Figure 12.2 shows how the pain signal travels from the peripheral nociceptors, through Aδ- and C-fiber axons to the nerve roots, then to the spinal cord, from there to the brainstem, to the thalamus, and finally to the cortex, which leads to an awareness of pain.

Pain may be classified in the following categories (Woolf 2004):

Pain is also divided into acute or chronic pain. Pain with a duration of more than three months is medically classified as chronic.

In sports injuries, one of the purposes of the inflammatory pain experience is to promote healing of the injured tissues. The pain reduces movement of and contact with the injured body part to assist the body’s healing efforts. There is generally an organic connection between an injury and the pain sensation. Most soft tissue injuries probably heal within 3–4 months. There are many theories about exactly why pain may be experienced long after the actual injury has healed. One theory is that pain receptors may acquire increased sensitivity during an injury due to chemical metabolites; another is that the brain misinterprets signals from “low-threshold” mechanoreceptors, creating pain sensations instead of positional information.

Microscopically, as tissues are injured, the inflammatory process commences with the release of chemicals from damaged cells. Mast cells release histamine, which promotes vasodilatation of small blood vessels. White blood cells and other phagocytes also participate in the “inflammatory battle.” The injured blood vessels, in conjunction with vasodilatation and increased capillary permeability, create an increased swelling in the area (Nisell et al. 1999).

Macroscopically, inflammation has five common signs:

To reduce pain and inflammation, doctors or other healthcare providers sometimes recommend the patient takes nonsteroid antiinflammatory drugs (NSAIDs), such as aspirin, ibuprofen, ketoprofen, or naproxen sodium. For more severe pain, doctors may prescribe NSAIDs in prescription strengths. It should be noted, however, that the cause of pain and inflammation is never a deficiency of NSAIDs; instead the therapist must seek and treat the real cause of the ailment.

The body’s different tissue types react forcefully to the inflammatory processes; however, tendons seem not to react with inflammation during tissue damage except in the acute stage. Instead, injuries to tendons seem to tend to develop into chronic, sometimes degenerative, conditions, i.e. tendinosis and tendinopathies.

During rehabilitation of ligament and joint injuries, it is important to use different kinds of balance board to place stress on the proprioceptive system (Fig. 12.3). The body’s neuromuscular functions are also affected by tissue damage. A balance board, spring board, rope jumping, etc., help to assist the athlete’s proprioceptive system.

Acute fractures are emergencies and should be examined and treated in hospital. Fractures can be simple (closed) or compound (open) (Figs 12.5; 12.6), and are commonly accompanied by soft tissue injuries. Contact sports have a higher incidence of bone fractures, and commonly affected areas are the fingers, clavicle, radius, and tibia.

The symptoms are pain, swelling, discoloration, and possibly misalignment. After a proper examination and diagnosis, the bone is either reduced or not, depending on the possible misalignment; more complex fractures may require surgical intervention. A cast or splint is often used for 3–12 weeks, depending on the location in the body, to immobilize the affected body part.

Avulsion—a complete tear of a ligament or tendon attachment—is more common among children and adolescents.

Fractures stemming from overload injuries, i.e. stress fractures, are described further in the section “Overuse injuries” below.

Dislocations are another emergency to be examined, diagnosed, and treated at hospital. They are often caused by external violence, for example a shoulder dislocation created by a fall with extended arms, and sometimes cause fractures in addition. Dislocations may also be caused by internal violence, for example when an arm is hooked and the athlete forces through the movement, thus causing damage.

The most frequent dislocations are of the shoulders and finger joints. More stable joints like the hip, elbow, and ankle require greater forces to dislocate them. Dislocations are commonly associated with soft tissue damage to muscles, ligaments, joint capsules, and occasionally nerves.

Muscle injuries can be caused by internal forces, in which case they are called muscle strains. Muscles spanning two or more joints, for example the hamstrings, are more frequently exposed to this type of muscle injury, which is common among track and field athletes in sprinting, jumping, or other events involving explosive muscle contractions. Muscle strains are often located at the musculotendinous junction and are thought to occur in the interplay between high-speed concentric and eccentric muscle contractions.

