Your vastus lateralis is one of the four muscles in your thigh collectively known as the quadriceps muscles. Together, the quadriceps have responsibility for straightening your knee joint and extending your leg. If you place too much stress on your vastus lateralis or any other muscle in the quadriceps group, you can experience muscle strain.
The Vastus Lateralis
In addition to your vastus lateralis, the muscles in the quadriceps group include the rectus femoris, vastus intermedius and the vastus medialis. The vastus lateralis gets its name because it sits on the lateral or outside portion of your thigh. It attaches to a ridge near the top of your femur bone and extends downward to the outside edge of your patella or knee bone. While most muscle strains occur in the rectus femoris, you can also develop a strain in your vastus lateralis or your other quad muscles.
Muscle Strain
Muscle strains in your quadriceps occur when the pressure of activities such as kicking, sprinting, jumping or hopping overstresses one or more muscles and triggers tearing in the associated tissue. If you tear only a small number of your muscle fibers, you will develop a Grade 1 strain, which causes pain but doesn't reduce normal function. Grade 2 strains stem from more extensive muscle tearing and result in both pain and significant loss of function. Grade 3 strains stem from complete rupture of the affected muscle and result in pain and extensive loss of your normal function.
Symptoms
When you strain your vastus lateralis or any other quadriceps muscle, you will typically experience a sharp pain in the front of your thigh at the time of injury. If the damage is relatively minor, you'll probably feel that you can continue your current activity. However, more extensive forms of damage will trigger symptoms that include severe ongoing pain, muscle spasms and muscle weakness; these effects usually make continued activity difficult or impossible. Additional potential symptoms of a quadriceps strain include muscle stiffness and significant signs of bruising, swelling and tenderness.
Treatment
To treat Grade 1 and 2 muscle strains, your doctor will likely recommend that you rest your affected muscle, apply ice or another cold source, use a bandage to compress the injury site and elevate your leg above the level of your heart. In combination, these steps are commonly called the RICE rule or protocol. You can also use an over-the-counter painkiller to reduce your discomfort during this initial phase. When your pain levels drop, your doctor may ask you to see a physical therapist who will help restore your normal leg function. Individuals with Grade 2 strains sometimes require casts to protect their legs during healing. Individuals with Grade 3 strains may require surgery to repair their torn muscles.
