Systems and methods for restoring muscle function to the lumbar spine and kits for implanting the same

1. An electrode lead configured to be implanted in or adjacent to tissue associated with control of the lumbar spine, the electrode lead comprising:

an elongated lead body having a proximal end and a distal end;

one or more electrodes disposed along the distal end of the elongated lead body;

a first fixation element coupled to the elongated lead body at the distal end, the first fixation element comprising a first plurality of projections radially spaced around the elongated body; and

a second fixation element coupled to the elongated lead body distal to the first fixation element, the second fixation element comprising a second plurality of projections radially spaced around the elongated body and radially offset from the first plurality of projections, the first and the second fixation elements configured to transition from a delivery state, wherein the first and second fixation elements collapse inward toward the elongated lead body, to a deployed state, wherein the first fixation element is angled distally relative to the elongated lead body and the second fixation element is angled proximally relative to the elongated lead body and toward the first fixation element, to anchor the one or more electrodes in or adjacent to the tissue associated with control of the lumbar spine,

wherein at least one of the one or more electrodes is disposed between the first and second fixation elements.

2. The electrode lead of claim 1 , wherein the first and the second fixation elements do not overlap when collapsed inward toward the elongated lead body in the delivery state.

3. The electrode lead of claim 1 , wherein the one or more electrodes are configured to stimulate a dorsal ramus nerve, or fascicles thereof, that innervate a multifidus muscle.

4. The electrode lead of claim 1 , wherein the electrode lead is configured to be anchored to muscle tissue associated with control of the lumbar spine.

5. The electrode lead of claim 1 , wherein the electrode lead further comprises a strain relief portion.

6. The electrode lead of claim 1 , wherein the second plurality of projections are radially offset from the first plurality of projections by a predetermined angle.

7. The electrode lead of claim 6 , wherein the first plurality of projections are equidistally spaced apart radially from each other and the second plurality of projections are equidistally spaced apart radially from each other.

8. The electrode lead of claim 1 , wherein the first plurality of projections has three projections spaced apart by 120 degrees and the second plurality of projections has three projections spaced apart by 120 degrees.

9. The electrode lead of claim 8 , wherein the first plurality of projections are radially offset from the second plurality of projections by 60 degrees.

10. The electrode lead of claim 1 , wherein the first and the second fixation elements are composed of a flexible polymer.

11. The electrode lead of claim 1 , wherein the first fixation element is proximal to a distal-most electrode of the one or more electrodes and the second fixation element is distal to the distal-most electrode such that the distal-most electrode is positioned between the first and the second fixation elements.

12. The electrode lead of claim 1 , wherein the elongated lead body includes a stylet lumen extending therethrough, the stylet lumen configured to permit a stylet to be inserted therein.

13. A kit comprising the electrode lead of claim 1 and an implantable pulse generator.

14. A method for implanting an electrode lead in or adjacent to tissue associated with control of the lumbar spine for restoring muscle function of the lumbar spine to reduce back pain, the method comprising:

selecting an electrode lead comprising an elongated lead body having a proximal end and a distal end, one or more electrodes disposed along the distal end of the elongated lead body, a first fixation element comprising a first plurality of projections radially spaced around the elongated body, and a second fixation element comprising a second plurality of projections radially spaced around the elongated lead body distal to the first fixation element and radially offset from the first plurality of projections, wherein at least one of the one or more electrodes is disposed between the first and second fixation elements;

delivering the distal end of the elongated body in a delivery state where the first and second fixation elements are collapsed inward toward the elongated lead body; and

expanding the first and second fixation elements to a deployed state where the first fixation element is angled distally relative to the elongated lead body and the second fixation element is angled proximally relative to the elongated lead body and toward the first fixation element to anchor the one or more electrodes in or adjacent to the tissue associated with control of the lumbar spine.

15. The method of claim 14 , further comprising stimulating, via the one or more electrodes, the tissue associated with control of the lumbar spine to cause muscle contraction.

16. The method of claim 15 , wherein stimulating the tissue comprises stimulating a dorsal ramus nerve, or fascicles thereof, that innervate a multifidus muscle.

17. The method of claim 14 , further comprising coupling the proximal end of the electrode lead to an implantable pulse generator.

18. The method of claim 17 , further comprising:

selecting an external programmer and a handheld activator;

transferring programming data to the implantable pulse generator from the external programmer; and

operating the handheld activator to command the implantable pulse generator to provide electrical stimulation to stimulate the tissue via the one or more electrodes responsive to the programming data.

19. The method of claim 14 , further comprising:

selecting a tunneler comprising an elongated shaft, a proximal end having a handle, and a distal portion removably coupled to a tunneler tip;

selecting a sheath having a lumen extending therethrough configured to receive the elongated shaft of the tunneler;

tunneling the tunneler, the sheath, and the tunneler tip subcutaneously between a first incision site and a second incision site such that the sheath spans the first and second incision sites, the sheath having the tunneler disposed therein during the tunneling;

decoupling the tunneler tip from the distal portion of the tunneler;

removing the tunneler from the sheath while the sheath continues to span the first and second incision sites;

feeding the proximal end of the electrode lead through an end of the sheath until the proximal end of the electrode lead is exposed at the other end of the sheath;

removing the sheath from the subcutaneous tunnel between the first and second incision sites;

coupling the proximal end of the electrode lead to the implantable pulse generator; and

implanting the implantable pulse generator at the second incision site.