Muscle strains are classified as:

External forces may cause muscle injuries called muscle contusions, for example when one football player collides with another, and a knee crushes the quadriceps muscle toward the underlying femur, or through falling on a hard object. This type of muscle injury can potentially happen in any sport containing moments of contact, such as football, soccer, basketball, or ice hockey.

The symptoms of acute muscle injuries are commonly a sudden stabbing pain accompanied by difficulty contracting the injured muscle. Other symptoms are swelling, possible muscle cramping, and occasionally a palpable gap in the muscle tissue.

The bleeding caused by the injury can be either intermuscular or intramuscular. Intermuscular bleeding is localized between muscles due to a rupture of the muscle fascia. As the blood is spread over a larger area it causes a more visible hematoma, but it has a faster recovery time. An intramuscular hematoma remains within the muscle since the fascia is intact, and has a longer healing period since it is more difficult for the body to absorb the localized edema encapsulated within the muscle. It may additionally cause complications like severe scarring, impaired ROM and/or calcification or ossification of the scar tissue, i.e. myositis ossificans, which may require surgical intervention.

Muscle cramps may be defined as involuntary, often painful, muscle contractions. Their origin is still somewhat unclear, but Parisi et al. (2003) have divided muscle cramp into three categories, based on etiology:

Muscle cramps relating to physical activity are categorized as paraphysiological cramps. It is suggested that this type arises from a hydroelectrolytic imbalance caused by hard, long-term, and sometimes repetitive activity leading to hyperexcitability of the terminal nerve branches in the area. Research has additionally indicated low magnesium levels (Klarkeson et al. 1995). Dehydration, glycogen depletion, salt deficiency, previous muscle bleeding, small muscle ruptures, or the athlete’s general health are other possible causes.

The athlete should prevent cramping by adequate basic training, including warm-up routine, and ensuring proper nutrition and fluid, electrolyte, and glycogen deposit uptake (Peterson et al. 2001).

The sports massage therapist can perform cramp release using stretching, cryo-, and physiotherapy, for example strong effleurage and deep friction massage (Brukner et al. 2010). Another popular and effective method involves simultaneous relaxation, approximation, and compression of the cramping muscle combined with alternating isometric contractions of antagonistic muscles (Fig. 12.7). The athlete is asked to contract the antagonistic muscle for 4–5s whilst the approximation/compression is maintained and further increased between every isometric muscle contraction.

A sprain is a stretch or a tear of a ligament, and commonly occurs in conjunction with acute violence toward the affected joint. Sprains are classified as:

Since the symptoms of ligament sprains in different joints vary, it makes the classifications more difficult to use clinically. The possibilities for healing vary depending on whether the ligament is extracapsular (for example, the calcaneofibular ligament in the ankle), intracapsular (for example, the cruciate ligaments in the knee joint), or capsular (for example, the anterior talofibular ligament in the ankle) (Figs 12.8; 12.9). Intracapsular ligaments do not heal after a complete tear, while a capsular ligament can have better possibilities of doing so (Bahr et al. 2004).

Ligaments located in the ankle and knee joints are most frequently injured during sports activity. It is estimated that about 20 000 ankle sprains/day occur in the USA. Of these 70% occur in the anterior talofibular ligament. In the knee, there are 200 000 anterior cruciate ligament injuries/year, 100 000 requiring surgical intervention (American Association of Orthopedic Surgeons 2008).

Almost every acute spontaneous rupture of tendons is preceded by pathological changes in the tendon (Peterson et al. 2001). Tendon injuries are classified similarly to ligament injuries. Ruptures commonly present where the tendon’s blood supply is minimized, for example, for the Achilles tendon, almost 1in above the calcaneus. Many tendons that are exposed to injuries (for example, Achilles tendon, supraspinatus tendon, patellar ligament) may show degenerative changes as early as in the third decade (Maffulli et al. 2005).