by P.Novakovic, MD



PART II: EVALUATION OF THE PATIENT WITH PIRIFORMIS MUSCLE SYNDROME AND SCIATICA

1. EVALUATION OF THE PATIENT WITH PIRIFORMIS MUSCLE SYNDROME

In Part I of this article (see Jan-Feb issue of JMS) we discussed the anatomy and physiology of the piriformis muscle (PM). I hope that readers appreciate its unique anatomical position, its very intimate relations with vital neurological and vascular structures and the biomechanical role PM plays in our body.

In this part of the article we will discuss examination of the patient with tension or spasm in PM. To reinforce the practical value of the article I will use videos of various tests associated with PMS. These videos are from the Video Library of MEDICAL MASSAGE PROTOCOLs and www.scienceofmassage.com has allowed me to use them for educational purposes.

Before I present the evaluation of the patient with PMS we need to shortly review the development of its clinical picture. As you remember Fig. 4 in Part 1of this article (see Jan-Feb issue of JMS) presents the relations of PM in regard to the sciatic nerve. There are two ways the tension in PM may develop, and each scenario will produce a completely different picture:

Irritation of the sciatic nerve or Piriformis Muscle Syndrome (PMS)

If, as a result of various reasons, the tension in PM increases, the entire sciatic nerve or one of its portions (tibial or common peroneal) becomes irritated. In such cases the PM doesn’t work as a soft cushion protector of the sciatic nerve anymore, but rather it becomes a direct cause of the sciatic nerve’s irritation.

The patient with PMS doesn’t complain about pain or any other uncomfortable sensation in the gluteal area. He or she will complain about a variety of pathological conditions along the lower extremity from the symptoms identical to tension in the iliotibal tract to the plantar fasciitis. This is the most important part the practitioner must remember when examining any patient with PMS.

While you are reading this article countless number of patients are examined or treated for various pathological conditions on the lower extremity (e.g. knee osteoarthritis, restless leg syndrome, nocturnal leg muscle cramps, plantar fasciitis, etc.). Despite the fact that many of patients with PMS will get initial relief from medications or local therapies all these modalities will fail if the tension in the PM wasn’t addressed. Why is that? The reason is very simple – the patient with PMS rarely mentioned pain or any other uncomfortable sensation in the gluteal area to the health practitioner who conducted the initial examination.

In such cases the patient with knee osteoarthritis will be recommended for arthroscopic surgery to ‘clean up’ the joint, the patient with restless leg syndrome or nocturnal cramps will be treated with medications and the patient with plantar fasciitis will be recommended for expensive custom made shoe inserts. I can continue this list, but all these cases will be united by one common mistake, the health practitioners will treat the secondary symptoms instead of the initial trigger. This elusive trigger is tension in PM which slightly irritates the sciatic nerve and accurately mimics a clinical picture of various local abnormalities in the lower extremities.

Compression of the sciatic nerve or Sciatica (SC)

Let’s look at another scenario. The same patient now complains about pain in the gluteal area and this pain has a tendency to radiate down to the knee (a case of knee osteoarthritis), to the leg (restless leg syndrome or nocturnal cramps) or the foot (a case of plantar fasciitis). Now everybody suddenly agree that the patient has tension in PM and the reason for the clinical symptoms is compression of the sciatic nerve in the gluteal area by this muscle.

What is the difference between the first and second case? The answer is very simple: In the first case the tension in the PM is mild and the sciatic nerve is just slightly irritated. In such a case the clinical symptoms are located in the parts of the leg where irritated fibers of the sciatic nerve end and their irritation is a trigger of local clinical symptoms. Without correct examination of PM the peripheral symptoms can be easily misread as local abnormalities and be treated accordingly without addressing PM as a part of the treatment.

In the second case, tension in the PM has increased to the degree that the sciatic nerve is now compressed, and this triggers the full clinical picture of Sciatica. In the last case the diagnosis is obvious and the treatment of Sciatica will now include, or solely concentrate on the PM.

You, as practitioners, see the clients with peripheral symptoms of PMS on a daily basis. In many cases their symptoms will be treated as local abnormalities. However, without accurate examination and proper treatment of PM there is no way stable clinical results can be achieved.

