Background: Sarcopenia related to advancement in aging among geriatric population remains common and a major challenge in clinical evaluation or management. Many geriatric people have ongoing disability related daily activities particularly related to large muscle sarcopenia. A uni-dimensional measure of limitation in activity is needed to monitor progress in function. However, the current measures are either patient reported or multidimensional constructs such as activity level, Performance-based construct of activities of daily life is scarce in this population. Therefore, the aim was to develop the clinician-observed large muscle performance test (LAMP), a interval level uni-dimensional measure of actual performance of daily activities, reflecting limitations of activity related to large muscle sarcopenia. Methods; A prospective clinician observed outcome measure (LAMP-test) development study will be conducted and the constructs will be based on the actual performance of repetitive activities reflecting the ADL related to large muscle groups among geriatric population. This study is approved by the IEC, MMCHRI, India and Initially a conceptual framework will be drafted followed by item generation; (existing sarcopenic measures, existing ADL measures in Geriatric, literature informed drafting of conceptual framework, Focus group), and item selection; (selection criteria, importance, and feasibility ratings, pilot testing, Rasch analysis). Based on the focus group interviews with 10 geriatric adults, 2 geriatric physicians, 4 physiotherapists and a literature review informed drafting of conceptual framework will be development. The recommendations of COSMIN for development new tool will be used. A cognitive debriefing interview with 10 older adults of both gender, and 8 health professionals will be conducted to ascertain content validity. The LAMP test tool will be field tested with 250 community dwelling geriatric people. Rasch psychometric analysis will be conducted for scale reduction, and psychometric testing of the LAMP tool with an additional 125 participants. Discussion;This research will help development of a new clinician observed measure with functional dimension construct with potentially good psychometric properties to evaluate the large muscle group based ADL related functional strength among geriatric people. It is envisioned that the LAMP-test will be a promising outcome tool to measure large muscle group sarcopenia related activity limitations among older people. The construct of content will be uni-dimensional and feasible for use in both clinical and home settings, and a suitable tool for researches exploring activity limitations related sarcopenia among geriatric people.