Below, is an example of the way athletes are trained in by plyometric box jumping. Resisting the impact to make the spring mechanism stronger.
Not many doctors would recommend this to their patients because one might think that impact is going to be damaging to the joints of a patient.
The impact is only damaging to the joints of the patient if we don’t have a an intact spring mechanism.
THAT IS THE DIFFERENCE
In this case he is jumping down with the force of the landing mass distributed across the feet.
When you run you launch the weight in the air and land on one foot.
For instance let’s say you have 20 people in an aerobics class who are jumping, bounding and hopping.
If 10 of them get shin splints, back pain, knee pain, plantar fascitis, heel spurs or any number of 10-12 different conditions related to impacts you would go to the doctor. You might hear Oh my, those impacts are not good for you.
Stop that activity, as that is bad for your knees, ect.
In reality this is how athletes are trained.
It is these impacts that actually make the body healthier again, AS LONG AS THE SPRING MECHANISM IS INTACT.
Here is an example of impact exercises that are performed to be able to maximize the spring strength for jumping.
They are called speed bounds:
As you can see he is jumping on 1 foot throwing his body into very high velocity jumps or bounds.
In these jumps he can put an impact of between 5-10 times the bodyweight.
So if this man weighs 180 pounds then the impact force is close to 600-1000 pounds of force on the human foot and the joints up to the head.
If your human spring mechanism can handle the impact force that means it is below the yield strength. That also means it is beneficial positive stress on your muscles, joints and bones to provide adaptation for them to get stronger for the next training session or competition.
They call this “training”
You need to graduate into these high impact training sessions.