Aszmann et al reported the areas that are most susceptible to mechanical trauma are in Types A, B and C. 10 Grothhaus et al reported results of 29 cadaver studies and found the lateral femoral cutaneous nerve was potentially at risk along the inguinal ligament as far as 7.3 cm medial to the ASIS and as much as 11.3 cm distal on the sartorius muscle from the ASIS. 9
Because of the unique course the LFCN may take, a working knowledge of these potential variations can be useful for the acupuncturist when diagnosing the site of entrapment, the tissues affected and the myofascial channels involved in the condition.
Meralgia Paresthetica produces similar signs and symptoms as those associated with upper lumbar nerve root (L1‐L3) injury and trochanteric bursitis. These two conditions should be ruled out with the associated exams. When differentiating potential injury diagnosis for anterior thigh pain and/or paresthesia, meralgia paresthetica should be considered especially when particular postures are present and the history includes repetitive activities, which can result in the compression or lengthening of the tissues in the anterior thigh and inguinal regions.
Common postures associated with this condition are increased lumbar lordosis with an anterior pelvic tilt that would compress the region,and an anterior hip shift that lengthens the involved tissues.
Because of the variation in regions of nerve entrapment, each patient will have their own unique clinical presentation and distribution of symptoms.
- Patients may complain of pain, burning, numbness, muscle aches, coldness, lightning pain, or buzzing in their lateral or anterolateral thigh.
- The patient may have a history of similar paresthesia, which in the past has resolved quickly but has increased significantly after an increase in a particular activity.
- Patients may report pain with prolonged standing and walking and alleviation with sitting.Sitting may reduce or change the tension in the LFCN or inguinal ligament, thus reducing symptoms.
- Modified Ober’s Test is a provocative test to induce MP symptoms.
- Pelvic Compression Test—This maneuver is used for when symptoms are present. A positive test will decrease the patient’s symptoms.
- Standing Lunge—The tissues of the anterior thigh can be stretched and can increase symptoms.
- Straight Leg Raise Test and Slump’s Test are two exams for radicular pain coming from the lumbar spine that can help rule out MP.
- Tinel’s Sign can be used at the different locations of LFCN entrapment.
- Painful palpation of the trochanteric bursae with matching history to diagnose GT bursitis.
- MP has been related to the following factors: obesity, pregnancy, tight garments such as jeans, military armor and police uniforms, seat belts, direct trauma, muscle spasm and scoliosis. 11-12 Metabolic factors reported include diabetes mellitus, alcoholism, and lead poisoning. 13
- MP has also been reported as a post‐surgical complication after hip joint replacement and spine surgery. 14
The primary channel sinews (jingjin) affected are the Spleen and Stomach. The sartorius muscle attachment is part of the Spleen jingjin and the inguinal ligament, especially due to its abdominal connection, belongs to the Stomach jingjin.
The practitioner will need to consider points along these channels to influence their effect on the condition such as with cleft-xi points, connecting-luo and source-yuan points. Myofascial work after acupuncture treatment is necessary for long-lasting results.
The practitioner should also prescribe postural and therapeutic exercises to enhance the effect of the treatment and encourage new tissue positioning. For best results, local, adjacent and distal points should be used based on TCM channel theory with the constitution of the patient addressed.
The following is a discussion on local points, target tissue needle technique, moxibustion and a few common therapeutic exercises:
- ST 31 (biguan)—Upper motor point of the rectus femoris and local point for the LFCN entrapment site found distal to the ASIS (Type D).
- Sartorius motor points (proximal and distal)—The sartorius is involved in Types B, C and D nerve entrapment sites. In addition, the sartorius (belonging to the Spleen sinew channel) is fascially connected to the inguinal ligament and tension between these two structures have an influence on the other.
- GB 27 (wushu)—Propagate the needle sensation down the leg following the ST channel or toward the groin.