Running Style Differences April 27 2013, 0 Comments
Browsing YouTube the other day, I came across an excellent collection of slow-motion videos from Harvard Skeletal Biology Lab (skeletonheb) showing the differences between various types of running. Each video has a graphical time-trace of the impact of the footfall, which rises to an incredible two-and-a-half times the runner's body weight with each step, irrespective of style or shoes, making the quality of this impact the differential for each case.
In the first video, a barefoot runner is landing with a heel strike - click on the image to get the video.
Things to consider here:-
- The toes are curled up to present the heel for landing, meaning that the muscles in the shins are under tension.
- The landing is on a very small area at the tip of the heel, and you can see the impact of the landing travelling up through the leg. The force-trace underneath starts with a near-vertical line, meaning that the impact happens very suddenly, and this combination of suddenness and small landing area means that he pressure (force divided by area) is extremely high.
- The rest of the foot lands passivley - you can see it wobble as it comes into contact with the ground, and the toes actually bounce on landing.
- Looking at the instep and the calf muscle, they wobble on impact, suggesting that they are not under tension.
- Again, the toes are curled up to present the heel for landing, and the shin muscles are therefore in tension.
- The padding in the heel does reduce the suddenness of the first impact, although the line is still very steep.
- We cannot see what is happening with the instep, but the calf is still wobbling on impact, suggesting it is not under tension.
- Before landing, the foot and leg are relaxed, with the foot pointing slightly downwards.
- The landing is on the outside of the front foot, rolling across to the whole of the front-foot, before the heel is lowered to the ground. So the impact is progressively spread over a larger area of foot, keeping the pressure down.
- The muscles in the instep and calf can be seen immediately under tension during this process, as they work to cushion and absorb the impact by the time that the heel reaches the ground.
- The force trace has a shallower slope, with a much more gradual application of the force, rather than a sudden one.