Diagnosing low back pain

How to understand all the causes of lower back pain and give the patient sound recommendations?

To do this, patients with back problems need to be asked the following questions:

• Tell us about your problems in the lower back (lumbar region).
• What are your symptoms?
• Have you experienced weakness, numbness or sudden sharp pain?
• Does the pain/numbness radiate anywhere?
• Have you experienced any changes in your bowel movements and urination?
• How do back problems affect your work/school/housekeeping?
• How do your back problems affect your leisure/entertainment activities?
• What is your life like in general?
• Do you have any problems at work or at home?
• Tell us what you know about back problems; have you experienced lower back pain before, do you have a relative or friend with back problems?
• What concerns do you have about this issue?
• What tests are you expecting to perform?
• What treatment are you counting on?
• What changes can you make at work/home/school to minimize your temporary discomfort?

In addition, it is necessary to pay attention to the following signs:

1. Age. The older the patient, the more likely he or she is to develop the most common spinal diseases: osteochondrosis and osteoarthrosis. However, it should not be forgotten that along with these "age-related" diseases, the risk of malignant neoplasms increases in the elderly. For young patients, the most common cause of lower back pain is minor injuries during sports. Of the spinal diseases, the most common cause is spondyloarthropathies. In addition to lower back pain, these patients necessarily have other manifestations of the disease (psoriasis, uveitis, urethritis, diarrhea, etc.). In children under 10 years of age, when lower back pain occurs, kidney disease and organic diseases of the spine (tumor, osteomyelitis, tuberculosis) are first excluded.
2. The connection of pain with a previous injury, physical activity. Such a connection is present during the development of injuries or manifestations of osteochondrosis.
3. Side of pain. One-sided pain is typical for osteochondrosis, two-sided pain is typical for osteochondropathy.
4. The nature of pain. The sudden onset of severe pain that does not subside with traditional analgesics and is accompanied by collapse, paresis with decreased sensitivity, indicates the presence of a ruptured abdominal aortic aneurysm or hemorrhage into the retroperitoneal tissue - situations that require emergency medical care.
5. Changes in pain during movement, at rest, in different positions. With osteochondrosis, pain increases with movement and in a sitting position, and goes away in a lying position. Spondyloarthropathies are characterized by a directly opposite attitude to motor activity: pain increases at rest and goes away with movement.
6. Circadian rhythm of pain. Most diseases of the spine have a circadian rhythm of pain. The exceptions are malignant neoplasms, osteomyelitis and tuberculosis of the spine, when the pain is constant throughout the day.

Diagnosis of low back pain is aided by: medical history; identification of serious causes of low back pain; identification of radiculopathy; determination of the risk of prolonged pain and disability.

Lumbar Nerve Impingement Testing

1. Ask the patient to lie on his back and straighten up as much as possible on the couch.	4. Watch for any pelvic movement before complaints occur. True sciatic tension should cause complaints before the hamstrings are stretched enough to move the pelvis.
2. Place one hand above the knee of the leg being tested, apply enough pressure to the knee to straighten the knee as much as possible. Ask the patient to relax.	5. Determine the level of the leg lift at which the patient's complaints appear. Then determine the most distant place of discomfort experienced: back, hip, knee, below the knee.
3. With the palm of one hand, grasp the heel, slowly raise the straightened limb. Tell the patient: “If this bothers you, let me know, I will stop.”	6. Keeping your leg extended and raised, pull your ankle forward. Determine if this causes pain. Rotating your limb inward can also increase pressure on the sciatic nerve endings.

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Examination by a doctor for lower back pain

Physical examination - general examination, examination of the back: testing for pinched nerve endings; sensory testing (pain, numbness) and motor testing.

I would like to emphasize that the causes of lower back pain can be very different, lower back pain often serves as a signal of serious diseases of internal organs, therefore, when acute lower back pain occurs, self-medication should be avoided and a number of studies must be carried out to establish the correct diagnosis.

Additional tests and differential diagnostics help to make the correct diagnosis.