Of course, there are many patients with knee osteoarthritis or plantar fasciitis and these conditions aren’t the result of PMS, and they need to be treated locally. However, it is the practitioner’s job to find out if tension in PM is present or rule it out completely. This is why the initial examination of the patient is so important. This is the exact topic of this article.

Also the practitioner must remember that PMS and Sciatic Nerve Neuralgia (SNN) can be the results of the tension and pain in the lower back (i.e., Lumbalgia) or trauma or strain of the piriformis muscle itself. Thus the evaluation of the patient should start on the lower back to rule out tension in the:
1. Lumbalgia: Lumbar Erectors
2. Lumbalgia: Quadratus Lumborum Muscle
3. Lumbalgia: Short Lumbar Rotators
4. Lumbalgia: Sacroiliitis

Only after these pathological conditions are ruled out the practitioner may consider that he or she deals with the tension which has developed in the piriformis muscle itself as a result of its trauma, overload or body’s postural changes.

Questioning

The patient with PMS more than likely has a job which requires a lot of walking, lifting, long standing (e.g., construction worker, sales representative, etc) or prolonged sitting on hard surfaces. Excessive exercise and wearing high heels may be additional compromising factors.

We can split the patients with PMS into four groups according to the combination of clinical symptoms:

1. The patient complains about tension and pain in the gluteal area and these symptoms are not accompanied by peripheral sensory or motor deficit on the leg and foot. Pain increases during sitting, standing, squatting, or when crossing the legs. The patient has a tendency to limp.

This means that the PM has developed tension but the sciatic nerve is not affected at this point.

2. The patient doesn’t complain about pain in the gluteal area but he or she exhibits clinical symptoms on the different parts of the leg and foot (tingling, numbness, burning pain, muscle pain, muscle weakness, muscle atrophy, cramps at night, etc).

This means that tension in the PM started to slightly irritates the sciatic nerve.

3. The patient complains about pain in the gluteal area, this pain radiates down to the leg and foot producing a variety of the sensory and motor symptoms.

This means that the PM developed significant tension and it now compresses the sciatic nerve.

4. The patient has visceral abnormalities (deeply located aching pain in tension in the pelvic area, constipation, intense menstrual pains, dryness of the vagina, sexual dysfunction in men, difficulties during urination, etc) which may or may not be accompanied by pain in the gluteal area and peripheral symptoms of motor or sensory deficit in the lower extremity.

This means that the inner third of the PM located inside the pelvis irritates the sacral plexus which triggers the visceral symptoms.

If the patient has visceral abnormalities and peripheral symptoms of sensory or motor deficit it means that the entire PM is under significant tension and irritates the sacral plexus and sciatic and gluteal nerves at the same time.

Trigger Point Test (TPT)

TPT allows us to examine the middle and lateral thirds of the PM after it has left the pelvis and has appeared in the gluteal area. The video below shows the anatomical landmarks for the PM and application of TPT.

The dashed straight line in the video indicates the edge of the sacrum; the dashed U-shaped line indicates the greater trochanter; small circle indicates the insertion of the gluteus medius muscle (under the gluteus maximus muscle) into the tip of the greater trochanter; the x-sign indicates the insertion of the PM into the greater trochanter; the solid line indicates the middle line of the PM’ belly (under the gluteus maximus muscle), the black dot indicates the location of trigger point and place of the application of TPT.

The TPT is application of the pressure in the area of the major trigger point in the PM. This area is located in the center of the middle line of the PM, which connects the sacral edge and the greater trochanter. Please notice that the middle line of the PM originates from the sacral edge at a 90 degree angle. Also, please pay attention to the position of the practitioner’s arm and thumb during the application of TPT. The pressure should be directed toward the sacrum, i.e. almost applied horizontally.

There are three outcomes of the positive TPT:
1. The patient will exhibit the ‘Jump Symptom’ as soon as even the slightest pressure is applied to the PM. This means that the muscle carries an active trigger point and hypertonus there.
2. The patient feels pain radiating down to the lower extremity. In the majority of cases it is accompanied by an increase of already existing sensory abnormalities (e.g., tingling becomes numbness) or by their appearance. This means that the sciatic nerve is under direct irritation by the tensed PM.
3. The patient feels moderate pain in the gluteal area only under the finger, but the practitioner feels a rigid spindle which rolls under the thumb. This is a sign of chronic PMS when a latent trigger point as well as a myogelosis are responsible for the low grade, chronic irritation of the sciatic nerve.

