How to add constraints to the limbs of the FBX character model driven by IK

Question

I’m trying to add constraints to the limbs of my ik-driven fbx character model, hoping to prevent the model from making anti-human actions. I’m currently trying to use Vector3 to constrain the ik chain, but I don’t know how Vector3 acts on the model. I don’t know much about the constraints. The following are the constraints in my ik chain values:

leftLeg: {
        target: '左腿控制_L',
        effector: 'mixamorigLeftFoot',
        links: [
          {
            name: 'mixamorigLeftLeg',
            rotationMin: new THREE.Vector3(-Math.PI / 1.2, 0, 0),
            rotationMax: new THREE.Vector3(0, 0, 0) 
          },
          {
            name: 'mixamorigLeftUpLeg',
            rotationMin: new THREE.Vector3(-Math.PI / 1.5, -Math.PI, -Math.PI), 
            rotationMax: new THREE.Vector3(Math.PI / 1.7, Math.PI, -Math.PI/2) 
          }
        ]
      },

Why do ghosts appear and keep scurrying around when the movement reaches the minimum value?

Why do ghosts appear and keep scurrying around when the movement reaches the minimum value?