Influence of Verbal Suggestion on the Therapeutic Effect of the Joint Manipulation

The aim of the study is to evaluate the influence of verbal suggestion on the therapeutic effect of the joint manipulation of the lumbar spine in patients with chronic non-specific low back pain in relation to the pain level, stress, disability, function, sleepiness, tissue temperature and selected blood biochemical markers.

The study participants will be randomly assigned (sealed allocation envelopes) to the following groups:

* Group A (test intervention + placebo communication)
* Group B (test intervention + nocebo communication)
* Group C (test intervention + neutral communication)

The study will mainly consist of the three stages, i.e. before the intervention, immediately after the intervention and 24 hours later.

Pain is complex in nature and is closely related to the secretion of biochemical markers such as cortisol, serotonin and oxytocin. Higher levels of inflammatory markers, cytokines and chemokines have been found in patients with low back pain, which ultimately affect the clinical manifestations observed in the patients.

One of the methods of physiotherapeutic treatment of spinal disorders involving manual diagnostic and therapeutic techniques is manual therapy. In the therapy, among others, joint manipulation techniques are used. However, the mechanisms underlying the effects of the joint manipulation on the body have not been fully explained. Undoubtedly, one of the main mechanisms of action of manual therapy is pain modulation.

In recent years, research has been increasingly focusing on manipulation in a psychological context, including mechanisms of fear-avoidance, pain catastrophizing and kinesiophobia. Furthermore, manipulation can affect immune and endocrine system responses.

One of the significant non-specific effects accompanying any medical procedure is a placebo effect. The way health care professionals discuss, describe and inform patients about characteristic symptoms of a given disease its prevention, diagnosis and treatment, influences the patients' feelings and expectations, which in turn affect their psycho-biological reactions, subjective perception and treatment outcomes.

The appropriate choice of words by clinicians influences patients' responses to medical treatments and procedures, whether active or sham. The way in which information about the outcome of a treatment is communicated to patients can induce the reinforcing effects of a given treatment (placebo) or reverse the clinically proven effects of an active treatment, or even increase its adverse outcomes in the form of a nocebo effect.

The aim of the study is to evaluate the influence of verbal suggestion on the therapeutic effect of the joint manipulation of the lumbar spine in patients with chronic non-specific low back pain in relation to the pain level, stress, disability, function, sleepiness, tissue temperature and selected blood biochemical markers.

Research questions:

1. Does the type of verbal suggestion influence the effects of the joint manipulation in relation to the pain level?
2. Does the type of verbal suggestion influence the effects of the joint manipulation in relation to the stress level?
3. Does the type of verbal suggestion influence the effects of the joint manipulation in relation to the kinesiophobia level?
4. Does the type of verbal suggestion influence the effects of the joint manipulation in relation to the lumbar spine range of motion?
5. Does the type of verbal suggestion influence the effects of the joint manipulation in relation to the disability level?
6. Does the type of verbal suggestion influence the effects of the joint manipulation in relation to sleepiness?
7. Does the type of verbal suggestion influence the effects of the joint manipulation in relation to the tissue temperature of the lumbar spine region?
8. Does the type of verbal suggestion influence the effects of the joint manipulation in relation to the selected blood biochemical markers (cortisol, serotonin and oxytocin)?

The participants will be selected for the study from the group of students from John Paul II University in Biała Podlaska, Poland. The participation in the study will be voluntary.

The study will mainly consist of the three stages, i.e. before the intervention, immediately after the intervention and 24 hours later. Once, before the intervention, a scale will be used for the subjective assessment of the expectations for the treatment outcomes based on the GRoC methodology. The other research tools will be used in two stages: an information questionnaire (before the intervention and 24 hours after the intervention) and a scale for the subjective assessment of the treatment outcomes based on the GRoC methodology (immediately after the intervention and 24 hours later).

Eligibility Criteria:
Inclusion Criteria:

* participants with low back pain lasting more than 3 months,
* participants who have not been taking any non-steroidal anti-inflammatory drugs (NSAIDs) for at least one week prior to the start of the study,
* participants who are not taking any steroid drugs,
* participants who have never had the joint manipulation before,
* participants within the age range of 19-30 years,
* written consent to participate in the study.

Exclusion Criteria:

* participants who are students of physiotherapy,
* participants with a BMI \>33,
* participants after a lumbar spine surgery,
* participants who, in the 6 months prior to the start of the study, suffered from a lumbar spine injury,
* participants with diabetes,
* participants with rheumatic diseases,
* participants with endometriosis,
* participants with endocrine diseases,
* participants with acute inflammation in the lumbar spine region and sciatica symptoms.