The Adductor Magnus and its role in Squatting: Part 1 – Anatomy

October 26, 2010

Adductor Magnus (highlighted) – Front View

In this series I will demonstrate the importance of the Adductor Magnus muscle in performing a proper squat. Part one reviews the functional anatomy of the muscle:

Adductor magnus is a large fan-shaped muscle, with short horizontal, oblique and vertical fibers. The horizontal fibers are often known as ‘adductor minimus’. The vertical fibers are sometimes referred to as the ‘fourth hamstring’ due to the shared neural innervation and function with the hamstrings group.

From: Proximally, adductor magnus has a continuous curvilinear attachment onto the lateral surface of the conjoined ischiopubic ramus and the infero-lateral aspect of the ischial tuberosity. However, the muscle is functionally divided into two components by proximal attachment, distal attachment, neurological innervation, and function.

1. Adductor part – inferior ramus of the pubis, ramus of the ischium

2. Hamstrings part – ischial tuberosity

To:

Adductor part – gluteal tuberosity, linea aspera, medial supracondylar line

Adductor Magnus – Posterior view

Hamstrings part– adductor tubercle on the superior aspect of the medial epicondyle of the femur

Innervation:

Adductor part – obturator nerve (L2, 3, 4)

Hamstrings part – tibial part of sciatic nerve (L4)

Action: collectively adducts thigh. Adductor part flexes thigh, hamstrings part extends thigh.

Due to the dual neural innervation, the Adductor Magnus muscle functions as both an adductor and extensor of the hip. As will be discussed in the next part of this series, when performing the squat exercise to proper depth (where the hip joint is below the patellae), this muscle, along with the hamstrings and gluteus maximus, become the main synergists of the movement. Problems with the Adductor Magnus (in terms of length or force generation ability) can prevent proper form either on the decent portion of the manoeuvre, or when ascending out of the ‘basement’ (lowest portion of the squat).

****pictures courtesy of Primal Anatomy (2009)