Why do we get injured?

  • 17 June 2014
  • Laura Dutton

It is frustrating for us all when we experience niggles that don't go away. I'm sure you have all been there at some point particularly if you participate in sport. It can be devastating!! I see so many athletes that have trained so hard and then be stopped by an injury.  Why does this happen particularly if we train according to training programmes?

Injury is when there is tissue stress. A great formula to demonstrate tissue stress is:-

Predisposing factors  +  Triggers =  Tissue Stress

Predisposing factors are our relative risks for injury including our lower limb biomechanics, alignment, muscle strength, length and motion control

Triggers are factors that alter the load level. These include changes in training frequency, intensity, illness, operation, equipment and trauma. 

To explain the formula above, we all have biomechanical asymmetry, tightness, weaknesses in certain areas and we may always tick along at the same intensity of training without ever a problem. However, problems arise when we then overload our training in some way e.g training for a race and maybe increasing more than one variable in one go. People may bring about speed sessions in the week therefore increasing intensity at the same time as increasing duration/distance at the weekend. Or it could occur whereby you go to a training camp and suddenly increase the intensity/frequency of your training.   Also in my experience I often see athletes with injuries after a period of rest.  Rest can be important particularly if it's 1-2 days a week or rest after a hard event however rest of more than 5 days can be significant in bringing about detraining effects and then resuming normal training after this period of rest can bring about detrimental effects mimicking overload. 

The Graph Below Demonstrates Tissue Homeostasis

Tissues live in the hatched "zone of tissue homeostasis" on the graph. If we are trying to get stronger we have to overload our tissues above this zone and into the green section (Supraphysiological Overload) where tissues naturally break down with overload. However, if we then allow enough recovery time after the overloading event the tissues will repair, adapt and get stronger.  So effectively as the structures strengthen over time this green section will move to the right on the graph which shows the tissues can tolerate more load before reaching structural failure.  Likewise, if we don't train to the same volume, the "zone of tissue homeostasis" then reduces and the green zone moves to the left, meaning that we have less tolerance of load and increased risk of injury, particularly when increasing training after a period of rest and training upto the level you were training previously.

Tips to Avoid Injury

1. Increase load gradually. Make no more than 10 % increases in your training per week. e.g. If you are new to running or training for a race and you initially are running 2-3 times a week. Keep the runs in the week short, steady and the same length and make the weekend run the long run which you can gradually increase the distance by 10% week by week. 

2. If  you have had a week off with illness/injury again go easy, return to training gradually, perhaps take a step back from where you left off. We find the most common factor when tracing back injuries often occurs when returning to training after a period of rest. 

3. Incorporate a rest day in your weekly training plan. This can be cross training or core stability work.

4. Listen to your body. If you are feeling tired or complain of any niggles ease off and go steady or stop and rest for a day or 2.  Rest is important to allow that overloaded tissue to repair and get stronger.

5. Change only one variable of your training in one week. Again with running, it is best to change and increase the distance first over a few weeks. Once you are happy with the distance, you can then increase frequency of sessions in a week and then you can improve the intensity and introduce speed work/hills into your session.

6. When changing footwear, bike or rackets for your desired sport, this minor change may alter your body dynamics a little, and therefore requires time to adjust to avoid injury.

*If your niggle persists after a few days/week rest then seek medical advice



About Laura Dutton

Laura Dutton Physiotherapist

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  • nick hepburn
  • 6 Nov 2020
  • 8:06 pm

i am 17 and have shin splint

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