BODY SCIENCE
Mechanics Before Shoes
In recent years, there has been much debate regarding barefoot running and the various levels of cushioning found in running shoes, but running well and staying injury-free isn’ t just about the shoes.
– BY ERNEST HOBBS, BIOMECHANIST
ssentially, if early man was barefoot while hunting, why are we encouraged to wear built up shoes? And if shoes are more fitting for modern man, how much cushioning is best for
Erunning? This is further argued when statistics suggest that injury rates among runners have not noticeably reduced, even though the technology of running shoes has changed significantly over the last few decades.
Heavily cushioned shoes have been found to promote heel-striking during running by reducing the pain experienced as the heel strikes the ground. However, the impact forces experienced when heel-striking may increase the risk of developing a range of injuries, such as shin splints and stress fractures. Barefoot running was suggested to discourage a runner from heel-striking, as the sudden impact on an un-cushioned heel would cause pain, resulting in a runner adopting a midor forefoot striking pattern.
The problem with this theory is that not all runners will change to a mid- or forefoot striking pattern, and heel-striking on an un-cushioned heel places a runner at even greater risk of injury than heel striking in a cushioned shoe. This emphasises the need to adopt a forefoot strike when transitioning to barefoot running, and highlights the importance of running mechanics, more so than running shoes only.
STRIKE PATTERN
Since running mechanics come first and running shoes come second, how does forefoot-striking differ from heel-striking? Forefoot-striking involves a shorter stride length, with the foot making ground contact closer to the body. The knee is straighter at mid-stance and the foot makes contact with the toes pointing down rather than the toes pointing up as with heel-striking. With the knee bending less, the thigh muscles work less hard to absorb the impact of running.
Unfortunately, this means that the calf works harder to absorb the impact, increasing the risk of calf and Achilles injuries. Additionally, with the small bones of the forefoot coming in contact with the ground before the bigger heel bone, these small bones are also at greater risk of injury. Studies have found that runners with greater leg stiffness( less bending of the knee and ankle) tend to suffer from more skeletal injuries, whereas runners with less leg stiffness had a greater incidence of injury to the soft tissues, such as muscles and tendons.
Even though the appropriate running shoes are essential, it is more important to consider the striking pattern a runner uses. Running shoes are less likely to prevent an injury, but adjusting running mechanics and the foot-strike pattern may reduce the strain a runner experiences, thus alleviating pain and lowering risk of injury. Consult a relevant professional to determine the most appropriate approach, since each runner’ s needs may be different.
About the Author Ernest is a biomechanical, video, and running gait analyst at the High Performance Centre( HPC) of the University of Pretoria.
• They contain vital vitamins and minerals, like vitamin C, potassium, folate and beta-carotene.
• They’ re low in fat and calories, yet fill us up, so they help with appetite and weight control.
WHAT COUNTS AS A PORTION?
Each different fruit contains various combinations of fibre, vitamins, minerals and antioxidants, so to get the best benefit, eat a variety of fruit daily, especially differently coloured fruits. Most fruit-containing foods can count towards your three fruit servings per day, but there is a limit to how many portions they provide, regardless of the amount. For example:
• Fresh fruit: 80g of fresh fruit equals one fruit portion, e. g. 1 medium apple, 3 apricots, 4 heaped tablespoons of blueberries.
• Dried fruit: 30g dried fruit equals one fruit portion, e. g. 2 figs or 1 heaped tablespoon of raisins.
• Tinned fruit: 80g tinned fruit equals one fruit portion, e. g. 2 pear halves or 2 pineapple rings
• Fruit juice: A small glass( 150ml) of pure fruit juice counts as one fruit serving, but you can only count one serving of fruit juice towards your three fruit servings per day. This is because unlike fresh fruit, the juicing process squeezes out natural sugar that is normally found between the cells of fruit, which is harmful to your teeth.
WEIGHT-GAIN WORRIES?
Many people make the mistake of thinking fruit is sugar and will cause you to gain weight. The truth is, fruit is made up of various types of sugars, but the main type is fructose, which has a different metabolic pathway and a lower glycaemic( blood sugar) response compared to glucose, which is found in candy and sweet, refined carbs. Fruit also contains fibre, which lowers the glycaemic response even further. Thus if you eat a lot of fruit at one time, the sugar load in the blood can rise unfavourably, but not if you eat one to two portions at a time. The key is to have a variety of fruits and spread them out throughout the day.
41