A contusion to the quadriceps usually develops from a severe impact to a relaxed muscle, compressing the muscle against the hard surface of the femur.
The degree of the injury is often based on loss of knee flexion. The individual may say he got a "charlie horse."
Mild to severe quadriceps contusions incur varying degrees of the following symptoms:
- Transitory loss of function (weakness of the thigh muscles)
- Point tenderness over the contused area
- Loss of knee flexion
- Awkward walking and/or running motion.
Left untreated, a quadriceps contusion can lead to more serious complications, including myositis ossificans - bony deposits or ossification in the muscle.
A quadriceps strain often occurs from a fall on a bent knee or a sudden contraction of that muscle. Examples include kicking a ball or jumping.
A quadriceps strain often will result when a muscle is weakened. A tear of the quadriceps can result in a partial or complete disruption of the muscle fibers.
Symptoms include pain, point tenderness, spasm and possible loss of function or full range of motion.
A complete rupture of the quadriceps can leave the patient with little to no disability or discomfort but with a deformity in the anterior thigh.
Hamstring Strain or Tear
A hamstring strain/tear occurs most frequently with a change of direction or from starting a slowing motion (deceleration).
Possible contributing factors for the strain or tear include muscle fatigue, leg-length discrepancy, tight hamstrings, improper form and imbalance of strength between the quadriceps and/or the hamstrings muscle group.
The strain or tear can involve the muscle belly or the bony attachment or the ischial tuberosity. Symptoms include pain and immediate loss of function-knee flexion.
Discoloration may occur one to two days after the injury.
The vastus medialis oblique (VMO) is the most medial of the four quadriceps muscles. It begins at the top of the femur and inferiorly attaches to the rectus femoris muscle and to the lateral and proximal patella.
The VMO is particularly important because it serves as a major stabilizer for patella tracking.
VMO weakness is often one of the contributing factors in anterior knee pain. Specific exercises can help to strengthen this muscle as well as the quadriceps muscles as a unit.