Vastus Lateralis is one of the muscles of our quadriceps muscle group present in our leg body part. Vastus lateralis is the strongest muscle among all four muscles (Vastus lateralis, Vastus medalis, Vastus intermedius, and rectus femoris) of our quadriceps muscle group.
Together, quadriceps muscle act on the hip and knee joint to promote the movement of our body as well as provide strength and stability to our physique. These quadriceps muscles are involved in our daily life’s necessary activities like walking, running, stair climbing, jumping, etc.
Mostly they provide power and essential mechanics to perform these activities and it absorbs the impact or external pressure coming by the impact activities like jumping, etc. Even you can release our dependence on quadriceps muscle by the fact/mechanism that they work as a whole in order to allow a person to stand up from the sitting position. Predominantly quadriceps muscle controls the movement of knee joint i.e knee extension. Thus for better health of your knee joint throughout your life, the need to strengthen your quadriceps muscle becomes crucial. If the muscles of the Quadricep muscle group are either weak or tight then this surely going to give you problems like knee pain, postural abnormalities, gait distance., etc.
FACTS The vastus Lateralis is the recommended site for the intramuscular injection in infants less than 7 months old and for those who are unable to walk due to old age or due to loss of muscular strength of legs.
Vastus Lateralis Muscle gives the shape to your outer thigh, as when you see the well developed vastus laterals muscle you will notice the well-developed curvature at the outer thigh, and it always looks to stunning and eye-catching. Thus to impart overall balance & aesthetics touch to your physique, a well developed Vastus laterals muscle is much-valued addition.
Vastus lateralis muscle is located at the most outermost part of our thigh, as you can figure it out from the image of the exact location of the image of vastus lateralis muscle. Vastus lateralis improves your overall athletic performance as it is the strongest muscle present in your front of you thighs thus it imparts you the much-needed acceleration during the athletic activity.
Vastus Lateralis Muscle got his name from the Latin words “Vastus” which means vast or big and the “Lateralis” is derived from the lateral word which means any body part which is located away from body’s midline. You can see that this muscle is big in size & it is located at the outermost part of our thigh, thus this way it got his name “Vastus Lateralis”
ORIGIN
As we have already seen the Vastus Lateralis and one thing which you have already figured out that this is huge muscle thus being a huge muscle its origin is also distributed to a number of points at our thigh bone FEMUR. Basically, Vastus Lateralis muscle originate from three different points present in our femur bone which is:-
1. Intertrochanteric lines
The Intertrochanteric lines are also called the spiral line of the femur. It is a line located on the front (anterior side) of the proximal (near) end of the femur. Intertrochanteric lines are the rough variable ridge stretches between the greater trochanter and the lesser trochanter forming the base of the neck of the femur.
Our Vastus Lateralis muscle use to originate from the upper part of this Intertrochanteric line.
The interesting fact about this Intertrochanteric line is that our body’s strongest ligament, the ILIOFEMORAL LIGAMENT which strengthens the capsule of the hip joint also attaches to this Intertrochanteric line.
2. Greater Trochanter of the Femur Before letting you know about the greater trochanter firstly you should be well aware of the trochanter. Basically, trochanter is the bony prominence towards the near end of the thigh bone (femur), you can also say it as a process, as we know that in anatomy, anything which comes out from a bone is known as “process”. Thus similarly this “process” is known as trochanter when we talk about thigh bone (femur). Trochanters are basically the point at which the thigh muscle i.e quadriceps muscles use to originate and the gluteal muscles use to insert. The greater trochanter is the major bony prominence of the femur bone which is located at the proximal (near) and lateral (outside) part of the shaft of the femur. Greater trochanter large in size and thus it is also called as the major trochanter or outer trochanter or simply it is called as the lateral process of the femur. The lesser trochanter is the minor bony prominence that projects from the proximal (near) and medial (inside) part of the shaft of the femur. The lesser trochanter is small in size and thus it is also called minor trochanter or inner trochanter or simply the medial process of the femur.
3. Lateral Linea Aspera
Firstly let be very clear about LINEA ASPERA, simply it a rough line present on the posterior side of our femur bone. Linea Aspera appears as a ridge of the roughened surface present in posterior side of the thigh bone (femur).
The Linea Aspera is prolonged by three ridges which are:-
a) The Lateral Ridge It is the toughest ridge which runs almost vertically upwards to the base of the greater trochanter. This lateral ridge serves as one of the three origin points of Vastus Lateralis Muscle and it also termed as the gluteal tuberosity & it gives attachment to the Gluteus Maximus muscle of Glute Muscle Group.
b) The Intermediate Ridge
It is continued to the base of the lesser trochanter and gives attachment to the Pectineus Muscles. The Intermediate ridge is also called as the pectineal line.
c) The Medial Ridge It is located on the inner side of the shaft of the femur just opposite to the lateral ridge of the Linea Aspera. At this medial ridge of Linea Aspera, the Iliacus is inserted.
INSERTION
The Vastus Lateralis Muscle gets to combine with other muscles of a quadriceps muscle group (Vastus medalis, Vastus intermedius, and rectus femoris) and forms a tendon, and this tendon attaches with the patella bone at the knee joint.
For better stability of this patella bone, there is a ligament/tendon called as a patellar tendon/ patellar ligament which connects this patella bone to the tibia bone (shin bone), here this patellar tendon/patellar ligament gets attach to the tibia bone at the tibial tuberosity, thus this whole structure provides dynamic stability & strength to our knee joint while movement. ACTION OF VASTUS LATERALIS
Our Vastus Lateralis Muscle serves two main functions which are:-
1. Knee Extension
Knee Extension is the action in which you extend your leg at your knee joint thus making your legs straight. Simply when you come from a sitting position to a standing position the action you just did is the knee extension as now your legs become straight at the knee joint.
Knee Extension is the predominant action of the vastus lateralis muscle even it is the predominant action of all the muscles of the quadriceps muscle group. All four muscle of the quadriceps muscle act to straighten the leg at the knee joint.
2. Knee Stabilisation
As the Vastus Lateralis muscle combines with the other muscle of the quadriceps muscle group to form a tendon and this tendon inserts into the patella and from the patella, a tendon/ ligament originates and insert into the tibial tuberosity of the tibia bone. Thus in this way Vastus lateralis muscle crosses the knee joints and provides stability during any low to high impact activities i. e jumping, running, etc. For more details watch our video on VASTUS LATERALIS on youtube https://www.youtube.com/watch?v=oHFLN7ubczA&t=362s
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