In a kipping pull-up, which of the following is considered a fault?

• A. Bent arms in the hang
• B. Proper thumb placement
• C. Keeping knees locked
• D. Stable hips

Answer: (B)

Grip and hand position set up the bar for a safe, fluid kipping motion. The thumbs play a big role in how securely and how smoothly you can hold onto the bar as you swing and transition from the kip to the pull. In this particular assessment framing, the cue given treats the way the thumbs are placed as a fault because it can interfere with grip stability and wrist alignment during the explosive portion of the movement. If the thumbs are positioned in a way that concentrates grip around the bar or otherwise restricts the wrist’s ability to rotate naturally, the bar is more likely to roll or slip in the hands, and the bar path can become unstable—leading to compromised form or a failed rep.

By contrast, the other points describe faults that clearly disrupt the pattern of a proper kip: bending the arms in the hang breaks the straight-arm setup that initiates the swing; keeping knees locked tends to rob you of the hip-driven momentum; and unstable hips directly disturb the kip’s timing and power transfer. The grip issue, though, is a foundational factor that affects bar control throughout the movement, which is why it’s highlighted as the fault in this item.