Author(s): CHEN, E., BERGDAHL, A., ROBERTS, M., Institution: CONCORDIA UNIVERSITY, MONTREAL, Country: CANADA, Abstract-ID: 899

INTRODUCTION:
While online exercise programs for older adults have been an increasingly popular form of balance training [1], there are no quantitative methods to remotely assess postural stability. The aim of this study  was to investigate the validity and reliability of Kinovea, a free video sports analysis software, for tracking shoulder and hip sway. The assessment involved a comparison with the gold-standard center of pressure (CoP) analyses conducted using force plates [2].
METHODS:
10 women (73.9 ± 5.7 years old) completed three 30-second quiet standing trials on force plates in three staggered conditions: eyes open (EO), eyes closed (EC) and foam with eyes open (FOAM). Trials were filmed from a sagittal view and frame-by-frame analysis of anteroposterior shoulder and hip sway was completed by two blinded raters. Pearson’s Correlation Coefficient (r) was used to determine the validity of shoulder and hip sway to CoP displacement. Intraclass Correlation Coefficients (ICC2,1) assessed inter-rater reliability (ɑ=.05). 
RESULTS:
As conditions increased in difficulty from EO to EC to FOAM, anteroposterior CoP increased (mEO=2.27 ± 0.70 cm; mEC=3.17 ± 1.34 cm; mFOAM=3.46 ± 1.07 cm). Raters demonstrated excellent inter-rater reliability across all conditions for the shoulder (ICC2,1=0.96-.98, p≤.001), and ranged from moderate-good for hip sway (ICC2,1=0.37-0.64, p≤.001). Both raters showed significant moderate correlations between shoulder sway and CoP in all conditions (r=0.54-0.69, p=.002-.001). Raters found diverging relationships between hip sway and CoP ranging from weak-moderate during EO (r2=.39, p2=.032; r1=0.58, p1=.008), moderate-strong for EC (r1=.70, p1≤.001; r2=.60, p2≤.001). Both raters showed moderate correlation during FOAM (r1=.67, p1≤.001; r2=.67, p2≤.001).
CONCLUSION:
As CoP displacements became larger, Kinovea showed greater validity and reliability. Shoulder sway is a valid and highly reliable method for remote postural stability assessment. While acceptable, hip sway was greatly influenced by artefacts such as hand movement. Kinovea provides a free and accessible method for online researchers and clinicians to assess the fall risk and effectiveness of balance training among older participants. Future studies should explore the use of AI video tracking to speed-up analyses.