Vastus Medialis
The vastus medialis is the most medial muscle of the quadriceps group, forming the innermost portion of the powerful extensor complex.
It is easily recognized by its distinctive “teardrop” shape just above the knee joint, in well-trained individuals, such as bodybuilders, sprinters, athletes, and those who consistently perform hypertrophy training for the legs.
It works with other quadriceps muscles in the knee joint movements, essential for everyday activities and athletic performance as well.
Anatomy:
The vastus medialis muscle is located in the anteromedial aspect of the thigh.
Proximal attachment:
Proximally, it attaches to the
- Medial lip of the linea aspera
- Intertrochantric line
- Pectineal line
- Medial supracondylar line of the femur
Distal attachment:
As the muscle descends, the fibers run more horizontally. This part is often referred to as the vastus medialis obliquus.
It merges with other quadriceps muscles, forming the quadriceps tendon, and attaches to the base of the patella. Then, it continues as the patellar tendon and attaches to the tibial tuberosity.
Nerve innervation:
The vastus medialis gets innervated by the Femoral nerve(L2, L3, L4).
Blood supply:
Arterial supply: Femoral artery
Venous drainage: Femoral vein
Function
Concentric contraction (shortening):
Standard mover action:(distal attachment moving towards proximal)
Knee extension:
The vastus medialis passes anterior to the knee joint, thereby helping to extend the leg at the knee joint.
Reverse mover action: (proximal segment moving towards distal)
The vastus medialis extends the thigh at the knee joint, allowing us to stand up from a seated position by lifting the thigh and the entire body along with it.
Eccentric contraction (lengthening):
When the vastus medialis contracts eccentrically, it helps in controlling and slowing down the knee flexion.
Isometric contraction:
Vastus medialis contracts isometrically to stabilize the knee joint, both the tibiofemoral and patellofemoral joints.
Pennation of Vastus medialis and force production:
Pennation is the angled arrangement of muscle fibers to the common tendon, which allows more fibers to fit into the given cross-sectional area. More fibers → larger cross-sectional area generates greater force production.
The vastus medialis is a unipennate muscle, with fibers slanting in a single direction toward the central tendon. This angled structure boosts its ability to generate force, making it an important contributor to powerful and explosive movements.
Patellar tracking:
Another crucial function of the vastus medialis is its role in patellar tracking, which refers to the gliding of the patella within the trochlear groove in the femur when the knee is flexed and extended.
The lower fibers of the vastus medialis run more horizontally and connect to the medial border of the patella through the quadriceps tendon. Thus, it pulls the patella medially (toward the inside of the knee). This counteracts the lateral (outward) pull of the vastus lateralis, thereby keeping the patella centered in the groove. By maintaining this balance, the vastus medialis ensures smooth and controlled patellar movement, reducing the risk of maltracking and associated knee issues.
Purpose
The main purpose of the vastus medialis is its coordinated contribution in the extension of the knee joint along with other quadriceps muscles. Besides being a major contributor to the force production for the knee extension, the vastus medialis has some additional purposes as well.
Patellar stabilization:
The vastus medialis plays a major role in patellar stabilization. Through its attachment to the patella, it stabilizes the patella in position and also the patellofemoral joint.
Knee joint dynamic stabilization:
The lower (oblique) fibers of the vastus medialis running along the medial aspect of the knee joint provide dynamic stabilization to the tibiofemoral joint during knee joint flexion and extension. This helps to maintain smoother knee joint mechanics.
Azarudheen is a passionate physiotherapist and exercise prescriptor with a deeply rooted belief in the transformative power of movement and education. His journey began in 2013 as a first-year physiotherapy student, balancing academics with part-time work to support his ambitions. Early in his career, he sought practical experience and began working at a fitness center, eventually transitioning into roles that expanded his knowledge and skill set in both clinical practice and teaching.
Driven by a relentless curiosity and desire for growth, Azarudheen took on an anatomy tutor position, believing in the value of continuous learning. A pivotal turning point came with his experience in cardiopulmonary rehabilitation at PSG Hospitals, where he worked closely with lung transplant patients. This experience emphasized the life-changing impact of functional movement and patient education, inspiring him to dive deeper into respiratory and cardiovascular physiology.
With strong support and belief in his vision, Azarudheen pursued a Master’s in Exercise and Sports Science at Manipal University—choosing it over conventional MPT programs to focus more on biomechanics, exercise physiology, strength and conditioning, and lifestyle health. His dedication was evident as he spent late nights at the library, worked part-time in gyms and cricket academies, and honed his craft through practical application.
In 2022, despite initial doubts, he opened his first clinic in his hometown—an act of courage and self-belief supported by his family and mentors. Built from the ground up, this clinic marked the start of a new era. Today, Azarudheen leads a growing team of 21 physiotherapists across two thriving clinics in Chennai and Coimbatore. His philosophy centers on patient education, movement optimization, and professional growth, and he continues to evolve both as a clinician and a leader.
Azarudheen’s journey reflects the power of perseverance, vision, and lifelong learning. He is not only a practitioner but also a mentor and advocate for a more thoughtful, movement-centered approach to healthcare.