Vastus+Lateralis

toc =Description = The vastus lateralis (sometimes referred to as vastus externus) muscle is located in the anterior (extensor) compartment of the thigh. The muscle’s origin lies at the upper part of the intertrochanteric line, the anterior and inferior borders of the greater trochanter, lateral margin of the gluteal tuberosisty and the superior half of the lateral lip of the linea aspera. The muscle runs inferiorly towards the knee joint towards the location of its insertion point. It inserts at the patella, first via the quadriceps tendon and then the tibial tuberosity via the patellar ligament. The muscle acts to extend the leg at the knee joint (when getting up from a squatting position) and stabilise the knee as well. It is innervated by the femoral nerve and receives blood supply from the femoral artery.
 * Author: Khensani Ngobeni**

=Interactions and relations to other Muscles =

Vastus lateralis lies next to the rectus femoris, and the vastus intermedius muscles. These muscles all including the vastus medialis form part of the anterior compartment of the thigh. The tensor fasciae latae lies superiorly to the vastus lateralis. The muscles in the anterior compartment, act together to extend the leg at the knee joint, thus making these synergists of each other. These also stabilise the knee joint. The antagonists for the vastus lateralis is the hamstring group of muscles. These are the semitendinosus, semimembranosus and biceps femoris muscles.

=Relevance to Occupational Therapy =

As a part of the quadraceps muscles, dysfunction of the vastus lateralis muscle results in the restriction of movement in the leg. The most affected part will be the range of motion of extension at the knee joint. This restriction in walking may affect an individual’s participation certain activities. This would be the point at which an occupational therapist will help to rehabilitate in helping to adapt their environment to suit the individual’s need that have been created from the muscles dysfunction. In other circumstances where there is paralysis in the lower limbs the vastus lateralis will be inactive and require of an OT to rehabilitate and help in adapting to the inability to move the limbs in everyday activities. An OT’s knowledge of the muscle and the group it lies within, with regards to its action, location, innervation, blood supply and other information about the muscle, will help with treating effectively. An OT could help the client to perform activities such as standing on their toes as this requires great knee stabilisation in a graded manner in order to ensure muscle strengthening.

=References = Totora, J., G. & Derrickson, B. Principles of Anatomy and Physiology. Volume 1 - Organization, Support and Movement, and Control Systems of the Human Body. 12th ed.  Grant, A. & Waugh, A. Anatomy and Physiology in Health and Illness. 11th ed. Churchill Livingston 2010  www.rossandwilson.com/