JMIR Publications

ABSTRACT

Background:

Elderly patients with knee osteoarthritis (KOA) have a significantly increased risk of falls, and their balance impairments involve abnormal central compensatory control and instability in the peripheral musculoskeletal system. This aligns with the core TCM pathogenesis concept of "gradual depletion of kidney essence, insufficient marrow sea, and dysfunction of the “Brain-Tendon-Bone" axis. However, current fall prevention research mostly focuses on single dimensions, and there remains a lack of clinical multimodal studies integrating all three aspects—Brain, Tendon, and Bone.

Objective:

Based on the theoretical framework of the "Brain-Tendon-Bone" axis, this study aims to compare differences between fall-prone and non-fall-prone elderly KOA patients across multiple levels—including central nervous function (brain activation patterns), peripheral characteristics (muscle and tendon activation features), and bone quality—to identify independent risk factors associated with falls in KOA patients, thereby providing an integrative TCM approach for fall prevention and management in older adults.

Methods:

This is a single-center, age- and sex-matched case-control study. A total of 60 elderly KOA patients (Kellgren-Lawrence grade II–III) will be enrolled and divided into a case group (n=30) and a control group (n=30) based on whether they experienced at least one fall within the past 12 months. All participants will undergo clinical assessments using standardized scales, Berg Balance Scale (BBS), Timed Up and Go test (TUG) single-task and dual-task, single-leg stance test, Functional Gait Assessment (FGA), Visual Analog Scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Falls Efficacy Scale-International (FES-I), and Hospital Anxiety and Depression Scale (HADS). Functional near-infrared spectroscopy (fNIRS) will measure changes in oxygenated hemoglobin concentration in the prefrontal cortex, supplementary motor area, and primary motor cortex during balance tasks. Surface electromyography (sEMG) combined with 3D motion capture will assess muscle activation timing, vastus medialis obliquus/vastus lateralis (VMO/VL) ratio, and gait stability. Dual-energy X-ray absorptiometry (DXA) will evaluate femoral neck bone mineral density (BMD) and trabecular bone score (TBS). The primary outcome measures are the Berg Balance Scale and Timed Up and Go test; secondary outcomes include parameters from all other assessed dimensions. Paired tests will compare group differences, binary logistic regression will identify independent fall risk factors, and correlation analyses will validate the pathogenic chain described as "brain dysfunction, tendons failing to stabilize bones, and bones deprived of nourishment".

Results:

The study received ethical approval in May 2026 (approval number: KT2026050905), recruitment is scheduled to begin in January 2027, enrollment will be completed by September 2027, and all data analyses and final reporting are expected to be completed by December 2028.

Conclusions:

By applying the "Brain-Tendon-Bone" axis theory to investigate the clinical mechanisms underlying falls in elderly KOA patients, this study will use multimodal techniques to simultaneously analyze central and peripheral features across multiple physiological systems. It is expected to provide verifiable clinical evidence supporting an integrative TCM perspective for managing falls in elderly KOA patients. Clinical Trial: ITMCTR2026001838