Muscles of the Knee Mr. Brewer

Muscles of the Knee Quadriceps (4) – - Vastus Medialis - Vastus Intermediate - Vastus Lateralis - Rectus Femoris Insertion/Origin: Distal insertion of all quadricep muscles are located at the tibial tuberosity via the quadricep tendon. The 3 vastus quadricep muscles attach superiorly to the proximal portion of the Femur WITHOUT crossing the hip joint.

Muscles Vastus Muscles Do NOT cross the hip joint. Because of that, they are only responsible for knee extension. VMO (Vastus Medialis Oblique) is an important muscle to focus on rehabbing following major knee surgery. Responsible for the last 15 degrees of Knee Extension, also known as “Terminal Knee Extension” https://www.youtube.com/watch?v=ZscBVtoX62U

Rectus Femoris Rectus Femoris: The most superficial of the quadricep muscles Important to recognize when considering treatment options. Responsible for not only knee extension, like the rest of the quadricep muscles, but also HIP Flexion. This is because the Rectus Femoris crosses the hip joint and attaches proximally to the anterior inferior iliac spine of the hip bone.

Muscles Rectus Femoris: The Rectus Femoris is the only Quadricep to cross both the knee AND hip joints. Therefore the Rectus Femoris not only is involved in Knee extension, but also Hip Flexion. Video showing hip flexion exercises and movements, along with techniques for stretching: https://www.youtube.com/watch?v=eVbmiI4YSdU

Hamstring Muscles

Hamstring Hamstring Muscles (3): Biceps Femoris Lone lateral hamstring muscle “Biceps” meaning 2 heads Distally: the biceps femoris does cross the knee joint and both the short-head and long-head come together and attach to the Head of the Fibula. Proximally: Long-head crosses the hip joint and attaches to the pelvis. Short-head attaches to the posterior femur along the middle 1/3. * Both heads are active with knee flexion, but the long-head assists with Hip-extension as well.

Hamstrings Semitendinosus and Semimembranosus Medial Hamstring muscles Both originate proximally to the ischial tuberosity of the pelvic bones. Both insert distally to the medial surface of the tibia.

Hamstring Action (at the knee) Knee Flexion: All 3 of the Hamstring muscles have roles in Knee Flexion. C1 and C2 is an example of “bilateral knee flexion” E1 and E2 are examples of “unilateral knee flexion” F1 and F2 are examples of “bilateral knee flexion” (focusing on the eccentric contractions of the hamstring muscles)