Muscle strains: causes, symptoms and remedies

15 March 2021

What to do in the case of a muscle strain? How does it impact doing sports? What’s the treatment and how long does it take to recover? Let’s find out together.

Muscle strains, or muscle distractions, are muscular injuries that lead to breakage of the fibres that make up a muscle, ranging from slight to serious. The areas most subject to straining vary: in fact we talk of a strained back muscle, a strained calf muscle, but it can also happen in the shoulder, chest, thigh or groin.

What is a muscle strain?

Muscle injuries represent a frequent and at times misunderstood problem, which, if neglected, can lead to serious functional issues: in fact it is often underestimated by the same patient who carries on regardless, without seeking proper examinations.
In a sports context, acute muscle injuries, including muscle strains, are frequently found in all disciplines and the occurrence is calculated at 10% to 30% of all sports traumas.

Sport and muscle strains: frequency and risk factors

The increasing care for our bodies and the rise in the number of participants in all types of sport have led to a significant increase in muscle strains. In most cases, bi-articular or poly-articular muscles are involved, which contain large quantities of white fibres, such as the thigh muscles (e.g. quadriceps and femoral biceps).

– The sports that require lactic acid anaerobic exercise (exercising for 0.5 to 4 minutes), such as sprinters in athletics, can suffer from muscle injuries more easily, as the accumulation of lactic acid can make changes to neuromotor coordination.

– In contact sports, injuries can be caused directly on impact; these are frequent in the muscles particularly exposed to trauma: quadriceps and the tensor fasciae latae of the thigh, calf, and the deltoid in the upper limbs (e.g. rugby, American football, hockey, boxing, football).

– In solo or non-contact sports, the main injuries found are those caused indirectly by sudden stretches beyond the physiological limit of the muscle itself. These often occur in those with less muscle flexibility, who take up physical exercise without training or who don’t complete the necessary warm-up phases, and in sprinters due to rapid changes in direction.

Here are the 6 main risk factors:

1. Poor muscle flexibility
2. Being unused to performing a specific gesture
3. Excessive muscle fatigue
4. Weakening of muscles from a previous injury not completely rehabilitated
5. Scarring from a previous injury
6. Increased muscle tension created both by physiological factors and also psychological factors due to competition

Classification and symptoms of muscle injuries

Muscle injuries can be classified in groups according to the causes of trauma, damage and symptoms reported by the patient. Here we look at the classification according to the aetiology (cause), clinical phase and the clinical and radiological semeiotics.

Classification according to causes and severity (aetiology)

Muscle injuries can be distinguished according to what causes them. Indirect injuries, which can be defined as muscle distractions, occur when the muscle is stretched during a contraction (eccentric phase) creating tension beyond the level that it can withstand, or when the contraction lengthens the antagonist (opposing) muscle beyond its limit, causing damage. In this case, in ascending order of severity, we talk of contracture, strain, grade I strain, grade II strain, and grade III strain.

Direct injuries (or contusions) are caused by direct trauma (impact with adversaries or against objects) The more the muscle is relaxed during the trauma, and the more the force of impact, the worse the damage is. In this case they are divided into 3 grades: mild, moderate, and severe.

Classification according to injury caused (clinical)

Muscular injuries are classified according to the clinical phase: acute injury (significant inflammation and symptoms), chronic injury (where the injury zone and symptomatic zone may differ due to an alteration of normal biomechanics), acute exacerbation of chronic injury (repetition of an inflammatory phase of a previous injury) and sub-clinical functional alteration (when a subject, though without symptoms, loses strength, speed and coordination in a sports movement).

Classification according to symptoms and recovery time

This is based on symptoms and pathological anatomy. These are classified, in order of severity, as

– stage 0: pain occurring after training, also known as DOMS, with rapid recovery
– stage 1: muscle pain and contracture, recovery in a few days
– stage 2: increased muscle damage with haematoma, healing in 8-10 days
– stage 3: advanced damage, recovery in 3-12 weeks
– stage 4: complete breakage or detachment of muscle, recovery evaluated on a case by case basis.

What to do in the case of a muscle strain: diagnosis and treatment

The specialist doctor makes use of a number of instrumental examinations and clinical tests for the diagnosis of muscle strain:

Ultrasound
– CAT scan or MRI
– Examination of muscular trophism
Manual examination of strength
– Description of how the injury happened

What to do immediately? Immediately after a muscle strain or injury, a protocol of protection and offload should be followed, above all in the case of major injuries, consisting in:

– Offload: in the phases immediately after the trauma, the injured area of the body can be protected by using crutches to offload the weight of the patient.
– Compression: bandages to compress and offload the muscle. This also serves to mitigate pain and reflex contracture, which can make tissue laceration worse.
– Rest: this guarantees that the injury does not worsen both in terms of inflammation and size.
– Criotherapy: ice plays an essential role in limiting inflammation. It should be applied as soon as possible and be continued for the first 3-4 days for 20 minutes per application, with at least 6-7 applications daily.
– Elevation: placing the limb in an elevated position helps re-absorption of liquids and degeneration products.

Physical therapies can also be a great help to combat inflammation and to speed up recovery, commonly found, for example, in TECAR and LASER therapies.

Recovery exercises

Once the first acute phase is resolved and when time permits, the patient then moves onto therapeutic exercise in order to re-educate the damaged muscle.
This starts with isometric contractions, followed by isotonic contractions, and lastly eccentric contractions. Stretching exercises, also used to retrieve flexibility and for proprioceptive re-education (such as exercises on boards or mats with surfaces of variable consistency) are essential in this second phase.
In the last phase, returning to sport, a specific training programme is devised, with plyometric exercises, i.e. dynamic high speed exercises, and sport-specific exercises. This part is usually managed by a Graduate in Sports Sciences, who works in close contact with the Physiotherapist who followed the previous phases, and with the registered doctor.

How can I prevent muscle strains and injuries?

The prevention of muscle strains lies above all in a careful evaluation of the musculo-skeletal conditions of the patient or athlete, highlighting any incorrect approaches, high localised muscle tension, alterations in the relationship between agonist and antagonist muscles, poor physical training and/or muscle flexibility.
The training activity must therefore avoid excessive functional overload, which may lead to metabolic alterations of the muscle.
An extremely important factors is the education in warm-up exercises, which prepare the athlete mentally and physically for performance. The physiological effect is to increase peripheral vascularisation, starting metabolic processes at the basis of specific muscle contractions.
The metabolic activity of the muscle may also be negatively influenced by an incorrect diet or electrolytic alterations (calcium and magnesium), and therefore these parameters should also be kept under control.
Lastly, the training materials or terrains may also contribute to the risk of muscle injuries, and therefore the choice of footwear is also important, as well as the correct evaluation of plantar support.

Conclusions

Given the complexity and variability of the types of muscle strains in particular, and muscle injuries more generally, it is essential to immediately identify and location and severity of the injury, to enable prompt and precise intervention, avoiding undesired developments.
Hence a prompt medical and instrumental diagnosis, combined with rapid start of a rehabilitation programme can speed up the healing time and improve final results.

Source: “Trattato di medicina fisica e riabilitazione” [“An essay on physical medicine and rehabilitation”] by Valobra, Gatto, Monticone, edited by Utet Scienze Mediche, 2008