# Body tracking within a group - strange joint positions that don't appear to update for some people

**URL:** <https://community.stereolabs.com/t/body-tracking-within-a-group-strange-joint-positions-that-dont-appear-to-update-for-some-people/2801>\
**Category:** C++\
**Created:** [June 13, 2023, 5:56am UTC](https://community.stereolabs.com/t/body-tracking-within-a-group-strange-joint-positions-that-dont-appear-to-update-for-some-people/2801 "2023-06-13T05:56:11Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![trent](https://community.stereolabs.com/letter_avatar_proxy/v4/letter/t/f05b48/32.png) [@trent](https://community.stereolabs.com/u/trent)\
**Post date:** [June 13, 2023, 5:56am UTC](https://community.stereolabs.com/t/body-tracking-within-a-group-strange-joint-positions-that-dont-appear-to-update-for-some-people/2801/1 "2023-06-13T05:56:11Z")

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Hi, today I was performing a group test with the Zed 2i- tracking people via body tracking (BODY\_TRACKING\_MODEL::HUMAN\_BODY\_FAST + BODY\_FORMAT::BODY\_18). I screen recorded for about 2 minutes- and noticed the joint positions of 2 people in the group were distorted and appeared frozen but still continued tracking the users main position as they walked around.

Have attached 2 screenshots- showing the issue. Tracked user ID 173 (left of first image) and ID 124 (right of 2nd image).

Was wondering if this is common issue / bug / or any advice on how I could fix?

![Screen Shot 2023-06-13 at 3.31.30 pm](https://community.stereolabs.com/uploads/default/original/2X/0/0595bc25694c95f02eae4e76006059a49d5e1256.png)  
 ![Screen Shot 2023-06-13 at 3.32.00 pm](https://community.stereolabs.com/uploads/default/original/2X/2/2581d51edf1007eff79c933ba1b9e07483e981b5.png)

Thanks!

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**Author:** ![JPlou](https://community.stereolabs.com/user_avatar/community.stereolabs.com/jplou/32/1012_2.png) [@JPlou](https://community.stereolabs.com/u/JPlou)\
**Post date:** [June 13, 2023, 8:37am UTC](https://community.stereolabs.com/t/body-tracking-within-a-group-strange-joint-positions-that-dont-appear-to-update-for-some-people/2801/2 "2023-06-13T08:37:27Z")

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Hi @trent ,

First, sorry but to my knowledge it’s not a common issue.

What version of the SDK and what depth mode was being used?  
Can you share the result of ZED Diagnostic (Windows: `C:\Program Files (x86)\ZED SDK\tools\ZED Diagnostic.exe` / Linux: `/usr/local/zed/tools/ZED_Diagnostic`) and a SVO reproducing the issue to [support@stereolabs.com](mailto:support@stereolabs.com)? It will help a lot in investigating this quickly.

Best,  
Jean-Loup