To train the hamstring portion (hip extension), you need hip extension with a wide stance. To train the adductor portion (leg adduction), you need resistance pulling you outward.

As you descend into a squat, the adductor magnus prevents your knees from caving inward (valgus collapse). It keeps the femur in a neutral alignment relative to the pelvis.

Why? Look at a deep squat. As you descend past parallel, your hamstrings actually slacken because they attach above the knee and below the hip. When the knee bends, the hamstring tension drops. However, the Adductor Magnus doesn't have this problem.

If the Adductor Magnus is chronically tight, it pulls on the sit bone, which pulls on the sacrotuberous ligament, which torques the sacrum, leading to...

When people talk about leg strength, the conversation almost always starts and ends with the glutes and the quads. Squat depth? “Squeeze your glutes.” Deadlift lockout? “Drive your hips through.” While the glutes certainly deserve their crown as the king of posterior chain power, there is a silent guardian, a watchful protector lurking deep in your inner thigh: The Adductor Magnus.