What animation deformity is
Animation deformity (sometimes called "breast animation" or dynamic distortion) is movement or distortion of a breast implant when the pectoral (chest) muscle contracts. When you flex — pressing your hands together, doing a push-up, or simply tensing — the implant may flatten, ride upward or outward, ripple, or take on a temporarily abnormal shape, then return to normal when the muscle relaxes. It's most noticeable in active people, athletes and anyone whose work or training involves the chest.
Why it happens
Animation deformity is a direct consequence of where the implant sits relative to the pectoral muscle. When implants are placed under the muscle (the subpectoral or "dual-plane" position), the muscle lies directly over the implant. Every time that muscle contracts, it presses on and moves the implant beneath it — producing the distortion. The submuscular position has real advantages (more upper-pole coverage, lower capsular contracture rates, easier mammograms), so it's widely used — but animation is its trade-off. Implants placed over the muscle don't have a muscle sitting on top of them, so they don't animate.
How animation deformity is corrected
The definitive fix is a site change: moving the implant from under the muscle to over it (a subpectoral-to-prepectoral conversion). Because the implant then sits in front of the muscle, contracting the muscle no longer distorts it, and the animation resolves.
The challenge of moving an implant to the prepectoral plane is ensuring there's enough soft-tissue coverage in its new position, so the implant isn't too palpable or prone to rippling. This is usually addressed with:
- Acellular dermal matrix (ADM) — a supportive tissue-matrix sheet placed over the implant to add coverage and support in the new pocket.
- Fat grafting — transferring your own fat to thicken the soft-tissue layer, especially over the upper pole and edges.
- Closing the old pocket — the previous submuscular space is repaired so the implant stays securely in its new position.
Choosing a cohesive silicone implant in the new position also helps keep the result smooth, since silicone resists rippling better than saline (see saline vs silicone for revision).
Is it worth correcting?
Animation deformity isn't dangerous, so correction is a personal decision based on how much it bothers you. For some people it's a minor curiosity; for others — particularly the very active — it's a daily frustration that makes the result feel unnatural. Modern prepectoral techniques with ADM and fat grafting have made site change a reliable solution, which is why it's become a common revision request. The planning is individual, weighing your tissue thickness, implant choice and goals — the same individualised assessment described on our what is breast revision page.
The bottom line: animation deformity comes from a muscle sitting on top of your implant, and the fix is to move the implant in front of the muscle — with added coverage to keep the new result smooth and natural.
