The anterior medial surface of the thigh contains numerous muscles vital for activities of daily living (ADLs).

One of the most significant muscles on the anterior surface of the femur is the quadriceps femoris. Known as the most voluminous muscle in the human body, it covers nearly the entire anterior thigh surface [1]. The only muscle running along the front of the quadriceps femoris is the sartorius muscle. The quadriceps femoris comprises four heads, essentially four muscles merging in the lower part into a single tendon, the patellar tendon, which attaches to the tibial tuberosity. Three of these heads (the vastus medialis, vastus lateralis, and rectus femoris) are located superficially. The fourth head, the vastus intermedius, lies directly on the femur and is covered by other muscles, making it invisible without removing the superficial layers of soft tissue.

The rectus femoris muscle is centrally located and originates from the anterior inferior iliac spine and the superior part of the acetabulum of the hip. Its functions include hip flexion and knee extension. The remaining muscles primarily function in knee extension and patella stabilization. The vastus medialis muscle originates from the lower part of the intertrochanteric line and the medial lip of the linea aspera. The vastus intermedius muscle lies beneath the other quadriceps muscles, attaching to the front and lateral surface of the femur and the lateral lip of the linea aspera. The vastus lateralis, the final muscle in this group, originates from the lateral side of the greater trochanter, the gluteal tuberosity, and the lateral lip of the linea aspera.

Some studies have noted the existence of extra heads of the quadriceps femoris muscle as part of anatomical variations, including: head beginning proximally with the rectus femoris muscle running through the anterior compartment of the femur. Additionally, separate heads have been identified within the vastus lateralis muscle, categorized as superficial, intermediate, and deep heads. [2] Another extra head was observed between the vastus medialis and vastus lateralis muscles. [3]

The sartorius muscle runs above the quadriceps femoris muscle. It originates from the anterior superior iliac spine and inserts on the upper medial surface of the tibia (pes anserinus). This muscle functions as a hip flexor, weak abductor, and external rotator. Additionally, it flexes the knee and medially rotates the leg when the knee is flexed [4]

The medial compartment of the thigh contains muscles such as the adductor longus and gracilis and also muscles which are not shown in the graphic: adductor magnus and brevis.

The group of adductors (the adductor magnus, longus and brevis) originates from the pubic bone and ischium and runs along the medial part of femur. They attach to the upper posterior part of the femoral shaft and linea aspera (the adductor brevis), in the half of length of femur medially (the adductor longus) and along the entire length of the medial femoral shaft to the adductor tubercle on the medial condyle (the adductor magnus). These muscles adduct the lower limb at the hip joint. Additionally, the adductor magnus internally rotates the hip and stabilizes the pelvis, while the adductor longus assists in hip flexion and rotation. [5]

The gracilis muscle is a thin, flat, superficial muscle on the medial comparment of the thigh. It attaches to the medial aspect of the ischiopubic ramus and medial side of the tibia at a site called pes anserinus. [6] The gracilis functions as a flexor of the knee, and an adductor and internal rotator of the thigh.

  1. Bordoni, Bruno, and Matthew Varacallo. “Anatomy, Bony Pelvis and Lower Limb: Thigh Quadriceps Muscle.” StatPearls, StatPearls Publishing, 2024. PubMed, http://www.ncbi.nlm.nih.gov/books/NBK513334/
  2. Angullo-Gómez, Pedro, i in. „Quadriceps femoris muscle: anatomical variations, population frequencies and clinical implications”. Folia Morphologica, december 2023, s. VM/OJS/J/97238. DOI.org (Crossref), https://doi.org/10.5603/fm.97238
  3. Omakobia, Eugene, i in. „A Rare Case of Aberrant Quadriceps Muscle Anatomy Preventing Anterolateral Thigh Flap Harvest”. JPRAS Open, t. 7, march 2016, s. 19–22. DOI.org (Crossref), https://doi.org/10.1016/j.jpra.2016.01.002
  4. Moore, Keith L., i in. Clinically oriented anatomy. 7th ed, Wolters Kluwer/Lippincott Williams & Wilkins Health, 2014
  5. Kendall, Florence Peterson, i Florence Peterson Kendall, redaktorzy. Muscles: testing and function with posture and pain. 5th ed, Lippincott Williams & Wilkins, 2005
  6. Marieb, Elaine Nicpon, i Katja Hoehn. Human Anatomy & Physiology. 10. ed., Global ed, Pearson Education Limited, 2016