One of the things I used to enjoy as a youngster was Dundee Cake, a famous traditional Scottish fruit cake with a rich flavour.

Not long ago, one of the reporters on The One Show went up to Bonny Dundee to be put through his paces by Professor Rami Abboud of the Foot Pressure Analysis Lab/Clinic at the university.  From work there, it seems that the designers of trainers have done their job only too well, so that today’s joggers put down their heels first when they run, rather than the ball of the foot.

While the trainer does cushion the impact, what remains travels up a straight leg and a lot of energy is dissipated in the knee joint.  Those who, like myself, have attempted to study viscoelasticity will know that springy materials can store energy and release it, while soft ones simply absorb it.  Cartilage falls into the latter category, and as Wikipedia puts it:

Cartilage has limited repaircapabilities: Because chondrocytes are bound in lacunae, they cannot migrate to damaged areas. Therefore if damaged, it is difficult to heal. Also, because hyaline cartilage does not have a blood supply, the deposition of new matrix is slow. Damaged hyaline cartilage is usually replaced by fibrocartilage scar tissue. Over the last years, surgeons and scientists have elaborated a series of cartilage repair procedures that help to postpone the need for joint replacement.

But we’d rather not have to do that.  Our ancestors, whether barefoot or in leather sandals, would have run on the ball of the foot.  Tests at Dundee (including a live demonstration on the reporter) show that in this case the energy of impact is taken up by the muscles, and much of it is released again when the leg relaxes.

So there is definitely a health benefit. With limited access to journals, I have not been able to read more deeply into the biophysics of it all. But in the meantime, watch this space, and

MIND HOW YOU JOG!