What is the vastus lateralis muscle?
The vastus lateralis muscle is one of the quadriceps muscles in the thigh, it is located on the lateral (outside) aspect of the thigh. It originates on the femur (thigh bone) and inserts on the patella (knee cap) and tibia (shin bone). It is responsible for extending the knee, along with the rectus femoris, vastus medialis and vastus intermedius muscles. (1)
Origin, insertion and function
Origin:
- Greater trochanter of femur (thigh bone)
- Lateral lip of linea aspera of femur
- Gluteal tuberosity of femur
- Patellar ligament
Insertion:
- Patella (knee cap)
- Tibia (shin bone)
Function:
- Extends the knee
- Assist in stabilizing the knee joint
- It is used in activities such as walking, running, jumping, and climbing stairs.
![Vastus lateralis muscle](https://upload.wikimedia.org/wikipedia/commons/f/f2/Vastus_lateralis_muscle.png)
Common signs of weak vastus lateralis muscles
Common signs that may indicate your vastus lateralis is weak include:
- Difficulty extending the knee, such as when trying to straighten the leg while standing or when climbing stairs
- Knee pain or discomfort, particularly when squatting or lunging
- Inability to maintain proper form during exercises such as squats and lunges
- Inability to perform activities that require a lot of knee extension, such as cycling uphill or climbing stairs
- Instability of knee joint
- Reduced power and endurance during activities such as running or jumping
- Pain or discomfort in the lateral aspect of the thigh
- A feeling of “giving out” or buckling in the knee
- Uneven muscle development or asymmetry in the thigh
- Inability to perform exercises that target the quadriceps, such as leg press or leg extension
- Inability to perform activities that require a lot of knee extension and stability, such as cycling uphill or climbing stairs
Please note that it is important to see a doctor or physical therapist if you are experiencing any pain or discomfort, or if you have any pre-existing medical conditions or injuries.
Exercises to strengthen the vastus lateralis muscle
These exercises can help make your vastus lateralis stronger:
Squats
- Stand with your feet hip-width apart and your toes pointing forward.
- Slowly lower your body as if you are sitting back into a chair, keeping your back straight and your knees behind your toes.
- Push through your heels to return to the starting position.
- Repeat the movement for the desired number of reps.
Lunges
- Start by standing with your feet hip-width apart.
- Step forward with one foot, and lower your body until your thigh is parallel to the floor and your knee is at a 90-degree angle.
- Push through the heel of your front foot to return to the starting position.
- Repeat the movement for the desired number of reps, then switch legs.
Step-ups
- Stand in front of a bench or step, with your feet hip-width apart.
- Step up onto the bench or step with one foot, then bring your other foot up to meet it.
- Step back down with one foot, then the other.
- Repeat the movement for the desired number of reps, then switch legs.
Leg press
- Sit in a leg press machine with your back against the pad and your feet on the platform.
- Slowly press the platform away from your body, straightening your legs.
- Pause and then slowly release the platform back to the starting position.
- Repeat the movement for the desired number of reps.
Leg extension
- Sit in a leg extension machine with your back against the pad, and the ankle pad on top of your lower shins.
- Slowly lift the weight by extending your legs.
- Pause and then slowly lower the weight back to the starting position.
- Repeat the movement for the desired number of reps.
Single-leg exercises, such as single-leg squats, lunges, and step-ups, can also be effective in targeting and strengthening the vastus lateralis.
It is important to use proper form and technique, and to start with a light weight. It is also important to check with a doctor or physical therapist before starting any new exercise program, especially if you have any pre-existing medical conditions or injuries.
References:
- Biondi NL, Varacallo M. Anatomy, Bony Pelvis and Lower Limb, Vastus Lateralis Muscle. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532309/