Shift Sprinting Camera Animation Based on?

The question i would like to ask is this -

How would I reference to my character motor to check if "if grounded" and or if speed is > 0. If anyone these are true I would have my character animate at the "Cam Walk" animation.

Here's the script I currently have -

---

 function Start () {

     animation["Cam Walk"].wrapMode = WrapMode.Loop;
     animation["Cam Walk"].speed = 4;
     animation["Cam Walk"].layer = 1;
     animation["Cam Walk"].blendMode = AnimationBlendMode.Blend;

}

function Update () {

         if(Input.GetButtonDown("ADS")) { 

                 animation.Play("Cam DOF");

}

         if(Input.GetButtonUp("ADS")) { 

                 animation.Play("Cam DOF Off");

}

// Walking and Running Anims.

     if(Input.GetKeyDown(KeyCode.LeftShift)) {
             animation.CrossFade("Cam Walk", 0.1);
     
 }
 
             if(Input.GetKeyUp(KeyCode.LeftShift)) {
                     animation.Stop("Cam Walk");
     
 }

}