Sports injuries and the factors that increase the risk of sports injury can be very complication. However, one thing that has been consistently identified in scientific study is that training errors directly increase the risk of injury. 

While this post will mostly focus on running injuries, the training principles it discusses are relevant to any athlete, coach or clinician such as a physical therapist who works with athletes.

Sports injuries can be divided into two main types:  traumatic injuries and so-called overuse injuries.  Traumatic injuries are the result of tissue failure after a single application of force, such as a sprain, strain or fracture; while overuse injuries are the result of repetitive force placed on tissues over time without allowing for recovery 

Unfortunately, it is a commonly believed (especially by physical therapists and trainers) that abnormal posture may lead to running injuries, particularly “overuse injuries”. Although this may seem like common sense, body anatomy varies greatly between people and there is actually no evidence that abnormal posture leads to overuse injuries, even among elite athletes. In addition, other factors such as the use of orthotics in the shoes, decreased range of motion, warm-up exercises, muscular imbalances, skill level and running frequency have not been found to have a direct correlation with injuries. 

In the running world, about 70% of all injuries have been shown to be associated with training error.  The training error most closely tied to overuse injuries is underestimating the principle of recovery and adaptation. If in fact all overuse injuries were correctly classified as such, then all runners (and all athletes more generally) would be injured at the same point in training. Therefore, the assessment and treatment of athletes for “overuse injuries” must be re-examined. It is necessary to understand both the training program and the mechanical factors that led to the injury, as well as the biomechanics that contributed. This way sports performance professionals can help athletes rehabilitate well and return to sports safely. 

Physiologically, a stimulus applied to tissues (such as a muscle, tendon, etc.) will initiate a response at the cellular level, resulting over time (with sufficient recovery) in an adaptation.The adaptation will lead to an increase in tissue strength and response. Here is a simple example: if a basketball player jumps 20 times on Monday, applying mechanical loading  to the calf muscles, in an effort to return from an ankle sprain, and then rests for two days (adaptation and recovery), by Thursday the basketball player will be able to jump more than 20 times, as his/her calf musculature will have adapted to the stimulus received on Monday. 

As these types of under-recovery injuries are caused by stimulus during training, training is also their solution. But it must be training that takes into account balance between stimulus and adaptation (and recovery). This balance must be determined wisely (depending on the sport) to promote healing and increase the demands of the sport. Ignoring this balance will result in injury, as the stimulus will exceed the rate of adaptation. 

In summary, the tissues in the human body are able to respond to stresses placed on them in sports by recovering and adapting amazingly well.