How can I move this part in a rectangle when I press a key? [C#]

I am trying to get an object to move in a rectangle when I use either the"Horizontal" or "Vertical" input axes. What I have tried keeps on adding to the position, making the localPosition extremely high, eventually to an error. If I am doing something wrong, please tell me. Any help will be appreciated. (The part is an inverse kinematic tracker part)

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class IkProceduralAnimation : MonoBehaviour {
     Animator anim;
     public Transform LeftArmIkTarget;
     public Transform RightArmIkTarget;
     public Transform LeftLegIkTarget;
     public Transform RightLegIkTarget;
 
     public Transform Head;
     public Transform UpperTorso;
     public Transform LowerTorso;
     public Transform LeftEye;
     public Transform RightEye;
 
     float ikWeight = 1;
 
 
     // Use this for initialization
     void Start () {
         anim = GetComponent<Animator>();
     }
     
     // Update is called once per frame
     void Update () {
         if (Input.GetAxis("Vertical") != 0 || Input.GetAxis("Horizontal") != 0)
         {
             StartCoroutine("Walk");
             
         }
     }
     IEnumerator Walk()
     {
 
         float LeftLegMovementHeight = 0.01f;
         float LeftLegMovementWidth = 0.01f;
         float LeftLegMovementSpeed = 2;
 
         yield return new WaitForSeconds(0.1f);
         Debug.Log("LegUp");
         LeftLegIkTarget.localPosition += Vector3.Lerp(LeftLegIkTarget.localPosition,new Vector3(0,0,LeftLegMovementWidth),Time.deltaTime*LeftLegMovementSpeed);
         yield return new WaitForSeconds(0.1f);
         Debug.Log("LeftForward");
         LeftLegIkTarget.localPosition += Vector3.Lerp(LeftLegIkTarget.localPosition, new Vector3(0, LeftLegMovementHeight, 0), Time.deltaTime * LeftLegMovementSpeed);
         yield return new WaitForSeconds(0.1f);
         Debug.Log("LegDown");
         LeftLegIkTarget.localPosition += Vector3.Lerp(LeftLegIkTarget.localPosition, new Vector3(0, 0, -LeftLegMovementWidth), Time.deltaTime * LeftLegMovementSpeed);
         yield return new WaitForSeconds(0.1f);
         Debug.Log("LegBack");
         LeftLegIkTarget.localPosition += Vector3.Lerp(LeftLegIkTarget.localPosition, new Vector3(0, -LeftLegMovementHeight, 0), Time.deltaTime * LeftLegMovementSpeed);
     }
 
     void OnAnimatorIK ()
     {
         anim.SetIKPositionWeight(AvatarIKGoal.LeftFoot, ikWeight);
         anim.SetIKPosition(AvatarIKGoal.LeftFoot, LeftLegIkTarget.position);
 
         anim.SetIKPositionWeight(AvatarIKGoal.RightFoot, ikWeight);
         anim.SetIKPosition(AvatarIKGoal.RightFoot, RightLegIkTarget.position);
 
         anim.SetIKPositionWeight(AvatarIKGoal.LeftHand, ikWeight);
         anim.SetIKPosition(AvatarIKGoal.LeftHand, LeftArmIkTarget.position);
 
         anim.SetIKPositionWeight(AvatarIKGoal.RightHand, ikWeight);
         anim.SetIKPosition(AvatarIKGoal.RightHand, RightArmIkTarget.position);
     }
 
    
 }