The clinical value of TPT is very important because the trigger point therapy part of the session will be applied in the same area.

Freiberg’s Sign (FS)

First part of FS

This is the most valuable part of the test. The practitioner should observe the position of the patient’s lower extremity on the affected side while he or she walks or is lying on the table.

The tension in the PM will cause the outer rotation of the lower extremity on the affected side. It is visible as the outer rotation of the foot while the patient walks or lying on the back. The video shows the clinical application of FS. Pay attention to the outer rotation of the right foot while the patient walks and lying on her back.

The first part of the FS is very informative, because it alerts the practitioner about PMS from the simple observation of the outer foot rotation during the patient’s walking or laying down.

Second part of FS

The practitioner should passively rotate the lower extremity medially. FS is considered positive if the patient feels the pain in the gluteal area during the medial rotation in the hip joint. The second part of FS is less informative when compared to the Bonnet’s Test described below.

Bonnet’s Test (BT)

BT has great clinical value. This is the only test which allows the practitioner to evaluate the condition of the medial or inner third of the PM located in the pelvis. BT has lesser clinical value for the evaluation of the middle and lateral thirds of the PM located in the gluteal area. For this reason, the TPT is much more informative. Thus the practitioner must conduct both tests in order to have complete information about the tension in the PM. The video below shows the application of BT.

During the application of BT, the practitioner should perform the next sequence of passive movements: flexion of knee, adduction, medial rotation, and flexion in the hip joint. The patient may feel pain in the gluteal area and around the greater trochanter after final flexion in the hip joint. This pain is a result of tension or an active trigger point in the middle and lateral thirds of the PM.

During test, the practitioner needs to obtain information about the inner third of the PM located in the pelvis. This is why he or she should ask the patient to concentrate on the sensations in the sacrum and lower pelvis (ask patient to close eyes). If there is a tension in the medial (i.e., inner) third of the PM, the patient will feel deep moderate pain or tension with poorly defined location in the lower pelvis and inguinal area on the examined side at the end of hip flexion. In such cases, BT is considerate positive.

A positive BT means that the practitioner is dealing with much more complicated case of PMS because of the involvement of the inner third of the muscle. From the treatment perspective it means that the practitioner must use Postisometric Muscle Relaxation as the only tool to effectively release tension in the medial third of the PM.

2. EVALUATION OF THE PATIENT WITH SCIATICA (SC)

SC can be the result of irritation or compression of the L4-S1 spinal nerves by a bulging intervertebral disk or tensed paravertebral muscles (i.e., Lumbalgia or lower back pain), as well as irritation or compression of the sciatic nerve by the piriformis muscle (i.e., PMS), or both causes may be combined. Thus, the practitioner should differentiate between both causes in analysing the clinical picture.

In the case of Lumbalgia, pain and restriction of movement in the lumbar spine are the main symptoms. The pain is more intense, radiating all the way down to the plantar surface or top of the foot. A diagnostic evaluation shows a muscular spasm in the lower back as well as in the gluteal area, and frequently, compensatory Scoliosis to the same side.

Bonnet’s Test is mostly negative (except in cases of entire PM involvement), but the Trigger Point Test is positive as the result of protective muscular tension which has developed in the gluteal muscles and the PM itself.

In the case of PMS, the sciatica pain is less acute and patients are more mobile. There is no acute pain in the lower back. The pain and areas of sensory deficit originate in the gluteal area, and radiate down the leg, but more often to the lateral surface of the lower third of the leg and top of the foot because part of the sciatic nerve, which carries fibers of common peroneal nerve, is more frequently affected. Local tension and intense pain can be found during the application of the Trigger Point Test.

Sensory Test (ST)

The sciatic nerve does not have sensory branches in the thigh area, but the patient frequently feels the radiation of the pain along the thigh. On the posterior surface of the lower third of the thigh, the sciatic nerve splits into the tibial and the common peroneal nerves which support the sensory and motor innervation of the leg and foot. Patients with SNN complain of radiating pain, tingling, numbness, or hyperalgesia of the foot, and leg and thigh.

