Injuries effecting endurance sports are generally the result of the repeated ‘submaximal’ loading. This is loading which isn’t large enough to tear a muscle or break a bone but leads to a gradual breakdown of tissue. These injuries generally progress from a mild onset, which is often ignored, to having a progressively greater impact on continued activity and pain at rest.
The factors that influence the development of over-use injuries can be classified in three categories:
- Biomechanical issues
- Technical issues
- Training Errors
Biomechanics is concerned with how the body moves and what effects the movement of force through the body. An assessment of an individual’s biomechanics will reveal what is tight, what is weak, what is poorly controlled and what structural problems exist.
Typically biomechanics are not considered until something goes wrong but should always be looked at along with technical problems to get an understanding of what forces are being put on the body and how the body is able to deal with them.
The human body is very good at compensating and will find a way of managing as best it can to get a job done. It is when these coping mechanisms fail that excessive overload and injury develops.
When considering the forces applied to the body the important thing is the balance between mobility and control.
The more mobility you have, the more movement you need to control.
Stiffness is also important to consider as the body, like everything, moves in the path of least resistance. If a structure is stiff it is able to resist a large amount of force before breaking but the force will move to the next easiest point. It is controlling the movement, which is key to preventing injury.
Technique has a large influence on the size and direction of forces applied to the body.
Problems with technique reduce movement efficiency, increasing the effort you need to put in for the same result. This increases the amount of force that the body has to deal with leading to earlier fatigue and further loss of form.
Immediately, with loss of efficiency, we can see an effect on performance, such as a runner losing form in a sprint finish, effort increases, speed decreases and they get caught on the line. Over time, persistent inefficient movement increases the risk or frequency of injury.
Common technique problems that reduce efficiency in running include:
- Over striding
Training error most commonly relates to an aggressive increase in quantity and/or intensity:
Too much – Too hard – Too soon
Over loading the body is necessary to stimulate change but progression of training loads and intensity needs to be carefully controlled and increased over months and years as the body develops. As muscle strength increases the tendons, attachments to the bone and the underlying bone strengthen to be able to transfer force. If they are loaded too frequently, with too much intensity or for too long they can become fatigued, their ability to control and transfer load reduces and they can degenerate or inflame and become painful.
It is worth noting that changing loads can involve changing the way force is applied, such as:
- Changes in running surface e.g. cambers of roads and footpaths or changing from road to trail etc involves changing angles of loading, hardness or stability of the running surface.
- Ageing footwear usually involves the compression of part of the sole, which leads to a change in the angle that the foot strikes the ground and changes the rate and amount of pronation through the foot and ankle.
- Changing technique can lead to the loading of weak tissue and adequate time is required to allow the development of appropriate strength.
To reduce the risk of injury we need to look at how much load is put on the body, how the body is able to manage this load and then to control how the training loads are progressed.
Having assessed an individual’s biomechanics it is possible to address structural problems and develop an individual conditioning program for mobility, strength and endurance.
Assessment of the running action will highlight problems with movements which increase load and reduce efficiency. Correction of these problems reduces the stress that can lead to injury but also increases speed.
A review of training, progression and injury history will give an idea of the tolerance to training and will help to predict a safe rate of progression of the conditioning program. This will all be used by a skilled coach to design a program, which is challenging enough to force improvement while minimizing the risk of injury.