Dynamic Video Assessment of Axial Postural Abnormalities in Parkinson's Disease: A Pilot Study

Background: Axial postural abnormalities (APAs) are frequent and disabling axial symptoms of Parkinson's disease (PD). Image-based measurement is considered the gold standard but may not accurately detect the true severity of APAs because these symptoms can appear or get worse under dynamic conditions. Objective: The aim was to evaluate quantitative changes in APAs degree during prolonged standing and walking in both single- and dual-task conditions (motor + cognitive). Methods: We measured the degree of anterior and lateral trunk flexion (LTF) of 16 PD patients using AutoPosturePD during 4 tasks of 3 min each: (1) standing in place in a quiet condition, (2) standing in place while reading, (3) walking without performing other tasks, and (4) walking performing a cognitive task. Results: During prolonged standing, we found a significant LTF worsening under both single- and dual-task conditions over time (P: 0.010 and 0.018); anterior trunk flexion (ATF) with thoracic and lumbar fulcrum showed a significant worsening only under dual-task conditions (P < 0.05). All trunk flexion angles were higher during dual task compared to single task, and the difference in dual task was already statistically significant after 1 min. During walking, only ATF with lumbar fulcrum showed a significant worsening (P < 0.05), observed in dual task already after 1 min. Conclusions: Our pilot study suggests that one minute standing while reading may be sufficient to obtain a more reliable measure of the severity of LTF and ATF, with an expected change of ~ 7° for LTF and ATF with thoracic fulcrum and 11° for ATF with lumbar fulcrum.