Injuries during sport and exercise are very commonly linked to our “biomechanics” Key to our biomechanics are our feet. Our feet are responsible for distributing the impact of every step. When you consider that up to three times body weight is placed through each foot during each step while running, it is easy to appreciate how perfect the structure of the foot must be able to handle such stress.
The foot has evolved uniquely not only to allow humans to walk upright but also as a specialised structure for stability and shock absorption. Most people do not have perfect biomechanics, and so sports shoes are an essential part of our training equipment. The sports shoe serves as a structural and functional extension of the foot. Chosen wisely it can have a beneficial influence on our activities. However, improperly chosen the shoe can amplify anatomical and functional flaws and thereby increase the risk of injury.
The foot consists of 26 bones and a multitude of ligaments and joints. The foot is divided into three main sections:
- The rear-foot is designed to allow our foot to contact the ground and absorb the impact.
- The mid-foot comprises a set of bones that are structured in an arch formation to provide support.
- The forefoot is designed to allow us to push off the ground later in the step.
All the structures in the foot have to function in a coordinated manner for us to be able to walk and run. Each step consists of a set of movements, which occur in a specific sequence with split second timing. Abnormal function can disrupt the whole mechanism and increase the likelihood of injury in the foot, ankle, knee, leg, hip and back.
When you take a step, your foot typically hits the ground heel-first and rolls toward your toes, flattening the arch slightly. As you push off the ball of your foot, your arch springs back and does not touch the ground. That’s how normal feet are supposed to work. Unfortunately, many feet aren’t normal:
- If your foot rolls too much toward the inside, it’s called over-pronation. This leads to arch strain and pain on the inside of the knee.
- If your foot rolls too much to the outside, that’s under-pronation, and you’re more susceptible to ankle sprains and stress fractures.
Your footprint is the clue:
- If your footprint looks like an oblong pancake with toes. This may suggest that you pronate excessively or have flat feet. Your sports shoe may need additional “control” features – soles designed to halt that rolling-in motion.
- If there’s little or no connection in your footprint between the front part of the foot and the heel, you under-pronate or have a high arch. This means a lot of your weight is landing on the outside edge of your foot. You may need “extra stability” sports shoes, which are built with extra cushioning to remedy this problem. If you are prone to ankle sprains, wear high-top athletic shoes that cover the foot and ankle snugly to minimize damage from twists.
Fit – the best designed shoes in the world will not do their job if they do not fit properly. Avoid foot problems by following these guidelines:
- Don’t go just by size. Have your feet measured.
- Visit the shoe store at the end of a workout, ideally also towards the end of the day, when your feet are largest.
- Wear the sock you normally wear when working out.
- Fit the shoe to the largest foot.
- Make sure the shoe provides at least one thumb’s breadth of space from the longest toe to the end of the toe box.
- If you have bunions or hammertoes, find a shoe with a wide toe box. You should be able to fully extend your toes when you’re standing.
If you begin to develop foot or ankle problems, adjustments in the shoes can help relieve the symptoms.
- A heel cup can help alleviate pain beneath the heel (plantar fasciitis). Made of plastic or rubber, a heel cup reduces pressure on the tender spot.
- An arch support can help treat pain in the arch of the foot. Arch supports can be placed in a shoe after removing the insole that comes with the shoe.
- Orthotics: long term (chronic) and complicated problems of the feet may require specially designed inserts (orthotic) made of materials that concentrate relief on a particular area while supporting other areas. To obtain the best relief for such problems, see a specialist in this area.
- A metatarsal pad can help relieve pain beneath the ball of the big toe (sesamoiditis) or beneath the ball of the other toes (metatarsalgia). It spreads pressure normally placed on the ball of the foot.
There is a trend towards minimalist footwear. The underlying idea is that “over designed” shoes create unnatural motion and ultimately, injuries. The suggestion is to walk barefoot or with minimalist footwear (specialist lightweight shoes with very little structure or support). This is controversial (though not without some merit perhaps) and beyond the scope of this article. We do suggest you read further in this area if it appeals to you.
Active living is perhaps the single biggest predictor of current and future wellness. Choosing good shoes that support this lifestyle while reducing injury risk is worthwhile, indeed essential. The field is complex and the big manufacturers tend to confuse us with a constant flow of new designs and models. But stick to the basics as described here, and be prepared to experiment a bit, and you should be able to find a shoe that fits!