What Is Meant by Vastus Lateralis Muscle?
The vastus lateralis muscle is the most significant muscle among all the quadriceps muscles. This muscle is present in the lateral or outer side of the thigh. The vastus lateralis muscle helps extend the knee joint and other quadriceps muscles. This muscle plays a significant role in maintaining thigh and knee cap position during walking and running.
What Is the Anatomy of the Vastus Lateralis Muscle?
This muscle is usually present in the thigh bone and originates from the upper intertrochanteric region. From the region of the origin, the vastus lateralis moves down the lateral thigh and inserts into the elevated region of the upper shin. This muscle is a large and flat structure, along with many attachments.
What Is the Function and Role of the Vastus Lateralis Muscle?
The primary function of the vastus lateralis muscle is to extend or straighten the knee along with other quadriceps muscles. These quadricep muscles extend the knee while walking, running, climbing stairs, getting up from a seated position, etc. The vastus lateralis muscle, which is present in the later region of the thigh, and the vastus medialis muscle, which is present in the inner region of the thigh, work together to maintain the proper position of the kneecap which is present in the femoral groove of the thigh bone. When vastus lateralis fails to function correctly, it leads to knee pain.
How Is the Quad Strain Classified?
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Grade 1: This strain is mild, and only a few muscle fibers are affected. There is no loss of strength, and the range of motion is not restricted. There may be mild pain or tenderness.
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Grade 2: Moderate pain where half of the fibers in the muscle are torn. There will be pain, swelling, and a decrease in muscle strength.
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Grade 3: This condition causes severe strain where the whole muscle is ruptured. In this condition, either the tendon is separated from the muscle or the muscle is torn into two different parts. This strain causes severe pain and loss of function.
What Is the Condition That Causes Injury to the Vastus Lateralis Muscle?
Any injury that occurs to the quadriceps muscle will result in severe pain. Quadricep muscle strain is prevalent in sportspeople and athletes. Those conditions that affect this muscle include
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Vastus Lateralis Strain: Quad muscle strain is caused due to a sudden force to the thigh. This can result in muscle pain, swelling, and bruising over the thigh. This can cause difficulty while walking.
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Patellar Tendinitis: Patellar tendinitis is where the quad tendon, which courses over the kneecap, gets irritated.
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PFSS (Patellofemoral Stress Syndrome): This condition occurs when the kneecap is trapped improperly in the femoral groove present in the knee joint. This can make walking and running difficult.
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Femoral Nerve Compression: The femoral nerve can be pinched or irritated due to underlying conditions such as arthritis, herniated disc, or lumbar stenosis. This condition results in numbness, tingling, or pain in the thigh.
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Iliotibial Band Friction Syndrome: Tight or weak muscles can result in an irritated iliotibial band involving vastus lateralis.
What Are the Causes of Vastus Lateralis Injury?
There are two leading causes:
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Acute Injury: Acute injury is caused when there is a single traumatic event. This is usually seen in sports people involved in soccer, basketball, or rugby. In this condition, there will be a link between the cause and the symptoms.
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Overuse: This injury is chronic or exercise-induced. This strain occurs over a long period. This condition occurs due to repetitive injury of the muscle. Diagnosing the condition as the cause is tough, and the symptoms have a less obvious link.
How Is Vastus Lateralis Injury Diagnosed?
The symptoms experienced by the person vary greatly from sharp thigh pain or hip pain related to movements to vague pain, swelling in the thigh, reduction in strength, etc. A typical finding during a physical examination performed by the doctor is tenderness on direct palpitation, and another finding is the occurrence of pain on stretching and resisted muscle motion.
Some imaging tests are recommended, such as:
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Ultrasound utilizes sound waves to form the images of the inside of the body.
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MRI (Magnetic Resonance Imaging) uses magnetic as well as radio waves to get images of the inside of the body.
How Is Vastus Lateralis Injury Managed?
Any injury to the vastus lateralis muscle can cause pain, swelling, and lower the range of motion. There are many methods through which the injury caused to the vastus lateralis muscle can be managed. Some are:
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Heat and Ice Packs: In the initial days of the injury, ice packs can be applied over the lateral thigh to help manage pain, swelling, and inflammation. Ice should be applied for 10 to 15 minutes, and frost burns should be avoided. Heat packs can be applied after two to three days, enhancing blood flow and tissue mobility. The heat pack should be applied for 10 to 15 minutes.
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Massage: Once this muscle gets injured, massage can help increase blood circulation and tissue mobility. Massaging the affected area before movements like stretching can help to improve motion.
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Stretching: Post vastus lateralis injury stretching should be done to enhance the mobility and functioning of the muscle.
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Exercises: Regular exercise helps to improve the vastus lateralis injury condition. If the irritation in the femoral nerve causes the condition, back exercises can help manage the pain and swelling caused. The exercises are designed in such a way as to remove the pressure on the nerve. Strengthening exercises such as squats, straight leg raises, leg extensions, lunges, etc., can be performed. Strengthening exercises are very important and must be followed regularly with proper break intervals. Any exercise should be stopped if the person feels any pain or discomfort.
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Function Training: The main goal of the physical therapist is to make the person return to perform their normal functions after a vastus lateralis injury. This can be confirmed when the quad muscles function usually with regular balance exercise.
Conclusion
Vastus lateralis is one of the quad muscles. Any injury or damage to this muscle can result in pain, swelling of the muscle, or inflammation. Injury to this muscle can cause restricted movements. This muscle usually is involved in stretching of the knee along with other quad muscles. Injury to vastus muscle can be managed through various methods such as ice and heat packs, regular exercise, stretching, massage, etc.
