the function of a strain relief loop of an implantable medical lead is preserved by inhibiting restriction of the strain relief loop from tissue growth onto the strain relief loop . the restriction may be inhibited by either obstructing tissue growth and / or by utilizing a mechanical advantage to overcome the restriction . the tissue growth may be obstructed be isolating the interior of the strain relief loop such as by enclosing the strain relief loop or including an object within the loop . the mechanical advantage to overcome restriction from tissue growth may be provided in various ways such as utilizing a spring loaded mechanism or a structure such as an elastic mesh , tube , or mold having an inherent bias toward a steady state position .