# Avatars upper body spasms violently when moving

**URL:** <https://ask.vrchat.com/t/avatars-upper-body-spasms-violently-when-moving/46968>\
**Category:** Avatars\
**Tags:** avatar, sdk3\
**Created:** [October 19, 2025, 5:45pm UTC](https://ask.vrchat.com/t/avatars-upper-body-spasms-violently-when-moving/46968 "2025-10-19T17:45:31Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![bitmotte](https://yyz1.discourse-cdn.com/vrchat/user_avatar/ask.vrchat.com/bitmotte/32/42596_2.png) [@bitmotte](https://ask.vrchat.com/u/bitmotte)\
**Post date:** [October 19, 2025, 5:45pm UTC](https://ask.vrchat.com/t/avatars-upper-body-spasms-violently-when-moving/46968/1 "2025-10-19T17:45:31Z")

</div>

Video example:

[![](https://global.discourse-cdn.com/vrchat/original/3X/6/9/69908040faceeb90dd4e868c3b2d5d56a16b2c09.jpeg "avatar spasms") ](https://www.youtube.com/watch?v=nLe8ItrI4YE)

Hello, whenever my avatar moves, the upper body spasms.  
It seems to occur more when the arms are fully outwards like a zombie.

I have checked, and there are no phys-bones affecting the upper body.  
It does not occur on other avatars, which means it’s not an issue with my headset.  
It has happened on some of my other avatars, from what I remember.  
It also occurs on Quest, from what I remember  
The avatar does have GoGo Loco, but it still occurs when removing it.

If anyone knows how to fix this, help would be appreciated.

---

<div class="post-metadata">

**Author:** ![bitmotte](https://yyz1.discourse-cdn.com/vrchat/user_avatar/ask.vrchat.com/bitmotte/32/42596_2.png) [@bitmotte](https://ask.vrchat.com/u/bitmotte)\
**Post date:** [October 19, 2025, 6:39pm UTC](https://ask.vrchat.com/t/avatars-upper-body-spasms-violently-when-moving/46968/2 "2025-10-19T18:39:09Z")

</div>

Nevermind. I did some more testing and It turns out that since I had really tiny bones taking placed of the spine, neck and shoulders since I didn’t need those bones but VRChat did, those caused the issue. Scaling them up fixed it.