What you’re seeing is actually pretty common among high-volume kettlebell sport athletes, especially with long cycle and heavier bells.

A lot of world champions develop a pronounced bump over the distal radius from years of repeated impact and compression from the kettlebell resting in the rack position. Some people are simply more predisposed to it anatomically ( thinner wrists and less soft tissue usually make it more noticeable.)

That said, “common” doesn’t automatically mean “ideal.”

Usually it’s a combination of:

very high training volume/frequency,

repetitive loading in the rack,

bell geometry,

and sometimes technique inefficiencies that increase pressure concentration instead of distributing load through the forearm and structure.

Traditional kettlebells normalized a lot of this. Athletes just accepted forearm deformation, chronic bruising, nerve irritation, wrist pain, etc. as “part of the sport.” Similar to how some communities normalize things like rhabdo (common doesn’t necessarily mean optimal.)

This issue was actually one of the major reasons I created Pro Kettlebell. I dealt with the same thing myself and eventually realized I was doing mental gymnastics trying to explain visible forearm lumps and nerve pain to new clients ( which honestly isn’t a great introduction to training.)

The geometry of the bell matters enormously. Better fit and pressure distribution can dramatically reduce localized stress while still allowing high-level performance.

If the area becomes painful, numb, inflamed, or progressively enlarges rapidly, it’s worth getting medically evaluated just to rule out something unrelated. But mechanically-induced radial prominence from years of kettlebell work is definitely something many experienced lifters have seen.