Some authors claim that patients with musculoskeletal pain tend to underestimate their levels of muscle tension. The results of studies find evidences of the deficits in the perception of muscular tension in patients with chronic pain, being this the pathogenic factor in some musculoskeletal alterations. These studies show that patients with chronic pain can not identify their muscle tension and suggest that this contributes to maintaining pain. Thus, positive results have been found with relaxation and electromyographic biofeedback in patients with chronic pain. If these symptoms are due to excessive stress, patients should be able to benefit from regulation of muscle activity through BFB-EMG, thus learning to regulate the physiological variable. The study will be carried out in the electrotherapy laboratory of the Health Sciences Building of the University of Almeria. Initially, the sample will be chosen and the informed consent of the subjects will be obtained. Before the start of treatment, a baseline assessment of the dependent variables will be performed. Subsequently subjects will undergo three sessions of manipulative therapy over 12 weeks (one session per week). After the therapeutic intervention, a new determination of the dependent variables will be performed.

Fibromyalgia (FM) affects nearly 2.4% of the Spanish population, mostly women aged between 40 and 60. This disease, which is characterized by a disturbance in their pain regulation with an increased sensitivity to painful stimuli and a decrease of pain threshold, has a strong impact on the patients' health and their quality of life, restricting the realization of their daily activities. Moreover, it presents a high prevalence of comorbidities, which increases the needs of these patients in terms of effective therapeutic management leading to higher health requirements.

In addition to that, FM response to drug treatments is low and its symptoms become more frequent simultaneously with adverse effects, and according to that, an individualized analysis becomes necessary as well as a multidisciplinary approach, since there is no absolute treatment up to now.

This study aims to compare the improvements obtained in the quality of life, pain and other FM symptoms respectively, by means of applying physical therapies (such as aerobic biodance exercise in aquatic environment and stretching exercises) and psychological treatments, such as electromyographic biofeedback (BFB-EMGS) based training.

Objectives:

To comparatively analyze the level of improvement that can be reached by FM patients, by means of pool exercises based treatments, stretching exercises and BFB-EMGS therapies.

Methodology:

The sample of this study consisted of FM diagnosed individuals who verified the following inclusion criteria:

• Aged over 18 years and below 69 years.
• FM diagnosed according to the American College of Rheumatology (ACR) criteria.
• To continue with their unchanged drug treatment for the duration of the study.
• To attend at least 60% of sessions to be considered to have completed both aquatic aerobic exercise treatment and stretching therapy, or to complete at least 12 sessions in the BFB-EMGS training case.

In addition to that, the exclusion criteria were:

• Aged over 69 years or below 18 years.
• To be involved in other non-pharmacological treatments.
• To display disorders such as heart, kidney or liver failures, which prevent the development of treatments.
• Other physical or mental disorders that could endanger the patient's health.
• Not have completed the minimum number of sessions of the corresponding therapy. Thus, this is an experimental study with randomized clinical trial design, consisting of three intervention groups, namely, aquatic aerobics group, stretching group and BFB-EMGS with stretching group. All groups were composed of 35 patients and were assessed before and after 12 weeks of treatment by a single investigator blinded to patient allocation.

Comparisons were established within each group, before and after 12 weeks of treatment (intragroup) and between groups (intergroup). In this way, all patient were asked to sign an informed consent and their demographics and health data were recorded in the first meeting.

Dependent variables.

• FM Impact Questionnaire (FIQ).
• McGill-Melzack questionnaire.
• Visual Analog pain Scale (VAS).
• The depression scale was estimated by means of the Center for Epidemiologic Studies Depression (CES-D).
• Pressure algometry.
• The anxiety was measured by the State Anxiety Inventory (SAI).
• The sleep quality was measured by the Pittsburgh Sleep Quality Index (PSQI).
• The number of tender points in each patient. Independent variables.
• Aerobic biodance program in pool;
• Stretching exercises program;
• BFB-EMGS training;

Inclusion Criteria:

• Aged 18 to 72 years and diagnosed with FMS according to 2010 ACR criteria. Before being included in the study, all the subjects must have signed an informed consent to ensure their participation, stating that it may be left at any time if were necessary.

Exclusion Criteria:

• Patients with physical or mental illness, infections, fever, hypotension, respiratory disorders which prevent the treatment realization, patients who do not maintain usual treatment during the study period or who do not perform the full intervention.