Here is the design of a clinical trial:

Official Title: Effects of Global Postural Exercises Versus Specific Therapeutic Neck Exercises on Pain, Disability, Postural Control, and Neuromuscular Efficiency in Women With Chronic Nonspecific Neck Pain

Included conditions:
- Neck Pain
- Chronic Pain

Study Armgroups:
- {'label': 'GPR Group', 'type': 'EXPERIMENTAL', 'description': 'Global Postural Reeducation with 2 parts in each session:\n\n1. st: 2 postures in lying position - without gravity load (15 minutes each posture): The aim of these postures is to achieve and maintain postural balance and to stretch the posterior muscle chain. In order to achieve this, specific exercises in the lying position are used. That exercises involve a precise use of contractions, stretch reflexes, light and controlled manual tractions and sustained elongations.\n\n   The maintenance of alignment during posture will be achieved by verbal commands and manual contact of the therapist, guaranteeing the active engagement of patient to reach the correct posture.\n2. st: Standing posture - integration under gravity load (10 minutes): With the participant standing the physiotherapist makes final corrections for postural integration.', 'interventionNames': ['Other: Global Postural Reeducation']}
- {'label': 'Exercise Group', 'type': 'EXPERIMENTAL', 'description': 'Therapeutic exercises. That they will be divided into 3 phases:\n\nThe exercises in these phases will consist in active exercises of the cervical spine and shoulder girdle, motor control exercises, and finally strength and endurance of the cervical flexors and extensors and of the musculature of the shoulder girdle.', 'interventionNames': ['Other: Exercise Therapeutic']}

Interventions:
- {'type': 'OTHER', 'name': 'Global Postural Reeducation', 'description': 'The participants will receive treatment along 4 weeks, 2 sessions per week, and 40-45 minutes each session.\n\nIn the treatment 3 of the therapeutic postures of GPR method to will carry out following Souchard\'s principles of "Global Postural Reeducation"', 'armGroupLabels': ['GPR Group']}
- {'type': 'OTHER', 'name': 'Exercise Therapeutic', 'description': 'The participants will receive treatment along 4 weeks, 2 sessions per week, and 40-45 minutes each session.\n\nThe treatment will be divided into 3 phases, where it initially starts with phase 1 (3 treatments) and progresses to phase 2 (3 treatments) until reaching stage 3 (2 treatments).', 'armGroupLabels': ['Exercise Group']}

Primary Outcomes:
- {'measure': 'Changes in neck pain intensity before, during and after the intervention', 'description': 'Numerical Pain Rating Scale (NPRS) will be used. It is a scale used to quantify the patient\'s pain level on an 11-point numerical scale 0-10 with 0 being "no pain" and 10 being the "worst possible pain."', 'timeFrame': '5 weeks. 4 time points: 1) Baseline (pre-intervention); 2) Second pre-intervention (1 week later); 3) 1st post-intervention after four sessions (1+2 weeks later); 4) Final, 2nd post-intervention (1+4 weeks later)'}
- {'measure': 'Changes in disability before, during and after the intervention', 'description': 'The Neck Disability Index (NDI) will be used. It is a modification of the Oswestry Low Back Pain Disability Index. It is a scale used to measure disability associated with cervical pain due to acute or chronic conditions. He has 10 items: 7 related to activities of daily living, 2 related to pain and 1 related to concentration. The test can be interpreted with a maximum score of 50.\n\n0 - 4 = no disability 5 - 14 = mild 15 - 24 = moderate 25 - 34 = severe above 34 = complete', 'timeFrame': '5 weeks. 3 time points: 1) Baseline (pre-intervention); 2) Second pre-intervention (1 week later); 3) Final, 2nd post-intervention (1+4 weeks later)'}

Please estimate the sample size based on the assumption: 
The sample size calculation assumes an alpha risk of 0.05, a beta risk of 0.2 (power of 80%), and a 15% loss rate during the study.
2.2. Participants, Recruitment and Sample Size Calculation
        A sample of 62 women with CNSNP were recruited between 30 and 65 years old from the community in Guarda, Portugal. Participants were recruited through an online google form, with a questionnaire in Google Docs format, which was disseminated through social network postings (Facebook and Instagram) and the sending of institutional emails from Polytechnic Institute of Guarda to its workers. There were two physiotherapist assessors, who initially assessed participants that responded to the advertisements, and they were different from the physiotherapists who performed the interventions in both groups. In the first visit, the participants provided oral and written forms of all necessary information about the trial, including the study purpose and procedure. After voluntarily signing the informed consent statement, if through a detailed interview they met all inclusion, exclusion, and withdrawal criteria (Table 1), they enrolled into the trial to begin with an initial evaluation with the assessors.
        The sample size calculation has been made based on the potential modification of the primary outcomes, neck pain intensity, and neck disability (NPRS and the NDI-PT) from baseline to final assessments. For repeated measurements of the estimated sample size, accepting an alpha risk of 0.05 and a beta risk of 0.2 in a two-sided test, 26 subjects were necessary in the first group and 26 in the second to recognize a statistically significant difference greater than or equal to 2 units (SD = 1.75) (NPRS) or 7 units (SD = 6) (NDI), and to detect small differences in standardized means between groups (Cohenâs d = 0.8), since the intervention with therapeutic exercise is known to have a beneficial effect and we want to assess whether the intervention with GPR has similar or even greater effects. Finally, considering a 15% loss rate during the study, and in order to end up with a sample of 52 subjects, based on the power analysis results, the final sample to be recruited was 62 subjects, 31 in each group. The sample size calculation was made with the software âPASS 15 (NCSS statistical software)â and âThe R Project for Statistical Computingâ.