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Maximum external rotation of the shoulder, commonly referred to as “layback” is essential for quarterbacks. Layback is key for velocity, accuracy, and efficiency.
Let’s break down why this is so essential and how it impacts a quarterback’s mechanics.
Maximum external rotation (MER) occurs during the late cocking phase of the throwing motion, when the shoulder rotates backward to its furthest position before transitioning into the acceleration phase. In this position, the humerus (upper arm bone) is rotated laterally away from the body while the forearm is positioned at a 90-degree angle relative to the upper arm, just before the arm is brought forward.
This is the “wind-up” where the quarterback’s arm reaches the furthest point back, creating the stretch necessary to generate force as the arm whips forward into the throw.
The shoulder’s maximum external rotation is critical in utilizing the stretch-shortening cycle (SSC). When the arm reaches this extreme external rotation, the muscles and connective tissues around the shoulder (especially the rotator cuff and posterior capsule) are stretched. This creates stored elastic energy, which is then released during the rapid internal rotation of the arm in the acceleration phase.
Just like a rubber band that stretches before it snaps forward, a quarterback’s layback position helps load the shoulder musculature to release stored energy, producing faster arm speeds and, ultimately, higher ball velocity. The more effective a quarterback is at reaching this external rotation, the more energy they can produce without relying solely on brute muscular force.
Maximum external rotation increases the distance over which torque is applied to the football. Torque is a product of force applied over a lever arm. When throwing, a greater range of external rotation allows for more rotational force to be applied over a longer path as the arm internally rotates, which translates to higher velocity throws.
Greater layback = longer distance the lever arm travels = more power and velocity.
The shoulder’s layback position plays a pivotal role in the kinetic chain, where energy is transferred from the lower body, through the core, and up through the throwing arm. Proper layback ensures that energy is effectively transferred from the legs and torso to the arm during the throwing motion. If a quarterback doesn’t reach maximum external rotation, they may compensate by overusing their arm, reducing their efficiency and increasing the likelihood of arm fatigue and injury. In addition, when not reaching proper layback, the timing of hip rotation is often too late resulting in a loss of velocity.
Layback is not only about power—it also helps with accuracy and consistency. When a quarterback reaches optimal external rotation, it helps them maintain proper arm slot and control over release/extension. This position allows for a more consistent release point and reduces variability in arm path, leading to better accuracy. A more efficient layback motion also allows the quarterback to have better wrist positioning for optimal spin.
It’s important to note that not all quarterbacks achieve optimal layback naturally. Several biomechanical factors can limit or enhance a quarterback’s ability to achieve maximum external rotation:
Scapular control is paramount in reaching full layback. If a quarterback has poor scapular retraction or upward rotation, the humerus will be unable to fully rotate externally. This is why training for thoracic mobility and scapular stability is essential, as it directly impacts the shoulder’s ability to reach maximum external rotation.
Athletes who lack shoulder mobility, especially in the posterior capsule, or have an imbalance between internal and external rotators, will struggle to reach maximum layback. Over time, limited mobility can also lead to compensatory mechanics, such as excessive elbow valgus or “dropping” the elbow during the throw.
Strength imbalances between the internal rotators and external rotators can limit a quarterback’s ability to achieve and maintain layback. Overdeveloped internal rotators often overpower the external rotators, preventing the necessary range of motion.
This is why a comprehensive shoulder strengthening program that focuses on both mobility and stability is vital. Strengthening the rotator cuff, particularly the external rotators, helps protect the shoulder from the repetitive stresses of throwing and enhances layback capacity.
If there is a breakdown in the timing of the kinetic chain—such as premature trunk rotation or inefficient lower body rotation—the quarterback may struggle to reach optimal layback. A quarterback must rely on proper hip and torso rotation to allow the arm to reach full external rotation. If the lower body isn’t driving the motion, the arm will compensate, leading to a less effective layback position.
Achieving optimal layback doesn’t just happen—it requires time, dedication, and specific training, especially at the elite level. Here are a few strategies we use with quarterbacks to improve their layback and overall throwing mechanics:
Incorporating dynamic stretches like thoracic spine rotations/extensions helps increase shoulder mobility and range of motion. Soft tissue work with foam rollers and resistance bands also helps to improve scapular mechanics, allowing the arm to rotate freely.
Rotator cuff strengthening exercises, like supine external rotations with DB or seated internal rotations with DB, are essential for both injury prevention and optimizing layback. I focus on maintaining the balance between the internal and external rotators to ensure a quarterback can reach maximum external rotation while maintaining shoulder health.
Since layback is heavily influenced by the kinetic chain, I emphasize core strength and rotational power. Exercises like medicine ball throws, cable pulls, and resisted trunk rotations improve the transfer of force from the lower body to the upper body, creating a more efficient throwing motion.
Using video analysis, I help quarterbacks become aware of their layback positioning and overall throwing mechanics. Drills that focus on sequencing the lower body, torso, and arm movements in the right order are essential for developing proper layback mechanics.
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