Suppose a manual therapist found cause to contact the Lumbar Plexus in the abdomen. Maybe it’s sensitized or entrapped. Maybe the therapist suspects distal irritation to stem from a proximal cause. How on earth could they engage the plexus with reasonable confidence, given its depth and palpatory obscurity?
The short answer: Grab what the plexus grabs.
The same tissues that supposedly obscure it are your greatest tools. The loose connective tissue within its layer. The interfacing fascial planes. The perforated and innervated tissues.
The body’s mechanical resting state is sometimes called a “Pre-Stress” or (or pre-load, or tensegrity) in which all tissues are suspended together in a balance of fluid pressure and membranous tension. Any act of therapeutic contact depends on modifying this pre-stress, at least temporarily, to make an assessment or elicit a physiologic change. Nerves also exist in pre-stress, pressurized from within and gently tensioned along their length.
So the method for meaningful contact is to ‘hook’ tissues mechanically linked to the Plexus — like the anterior thoracolumbar fascia and the muscular abdominal wall — and deform them in a way that is likely to change the basal pressure/tension on the associated nerves.
Likewise the innervated tissues can be a tool for engagement. The Lumbar Plexus ventral rami must perforate through the Psoas muscle and then course laterally and inferiorly within the pelvic bowl, behind the kidney capsule and peritoneal balloon. The dorsal rami peel off posteriorly just lateral to the intervertebral foramen, sending branches around the facet capsules, into the paraspinal muscles, and into the skin of the low back and buttocks.
All of these interfacing, perforated, and innervated tissues form a connected fabric — a neurofascia — whose skillful co-engagement might allow for a meaningful contact with the lumbar plexus nerves.
Caveats to keep in mind:
Depth ≠ Pressure! You will notice I am not “deep tissueing” any muscles here. Gentle and slow deformation is enough to get dramatic change in the defensive behavior (pain, guarding, inflammation) of the nervous system.
Palpation ≠ Objective finding! It is Practitioner-Subjective. You will also notice that despite the richness of my experience, I am not compelling my patient to accept my observations as fact. I am not making key diagnoses or assessments based solely on palpation either. What I am doing: Stating what I am feeling. Using palpation to ask more subtle questions of the body. Refining the location and depth of my work. Scanning for sensitized or abnormal tissues.
Tactics ≠ Strategy! As usual it feels incomplete to share videos of manual therapy “moves”, without also constructing the clinical reasoning process that makes them coherent. I shall ask your patience with the infrequency of my posts. And I’ll welcome you, internet friends, to be incensed or inspired according to your inclination.