Validation and reliability analysis of two bulb-type devices for assessing handgrip strength in typical 6-year-old children

• Grant number: 25/08715-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Ana Cláudia Mattiello-Sverzut
• Grantee: Eloísa Santos Bertola
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Introduction. Handgrip strength is assessed using hydraulic, mechanical, electronic or pneumatic dynamometers, whose measurements are expressed in units of force or pressure. The North Coast bulb dynamometer and the Manual Pressure Device (MPD) are better suited for assessing children's handgrip strength, as they are lighter, fit better to the child's hand and are less expensive than the gold standard dynamometer (JAMAR®). However, these instruments have not had their validity and reliability tested for this population. Objective: to analyze the validity and reliability of the North Coast bulb and DMP to assess the handgrip pressure of typical 6-year-old children, using JAMAR® as the gold standard. Method: Cross-sectional study, with a sample of 82 typical children, aged 6, recruited from the community and from a private school in Ribeirão Preto. Children with a history of fracture in the upper limb in the last year and with chronic, respiratory and cardiac diseases will not be included. Children who do not understand the commands for carrying out the test and children who do not maintain their positioning while carrying out the tests will be excluded. Handgrip pressure measurements will be collected with the North Coast and DMP and handgrip strength measurements will be collected with JAMAR®. The preferred hand will be used, following the positioning of the American Society of Hand Therapy, with the instruments presented in random order. Data processing and analysis: Descriptive statistical analysis will be performed, Pearson Correlation for the validity of the instruments, ICC for reliability, with subsequent Bland-Altman analysis for agreement of the measurements.