Video-based dual-task Four-Square Step Test for fall risk assessment in Parkinson’s disease
摘要
Fall risk threatens independence in Parkinson’s disease (PD), particularly under combined cognitive–motor demands. This study proposes a video-based artificial intelligence (AI) framework to identify the most sensitive dual-task condition of the Four-Square Step Test (FSST) for fall-risk assessment. Thirty PD patients were recorded with a fixed RGB camera performing the FSST under single-task and three dual-task conditions: reciting days backward, holding a glass of water, and ball transfer. From each recording, silhouette masks and skeleton keypoints were extracted and fused into frame-level embeddings, fed into a multitask temporal convolutional network (TCN) jointly predicting task type and binary fall-risk. Videos were labeled high or low fall-risk using the clinician-measured 9.68 s threshold; model weights were initialized via transfer learning from 40 healthy adults. Clinically, completion times correlated with the Timed Up and Go test (