Due to the importance of the functions of the gluteus medium, mainly during gait, it becomes essential to strengthening early in the musculature. The association of muscle strengthening with the Functional Electric Stimulation (FES) comes to accelerate stabilization of hip, leading to functional rehabilitation early and improves the quality of life through rehabilitation in social life and activities of daily life. Thus, it becomes a relevant study to assess objectively the implications of FES in muscle strengthening of gluteus medium associated with the Physiotherapy Protocol Total Hip Arthroplasty (PPTHA), through the assessment of motor performance in patients undergoing surgery for Total Hip Arthroplasty (THA), aiming to better rehabilitation strategies for this population.

The objective of the research is to assess the effects of functional rehabilitation through PPTHA associated with FES in the gluteus medium compared only with the PPTHA, in patients undergoing surgery for THA.

The principal hypothesis is that there is difference between the functional rehabilitation of the patients undergoing PPTHA associated with the FES of gluteus medium, after THA and the patients submitted only to PPTHA.

The data collection, evolution and physiotherapy treatment will be carried out on the premises of the Hospital de Clinical de Porto Alegre (HCPA), after approval by the Ethics and Research Committee (ERC) of the institution. The population will consist of patients undergoing surgery for THA at HCPA.

The researchers invite patients that intern consecutively at HCPA, for surgery of THA and fall within the eligibility criteria, to participate in the research. They will be informed about the study, objectives, benefits and potential risks. After the informed consent of the patients and signed the Free and Informed Consent, the patients will be randomized into two groups: Intervention Group that will perform the PPTHA associated with FES in the gluteus medium; and a Control Group that will perform only the PPTHA.

All patients are evaluated by physiotherapists of Hip Surgery Group of HCPA (HSGHCPA), who helped in the process of randomization, while revaluations are performed at hospital discharge through blinding simple by a researcher linked to the work that will take place only the revaluations and do not have access to the methodological aspects and randomization of the study, the patients are also instructed to not inform what kind of intervention received. The perform assessments are carried out through Amnesia idealized by authors, composed by identification data, history of pathology and current history of previous pathologist. In addition, all patients also underwent the following evaluations: before the intervention and after completion of the interventions, pre hospital discharge.

The evaluation of joint ranges of motion will be carried out through the goniometry which will be performed in accordance with the methodology proposed by Manual Goniometry. Will be assessed by means of goniometry the movements of flexion, extension, adduction, abduction, internal and external rotation of both sides of the hip.

The maximum muscle strength of the gluteus medium will be evaluated through a dynamometer load coupled to a support, stuck to the knee of the patient that will be in lateral decubitus, and will cause the movement of hip extension with both legs. The force shall be measured three times with intervals of 2 minutes of rest between the assessments. The maximum value obtained will be used as voluntary force maximum of the gluteus medium.

Clinical evaluations and functional will be measured by means of the scores of Merle D'aubigne and Postel that has as objective to evaluate the motor performance regarding pain, gait and mobility. The clinical evaluation, the maximum score for pain (total absence), mobility (equal to normal hip) and gear (normal) is 6 and the sum total of the three evaluated areas is 18. The functional assessment the maximum score for pain (no pain) and ability to ambulate (normal) is 12.

The structural adaptations of the gluteus medium from the rehabilitation will be assessed by means of images of ultrasound. For evaluation of muscle architecture will be used a System of portable ultrasound (VIVID i®, GE) with a probe of linear arrangement (60 mm, 7.5 MegaHertz (MHz) - VIVID i®, GE). The portable system will allow the easy scroll for assessment of patients in Inpatient Units. A single researcher is responsible for collection of all images, which are obtained with the muscles at rest. Maps are made in layers of acetate to ensure that images are collected in the same points during the assessments pre and post-training. These images are used in the evaluation of the following parameters of muscle architecture: (1) muscle thickness, which is measured by means of a perpendicular line between the superficial aponeurosis and the deep aponeurosis muscle; (2) length of volume, which represents the length of the muscle fiber and is a parameter that denotes the number of sarcomeres aligned in series and (3) angle of affliction of fibers, obtained by means of the angle formed between the deep aponeurosis and the volume, which is an indication of the size of the muscle fibers (i.e. the number sarcomeres aligned in parallel).

The Control Group receives daily visits of HSGHCPA workouts from PPTHA, already established at HCPA. Already the Intervention Group performs the PPTHA associated with FES during the hospital phase.

Inclusion Criteria:

• patients with Coxarthroses Primary and Secondary with THA indication

Exclusion Criteria:

• patients who refused to participate in this study,
• patients with indication for THA by fractures and bone tumors,
• THA review,
• anatomic abnormalities congenital and acquired,
• patients with neurologist lesions that do not understand the commands or with changes in sensitivity in lower limbs
• patients with postoperative infection.