Many people are well aware of the influence of the glutes, hamstrings, quadriceps, and calf muscles for the strength and integrity of the lower body. However, some these same people are often unaware of the adductor magnus and its far reaching influence on lower body function. Failure to incorporate adductor magnus training into an exercise program will result in compromised stability, force transfer, and strength of the lower extremities. If given enough time, injuries and strength limitations will occur if neglected.
Adductor Magnus
Second only to the gluteus maximus in volume, weight, and cross-sectional area, the adductor magnus is a large, powerful muscle that aids in the body in a number of movements across all three planes of movement (1). Originating at the ramus of the pubis and ischium, as well as the ischial tuberosity the muscle inserts on the linea aspera (Latin for “rough line”) of the femur.
Responsible for adduction, extension, flexion, as well as internal and external rotation (of the femur), the adductor magnus is active any time you are using your pelvis. Most prominently an adducutor (Latin for “to lead towards”), the AM draws the femur closer to the middle of the body. This translates to being a prime mover during any sort of lateral (side to side) movement and, at the same time, stabilizing the hip during forwards and backwards motion. If stabilization via the adductor magnus is compromised, other, smaller, muscles may need to pull more than there fair share of weight. In time this could mean injuries manifesting in and around these areas of compensation.
The most underrated aspect of the adductor magnus is the role it plays in hip extension. Thought to be a motion dominated by both the glutes and hamstrings, hip extension is heavily influenced by the adductor magnus. This is primarily the case when the hip is in a flexed position, say at the bottom of the squat or lunge. As the hip travels further into extension the adductor magnus works less, as the force is handled by the hamstrings and then glutes.
Muscle Electromyograph (EMG) readings show us that as an invidual progresses through hip extension the body simultaneously incorporates the glutes, adductor magnus, and hamstrings in an attempt to spread out the load over the changing joint angle (2). This ingenious design lends to the idea that the adductor magnus plays a role in the bigger movement systems of the body.
The least well known functions of the adductor magnus come in the form of flexion and internal/external rotation. The AM is thought to be responsible for the eccentric stabilization during internal rotation. This means that during the drive phase of gait (hip extension) the adductor magnus assists the glutes in creating torque at the femur. Though data does not suggest a major role for internal rotation, it is still a factor nonetheless.
In the case of external rotation the adductor magnus, along with the other adductor muscles plays a small role in rotating the femur laterally. The clinical significance of this is not well understood at this time.
Lastly, some of the anterior fibers originating on the ramus of the pubis are responsible for aiding in hip flexion.
Being the second largest muscle in the body, and dictating movements spanning all three dimensional planes, the adductor magnus is a muscle that demands your attention and respect. Forgoing both training and awareness of the muscle will result in you leaving potential on the table, as well as being at risk for injury. Just how to do so is dictated by just how the body incorporates the adductor magnus into into its own, larger, movement patterns.
Role In Muscular Systems
As alluded to before, the body does not function by isolating muscles. This would not only be less efficient but far too complex for the nervous system to handle. Instead, there are groups of muscles that synergize with one another to accomplish various movements. In the case of adductor magnus, it belongs to two different muscular systems, the anterior oblique and lateral subsystems.
Lateral Subsystem
The lateral muscular subsystem has one goal: to move the body in the frontal plane. This is the the lateral, side to side, movement that you may (or may not) be familiar with. Being the largest adductor (thus the name “magnus”) the AM is an influential member of this muscular system. It, along with the other adductors and abductors allow for the legs to gracefully move away and towards the midline of the body in a powerful and stabilized fashion. This means that any form of side stepping, or shuffling will incorporate the adductor magnus to varying degrees.
Though the average person does not have a great demand for lateral movement, athletes must be sufficient in the frontal plane of movement. A strong adductor magnus translates to increases in lateral acceleration and deceleration, a common theme in many terrestrial sports. This means an individual will be able to laterally move, and change directions, with ease.
Anterior Oblique Subsystem
In addition to moving the body in the frontal plane, the adductor magnus also helps with sagittal (forward/bacwark) movement by way of the Anterior Oblique Subsystem (AOS). Called such because it is located on the front of the body and travels at an oblique angle, the AOS is comprised of the oblique muscles of the abdomen and the adductors of the leg — the largset of which being the adductor magnus. This group of muscles works in unison, rotating the torso and generating torque at the hips. This motion helps to balance the body as it travels forward– the torque allowing for better force application and transfer.
Combined with the Posterior Oblique Subsystem (POS), the AOS helps to generate forward movement. Working with the design of the spine, both systems induce rotation, flexion/extension, along with lateral flexion. This means that all three dimensions are accounted for, translating to more stable and powerful movement.
Implications
From the average person to the professional athlete, the adductor magnus can have a wide ranging influence on life. A dysfunctional AM may lead to movement disorders which can result in pain anywhere along the length of the spine, potentially bleeding into the extremities. A strong and healthy adductor magnus leads to improved hip/spine stabilization, lateral movement, and forward gait; all of which are essential for life.
How Do I Train The Adductor Magnus?
Training the adductor magnus can be done through the use of traditional exercises, just bringing attention to the fact that the second strongest muscle in your body is located between your thighs. Some of the more effective exercise for the AM include unilateral movements that require significant ranges of hip flexion and extension. Additionally, incorporating hip adduction with hip extension exercises is another way to awaken the adductor magnus. Lastly, moving in the frontal plane through lateral exercises is yet one other means to target the AM. Some of these specific exercises include but are not limited to:
- Bear crawls
- Walking lunges
- Split squats
- Hip thrust with ball squeeze between the knees
- Partner resisted side shuffle
References
- Adductors. (2018, May 22). Retrieved from https://www.strengthandconditioningresearch.com/muscles/adductors/
- Vigotsky, Andrew & Bryanton, Megan. (2016). Relative Muscle Contributions to Net Joint Moments in the Barbell Back Squat.
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