4. Muscle and tendon injuries

In addition to the joints, the muscles are most often damaged. These injuries are usually of traumatic character, that is, they are generated by sudden impact, but naturally can also result from serial overuse. It is not our aim to deal with the clinical classification of muscle injuries – for more details, see, for example, publications by Chan and coauthors or Järvinen and coauthors (Chan et al. 2012, Järvinen et al. 2014). In the vast majority of cases, bruising or muscle strain occurs, and they are very frequent, especially in sports that require movements involving rapid limb contractions (Bartlett 2005), which is of course characteristic of the great majority of sports.

More rarely, sudden jerks or excessive effort can cause the muscle to rip partially or completely. Bleeding occurs at the site of the rupture, followed by an inflammatory reaction in the first day or two. However, this painful condition holds out the promise of faster healing than with joint injuries. The basic first steps in treatments include

• immobilisation for a maximum of a few days,

• ice-packing and cooling,

• elevation of the damaged part, then

• applying gradually increasing load,

which help to avoid further tearing and re-tearing, alleviating the degree of tissue death, diminishing the size of the hematoma produced, lessening inflammation, and reducing the amount of interstitial fluid (e.g. Järvinen et al. 2014; see also: Deal et al., 2002, Hurme et al., 1993, Schaser et al., 2007). These conservative treatments are generally sufficient to cure muscle damage. In addition, injury- and sport-specific treatments may be used if necessary. Although not mentioned in the literature among conservative treatments, a method also used to efficiently treat bruises and strains is poultices combined with medical creams that cause hyperaemia or other effects. It should be noted that conservative treatments also include a compression bandage applied to the injury, but its effectiveness is questionable (Thorsson et al. 1997).

Concerning the time needed for ruptured muscle injuries to heal, it can generally be said that a new functional tissue is already found at the site of injury around the seventh day, and about 90% of normal contractile force is already recovered (Bartlett 2005). However, the passive muscle strength is still only restored to as little as 77%, which, until the scar tissue is present, exposes the motor unit to an increased risk of re-injury (Bartlett 2005).

A transient and easily-managed, but unpleasantly painful condition is muscle spasm. We will discuss delayed onset muscular soreness (DOMS), which is common in sports, in the physiological section.

In the case of tendon injuries, it is possible for them to break off the bone (for example, in the case of a biceps tendon injury) or even to rupture (this, for example, is more common in the Achilles tendon); and, similarly to the injuries occurring in other structures, these can be caused by both long-term overuse or acute trauma.