Low back pain: evidence from clinical practice. Observational longitudinal study on 182 patients - Pathos

The present study highlights how dominant the “ascending” mechanical cause is, compared to any other hypothesis (discopathy, radicular compression, etc.) which only represent the natural consequence of the mechanical cause. The shape and the spatial organization of the body (erect posture), both in static and dynamic phase, are the result of continuous compromises (balance) that the body reaches with the surrounding environment and are maintained through the persistent contraction (postural tone) of muscle groups (vertical stabilization system - Karl Lewit). These muscle groups’ main function, which is used in ascension through feedforward and feedback mechanisms, is that of opposing gravity. Mechanical alterations or structural asymmetries which cause the pain, represent the breaking of that initial compromise: all conditions of hypotrophy and/or unilateral chronic stiffness of dynamic paired muscles, which cause pelvic misalignment, originate from alterations in the vertical stabilization system (postural alteration). The permanence in the state of alteration determines a parenchymal damage which exacerbates the pain sensation.

The observations on the etiology of back pain highlight how unlikely is that back pain is caused by discopathy or spinal canal stenosis. Regardless of the determined diagnosis, every case we studied has showed more or less relevant alterations related to the mechanical function of feet and lower limbs, with inevitable consequences on spine and pelvis balance. In particular, the state of alteration was related to the tone of the muscles directly involved in the plantar arch structure, in the tibia and femur alignment, in the pelvis balance and in the physiological curvature of the spine. As a matter of fact, it was easy to detect cases of functional collapse of the arches, internal rotation of the knees, misaligned pelvis and loss of physiological curvature of the spine. It was clear that the aching muscle groups were those more closely involved in the alteration (back stabilizer muscles, extensor digitorum longus muscle, peroneal, tibial, vastus lateralis, tensor fasciae latae, gluteus medius), causing the pain. In no case signs of neuropathic pain (painful nerve block) or radicular pain (metameric pain) have been observed. Therefore, it is believed that – when present – forms of spinal disc problems (dehydration, protrusion, herniation and extrusion) are always to be considered not as the “cause of pain” but as simple “consequences” of a mechanical alteration: the vertebral column adaptation to the uneven pressure on the feet and lower limbs lays the groundwork for a gradual loss in the physiological curves, exposing the discs to a progressive increase of the vertical loads.

It is no coincidence, in fact, that the pain usually appears in the proximity of the sacroiliac region first, extended to the lateral portion of the gluteus, aggravating the symptoms by involving peroneal muscles, extensor digitorum longus and, only ultimately, the upper thigh with tensor fasciae latae, biceps femoris and vastus lateralis.

Given the recurring posterior pelvic tilt and the consequent adaptation of the rachis (verticalization), the soreness determined by a prolonged sitting position and/or by forward flexion of the trunk, is not ascribable to discopathy or stenosis of the spinal canal, but it simply is the expression of the inability of the lumbar muscles to withstand the stress generated by incorrect posture. Moreover, considering the fact that the spinal cord compression (stenosis) cannot produce pain but, at most, an extrasegmental reference of paresthesia 14,15, muscle weakness with spastic gait (upper motor neuron lesion) and extensor plantar reflex, it is easier to feel a (burning) pain, loss of sensation and tingling as consequences of a chronic stiffness on a specific muscle group in a condition of functional impairment (because of the constriction and vasoconstriction).  

In the light of the examined data, it is clear that signs of hypotrophy play a primary role not only in the exacerbation of the pain sensation, but also in the motor limitation which consequently arises. Their presence has been registered in various capacities in 127 cases (69,8%):

- 86 active cases causing pain, of which 52 (39 in DL1 and 13 in DL2) manifested directly in the phase of movement limitation

- 42 silent cases, possible consequence of previous alterations now compensated but not necessarily resolved. Mainly present in low back pain (24 in DL0 and 16 in DL1), their tissue appears to be sclerotic, apparently asymptomatic, although painful to the touch. The observation conducted on approximately 2400 patients in the period from 2006 to 2018, has allowed us to verify the absolute capability to increase volume, stiffness and soreness.

In is interesting to notice that, the larger the area in state of alteration, the greater the percentage of presence of SI1:

- 25,8% of DL0 (16 of 62)

- 51,3% of DL1 (39 of 76)

- 68,4% of DL2 (13 of 19)

- 64,2% of DL3 (9 of 14)

- 81,1% of DL4 (9 of 11)

Given the above considerations, the hypothesis of defining these signs as biomarkers of motor dysfunction can certainly be confirmed. Deepening the knowledge about them can help to prevent the onset of pain or allow the formulation of an adequate program of functional recovery, therefore avoiding unnecessary, expensive, unpleasant and often harmful pharmacological protocols, sometimes combined with equally inadequate protocols of physical and instrumental therapy.

Although painful for the patient and difficult for the therapist, the practice of manipulative therapy proved to be extremely useful in treating acute or chronic lesions.

The neuromuscular intervention is aimed at producing mechanical hyperemia (possible increase in inflammation), causing the vasodilation of the skin and deep tissues, facilitating the elimination of inflammatory substances. Assuming that the viscoelastic structures possess sliding and hysteresis properties (ability to react to a stimulation), the application of an adequate force exploits the phenomenon of the viscous flow in the connective tissue structures.

Specific maneuvers have been performed on all the patients with physiological limitations of vertebral movements, which are generally associated with spontaneous vertebral pain and segmental symptoms (25 cases accounting for 13,7% of the cohort), even in acute inflammatory phase. The maneuvers that have been directly performed on the areas affected by the lesion, allowed an immediate restoration of the joint excursion capacity, with consequent improvement of the reported painful symptoms. Moreover, the repeated movement (typical of the mobilization) and the rapid manipulative gesture, have also been effective on the intrinsic paravertebral muscles, thus relieving joint tension occurring when the joint is led to the maximum range of excursion, with or without the final thrust movement (crucial in 25 cases, accounting for 13,7% of the patients).

From the observation of the data collected in the present study, it is evident that:

- 133 patients achieved a full recovery;

- 24 patients achieved an optimal recovery although still showing some forms of muscular stiffness;

- 29 patients achieved a good recovery with forms of muscle fatigue;

- 5 patients achieved a good recovery, though still presenting with forms of soreness.

In the authors’ opinion, differently from what was stated in practical guidelines published in conjunction by the American College of Physicians and the American Pain Society in 2007 (mentioning only a few good evidence supporting manual therapy for low back pain in the subacute and chronic phase), not only it is possible to achieve a full recovery of functional mobility in total absence of pain in the acute phase (achieved in 106 cases out of 182, accounting for 57,7% of patients), but the results of the study go far beyond “a few good evidence” even when considering subacute and chronic phases (of 76 cases out of 182, only 5 patients - 2,7% - have manifested soreness at follow-up). In order to structuring a truly valid and effective protocol, it is surely decisive to classify patients according to the type of pain manifested.

The authors certify the study was conducted without conflicts of interest.

31st October 2021