Nerve entrapment by the illio-psoas causing pain, tingling, and numbness in the groin, pelvic, abdominal, perenial, gential, and upper thigh area.

An update from my blog written on Jan 2011

This is a follow up on my blog written some 2 years ago explaining my experience with nerve entrapment by the illio-psoas muscle. At the time I was uncertain what exactly the cause of my symptoms were. I was just very pleased they were going away. After doing some research and talking to other medical professionals, my experience describes the onset, symptoms, and recovery of a illio-psoas muscle strain and nerve entrapment.

Many of the replies to the previous blog appear to be suffering from the same condition. Some however appear to not quite line up with this exact condition. Again I am a personal trainer, not a doctor or physical therapist so I could never give a diagnosis based on a blog reply nor could any medical professional.

Other possible conditions and injuries
Many of these symptoms line up with other conditions where nerve aggravation is present, but not from muscles or fascia. Commonly these symptoms can be a result of a spinal disc injury. A herniated disc can cause a lot of these issues (http://www.mayoclinic.com/health/herniated-disk/DS00893) as well as other conditions (http://en.wikipedia.org/wiki/Cauda_equina_syndrome [rare]), reproductive issues, cysts or growths. A few replies sound a lot like ostetis pubis (http://emedicine.medscape.com/article/87420-treatment#aw2aab6b6b2) which is a groin injury and more specifically the inflammation of the pubis symphosis. I know personally because I am currently recovering from this caused by a combination of sprinting and being overly tight in the adductors and rectus abdominus. Another future blog will describe this. There is also the possibility of reproductive issues. As you can see, there are a lot of possible injuries/issues associated with these symptoms. Any doctor can start to rule out any of the obvious conditions by getting various tests done. An MRI for the spine would be important to rule out any disc injury or condition.

Comments and Replies
Some of the replies to my blog are from people who had many tests come back negative and with their doctors having no idea what was wrong with them. Some doctors may blame it on psychological factors or some may just say, “you probably pulled something. Give it some time to rest and it probably will just go away.”. Most of the people reading my last blog had done this already with no success. For those who have gone through multiple doctors and tests, you may want to start to look at a muscle strain of illiopsoas as the primary cause. Others may have this in addition to other injuries which commonly coincide with low back injury.

Illiopsoas muscle strain and nerve entrapment

The illiopsoas is a muscle that can often contribute to low back and pelvic pain. A strain in this muscle will cause it to tighten up, produce muscle spasms, and create knots/trigger points in the muscle itself or fascia. There is also the possibility of hematoma in the muscle causing issues due the inflammation and enlargement of the muscle.

Here are excerpts from Travell and Simmons, The Trigger Point Manual taken from, www.triggerpoint.ca/index.php?p=1_64_Travell-Simons-Trigger-Point ,which has a very good list of relevant excerpts:

"ENTRAPMENT may occur because of pressure by the palpable bands of taut muscle fibers that are associated with myofascial TrPs, when the nerve passes through the muscle between taut bands, or when it is compressed between such a band and bone. The cause of the neurological symptoms and signs of neurapraxia that result is easily misinterpreted if this mechanism of entrapment is not recognized."

Travell and Simons; Myofascial Pain and Dysfunction, The Trigger Point Manual; 1999; pg. 94.


On untrained physician’s diagnosis on an unrecognized condition.

"It is all too easy for the physician to blame the patient's psyche for the inability of the physician to recognize the muscular skeletal sources of the patients pain. This wrong assumption can be and often is devastating to the patient."

Travell and Simons; Myofascial Pain and Dysfunction, The Trigger Point Manual; 1999; pg. 220


Common for athletes and vigorous exercisers 

“Good Sport” Syndrome

"The “good sport” syndrome is the opposite of hypochondriasis. The “good sport” has a stoical attitude and is determined to ignore pain. He or she charges forth engaging in activities with total disregard, if not outright defiance, of the pain, thereby overloading the muscles and aggravating trigger points. “Good sports” often believe that their pain is a sign of "weakness" and that they must push on to demonstrate their mastery of it. They must learn how this abuse of their muscles contributes to their pain, and how new ways of doing things can let them perform the activities important to them safely and comfortably."

