We ask a lot of our feet, we take them for granted and scarcely give a thought to how best to keep them healthy until something goes wrong. In
this month's Harvard Health Letter, there is a four page article about how feet work and "three steps" on how to look after them from Dr. James Ioli,
chief of podiatry at Harvard-affiliated Brigham and Women's Hospital in Boston and colleagues.
Our feet provide us with a steady base on which to stand or walk, they act as levers for forward and backward and sideways moves, and they absorb shock, for instance when we run and jump the impact of landing is a force equal to many times our body weight.
Our feet do all this with just 26 bones (one less than in our hands) and 33 joints all lashed together by an intricate architecture of 100 ligaments and extrinsic and intrinsic muscles and tendons that orchestrate the movement of the feet.
The extrinsic muscles start in the lower leg, wrap in a crisscross fashion around the ankle and finish in the foot, like a kind of sock, and enables the foot to articulate in several directions.
The intrinsic muscles, which start and end in the foot itself, comprise several layers across the sole and help to form an elegant and graceful arch along the length of the foot.
When a person walks normally, the weight starts in the heel and moves to the front of the foot. The heel hits the ground first and the shock of impact is absorbed by the heel or calcaneus bones and a layer of fatty tissue beneath. Then the foot rolls forward on its outside edge and causes the plantar fascia, a band of tissue along the bottom of the foot, to stretch out.
All this happens without thinking about it, and it's only when something goes wrong, and there is plenty that can, that we become aware of how much we rely on our feet.
Some people are born with foot problems like high arches (pes cavus) or clubfoot (talipes equinovarus) and in many cases these problems can be surgically treated.
Others are born with minor defects that can become more serious as we get older and especially if we put on weight.
One problem is overpronation, where the person walks or runs on the inside of their feet. This is not uncommon and for the most part people aren't bother by it, but some can end up with a range of problems like sore knees, sore ankles, fallen arches, or inflamed and worn out foot tissue.
The opposite of overpronation, called oversupination, or walking too far onto the outside edge of the foot, can also lead to similar problems.
Another problem is flexible flat feet, which affects around 1 in 5 adults. This is when the arches in the feet flatten out under weight but then return to their normal arched shape when the weight is taken off. Again, this does not usually affect many people who have it, but it can get worse as they age, and especially if they put on weight.
Then there is a range of problems that can be described as "self inflicted" because they arise from doing things like wearing high heels and badly fitting shoes. These include hammertoes and bunions which result from squeezing toes into too-narrow shoes, and we can also damage metatarsals (the long bones of the foot before the toes) and Achilles' tendons by over use of high heels.
Many people don't realize that as they age, the ligaments and tendons in their feet stretch out, causing them to grow by a half size or even more.
Also we tend to wear shoes far beyond their replacement stage, by which time the heel is no longer held firmly in place at the back, and the sole no longer absorbs shock effectively.
The authors recommend a three step approach to keeping feet healthy:
- WEAR GOOD SHOES: Buy low-heeled shoes that fit well and make sure there is plenty of room for your toes. Replace them regularly.
- STAY TRIM: Too much weight on your feet wears them out, and keeping to a healthy weight will benefit the rest of your body too.
- WALK: Not only is walking good general exercise, it strengthens and stretches the feet (and remember to change your shoes regularly).
Written by: Catharine Paddock, PhD