Role of Clinical Evaluation for the Diagnosis of Acute and Chronic Muscle Injuries

Fig. 5.1

Acute injury to the medial gastrocnemius: increased calf volume and characteristic forefoot gait

Fig. 5.2

Acute injury of the hip adductors: early development of a large hematoma

Palpation to search for a more or less localized tenseness and/or crepitus (Fig. 5.3). In some cases, exquisite pain is discovered within the contracted mass, in others a depressed area may be palpated in the muscle. In many cases the muscle is abnormally taut.

Fig. 5.3

Acute injury of the medial gastrocnemius: palpation disclosed a painful defect at the base of the muscle

Passive stretching is a routine practice: the adductor muscles are studied with the patient in the supine position, the hip in abduction; the hamstring muscles are evaluated by raising the leg in the supine position or by anterior flexion of the trunk in the upright position; the quadriceps is examined by flexing the knee while the patient is in the prone position; the triceps is explored by passive dorsiflexion of the foot with the knee first extended then flexed in order to dissociate the gastrocnemius from the soleus (Fig. 5.4)

Fig. 5.4

Gastrocnemius injury: passive knee flexion is limited and painful on the extended knee (a) and returns to normal on the flexed knee (b)

Contraction against resistance provides information on important elements depending on the result (possible, reduced resistance, impossible); the development, or not, of a depression or on the contrary a globular mass may be difficult to interpret: healthy muscles may be replacing the function of an injured muscle; soft tissue edema can mask a muscle deformity that will only be seen later after the swelling has subsided.

5.2.2 Clinical Presentations [4–6]

5.2.2.1 Muscle Contusion

The clinical presentation is variable, depending upon the severity of the trauma.

Benign contusion The initial traumatic event may have gone unnoticed, the athlete being able to continue sports activities. Painful discomfort may develop later leading to a retrospective recognition of the symptoms. Similarly, repeated microtrauma can lead to an insidious presentation with late-onset diffuse pain, in an imprecise localization, affecting the entire muscle.

The functional impotency can be marked, maximal before warm-up, rescinding with exercise and reappearing with forced movements or fatigue.

The physical examination reveals a slightly tense muscle compartment with edema and a taut muscle. Passive mobilization of the joints above and below the injury does not trigger pain. Inversely, mobilization against resistance is painful, providing objective pain-equivalent evidence of decreased resistance compared with the healthy side.

Severe contusion A sudden shock (kick, blunt trauma) may produce a severe contusion. The injured muscle is usually contracted when the traumatic event occurs. The characteristic feature is the formation of a hematoma due to rupture of the capillaries or small vessels. Laceration of a certain volume of muscle fibers may be associated. The hematoma may spread over the peripheral aspect of the muscle, form under the aponeurosis, or remain localized within the muscle mass (Fig. 5.5).

Fig. 5.5

Diffusion of the hematoma 72 h after injury

The patient reports a precise highly painful event followed by immediate and often total functional impotency.

At inspection the muscle is abnormally stiff and increased in volume. Palpation reveals exquisite pain, swelling, and painful stiffness of the injured area. In certain cases, any attempt for active contraction reveals complete impotency.

The clinical course varies with the severity of the injury. For a benign contusion, athletes generally return to sports activities rapidly. If the contusion is severe, recovery depends on the resorption of the hematoma which is generally uneventful once the hematoma has spread into the subcutaneous tissues or formed a distal ecchymosis (Fig. 5.6).

Fig. 5.6

Large ecchymosis on the posterior aspect of the thigh after proximal hamstring injury (a). Ecchymosis that developed three days after a pulled hamstrings (b)

Occasionally, fibrous scar tissue or an encysted or calcified hematoma may be a source of pain.

5.2.2.2 Overstretching

Theoretically, overstretching corresponds to stretching beyond the physiological limits of the muscle’s elastic capacity without causing anatomic damage. In practice, overstretching generally involves some damage to a few muscle fibers that rupture or tear out of the aponeurosis. These tears are much localized and are followed by the formation of a small serohematic cavity.

Pain onset is generally sudden but can be progressive in certain cases. Functional impairment is minimal or absent.

Sports activities can be continued but at the cost of painful discomfort and reduced performance.

The physical examination provides little information. There is no increase in muscle volume and no painful points at palpation, but the muscle is “tender” over the entire length. Contracture is moderate. Passive stretching may reproduce the pain, contrasting with the discomfort triggered by active contraction against resistance.

The clinical course is rapidly favorable with full recovery in a few days.

5.2.2.3 Muscle Tears

A muscle tear corresponds to the rupture of a more or less significant portion of muscle fibers.

Pain onset is sudden and intense. Patients report it was like being stabbed. All activity is stopped immediately.

The physical examination finds a swollen portion of the limb. There may be a subcutaneous ecchymosis that in some cases only develops a few days later. At palpation, a point of pain is found in the zone of contracture. In certain specific situations, particularly in the event of injury to a superficial muscle, a defect can be palpated in the muscle mass. Total impotency is the rule, but if contraction remains possible, the pain is very intense during isometric testing.

5.2.2.4 Muscle Ruptures

Muscle ruptures can be partial or total.

The incident is a sudden event causing intense pain during a muscle movement. There may be a crack or a pop. Functional impotency is total and generally immediate but sometimes delayed.

At the physical examination, there is a major tumefaction of a muscle segment (Fig. 5.7). An ecchymosis develops early and can be voluminous. It appears at the site of the muscle injury. Palpation may find a more or less voluminous hematoma that is sometimes fluctuant. In certain cases, there is a painful defect. Active contraction is rarely possible. When present, and if the swelling is not to important, a contracting tumefaction can be palpated underlying the rupture.