- Muscle calcification (Myositis ossificans): Sometimes, for unknown reasons, calcification occurs in a muscle (or other soft tissue) where there has been a major or minor tear. The diagnosis is often made because rehabilitation is not progressing as expected based on the primary assessment of the extent of the injury. After a few days you can see the calcifications on an ultrasound scan and after a few weeks it can be seen on an X-ray. (See X-ray and See ultrasound scan.) If a muscle haemorrhage is complicated by calcification in the muscle, expect a significantly extended rehabilitation period (Devilbiss Z, et al. 2018).
- Scar tissue formation in the muscle: After muscle tears, scar tissue formation often occurs, which in some cases can cause persistent discomfort. Scar tissue formation in the muscle is often the reason why rehabilitation is slower than expected with relapses long after the injury. There is usually localised soreness in the muscle with worsening with activation and stretching of the muscle. The scar tissue formation can often be seen on ultrasound scans.
- Haematoma musculi (Haematoma musculi): Muscle injuries always cause bleeding in the muscle to a greater or lesser extent. In some cases, the bleeding is diffuse between the muscle cells, while in other cases, the bleeding can pool into a large, well-defined haematoma in the muscle. The larger the pool, the longer it will take for the haemorrhage to subside and the muscle to heal. Haematomas in muscles often cause more pain than expected based on the primary assessment of the extent of the injury. The diagnosis is made by ultrasound scan. If the haemorrhage is large, it can be drained, which can be done under ultrasound guidance. Caution is advised with vigorous massage, which can lead to myositis ossificans (although evidence is limited).
- Fluid build-up in the muscle (Hygroma): After muscle injuries, fluid sometimes builds up in the muscle. The fluid accumulation can be of a significant size. The diagnosis is made by ultrasound scan. If the fluid build-up does not subside with relief, the build-up can be drained under ultrasound guidance. Fluid retention can be the reason why rehabilitation is not progressing as planned.
- Acute compartment syndrome: The muscle groups of the arms and legs are surrounded by tight muscle membranes (fascia) that are partially unyielding. If the bleeding and fluid accumulation in the muscles reaches a point where the pressure in the muscle group increases, this can cause damage to blood vessels and nerves. In acute cases, the blood vessels can close, causing severe damage to the muscles. The symptoms are increasing pain in the injured muscle on the arm or leg. The pain is often more severe than expected based on the primary assessment of the extent of the injury and may be accompanied by sensory disturbances. The diagnosis is primarily made by clinical examination, but in some cases it can be confirmed by muscle joint pressure measurement, which is associated with some uncertainty. Treatment for severe symptoms may include acute splitting of the muscle membrane. Mild cases are treated with offloading and painkillers. In severe symptoms, acute splinting may be necessary to avoid permanent damage to the muscle (Lam D, et al. 2023).
- Chronic musculoskeletal syndrome (Chronic Compartment Syndrome): The muscle groups of the arms and legs are surrounded by tight muscle membranes (fascia) that are partially unyielding. After previous muscle injuries or very rapidly increasing strength training of individual muscle groups, pain is sometimes felt in a muscle group on the leg after a few minutes of activity. You can feel the muscle ‘tightening’ and becoming hard and sore. If the activity is interrupted, the discomfort usually subsides quickly, but returns shortly after resuming the sporting activity. This may be because the muscle swells (after injury) or has grown faster than the muscle walls can expand (too rapid increase in training intensity), increasing pressure on blood vessels and nerves in the muscle group. The diagnosis is made during the clinical examination and can be confirmed by measuring the pressure in the musculature. The test is associated with some uncertainty (van der Kraats AM, et al. 2023). Treatment includes offloading and, after symptoms subside, slowly increasing exercise intensity within the pain threshold. If no progress is made, surgical splitting of the muscle spurs can be attempted, which is usually a minor procedure with good results if the diagnosis is correct (Williams S, et al. 2023).
