Standardization and optimization of force platform testing for balance assessment in cervical spondylotic myelopathy

This study aimed to compare the discriminative performance of different force platform testing methods for distinguishing patients with cervical spondylotic myelopathy (CSM) from asymptomatic controls and to evaluate the effects of arm position and test duration on individual balance parameters.

In this cross sectional study, 56 patients with CSM and 50 asymptomatic volunteers were enrolled between March to December 2025. Balance function was measured with the eMat 500 force platform under two standing postures, arms hanging down and arms extended forward, both performed with the feet together and the eyes closed, and each posture was tested at durations of 15, 30, and 60s. Receiver operating characteristic (ROC) curve analysis was used to compare the diagnostic value of the different posture and duration combinations.

The diagnostic efficiencies of the six test protocols were all different for the four balance parameters. The center of pressure (COP) trajectory length and the mediolateral centre of gravity velocity performed best at 15 s with arms hanging down, the anteroposterior centre of gravity velocity performed best at 60s with arms extended forward, and the area of the 95% confidence ellipse performed best at 30s with arms extended forward. Combined ROC analysis ranked the overall diagnostic performance of the six protocols from best to worst as follows: 30s with arms hanging down (AUC = 0.897), 15 s with arms hanging down (AUC = 0.890), 30s with arms extended forward (AUC = 0.878), 60s with arms extended forward (AUC = 0.869), 60s with arms hanging down (AUC = 0.855), and 15 s with arms extended forward (AUC = 0.840).

The research results indicate that the 30s both arms hanging down test has the highest diagnostic value. This testing approach has the potential to improve the efficiency of outpatient assessment for patients with CSM.