Functional Muscle-Bone Incongruity Index (FKUI): A Prospective Observational Study

The Functional Muscle-Bone Incongruity Index (FKUI) is a novel approach developed to evaluate the relationship between muscle function and bone health. This prospective observational study aims to investigate the clinical applicability of FKUI, which combines handgrip strength, total hip bone mineral density (BMD), and lumbar-hip BMD discordance. Approximately 200 adult participants undergoing routine DXA assessment will be enrolled. The study will examine whether the combined evaluation of muscle function and bone health parameters provides a more comprehensive assessment of musculoskeletal status than individual measures alone.

Inclusion Criteria: * Age 18 years or older * Attendance at the Physical Medicine and Rehabilitation outpatient clinic * Scheduled to undergo routine bone mineral density assessment by DXA as part of clinical evaluation * Ability to perform handgrip strength testing * Availability of lumbar spine and total hip bone mineral density measurements suitable for analysis * Ability and willingness to provide written informed consent Exclusion Criteria: Exclusion Criteria: * Age younger than 18 years * Secondary causes of osteoporosis (e.g., hyperparathyroidism, Cushing syndrome, malignancy, or other conditions affecting bone metabolism) * History of metabolic bone disease * Major trauma or fracture within the previous 6 months * Upper extremity disorders that may significantly affect handgrip strength measurement (e.g., severe osteoarthritis, neurological disorders, major deformities) * DXA measurements that are technically inadequate or unsuitable for analysis * Refusal or inability to provide written informed consent