I am unable to reproduce it constantly; when I was testing my mods in offline mode locally, this happened more frequently and during sprinting also. (probably a coincidence...)
This happened on both DayZ_Offline_Mode and Local_Server and real_Client.
For some reason this seemed to be more likely to occur around Position: 13333.671875, 19.276579, 5764.797852 as seen on the video
None of my mods edit player controls or animations. Current video uses only: @CF, @VPP and https://steamcommunity.com/sharedfiles/filedetails/?id=3343440904