Low back pain and kidney mobility, local osteopathic fascial manipulation decreases pain perception and improves renal mobility

Participants

• Numbers: 241 people (96 female and 145 male)
• Criteria of inclusion:
  • for the asymptomatic patients: voluntary participation, absence of history of low back pain or any other chronic pain able to interfere with daily activities or work, any current pain lower than 1 on the Visual Analog Scale (VAS)
  • for the participants with low back pain: age 18-60 years, non-specific pain in the lumbar region with a duration included between 3 weeks to 3 months, with or without slight neurological symptoms, MRI or ultrasound examinations to exclude pathologies of the spine and kidneys
• Criteria of exclusion: (for both groups of participants) injury, surgery or relevant pathologies of the back, the kidney area or the lower extremities; major structural spinal deformity (scoliosis, kyphosis, stenosis), ankylosing spondylitis or rheumatoid arthritis; fracture, tumor or spinal infection; bleeding; major neurological or psychiatric disorders; acute systemic infection; pregnancy; renal ptosis; litigation for back pain; current use of physiotherapy or manual therapy; use of analgesics or anti-inflammatories within the previous 72 hours
• Groups of study: 3 groups, of which 2 (the experimental ones) obtained by randomization
  • Group 1: asymptomatic, 101 people (30 female and 71 male, mean age 38.9 years)
  • Group 2: with low back pain, OMT, 109 people (55 female and 54 male, mean age 39.8 years)
  • Group 3: with low back pain, sham treatment, 31 people (11 female and 20 male, mean age 37.6 years)

Interventions and evaluations

• Real-time examination of the right kidney mobility during forced respiration through ultrasound with 5MHz probe
  • a score was calculated (Kidney Mobility Score, or KMS) on the difference between maximum expiration and maximum inspiration
  • in the asymptomatic group the assessment was only carried out once
  • in the experimental groups the assessment was carried out before and after the intervention
• Pain assessment through SF-MPQ on the day of recruitment and 3 days after the intervention
• 1 OMT or sham treatment session of the duration of 3 minutes and 30 seconds, preceded by osteopathic structural assessment of the thoracolumbar regions in order to identify areas of fascial or skeletal dysfunction
• OMT: Still technique for 2 minutes and fascial unwinding for 90 seconds
• Sham treatment: light touch imitating the OMT positions
• Assessment of kidney mobility carried out by a physician specialized in in the use of ultrasounds with 16-year experience
• Structural evaluation and OMT performed by an osteopath with 6-year experience
• Sham treatment performed by a person with no knowledge of anatomy and no experience in manual therapies

Results

Primary outcomes: kidney mobility was lower in the case of non-specific low back pain compared to the asymptomatic participants, in a statistically significant manner. In the OMT group, the post-treatment kidney mobility resulted greater than the pre-treatment measurement, and also greater than the same value in the sham treatment group, in a statistically significant manner. In the sham treatment group, on the contrary, the mobility did not change between pre- and post- treatment. In the same way, the OMT group showed, after treatment, lower pain than before treatment but also than the sham treatment, in a statistically significant way. In the sham treatment group, on the contrary, the pain did not change between before and after the intervention (indeed, it seems slightly increased).

Discussion

The kidney mobility was lower in people affected with non-specific low back pain. On the other hand, OMT has shown that it can improve kidney mobility and, at the same time, reduce low back pain, at least in the short term.
An interesting aspect of the study was to identify 3 different types of kidney mobility during respiration, which can explain the great inter-individual variability in kidney mobility highlighted in many studies.

The lesser kidney mobility in the case of non-specific low back pain could depend on viscero-somatic or somatic-visceral reflexes between the kidneys and the spine, on venous or lymphatic congestions or on mechanical tensions of the connective tissue, all elements on which OMT could have acted positively promoting a greater kidney mobility as a consequence. Therefore, the kidney mobility in question would depend less on a difference in the way of breathing (different studies showed that the resting breathing is the same between asymptomatic people and people suffering from low back pain).
With regard to pain, OMT may have reduced it by promoting an increase in parasympathetic tone at the autonomic level and by stimulating the secretion of endocannabinoids.

Naturally, these results need to be taken cautiously as the measurement of kidney mobility by ultrasound is particularly delicate and can be influenced by several factors. Furthermore, only the right kidney was examined, and the left kidney would not necessarily act in the same way.
Moreover, it must be taken into account that the percentage of women and men in the different groups was not the same, which may have influenced the results because of the different organic conformation that may probably affect the movement of the organs. Finally, studies on larger samples are needed.