The quadriceps muscles group includes four muscles located in the anterior thigh. This muscle group acts to extend the leg while straightening the knee. A severe pull or muscle tear, causes an abrupt, sudden, acute pain that occurs during activity (often while sprinting). It may be accompanied by swelling or bruises on the thigh. Muscle spasm, or knots in the muscle, are also very common symptoms of a quad injury. A pulled quadriceps is often the result of a strength imbalance between the quadriceps and the hamstring. Such an imbalance is not uncommon among runners, since running tends to work out the hamstrings much more than the quadriceps.
For immediate relief, Rest, Ice, Compression and elevation are the best immediate treatment for all pulls and strains. Once activity is started again, ice the muscle after exercise to reduce any swelling. Also, an anti-inflammatory can be helpful to reduce pain and inflammation. Proper stretching of the quadriceps is essential after recuperation. Stretch gently, but thoroughly. Never force a stretch.
Quad injury is graded using the 1-3 scale, with grade 1 strains being the least severe, and grade 3 being the worst. Depending on the severity of the strain, you may be able to feel a defect in the muscle, or a hole where the tear is. Preventing quadriceps strains involves a good warm up and stretching program prior to activities, as well as making sure you are properly conditioned for your sports activities, and preventing re-injury revolves around making sure you allow the first injury to heal before returning to sports, and going through rehabilitation to restore your strength and flexibility.