Vastus Medialis

A muscle consists of groups of muscle bundles that join into a tendon at each end. The muscle bundles in the quadriceps are the vastus medialis, rectus femoris, vastus inter-medialis and vastus lateralis. Each bundle is separately wrapped in a sheath of connective tissue. Each muscle is composed of many fibres, packaged into bundles of about... 

Fig. 4.19. Ultrasound demonstrates an acute grade I injury (less than 5%) of the vastus medialis (arrow) with minor bunching up of the muscle fibres (arrowheads)...

A lateral dislocation causes damage to the medial patello-femoral ligament and vastus medialis obliq-uis. It can also cause an osteochondral fracture from either the lateral femoral condyle which may be sheared of by the patella or alternatively there may be an avulsion of the medial facet of the patella. 

In the lower limbs the quadriceps femoris muscles are most severely affected and undergo progressive atrophy, particularly of the vastus medialis and lateralis, with relative sparing of the rectus femoris (Figure 9.2). As in the upper limbs the weakness is often more severe on the nondominant side. Weakness of the ankle dorsiflexors is also common but severe foot-drop occurs infrequently. Other muscle groups such as the hip extensors and abductors and ankle plantar flexors are usually only mildly affected. 

Gluteus medius, minimus, and tensor fascia lata Vastus lateralis and vastus intermedius Vastus medialis and vastus lateralis Tibialis anterior and extensor digitorum longus Gastrocnemius, soleus, and flexor hallucis longus Iliopsoas "... 

Avramidis K, Strike PW, Taylor PN. Effectiveness of electric stimulation of the vastus medialis muscle in the rehabilitation of patients after total knee arthroplasty. Arch Phys Med Rehabil 2003 84 1850-1853. 

Imbalance of muscle forces around joints has been associated with joint pain and functional limitations. Specifically, vastus medialis (VM) weakness in the knee extensor group has been related to mal-tracking of the patella, causing pain and leading to joint degeneration [11]. 

Fig. 13.2a-c Normal quadriceps muscle, a-c Schematic drawings of a coronal view through the anterior thigh showing the muscle bellies forming the quadriceps from deep (a) to superficial (c). a,b The vastus intermedius (VI) is the deepest muscle. On each side, it is partially covered by the vastus lateralis (VX) and the more distal vastus medialis (VM). c The rectus femoris (RF) is located more superficially. It arises from a direct (DT) and an indirect (IT) tendon from the anterior inferior iliac spine and inserts into a long flat tendon (asterisk) that forms the superficial layer of the quadriceps tendon... 

The vastus medialis and vastus lateralis muscles are respectively located on the medial and lateral sides of the rectus femoris (Figs. 13.1,13.2b,c). Both take their origin from the posterior aspect of the femur (linea aspera) and insert distally into the middle layer of the quadriceps tendon. The proximal tendon of the vastus lateralis is located in close rela-... 

Into the linea aspera, between the adductor magnus and the vastus medialis. 

If the electrode is inserted too medially and too deeply it will be in the vastus intermedius if inserted too laterally it will be in the vastus lateralis if inserted too distally and medially it will be in the vastus medialis. 

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