maximum capacity of adaptation has been reached. One of the first signs that the body has gone beyond its limits, is pain felt during or after practicing sports. Finally, morning stiffness and swelling are some other signs that rest is required.


The key to avoiding injury: stress quantification


In short, the ideal is for the body to experience a minimum amount of stress in order to create the adaptation required without exceeding the maximum adaptation limit. While remaining in this middle area, the body can adapt to stress and even increase its tolerance to the latter. That way, structures get stronger, which in turn allows for increased intensity while practicing sports without the risk of injury.

Mechanical stress quantification applies to injury prevention as well as in cases of recent injuries. Be that as it may, in the case of a chronic condition, when pain can be felt without even exceeding maximum capacity, you should speak to a healthcare professional.

Another variable to consider: the maximum capacity of adaptation is not a static line. Indeed, there are many factors that can influence its position. Fatigue, psychological stress and anxiety are but a few factors that may inhibit the body’s tolerance level, increase its vulnerability and reduce its ability to heal. Conversely, being active, happy and rested makes it easier for the body to adapt.

That’s what mechanical stress quantification is all about!

The moral of the story? The body adapts insofar as the stress exerted is not greater than its ability to adapt. Quantifying mechanical stress on a daily basis remains the best way to avoid injury. Here are some educational tools to that end!