GENERAL INFORMATION
The Vastus Medialis is one of the four components of the quadriceps femoris group, primarily responsible for knee extension. Located medially along the thigh, it plays a crucial role in stabilising the patella and the knee joint during movements. The muscle is particularly important for athletes and is often a focus in rehabilitation from knee injuries.
ORIGIN
This muscle originates from the intertrochanteric line, the medial lip of the linea aspera, and the upper part of the medial supracondylar line of the femur. It extends down the length of the thigh, emphasising its importance in connecting the upper leg to the knee.
INSERTION POINT
The Vastus Medialis inserts into the quadriceps tendon, which is connected to the patella. From there, it joins the patellar ligament, attaching to the tibial tuberosity. This insertion plays a significant role in knee mechanics, particularly in extending and stabilising the joint.
MAJOR ARTERIES
It receives blood supply from the femoral artery, ensuring sufficient oxygen and nutrients for muscle activity and recovery.
NEURAL INNERVATION
The femoral nerve, which originates from nerve roots L2 to L4, provides innervation. This nerve controls the muscle’s powerful contractions during movements.
TRIGGER POINT
Trigger points in the Vascular Medialis can lead to medial knee pain and may contribute to issues like patellofemoral pain syndrome, which commonly affects mobility and comfort.
CONCENTRIC FUNCTION
Concentrically, the Vastus Medialis extends the knee, which is crucial for activities such as running, jumping, and kicking.
ECCENTRIC FUNCTION
Eccentrically, it helps control the body’s lowering during squatting or descending stairs, protecting the knee joint by decelerating the movement.
ISOMETRIC FUNCTION
Isometrically, the muscle stabilises the patella and the knee during static postures, supporting the leg when the knee is extended and under load.
RELATED MUSCLE-SCIENTIFIC NAMES
- Vastus Lateralis: Located on the outer side of the thigh, it is essential for knee extension.
- Vastus Intermedius: Positioned between the vastus lateralis and vastus medialis, it contributes to knee extension.
- Rectus Femoris: Crosses both the hip and knee joints, aiding in hip flexion and knee extension.
- Sartorius: The longest muscle in the body, running from the hip to the knee, it flexes, abducts, and laterally rotates the thigh.
ANTAGONIST
- Hamstring Group: This group includes biceps femoris, semitendinosus, and semimembranosus, and it is responsible for knee flexion and hip extension.
- Gastrocnemius: Part of the calf muscle that flexes the knee and plantarflexes the ankle.
- Popliteus: Located at the back of the knee, it unlocks the knee joint and assists in knee flexion.
COMMON INJURIES
- Patellar tracking problems: Misalignment of the patella during knee movement, causing pain and dysfunction.
- Quadriceps tendonitis: Inflammation of the quadriceps tendon due to overuse.
- Patellofemoral pain syndrome: Pain around the patella due to misalignment or overuse, often called “runner’s knee.
EXERCISES
- Leg Extensions: Target the quadriceps, especially the Vastus Medialis, by extending the knee against resistance.
- Squats: Engage the muscle through its full range of motion, enhancing strength and stability.
- Step-Ups: Perform on a raised platform to focus on knee extension and stability, which are critical for Vastus Medialis activation.
- Terminal Knee Extensions: Use a resistance band around the lower leg, focusing on the final 30 degrees of knee extension to strengthen the Vastus Medialis specifically.
STRETCHES
- Quad Stretch: Stand and pull the ankle to the buttocks, focusing on elongating the front of the thigh.
- Foam Rolling: Roll the inner quadrant of the thigh to release tightness in the Vastus Medialis.
- Dynamic Leg Swings: Perform front-to-back swings to warm up and gently stretch the quadriceps.
- Kneeling Stretch: Kneel on one knee and push your hips forward to stretch the quadriceps of the back leg, targeting the Vastus Medialis.