“Injuries” from overuse in sport:events that occur overtime

Movements and strains cause repeated stress and microtraumas that challenge different parts of the body

Athletes of individual and team disciplines are subject to lesions caused by degenerative processes on tissues, joints and bones. These types of injuries should be distinguished from the acute ones.

There are mainly two types of injuries: the acute ones and those that come from overuse. Acute injuries are usually the result of a single traumatic event and, in the insurance sector, they are defined as accidental, violent and external events. On the other side, overuse injuries usually occur over a longer timeframe, as they are the result of a series of continuous microtraumas. These types of lesions fall under the definitions of pre-existence and deterioration.

Overuse lesions are very common among sports injuries as they are related to the repetitiveness of the athletic gesture carried out on a muscle-tendon or cartilage-bone apparatus. Therefore, these events affect different anatomical districts: tendons, muscles, cartilages, bags (sacs that contain synovial fluid) and bones. The process that brings to an overload injury can be defined as a balance between the quantity and intensity of the detrimental stimulus and the tissue ability to resist and regenerate. When this equilibrium is unbalanced towards “stress” an overload injury occurs.

Sports subject to overuse injuries

There are several disciplines in which an overload injury may arise; of course, the districts and anatomical tissues which are most stressed, with the execution of specific sports gestures, are affected. For example, in swimming it is the shoulder that may suffer from an injury known as the “swimmer’s shoulder”, a Musculo-skeletal condition affecting the rotator cuff. In tennis it is the elbow which suffers more frequently, with epicondylitis, better known as “tennis elbow”.

The knee and foot, as well, are usually exposed to this type of injuries. Running is one of the activities in which overuse injuries are on the agenda. Running in particular conditions exposes to cumulative micro-traumas which can affect the integrity of the tissues. The knee is the runner’s week point. Patella-femoral syndrome, characterized by an annoying pain in the anterior region of the knee, is one of the most common injuries caused by overuse.

Proceeding towards the foot, we may find the mid-tibial stress syndrome – the inflammation of the muscles, tendons and bones around the tibia – and the “feared” plantar fasciitis – the inflammation of the fascia, the fibrocartilaginous tissue which “flows” under the foot. As seen, even the bones may suffer from consequences of repeated micro-traumas over time. Eventually, they can lead to actual fractures, known as stress fractures, from lesions of the bone tissue, particularly of the joints of the lower limbs, such as those of the foot.

Specifically, we will analyse team sports injuries, basing on our work experience. In these disciplines, functional overload, in addition to the repetition of the athletic gestures, can be caused by:

• the timing and intensity of the movements
• the playing surfaces
• the training methods
• the playing role
• the footwear worn

In football and basketball, the most affected areas are:

1. plantar fasciitis
2. Achilles’ tendon
3. patellar tendon
4. adductor tendonitis
5. rectus adductor syndrome
6. stress fractures

The incidence rate for this type of injury is around 10% for basketball and 5% for football (out of the total claims considered).

Overuse injuries: case studies

Rupture of the Achilles tendon – it represents the acute episode resulting from a degenerative process (tendinosis), which is sometimes almost completely asymptomatic or preceded and accompanied by episodes of painful inflammation of the sheath. Involving more or less extensively the tendon structure, it determines a decrease in mechanical resistance, which can be overcome by a sudden stress, even if not excessive. It is not a disease but a simple degeneration of the tendon component.

The tendon injury is generally triggered by a “trauma” (movement of steps, change of direction or jump), which is not sufficiently efficient to produce the injury itself, which occurs because the tendon is already degenerated (worn and therefore weaker) and the “movement” is enough to damage it completely. This type of injury would never occur on a healthy person.

Plantar fasciitis and aponeurosis ruptures are diseases that affect the sole of the athlete’s foot, which can appear in sports which involve pushing or jumping. Tendon and aponeurotic lesions, are also defined as functional overload lesions, able to cause the injury with a direct or indirect mechanism. These types of injury can lead to fractures of the plantar aponeurosis. However, this represents the acute episode resulting from a degenerative process (tendinosis) which is sometimes almost completely asymptomatic or preceded and accompanied by episodes of painful inflammation. The tendinosis involves more or less extensively the tendon-aponeurotic structure, and it determines a decrease in mechanical resistance, which can be overcome by a sudden stress, even if not excessive.

Stress fractures, or “duration” fractures, are generally defined as bone lesions caused by repeated microtraumas or by a series of macro-traumas which – determining the prevalence of osteoclastic resorption phenomena in the context of bone remodeling – cause the collapse of the cortex and part of the spongiosa, with radiographic evidence of fracture at a certain point in their evolution. The aetiopathogenetic mechanisms identified are mainly two:

1. repeated bone overloads;
2. prolonged muscular actions on specific bones’ parts (direct muscle traction means the concentration in a small point of the bone surface of excessive traction forces due to repeated muscular traction).

Frequently, athletes who suffer from a stress fracture have recently changed or increased their physical activity. The workload is directly related to the incidence of stress fractures, as muscle fatigue causes an increase in the forces impacting on the bone, caused by a decrease in the buffering effect carried out by the muscular tissue.

To conclude, it is important to remember that overload injuries are caused by micro traumatism repeated over time, to which the tissue has not been able to react in terms of repair and adaptation. Therefore, it can be defined as “degeneration” and not “injury”. For these reasons, these types of lesions are not usually covered by the accident policy.