What and where is the adductor magnus muscle?
The adductor magnus is a large muscle on the inside of the thigh that could more accurately be described as multiple muscle sections (usually described as two to four sections). There is some debate about how many sections are most often present and there is some variability from person to person regarding how many distinct sections are present. In this post we’ll describe the two main sections. Although each of the muscle sections can contribute to different movements, sometimes even opposite movements, the sections are all considered to be one muscle.
Where is the adductor magnus muscle located?
The adductor magnus muscle is located on the inside of the thigh and has a large area of attachment from the pubic bone and ischium continuing down most of the femur. Portions of the adductor magnus are deep to a number of other muscles, including two of the other adductor muscles: pectineus and adductor longus.
Origin
The more proximal section of the adductor magnus muscle is also the most anterior of the sections. It attaches proximally to the inferior pubic ramus. The more distal section of the adductor magnus muscle attaches proximally to the ischial tuberosity and to the ischial ramus.
Insertion
The more proximal section of the adductor magnus muscle attaches distally to the upper part of the linea aspera of the femur. The more distal section of the adductor magnus attaches distally to the lower part of the linea aspera along the femur and to the adductor tubercle.
What actions does the adductor magnus muscle do?
There is still some debate among researchers about what actions each section of the adductor magnus muscle does. As the technology that is used to study muscle activity continues to advance, researchers learn more. The most current research suggests that the proximal and distal sections of the adductor magnus muscle have some actions in common, but can also contribute to actions unique to each section.
When in anatomical position both sections of the adductor magnus can contribute to adduction of the thigh at the hip and extension of the hip joint. When it comes to rotation however, the muscle sections differ in their actions. The proximal section of the adductor magnus muscle can contribute to at least some small amount of external rotation of the thigh, but the distal section of the adductor magnus muscle contributes to internal rotation of the thigh.
References
Benn, M.L., T. Pizzari, L. Rath, K. Tucker, and A. I. Semciw 2018. Adductor magnus: An EMG investigation into proximal and distal portions and direction specific action. Clinical Anatomy. 31:535–543.
Travell, J.G. and D.G. Simons. 1993. Adductor Muscles of the Hip. In Myofascial Pain and Dysfunction —The Trigger Point Manual. Volume 2.
