Because the hamstring part of the AM attaches to the adductor tubercle on the femur (near the knee), it maintains a consistent moment arm (leverage) throughout the squat. When your hamstrings "turn off" in the hole of a squat, the Adductor Magnus is working overtime to extend your hip.
The Adductor Magnus is unique among the medial thigh muscles because it receives innervation from , reflecting its dual functional nature. adductor magnus muscle
Take a slightly wider than hip-width stance. As you hinge back, focus on screwing your feet into the floor and "presenting your pockets" to the wall behind you. You will feel the medial hamstrings and the AM light up. Because the hamstring part of the AM attaches
The sumo stance is the king of AM training. By taking a wide stance with your toes turned out, the adductor magnus is placed under a massive stretch at the bottom of the lift. Driving the floor apart and extending the hips recruits the AM like no other exercise. Take a slightly wider than hip-width stance
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:
This is the isometric killer. Lie on your side, place your top leg on a bench, and lift your hips off the ground using your bottom leg's adductors.