Development, validation, and testing of an agriculture support exoskeleton in adjunct to conventional physiotherapy for farm labourers with chronic low back pain: A two-phase, mixed-methods, quasi-experimental pilot study protocol

BACKGROUND: Low back pain (LBP) affects 619 million people globally, with projections reaching 843 million by 2050. Farm labourers exhibit markedly higher prevalence than the general population, with lifetime (70-85%), 12-month (15-45%), and point (approximately 30%) prevalences driven by sustained trunk flexion, repetitive manual handling, and limited access to ergonomic or rehabilitative interventions. While conventional physiotherapy is the cornerstone of chronic LBP (CLBP) management, its effectiveness may be limited by ongoing mechanical loading during agricultural work. Back support exoskeletons (BSEs) have shown promise in reducing lumbar loading. However, no study has integrated exoskeleton development, validation, and clinical testing within a physiotherapy framework for farm labourers. The objective of the two-phase protocol is to design, develop, and laboratory-validate an agriculture support exoskeleton (AgSuEx), followed by examining the effects of AgSuEx-assisted physiotherapy compared with conventional physiotherapy alone on pain intensity, work productivity, disability, physical function, and quality of life (QOL) among farm labourers with CLBP. METHODS: The two-phase, mixed-methods, quasi-experimental pilot study will be conducted in Wardha district, Maharashtra, India. Phase I will involve participatory co-design, iterative engineering development, and laboratory validation of an AgSuEx using finite element analysis (FEA), multibody dynamics (MBD) simulation, surface electromyography (sEMG), inertial measurement units (IMUs), interface pressure mapping, and validated usability instruments, integrated with focus group discussions (FGDs) from farm labourers. Phase II will employ a quasi-experimental, non-equivalent control group pretest-posttest design with repeated measures. Farm labourers aged 25-49 years with CLBP will be assigned (1:1) to AgSuEx-assisted conventional physiotherapy or conventional physiotherapy alone for 6 weeks, with follow-up at 3 and 6 months. OUTCOMES: Phase I primary outcome: lumbar extensor sEMG activation. Phase II primary outcomes: pain intensity (Quadruple VAS) and work productivity. Secondary outcomes: functional disability (RODI), physical function (RMDQ), and QOL (SF-12). Device-specific outcomes (SUS, QUEAD and LPP) will be assessed across both phases. Outcome assessors and data analysts will be blinded to group assignment. CONCLUSION: This protocol will generate preliminary evidence on the feasibility, usability, and preliminary clinical effects of integrating a Make in India AgSuEx with conventional physiotherapy for farm laborers with CLBP. Findings will guide future larger-scale controlled trials and inform ergonomic and rehabilitative strategies for agrarian populations. TRIAL REGISTERED PROSPECTIVELY: Clinical Trial Registry- India CTRI/2025/11/097725 [Registered on: 20/11/2025]. Acknowledgement Number: REF/2025/11/116856. URL: https://ctri.nic.in/Clinicaltrials/pmaindet2.php?EncHid=MTQ1NzE3&Enc=&userName=Protocolversion4.0,4/09/2026.