Sitting or sidelying or standing
Ask the patient to wear shorts. Palpation on the skin is possible by lifting the shorts, if necessary, and placing the fingers on the mid-portion of the lateroanterior thigh.
Anterior or lateral to the patient.
Please sit. May I touch the side of your thigh? (or point to the demonstrated area).
Please straighten your knee (or demonstrate). (If needed, hold this position while I try to bend your knee.)
The vastus lateralis muscle commonly is considered one muscle without subdivisions.
If the vastus lateralis muscle were subdivided, the subdivisions would be the vastus lateralis longus and vastus lateralis oblique (obliquus). The vastus medialis muscle commonly is subdivided due to the clinical significance of the vastus medialis oblique muscle as separate from the clinical significance of the vastus medialis longus and the larger size of the vastus medialis oblique compared with the smaller vastus lateralis oblique. The oblique portions of both muscles are the distal portions that have fibers that are more horizontal and therefore have more effect on preventing patellar displacement and less effect on producing knee extension. The resultant of the quadriceps femoris group produces an overall extensor effect on the knee and lateral pull on the patella. Excessive patellar lateral displacement is prevented by the bony projection of the lateral femoral condyle and the vastus medialis oblique muscle. Preventing excessive patellar medial displacement, partially by the vastus lateralis oblique, is rarely a concern.
Guide the patient to sit. With the patient relaxed and with permission, place your fingers on the vastus lateralis (vastus lateralis longus) muscle belly in the mid-portion of the muscle on the lateroanteror thigh. Guide the patient to extend the knee. With unclear muscle activity, increase the contraction of the vastus lateralis by asking the patient to straighten the knee while you provide a push on the leg (i.e. body segment between the knee and the foot) in the direction of knee flexion.
If the vastus lateralis muscle were subdivided, the subdivisions would be the vastus lateralis longus and vastus lateralis oblique (obliquus). The vastus medialis muscle commonly is subdivided due to the clinical significance of the vastus medialis oblique muscle as separate from the clinical significance of the vastus medialis longus and the larger size of the vastus medialis oblique compared with the smaller vastus lateralis oblique. The oblique portions of both muscles are the distal portions that have fibers that are more horizontal and therefore have more effect on preventing patellar displacement and less effect on producing knee extension. The resultant of the quadriceps femoris group produces an overall extensor effect on the knee and lateral pull on the patella. Excessive patellar lateral displacement is prevented by the bony projection of the lateral femoral condyle and the vastus medialis oblique muscle. Preventing excessive patellar medial displacement, partially by the vastus lateralis oblique, is rarely a concern.
Guide the patient to sit. With the patient relaxed and with permission, place your fingers on the vastus lateralis (vastus lateralis longus) muscle belly in the mid-portion of the muscle on the lateroanteror thigh. Guide the patient to extend the knee. With unclear muscle activity, increase the contraction of the vastus lateralis by asking the patient to straighten the knee while you provide a push on the leg (i.e. body segment between the knee and the foot) in the direction of knee flexion.
VH - Vastus lateralis muscle and quadriceps tendon - on one side add the other quadriceps muscles