I have a ragdoll simulation for a physics based character up and running in box 2D. But if I try to run it at low frequencies like 60 Hz ( 240 .. or so doesn't work as well ) joints seem to be very unstable and jitter a lot even when I don't apply any forces on the ragdoll. I have to use really high frequencies close to 5000Hz to get a correct behaviour. I am wondering what I am doing wrong to cause this. My character dimensions are that of an average human body in meters and so is the weight for each body part.
When I try to pull the neck the two small bodies which are connected by revolute Joints get broken and they jitter in various positions. I am not sure if I am supposed to require such high frequency for this kind of simulation to work. I am using the standard position and velocity iterations ( 8 and 3 respectively )
Also as you can see there's a gap between the ground plan and the other bodies. Is that due to skin used as a safety region during collisions for polygons ? I am not sure ....