A quadriceps muscle strain is a critical tearing injury of the quadriceps. This injury occurs most often due to an acute stretching of the muscle, which can also be caused by a forceful contraction or repetitive function overloading. Repeated eccentric muscle contractions from the knee extensor mechanism can overload the quadriceps, which consists of four components. Acute strain injuries of the quadriceps are common in sports like rugby, soccer, or football. These sports daily require the sudden forceful eccentric contraction of the quadriceps during hip extension and knee flexion regulation. Higher forces across the muscle-tendon units with eccentric contraction can cause strain injury. Strains can also be caused by excessive passive stretching and activation of maximally stretched muscles. The rectus femoris most often strain the quadriceps muscles. Many factors predispose to a more frequent stress injury to this muscle and others. These contain muscles crossing the two joints, which include muscles with complex musculotendinous architecture and a high percentage of type II fibers. In acute muscle injury, muscle fatigue has also been shown to play a role.
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Anatomy
Quadriceps Femoris is both a hip flexor as well as a knee extensor. It is located in the anterior part of the thigh. It is made up of four sub-components:
- Vastus lateralis
- Vastus intermedius
- Rectus femoris
- Vastus medialis
The Rectus femoris is the only part of the muscle participating in both knee extension & hip flexion. The other three parts are only involved in knee extension. The quadriceps are the rectus femoris's most superficial part, where the quadriceps cross the knee and hip joints. This makes it more susceptible to stretch-induced strain injuries. Most strains occur at the muscle-tendon junction above the knee (both distal proximal, but more often at the muscle-tendon distal) and in the muscle itself.
Quadriceps Strain Grade
Strains can be categorized 1 through 3 depending on the severity of the injury. Grade 1 is mild, while grade 3 refers to a severe injury that causes a complete or nearly complete tear of the muscle.
Grade 1
A grade 1 quadriceps strain is not always severe enough to cause you to stop training. You may feel a twinge in your thighs or a tight feeling. Mild discomfort may be felt when the athlete is walking or running may be difficult. You may feel a lump or spasm around the injury site.
Grade 2
An athlete might feel sudden, sharp pain while running, kicking, and jumping or may be unable to play. The pain will make it hard to walk, and there may be swelling or mild bruising. When you press on the suspected location of the quad muscle tear, you will feel the pain. It is possible to cause pain by straightening your knee against resistance, and the injured athlete will be unable to bend the knee fully.
Grade 3
The symptoms include severe, sudden pain in one's front thigh. Crutches will not be possible as the patient may become unable to walk. Illness and swelling can be seen immediately, with significant bleeding within 24 hours. Static muscle contractions can be painful and may cause a bulge in the muscle. The patient can hope to be out of competition for 6 to 12 weeks.
Diagnosis
The therapist can easily find the most acute injuries in the quadriceps muscles simply by letting the patient tell how the injury occurred and doing a quick examination of the quadriceps muscles afterward. If the therapist isn't sure, he may use medical imaging to provide a definitive answer. Medical imaging can tell us, for example, the exact type and position of the muscle strain.
After taking a detailed history, should conduct a careful examination, including observation, palpation, and strength testing. Finally, an evaluation of motion should be done.
Observation: Quadriceps strain injuries may present with an obvious deformity like a bulge or defect in the abdominal muscles.
Ecchymosis can not develop until 24 hours after injury.
Anterior thigh palpation should include:
- Finding the length of the injured muscle.
- Finding the area of maximum tenderness.
- Feeling for any defects in the muscle.
Acute compartment syndrome should be considered if the facial envelope's tension surrounding the compartment and pain is out of ratio to the clinical condition.
Strength Testing: strength testing of the quadriceps must include knee extension and hip flexion resistance. Adequate strength testing of the rectus femoris must be able to resist knee extension while keeping the hip extended and flexed. This is best accomplished by evaluating the patient in a sitting and lying position in practice. The prone position also allows for optimal evaluation of quadriceps flexibility & motion. Patients with pain are usually able to feel it by passive stretching, resisted muscle activation, and direct palpation of the muscle strain.
Assessment of tenderness: Any palpable defect or strength that is present at the onset of muscle injury will help determine the severity of the injury. This will also provide direction for further testing and treatment.
Examination
Ely's Test : The Ely's test (or Duncan-ely test) is used to determine rectus Femoris spasticity and tightness.
There are also other methods of evaluating the results:
H vs. Q (Hamstrings/Quadriceps) ratio - A calculation in which the strength (peak torque) of the hamstring muscles in eccentric movement is divided by the power of the quadriceps in a concentric movement:
Dysbalances/Asymmetriesin the functional H/Q ratio significantly impacted injury incidence.
- Bruises
- Skin temperature
- ROM (Range of motion) decrease
- Sore end-feel
- Muscle strength loss
- Pain
Physical Therapy
The RICE method is used to provide the rest of the therapy. This includes:
- Rest
- Ice treatment
- Compression
- Elevation