A muscle injury is the most common type of injury for an athlete or anyone involved in sports.
A muscle strain is the rupture of muscle fibres, caused by excessive contraction, tension or direct blow on the muscle. It presents with pain, stiffening, and inability to move the muscle. Sports and other activities must be stopped, to avoid further damage to the muscle.
The causes of muscle strains are:

1. Inadequate warm-up or stretching leading to diminished muscle elasticity
2. Overtraining
3. Inadequate or inappropriate equipment when it is needed (shoes, sport kits etc)
4. Enviromental factors (too warm, too cold)
5. Inappropriate nutrition (food, liquids,, electrolytes)
6. Bad technique
7. Muscle imbalances
8. Muscle inefficiency. Muscles are trained to have endurance and are moulded to have elasticity. When they get tired or when they lack elasticity, they are vulnerable to injuries.

Muscle injuries happen in 10-30% of all sports injuries. However, they are often missed or underestimated, because the athlete continues his activity, despite the pain.
Muscle injuries are classified in three categories, based on the severity.
First degree: is a simple strain of the muscle fibres, that causes pain and functional limitations during activities
Second degree: a partial tear of muscle fibres accompanied by muscle spasm, hematoma and local oedema in the injured area. Later, scar tissue is formed in the muscle, leading to diminished muscle elasticity
Third degree: is a complete tear of the muscle, with excessive hematoma, and loss of function
The most common muscle injuries occur in the lower limb, and especially in the biceps femoral muscle, hamstrings, quadriceps and gastrocnemius muscle.
In the upper limb, muscle injuries occur in the biceps brachialis muscle, the deltoid muscle, the supraspinatus muscle and the triceps brachialis muscle.
Groin pain, also called athletic pubalgia, is often caused by muscle injuries of the abdominal or the hip adductor muscles. This is usually a chronic condition, requiring a long rehabilitation program, and surgical intervention in some cases.
Treatment
Following a first or second-degree muscle injury the limb should be immobilized in an elevated position, it should be wrapped and ice should be applied for 20-25 minutes. Cold should be applied many times during the first 48 hours to diminish pain, hematoma and oedema.
In the acute phase of the injury the use of PRP (platelet-rich plasma) or EPI (intra-tissue electrolysis) can help decrease the pain, improve the range of motion of adjacent joints, enhance the quality of the scar tissue by production of collagen instead of fibrous tissue, and decrease time needed to return to sports or activities of daily life (details in each separate chapter).
A physiotherapist can also help diminish pain and oedema with th use of TENS currents, cross-sectional currents and ice-therapy during the first days. The following days, the role of the physiotherapist is to increase the blood circulation in the injured site (with the use of ultrasound, LASER, warm patches, diathermy), which will enhance healing.
Isometric exercises are initiated, gradually increasing in frequency and intensity. Initially, the scar tissue that is formed is more stiff compared to normal muscle tissue, and this causes pain in every muscle contraction. Stretching exercises are also required.
In the next phase of rehabilitation, isotonic exercises are included to promote strengthening.
This is followed by exercises focusing on proprioception and neuromuscular training, aiming to retrain the muscle so that it is ready and safe to return to sports.
In a third-degree muscle injury, which is a complete muscle tear, surgical repair of the muscle fibres and immobilization of the muscle is needed. This is followed by gradual mobilization and strengthening, so that full recovery and return to sports can be achieved.
In case of wrong treatment or multiple recurrences the main complication is heterotopic ossification, which is the formation of calcified and ossified intramuscular hematomas. This limits muscle contraction and joint range of motion, and is usually coped with surgical removal of the damaged muscle tissue.
Groin pain is a special condition, that can lead to chronic problems. Detailed clinical examination can reveal whether it is an adductor-, inguinal-, iliopsoas-, or pubic-related condition and guide treatment. Our team collaborates with a general surgeon to treat this cases with minimal invasive methods (tenotomies, extra-peritoneal application of meshes etc).