ST allows us to examine the sensory innervation and detect which portion of the sciatic nerve (tibial and common peroneal) is under the greatest pressure. ST is the most informative on the foot where each nerve has its own special pattern of innervation. The common peroneal nerve innervates lateral surface and top of the foot, while the tibial nerve innervates the medial surface and bottom of the foot. The video below shows the application of the ST.

Ask the patient to close eyes and concentrate on the sensations while you simultaneously strike the skin on the same areas of each foot. The difference in the sensations on the affected side as compared to the unaffected side reported by the patient means that the sciatic nerve is irritated. Please notice that the practitioner needs to stroke the skin on the bottom of the foot very slowly in order to avoid the tickling sensation.

However the same clinical picture can be detected if the tibial or common peroneal nerves is irritated on the level below the piriformis muscle. This why the practitioner should also consider these possibilities using tests which are associated specifically with Common Peroneal Nerve Neuralgia and Tibial Nerve Neuralgia.

Palpation Test (PT)

The PT also belongs to sensory tests. PT allows us to examine the possible inflamation along the sciatic nerve. PT is application of the moderate pressure along the pathway of the sciatic nerve on the posterior thigh. The video below shows the application of PT. Pay attention to the position of the fingers during the examination.

PT is considered positive if the patient feels acute radiating pain along the sciatic nerve. In regard to the treatment the positive PT means that the practitioner must spend extra time on the posterior surface of the thigh addressing tension in the hamstring muscles.

Motor Test (MT)

The tibial portion of the sciatic nerve gives motor branches to the adductor magnus, the semimembranosus, the semitendinosus, and the long head of the biceps femoris muscles.

The common peroneal nerve portion of the sciatic nerve gives a motor branch to the short head of the biceps femoris muscle.

Thus, a motor deficit in the thigh results in weakness of the knee flexion. Also, patients may have a motor deficit of the leg and foot muscles according to the innervation of the common peroneal and/or tibial nerve.

The fact that the sciatic nerve innervates the hip and knee flexors before both portions of the sciatic nerve (i.e., tibial and common peroneal) split above the knee and go down their own pathways make the MT a very important diagnostic tool. If the patient exhibits the weakness of the knee flexion on the affected side compared to the unaffected side it greatly confirms the fact that the patient has SNN. The video below shows the application of the MT used to detect motor deficit on the thigh. The white arrow in the video indicates the direction of active knee flexion against the practitioner’s resistance.

Straight Leg Raise Test (SLRT)

The best way to detect the earliest stages of SNN, and what is even more important, to determine the presence of inflammation in the sciatic nerve itself, is to perform the so-called the Straight Leg Raise Test. This test has two parts and is conducted with the patient positioned on the back. Video below shows the application of the both parts of SLRT.




First part

The practitioner slowly lifts the patient’s leg by the foot without flexing the knee. Normally, this manoeuvre causes tension on the posterior surface of the thigh when the leg is highly elevated. If the patient has SNN, he or she starts to feel pain and tension in the gluteal area and on the posterior surface of the thigh when elevation of the lower extremity exceeds 30-40 degrees. The pain has a tendency to radiate along the common peroneal or the tibial nerve. This pain is a result of additional pressure exerted on the sciatic nerve by the tensed PM when the leg is lifted.

Second part

The second part of SLRT allows the practitioner to evaluate if there is actual inflammation along the sciatic nerve.

During the first part of the SLRT the practitioner detects the angle of elevation where the patient starts to feel pain or other uncomfortable sensations in the gluteal area and along the lower extremity.

For the second part of SLRT the practitioner should lower the leg slightly until these symptoms disappear. In such a case, the PM does not exert pressure on the sciatic nerve anymore. Now, the practitioner should apply passive dorsiflexion of the foot maintaining same position of the lower extremity.

Normally, the patient should feel slight tension of the soft tissue on the posterior surface of the thigh and leg. If the sciatic nerve is inflamed, the patient will again feel acute radiating pain along the posterior surface of the thigh and along the leg.

The PM besides the irritation of the sciatic nerve may irritate or compress superior and inferior gluteal nerves. These nerves innervate entire the entire gluteal area. This is why patients with PMS frequently complain about pain in the ‘buttock’ as a result of consequent tension in the gluteus maximus, medius or minimus muscles.


Category: Medical Massage

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