• Summary Sacroiliac joint dysfunction (ASI) is an alteration in the normal biomechanics of the joint, which leads to hypomobility or hypermobility of that joint. It is one of the most common causes of misdiagnosis in low back pain and when not treated correctly, it often evolves into chronic pain (30% to 42%) and disability. Manipulating the dysfunctional ASI appears to result in benefits and significantly positive changes at various levels, in all segments of the human body. With this investigation, we intend to clarify and deepen the possible correlation between the changes that normally accompany this dysfunction, as well as its possible reversibility with its normalization.
• Objectives

The investigators will essentially have two main objectives:

1. Mapping of the most evident symptomatic changes, when sacroiliac joint dysfunction is present, in terms of pain and muscle tone;

2. To try to understand the immediate, global and immediate effect of ASI manipulation.

   • Study design Quantitative, with experimental study design, with the sample comprising individuals with SIJ dysfunction, where all participants will be randomly allocated to the experimental, control and sham groups. It will be carried out at the University of Aveiro facilities.

Initially, we will assess the participants with sacroiliac dysfunction. The experimental will be manipulated, the control group will do nothing, and the sham group will be submitted to a hypothetical manipulation (sham manipulation). Consequently, the patients will be assessed again, measuring the subjective and objective degree of pain and muscle tone.

- Material and methods

We will make use of:

• Standing flexion test;
• Sitting Flexion Test;
• Faber Test;
• EVA , to subjectively assess pain;
• Pressure algometer, to objectively assess pain ;
• MyotonPro, to assess muscle tone;

Introduction

ASI dysfunction refers to a state of altered biomechanics of this joint . This dysfunction can result from repetitive stress , degeneration, lumbar deformities, inflammation, and previous lumbar fusion.

ASI dysfunction is an alteration in the normal biomechanics of the joint, which leads to hypomobility or hypermobility of that joint. It is one of the most common causes of misdiagnosis in low back pain and when not treated correctly, it often develops into chronic pain (30% to 42%) and disability.

The SIJ has a crucial function in mobility, stability and resistance against shear forces, and is also wrongly undervalued as the origin of low back pain and, with the increase in average life expectancy, it has become an extremely prevalent problem.

Manipulation of the SIJ in dysfunction appears to bring about benefits and significantly positive changes at various levels. The analysis of the results of two manipulative therapy techniques in patients with sacroiliac dysfunction revealed a statistically significant improvement immediately after treatment, after 48 hours and one month later, in terms of both pain and disability, as favourable developments were recorded in measurements using the VAS and the Oswestry Disability Index (ODI).

Even in asymptomatic individuals, there seem to be changes that are not just local, when manipulating the ASI, they came to the conclusion that the manipulation of the ASI applied bilaterally in asymptomatic people resulted in immediate changes in load distribution on the plantar support, in the orthostatic position, after baropodometric analysis using a force platform.

The benefits of this therapeutic approach were also defended, after a study in young females with SIJ dysfunction, subjected to a single SIJ manipulation session, in which the analysis of results after evaluation with EVA instruments and a digital algometer ( Model J- Tech ), indicate that the manipulation helped to alleviate the level of pain, with the effects lasting for 24 hours, immediately increasing the range of motion of internal and external rotations of the hips and lumbar flexion and extension.

Despite the existence of multiple studies on the benefits of this type of approach at various levels, in a more or less localized way, we did not find any study that showed correlated changes at a global level. With this work, we will seek to map the most evident symptomatological changes in the different regions of the human body associated with ASI dysfunction and evaluate the potential of manipulating the ASI in individuals with dysfunction of this joint, analyzing at specific points in the different segments, the initial state in terms of inequality of perceived pain and difference in muscle tone verified, measuring, following manipulation, the observable changes in these variables. As instruments for this assessment, we will use the following variables:

1. Pain - EVA and Pressure Algometer;
2. Muscle tone - MyotonPro ;

The main objective of this PhD thesis will be to understand the effect of manipulation on the dysfunction of the SIJD.

Objectives

1. Mapping of the most evident symptomatological changes, when sacroiliac joint dysfunction is present, in terms of pain and muscle tone;
2. To study the immediate effect of ASI manipulation and the hypothetical correlation with the changes recorded, in pain level and muscle tone.

Study Design and Methods

Study Design Experimental pilot study, where participants will be randomly allocated to experimental, control and sham groups. It will be carried out at the University of Aveiro facilities, with a sample of 21 students.

Participants The study sample will be a convenience sample, randomly selected from the universe of students at the University of Aveiro, invited to participate in the study.

• Inclusion criteria: young adults, of both sexes, aged between 18 and 30 years, with sacroiliac joint dysfunction demonstrated by standing flexion test, sitting flexion test and strength test with applied kinesiology.
• Exclusion criteria: students of the Bachelor's Degree in Physiotherapy, Individuals with neurological injuries, under the effect of local anesthetics, or subject to another type of therapeutic intervention, during the intervention period.
• Ethical considerations: All volunteers will be informed about the objectives of the study, procedures, methods of data collection and processing/confidentiality, as well as the possible benefits and harms. They will have the possibility to refuse participation at any time, and will be required to express their consent in light of the protocol of the Declaration of Helsinki.

Variables :

• Pain (EVA and algometer);
• Muscle tone (Myoton Pro).

Instruments : -

• EVA , to assess the subjective sensation of pain perceived by the participant;

• Pressure Algometer , to assess pain, used at the following points:

  • Lower limbs: muscular belly of the external calves, 8 cm below their origin and muscular belly of the internal calves, 12 cm below the insertion, cuboids and tarsal naviculars;
  • Upper limbs: bilaterally at the level of the muscular belly of the short portion of the biceps brachii, 9 cm above the elbow crease and muscular belly of the brachialis, 3 cm below the vertex of the V deltoid;
  • Cervical spine: At the level of the transverse processes of C4, bilaterally;
  • Lumbar spine: At the level of the transverse processes of L3, bilaterally;
  • Sacroiliac joints bilaterally, at the level of the posterior superior iliac spine, bilaterally;
  • Craniocervical transition, bilaterally, at the level of the occipital origin of the upper trapezius muscle;
  • External and internal joint interline, middle third, in both knees;
  • Iliac fossa bilaterally, 5 cm internally to the anterior superior iliac spine;
  • Transition from the hypochondrium to the lateral abdominal region, bilaterally;

• MyotonPro : at the same points used with the pressure algometer, at the level of the upper and lower limbs, to assess muscle tone.

Inclusion Criteria:

• Clinical diagnosis of sacroiliac joint dysfunction.

Exclusion Criteria:

• Students of the Bachelor's Degree in Physiotherapy;
• Individuals with neurological injuries:
• Under the effect of local anesthetics;
• Subject to another type of therapeutic intervention, during the intervention period.