Travell and Simons; Myofascial Pain and Dysfunction, The Trigger Point Manual; 1999; pg. 221

Depression and Pain

"A major, well recognized contributor to depression is chronic pain. On the other hand, pain may lower the pain threshold, intensify pain, and impair the response to specific myofascial therapy. Patients who have suffered myofascial pain for months or years are likely also to have developed secondary depression and sleep disturbances, and to have restricted their activity and exercise."

Travell and Simons; Myofascial Pain and Dysfunction, The Trigger Point Manual; 1999; pg. 110


Trigger Points and Nerve Entrapment by the Iliopsoas

Travell defined a trigger point as “a hyperirritable spot in skeletal muscle that is associated with a hypersensitive palpable nodule in a taut band. The spot is tender when pressed and can give rise to characteristic referred pain, motor dysfunction, and autonomic phenomena.”

“Acute myofascial pain due to TrPs caused by a clearly identifiable strain on one muscle is, as a rule, able to be fully relieved and normal function restored.”

The strain of the illiopsoas muscle leads to the formation of trigger points. These trigger points can refer pain in the classic pattern as shown below.

My previous blog talks about nerve entrapment from trigger points. In this situation, the pain will follow along through the nerve pathway giving way to these mysterious pains of many areas. There are a number of nerves passing through and along the psoas that can be irritated.

Again www.triggerpoint.ca/index.php?p=1_64_Travell-Simons-Trigger-Point has a great list of excerpts and information regarding trigger points.

Iliopsoas Anatomy
The iliopsoas is comprised of three muscles. The illiacus, psoas major, and psoas minor. They are often grouped together as the iliopsoas muscles because they work together to perform the same functions. They work to perform hip flexion and external rotation, lumbar spine extension, same side rotation, and lateral flexion.

The illiacus originates from the iliac fossa and inserts to the lesser trochanter of the femur.

The psoas major originates from vertebraes T-12 to L-5 and joins the illiacus to insert into the lesser trochanter. Being that this muscle originates from the lumbar spine, there are many nerves that run in, around, and along the psoas muscle. Nerve roots exit the vertebrae and many branches of these nerves come in direct contact with the psoas. The lumbar plexus, which is a plexus of nerves that includes nerves L-1 through L4 are in fact formed through the psoas. Like all nerves they branch into smaller nerves as you trace it further from its origin.

From Travell and Simmons

Common Trigger Point Pain Pattern
Trigger points can refer pain or other symptoms to other areas as seen in image 2. This is the common referral pattern of the iliopsoas from trigger points. Symptoms can arise in other areas as many people experience.

From Travell and Simmons

As stated earlier, strain or trauma to the psoas can lead to “knots” or trigger points that irritate the nerves or create pain along the nerves pathway. Describing each possible nerve that could be affected and tracing its path is tedious and lengthy for most readers. Instead of writing on this, below are some possible and common nerves that can become entrapped by trigger points in the psoas muscle and cause pain described in my previous blog.

Possible nerves that can be entrapped by the psoas and pain symptoms:
Notice the areas that these nerves supply as those are commonly symptomatic areas.
From Primal 3D Human Anatomy Regional Edition

Iiliohypogastric Nerve:
Originates from the ventral ramus of the L1 nerve with a small branch from the ventral ramus of the T12 nerve. They "pass inferolaterally through psoas major to emerge from their superolateral border with or above the ilio-inguinal nerves and passes over the anterior surface of quadratus lumborum to pierce transversus abdominis above the iliac crest." It branches into the Lateral cutaneous and anterior cutaneous branches.

It supplies the transversus abdominis and internal oblique muscles as well as the posterolateral gluteal and suprapubic skin (the region on the upper/side glute and just above the pubic bone).
Ilio-inguinal Nerve:
Originates from the ventral ramus of L1 nerve and "emerge from the superolateral border of psoas major with or below the iliohypogastric nerves. Each ilio-inguinal nerve passes obliquely across quadratus lumborum and the superior part of iliacus to pierce the transversus abdominis and internal oblique muscles. Subsequently, ilio-inguinal nerves pass deep to the aponeurosis of external oblique to enter the inguinal canal." It Branches into the anterior scrotal branches for males and labial branches and for females.

