Re: Lurker with some questions - Nerve Issue (also )

[Guest guest]

An EMG ... found that I have evidence of a pinched nerve

somewhere...Anyway, I have decreased sensation starting at or right

below the knee and no ankle reflexes...Recently, I have started to

have knee pain and a little back pain, so stuff appears to be

progressing.

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Here is some more detailed nerve info from my anatomy and physiology

text book, specifically, pages 497-500 of " Human Anatomy and

Physiology " by Elaine Marieb.

If you have any questions about any of the technical language in the

cited section below, just ask. At any rate, you know what your

symptoms and sensations are. Take a look at the nerve section from

Marieb and see if that points you in any particular direction or

suggests anything to you.

I can tell you right now that there are a number of possible causes

for nerve impingement or compression that go well beyond just a disc

problem. A very common cause of sciatic nerve problems is called

Piriformis Syndrome. The Piriformis is a muscle that runs between

the hip joint and the top of the pelvis. The sciatic nerve can pass

under it, over it, through it, or a combination. Depending on the

specific pattern, the muscle can compress the nerve against bone or

squeeze it between layers of the muscle itself. It can be treated

with different massage/bodywork techniques. Nerves of the lumbar

plexus that get impaired by the psoas muscle can also be treated

with massage/bodywork.

As a piece of side info, I had to treat Barb for this just last

night. Her hip has been bothering her, with pain radiating down the

leg and up into the low back. A quick assessment showed that it was

her Piriformis muscle that was the culprit, so that's what I treated.

At any rate, take a look at this and feel free to get back with me

for further bouncing of ideas and/or suggestions.

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" The sacral and lumbar plexuses overlap substantially, and since

many fibers of the lumbar plexus contribute to the sacral plexus via

the lumbosacral trunk, the two plexuses are often referred to as the

lumbosacral plexus. Although the lumbosacral plexus mainly serves

the lower limb, it also sends some branches to the abdomen, pelvis,

and buttock.

The lumbar plexus arises from the first four lumbar spinal nerves

and lies within the psoas major muscle. Its proximal branches

innervate parts of the abdominal wall muscles and the psoas muscle,

but the major branches of this plexus descend to innervate the

anterior and medial thigh. The femoral nerve, the largest terminal

nerve of this plexus, runs deep to the inguinal ligament to enter

the thigh and then divides into a number of large branches. The

motor branches innervate the anterior thigh muscles (quadriceps),

which are the principal thigh flexors and knee extensors...The

obturator nerve enters the medial thigh via the obturator foramen

and innervates the adductor muscles...

Compression of the spinal roots of the lumbar plexus, as by a

herniated disc, results in gait problems because the femoral nerve

serves the prime movers of both hip flexion and knee extension.

Anesthesia of the anterior thigh and pain in the medial thigh occur

if the obturator nerve is impaired.

The sacral plexus arises from spinal nerves L4-S4 and lies

immediately caudal to the lumbar plexus. Some fibers of the lumbar

plexus contribute to this plexus via the lumbosacral trunk...The

sacral plexus has about a dozen named branches. Around half of

these serve the buttock and lower limb; the others innervate pelvic

structures and the perineum...

The largest branch of the sacral plexus is the sciatic nerve, the

thickest and longest nerve in the body. It supplies nearly the

entire limb, except the anteromedial thigh.

Actually two nerves (the tibial and common fibular) wrapped in a

common sheath, the sciate nerve leaves the pelvis via the greater

sciatic notch. It courses deep in the gluteus maximus muscle and

enters the posterior thigh just medial to the hip joint...There it

gives off motor branches to the hamstring muscles (all thigh

extensors and knee flexors) and to the adductor magnus. Immediately

above the knee, its two divisions diverge.

The tibial nerve courses through the popliteal fossa (the region

jusdt posterior to the knee joint) and supplies the posterior

compartment muscles of the leg and the skin of the posterior calf

and sole of the foot. Important branches of the tibial nerve are

the sural, which serves the skin of the posterolateral leg, and the

plantar nerves, which serve most of the foot.

The common fibular (peroneal) nerve descends from its point of

origin, wraps around the head of the fibula and then divides into

superficial and deep branches. These branches innervate the knee

joint, the skin of the lateral calf and dorsum of the foot and the

muscles of the anterolateral leg (the extensors that dorsiflex the

foot).

The next largest branches of the sacral plexus are the superior and

inferior gluteal nerves. Together, they innervate the buottock

(gluteal) and tensor fasciae latae muscles...

Injury to the proximal part of the sciatic nerve, as might follow a

fall, disc herniation, or improper administration of an injection

into the buttock, results in a number of lower limb impairments,

depending on the precise nerve roots injured. Sciatica,

characterized by stabbing pain radiating over the course of the

sciatic nerve, is common. When the sciatic nerve is completely

transected, the leg is nearly useless. The leg cannot be flexed

(because the hamstrings are paralyzed), and all foot and ankle

movements are lost. The foot drops into plantar flexion (dangles),

a condition called footdrop...

If the lesion occurs below the knee, thigh muscles are spared. When

the tibial nerve is injured, the paralyzed calf muscles cannot

plantar flex the foot and a shuffling gait develops. The common

fibular nerve is susceptible to injury largely because of its

superficial location at the head and neck of the fibula. Even a

tight leg cast, or remaining too long in a side-lying position on a

firm mattress, can compress this nerve and cause footdrop.

The easiest way to remember which nerves serve each synovial joint

is to use Hilton's law, which says that 'any nerve serving a muscle

producing movement at a joint also innervates the joint itself and

the skin over the joint.' ... For example, the knee is crossed by

the quadriceps, gracilis and hamstring muscles. The nerves to these

muscles are the femoral nerve anteriorly and branches of the sciatic

and obturator nerves posteriorly. Consequently, these nerves

innervate the knee joint as well. "

[Guest guest]

Thanks for the info Mike (and the heads up). I'm printing it out and

adding it to my notebook.