in the Zone


How do we overcome the pull of gravity?

Our investigative team wanted to find out more about how the body generates power.

When you jump into the air, you are able to generate enough power to overcome the pull of gravity and lift your entire body into the air, but our team needed to understand exactly what was happening in a jump. Take a look at the force trace to see the different phases:

  1. Standing still - your force trace is equal to your weight
  2. Bending your knees - notice how the force is less as you drop down
  3. Pushing hard against the ground - producing a peak of force
  4. Flight time in the air - there is no force
  5. Landing - the body must cushion itself against the forces produced by contact with the ground.

The more force applied as you push against the ground, the more power you produce and the higher your jump will be. So how can we achieve this?

Firstly, the more muscles you use as your start the jump the more power you will be able to generate, so swinging your arms and even clenching your buttocks will help create more lift! Take a look at our short film, 'Sports Spotlight: Power' to see how we were able to measure the recruitment of muscles in the lab.

We discovered another springy secret to a big jump. At the end of each muscle are stretchy tendons that attach to your bones. When you crouch down before a jump, the tendons at top of your knees and the back of your ankles get slightly stretched. As you jump, they twang back to their resting length just like little rubber bands, adding an explosive edge to your jump. So, to get the highest jump, make sure you start with a crouch.

The Achilles tendon stretches from the heel to the bottom of the calf muscle

Uncovering the secrets of the spring in our step

Researchers believe the Achilles tendon could be the secret behind our life on two legs.

People sometimes refer to their weak spot as an ‘Achilles’ heel’ but in fact its namesake is a great strength of the human body.

Your Achilles tendon runs from the bottom of your calf muscle right down to your heel bone. If you stand on tip toes and look at your bare calf you may be able to see a dip where it starts.

A long and stretchy Achilles tendon is the reason human beings are so good at walking and running over long distances. Just like a spring it stores and releases energy during the stride, amplifying the power of the muscles and saving you energy.

Researchers investigating human evolution believe that looking for evidence of an Achilles tendon in early human fossils would be a good indicator of when humans evolved to be able to run on two legs.