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

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.

The aim was to evaluate quantitative changes in APAs degree during prolonged standing and walking in both single- and dual-task conditions (motor + cognitive).

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.

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.

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.