Dr Jonathan King

Sports Physician

Gosford, NSW

Running may seem "natural" to many athletes, in that relatively little attention is paid to technique compared with swimming or cycling. Many reading this article will have had an overuse injury related to running. One of the good aspects of the triathlon is that training is varied, and one does not need to spend hours on running training (unless you are training for the Ironman!).

The basis for successful competitive running lies in biomechanics, which is the way the pelvis and lower limbs are aligned when walking and running. There is the "ideal" gait that probably accounts for the success of many African athletes. The running gait can be divided into "stance" and "swing" phases. This topic can be complicated, and I will try to present the basics.

The "stance" phase starts with the heel-strike usually. Some athletes strike the ground with the forefoot. This is natural when sprinting, but can lead to problems in long distance running.

While the body is supported on one leg, the foot pronates. This can be appreciated when standing on one foot and bending the hip and knee. Weight is transferred to the inside of the foot. Heavy pronators tend to wear out the inside (medial) parts of the outer-soles (middle diagram).

While standing on one leg, rising up on the toes usually results in supination, when weight is transferred to the forefoot. When running, this is a natural progression as the foot is locked into a rigid lever to allow propulsion (lower diagram).

Excessive pronation can lead to overuse injuries, which includes:

1. "Shin splints" which refers to pain along the inner border of the lower leg (tibia).
2. "Runner’s knee", which is pain as a result of excessive contact between the kneecap and medial femoral condyle (upper part of the knee joint under the kneecap).
3. Plantar fasciitis starts as heel pain. The plantar fascia is a tight band extending from the heel to the toes. This acts like a big spring, and absorbs shock during the stance phase.
4. Stress fractures can occur in the foot and lower leg. A stress fracture is a microscopic fracture (failure) of the bone due to repetitive forces. Most athletes feel pain during the development of a stress fracture, and it is unwise to ignore persistent pain. An X-Ray will not show a recent stress fracture. Treatment can vary from relative rest to a plaster cast.

Supinators have poor shock absorbing biomechanics, and need shoes, which provide cushioning. Typical injuries include:

1. Pain in the lateral hip or lateral knee due to a tight iliotibial band. This requires stretching and massage.
2. Forefoot pain is due to inadequate shock absorption. This can lead to a stress fracture if not attended to early on in a training programme.

I have only mentioned a few injuries, as each athlete’s situation is unique. Factors like training programme, running surfaces, nutrition, and (absence of) menstrual periods also influence injury patterns.

General advice regarding running shoe selection

The shoe which best suits you depends on your foot-type, and running biomechanics. Those with "neutral" feet and good biomechanics can get away with buying the cheapest shoes!

Excessive pronators need shoes with the following characteristics:

1. Straight last (the sole should be straight)
2. Firm heel-counter
3. Firm mid-sole material (the shock absorbing material should be firm)
4. Shoe must be able to resist pronation.

Excessive supinators need:

1. A shoe with a curved last (the sole should be banana shaped)
2. Good shock absorption
3. A shoe that allows pronation

In this article I can only give general advice. A Podiatrist, Sports Physician, Running Coach, or well-trained shoe-salesperson should be able to help you in shoe selection.

If you are concerned about your running biomechanics, a Sports Podiatrist, Sports Physician, or Sports Physiotherapist may be able to help you. Those who live in the main cities may have access to the appropriate facilities. Triathletes who live outside the main centres may need to travel to get more specific advice regarding their problems.

I will be happy to answer any queries regarding this article!