Hypoalgesia induced by upper limb lateral elevation exercise in healthy individuals: an intra-rater reliability study

• Grant number: 24/09659-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Luiz Fernando Approbato Selistre
• Grantee: Ana Caroline de Brum Schneider
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Introduction: Decreased sensitivity to pressure pain after exercise has been demonstrated in the literature, being defined as exercise-induced hypoalgesia (EIH). EIH is considered a dynamic measure to assess pain modulation and it is suggested that the HIE response is mediated by the activation of descending inhibitory pain pathways. Experimentally, the HIE response can be assessed by the pressure pain threshold (PPT) and pressure pain tolerance threshold (PPTT). Its result is identified as a possible predictor of response to exercise treatment. It is an accessible assessment for clinical practice and repeated assessments during the therapeutic process can be useful for monitoring and evaluating a patient's treatment prognosis. Studies to date have shown low levels of reliability and none of them have used dynamic resistance exercise as a conditioning stimulus for EIH, despite it being widely used in rehabilitation protocols. Given that dynamic resistance has an effect on pain modulation in healthy individuals, considered stable for evaluation in the construct, and lateral elevation of the upper limbs has been used as a prognostic test for treatments in clinical studies, it is necessary to investigate its reliability and ensure that measurements are being carried out outside the error values. Objective: To investigate the intra-rater reliability of the EIH of lateral elevation of the upper limbs in healthy individuals. Methodology: Cross-sectional observational study. The sample size will be based on COSMIN criteria which recommends e50 participants. The procedures will be carried out over two days, separated by an interval of three to seven days. The assessment to quantify the response to the EIH test will be made by the PPT and PPTT, in the upper trapezius and quadriceps muscles, both on the individual's dominant side, immediately before and after the exercise condition. The assessor will be blind to the PPT and PPTT results. Statistical analysis: Intra-rater reliability will be calculated using the two-way random model with absolute agreement and thus determine the intraclass correlation coefficient (ICC). The EIH confidence interval,standard error of measurement (SEM) and minimum detectable change (MDC) will also be calculated.