It supplies the internal oblique muscle the skin of the superomedial thigh the root of the penis and the upper part of the scrotum in males, and the skin of the mons pubis and labium major for females.
Genitofemoral Nerve:
It originates from the ventral rami of the L1 and L2 nerves "and is formed in the substance of the psoas major muscle where it then emerges from its anterior surface, where it penetrates the psoas fascia. It divides into genital and femoral branches above the inguinal ligament."
Femoral Branch
It "enters the thigh behind the inguinal ligament" and "enters the femoral sheath lateral to the femoral artery, which it supplies. It then pierces the anterior femoral sheath and the fascia lata to terminate in the skin over the superior part of the femoral triangle."

It supplies the "femoral artery and the skin over the superior part of the femoral triangle."
Genital Branch
It descends "anterior to the external iliac arteries, which gives branches to, and enter the inguinal canals via the deep inguinal rings." In the male, "the genital branches emerge with the spermatic cord, to give off branches to the cremaster muscle, testicular autonomic plexus, and the skin of the scrotum adjacent to the thigh". In the female, they "accompany the round ligament of the uterus to terminate in the skin of the mons pubis and labium major."

It supplies the "external iliac arteries cremaster muscle, testicular autonomic plexus, and skin of the scrotum in males. It supplies the skin of the mons pubis and labium major in females."

In regard to all the nerves (iliohypogastric, ilio-inguinal, genitofemoral) above this was listed under pathology. The anatomy software had this exact excerpt under each of the three nerves, but I do realize it only menitons the genitofemoral nerve. It is possible this was a mistake in the software because I know there are a number of nerves that can be irritated by the psoas, not just the gentiofemoral nerve.
"Parathesis
•  Because the genitofemoral nerve runs through and on the ventral surface of the psoas muscle, paresthesias of this nerve can result from psoas abscesses or hematomas involving the body of this muscle.
•  Physically active patients on long term anticoagulation are susceptible to this kind of complication."

Other possible affected nerves: Femoral nerve, obturator nerve.

These nerves also pass through the psoas, so there is a possibility they can be affected by a psoas muscle strain and knots. I did not experience any symptoms from the areas that these nerves supply so therefore I did not include the details in this blog.

There is a possibility that I am missing other nerves or branches of nerves as this can be a complex system.

Nerves can be irritated anywhere along its path by a number of tissues. Again, this blog describes the psoas as the culprit. There are many other cases where another tissue can irritate one of these nerves.

I have come to the conclusion that my injury was a result of psoas muscle strain which lead to inflammation, hematoma, and/or trigger points. This injury is common to vigorously active exercisers including weight lifters, bodybuilders, American Football and rugby players. It seems as though many doctors would go with a disc injury diagnosis based on these symptoms which is understandable because they can match up. Some of the replies to the last blog strongly point to a disc injury. If the patient was the average sedentary person then most likely it would be a disc injury. Athletes and intense exercisers commonly have disc issues, but if the MRI comes back negative and the patient is goes through physical therapy with a diagnosis of a disc injury, they may be disappointed with failed results. Again, a number of issues have these symptoms but, a psoas muscle strain with these symptoms is quite common among vigorously active exercisers.

I suggest finding a doctor or therapist who is familiar with this condition if you suspect you have it. I would stay away from those who look perplexed when bringing up this issue or those who try to steer you in a different direction for recovery. Again, ruling out spine injury and other conditions with these symptoms is a very good idea.

My first blog exlaining my experience with this issue:
Pain, Pressure, Discomfort, Burning, Tingling, and Numbness in the Abdomen, Groin, Pelvic, Genital, and Upper Thigh Areas. My experience with these symptoms as the result of pinched nerves and other underlying issues.

For more information on this condition visit www.drgillick.com under clinical issues. He had the only detailed report that was searchable online which may or may not be currently available.

References:
1)Travell and Simons. Myofascial Pain and Dysfunction, The Trigger Point Manual. 1999.
2)John H. Gillick MD, MPH, FACA, FACP.. Iliopsoas Muscle Strain - The Filet Minion of Backaches. 2003. www.drgillick.com
3)Van Dyke, Holley, Anderson. Review of iliopsoas anatomy and pathology. Radiographics Jan 1987, vol 7, num. 1.
4)3D Human Anatomy: Regional Edition. Interactive Pelvis & Perineum. 2011.