Lumbar Nerve Impingement Testing

Testing	Nerve ending
	L4	L5	S1
Motor weakness	Quadriceps Strain	Dorsal flexion of the big toe and foot	Flexion of the foot and big toe
Examination-screening	Squat down and stand up	Walk on your heels	Walk on tiptoes
Reflexes	Decreased knee jerk reflex	There is no reliable method	Decreased ankle reflex

Research for the diagnosis of back pain syndrome

Cause of pain syndrome	Research
Non-radicular pain: - no history of trauma or risk factors - suspicion of a latent infection or neoplastic process - spondylolisthesis that is not amenable to conservative treatment or is accompanied by severe neurological symptoms	Radiography in anteroposterior and lateral projections. Osteoscintigraphy, MRI X-ray in flexion-extension positions, CT, MRI, bone scintigraphy
Radicular pain: - persistent symptoms of sciatica with obvious damage to the nerve root - sciatica with an undefined level of nerve root damage	MRI EMG, CT, MRI
Injury: - damage to the motor nerve trunk with minimal trauma in a patient with possible structural changes in bone tissue	Radiography after establishing the mechanism of injury
Suspected osteomyelitis - a point is identified above the vertebra that is painful upon palpation	MRI
History of neoplastic processes, clinical manifestations consistent with metastatic lesions	Osteoscintigraphy, MRI

The following algorithms #1-5 can also help in diagnosing lower back pain.

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Peculiarities of interviewing a patient with lower back pain

It is known that the most common reason for visiting an orthopedic doctor is lower back pain. When collecting anamnesis, special attention should be paid to clarifying the structure of the pain: its nature, what intensifies it, and what relieves it, in connection with what it arose. It is also important to clarify whether there are any disorders of the intestines or bladder. With pain in the lower back, the pain quite often radiates along the leg (sciatica): such pain can be accompanied by radicular symptoms.

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Examination of a patient complaining of lower back pain

The patient may remain in trousers with suspenders - this does not interfere with the examination and palpation of the back, determination of skin temperature and detection of local pain. The doctor evaluates the following movements: flexion (the patient bends forward and touches the tips of the toes with his fingers with straightened knee joints; it is important to note what part of this movement occurs due to the back, and what part - due to flexion at the hips: when the back is flexed, it has a smoothly rounded contour), extension (an arched deviation of the spine backward), lateral flexion (the patient bends to the side, and the hand moves down the corresponding thigh) and rotation (the feet are fixed, and the shoulders make circular movements alternately in each direction). Movements in the costovertebral joints are assessed by the difference in the volume of the chest at the moment of maximum inhalation and maximum exhalation (normally 5 cm). To assess the condition of the sacroiliac joints, the doctor places his hands on the iliac crests (the patient lies on his back) and presses on them in order to move the bones in these joints. If something is wrong, they will feel sore. Remember: when the torso is fully flexed forward, the line connecting the points located 10 cm above and 5 cm below C should lengthen by at least 5 cm. If the lengthening is less, this reliably indicates a limitation of flexion. Then the muscles on both legs are compared (it is necessary to measure the circumference of the hips), muscle strength, loss of sensitivity and the severity of reflexes are assessed (the knee reflex depends mainly on L4, and the Achilles reflex on S1; when examining the plantar reflex, the foot should go down).

Straight Leg Raise

In case of complaints of sciatica, the doctor should ask the patient to lie down on the couch and raise the straightened leg (maximum extension at the knee joint). In this case, the sciatic nerve is stretched and in the area of mechanical damage, radicular pain of a characteristic shooting nature occurs, radiating in accordance with the dermatome and increasing with coughing and sneezing. It is necessary to note the angle at which the straightened leg can be raised before pain occurs. If it is less than 45 °, then they speak of a positive Lasegue symptom.

Other parts of the body that may be examined

These are the iliac fossae (which was especially important in times when tuberculous psoas abscess was common), the abdomen, pelvis, rectum, and large arteries. It should be remembered that tumors from the mammary gland, bronchus, kidneys, thyroid, and prostate glands usually metastasize to the bones. Therefore, these are the organs that should be examined.

Laboratory and instrumental diagnostics of low back pain

First of all, the hemoglobin level, ESR (if it is significantly elevated, one should consider the possibility of myeloma disease), serum alkaline phosphatase activity (as a rule, it is sharply elevated in bone tumors and Paget's disease) and blood calcium content are determined. X-ray images of the back are taken in the anteroposterior, lateral and oblique projections (pelvis, lumbar spine). Then myelography and magnetic nuclear tomography are performed, which are capable of visualizing the equine tail. In this case, protrusion of the intervertebral disc, tumor and stenosis of the spinal canal should be excluded. The protein content in the cerebrospinal fluid obtained by myelography should be determined (it is elevated in the cerebrospinal fluid taken below the level of localization of the spinal cord tumor). The spinal canal is well visualized by ultrasound and CT (computed tomography). Radioisotope scanning can reveal "hot spots" of tumor or pyogenic infection. Electromyography (EMG) is used to confirm disturbances in innervation along the lumbar or sacral nerves.