Sway Fault¶

The Sway Fault is a core fault in which the hips move laterally — shifting sideways — during the forward swing instead of rotating around a stable vertical axis. Rather than turning through the ball, the player's lower body translates in the direction of the shot.

It is one of the four Core Leaks and, together with the Bucket Leak, is directly implicated in rotator cuff injury because it causes the Shoulder to receive force that the torso failed to manage.

Core Mechanism¶

The Kinetic Chain is a rotational system. Hip rotation generates angular momentum that travels upward through the torso in a sequenced, coiling motion. For this transfer to work, the hips must rotate — turning around a vertical axis while remaining in place laterally.

In the Sway Fault, the hips instead translate: they move sideways toward the target. The distinction is critical:

Motion Type	Effect on Chain
Rotation (correct)	Angular momentum generated; transfers upward through torso
Lateral translation (Sway Fault)	Linear momentum generated; does not convert to rotational force; chain has no axis to coil around

When the hips sway laterally, the rotational axis of the Kinetic Chain shifts or disappears entirely. The torso cannot coil properly. The Core cannot store and release elastic energy. Force that should have been amplified and transferred upward is instead pushed uselessly in the direction of movement.

How It Differs from the Bucket Leak¶

Both the Sway Fault and the Bucket Leak are pelvic-level failures, but they operate on different axes:

Fault	Axis of failure	Movement type
Bucket Leak	Sagittal (front-back)	Vertical tilt — hip drops
Sway Fault	Frontal (side-side)	Lateral translation — hips shift

The Bucket Leak collapses the rotational base vertically; the Sway Fault eliminates it laterally. Both result in the chain losing its stable axis, and both displace excess load to the shoulder.

Injury Pathway¶

The Sway Fault channels the rotator cuff overload mechanism identified in the source. When the Core fails to absorb and transfer force — whether through a Bucket Leak or a Sway Fault — the shoulder receives force that should have been managed in the torso. Chronic repetition across a competitive season accumulates load that produces the tears that end careers.

Visual Identification¶

The Sway Fault is visible as a sideways drift of the hips and torso in the direction of the shot during the forward swing. Unlike a powerful weight transfer or step-through (which occur before contact), the sway happens during the swing — the hips are moving laterally at the moment force should be rotating.

Players with a Sway Fault often feel like they are "hitting through" the ball aggressively, because the lateral motion creates a sensation of forward drive. The feel is deceptive — the energy is going sideways, not into the chain.

Correction Approach¶

Correcting the Sway Fault requires developing a clear kinesthetic distinction between rotation and translation. Key areas:

Establishing a stable rotational axis (spine angle, weight distribution)
Drills that physically constrain lateral movement while cueing rotation (wall drills, resistance band work)
Video feedback to make the lateral motion visible to the player

🌐 Read in Tiếng Việt — Vietnamese version of this wiki