Acute Sports Injuries - an introduction

Participation in sport and exercise has a number of health and wellness benefits - however it also carries with it a risk of injury. Sporting injuries can affect any type of musculoskeletal connective tissue - categorised as either acute or overuse based on the mechanism of injury and rapidity of symptom onset.

I'll focus on acute injuries in this series of posts and then move onto the overuse injuries later on

An acute injury is one that occurs during a single, identifiable traumatic event. They arise when the force applied to a tissue generates stresses/strains that are greater than the tissue can withstand. The net result is tissue failure which generates macroscopic damage and rapid onset of symptoms like pain and loss of function. The severity of the symptoms depends on the tissue injured and the extent of the damage.

Forces applied to a tissue can be derived from extrinsic (outside the body e.g. direct blow or collision with an external object ) or intrinsic (inside the body e.g. muscle contractile forces or joint and tissue biomechanics) sources. Knowing the cause of an injury has implications with regards to injury prevention. Extrinsically generated forces may be modified by altering equipment, playing surface or sport rules whilst intrinsically generated forces require an individual athlete's characteristics and capabilities to be considered (e.g. muscle strength, motor control, endurance and flexibility, joint range, biomechanics and proprioception).

In all cases of acute injury, an individual's characteristics and capabilities need to be considered in order to facilitate return to participation and prevent re-injury, as an acute injury always results in intrinsic changes. When a force is applied to a tissue, the nature of the force being applied (e.g. direction, magnitude and rate of loading) and the mechanical properties of the tissue in the direction of loading determine whether the tissue fails. This is determined by a combination of innate (non-modifiable) and environmental (modifiable) factors. Modifiable factors alter the safety factor between usual and injurious loads by either increasing or decreasing genetically endowed tissue strength. Modifiable factors include:

- Previous loading history and subsequent tissue adaptation

- The presence and degree of any underlying microscopic tissue damage

- History of previous acute injury to the tissue and extent of mechanical strength recovery

I'll leave this post here for now, keep an eye out for the next one which will focus on the pathophysiology and initial management of acute injuries

REFERENCES

Brukner, P., 2012. Brukner & Khan's clinical sports medicine. North Ryde: McGraw-Hill.