PTOtherJournal of neuroengineering and rehabilitation2021

Prediction and detection of freezing of gait in Parkinson's disease from plantar pressure data using long short-term memory neural-networks.

Gaurav Shalin, Scott Pardoel, Edward D Lemaire and 2 others

PMID 34838066

WHAT IT FOUND

Pressure insoles plus a small neural network detected 343 of 361 lab freeze episodes in seven people with Parkinson's.

It also identified some periods before freezes. The tiny sample makes this a feasibility signal, not a clinical tool.

Key findings

01Using plantar-pressure insoles, a two-layer LSTM model correctly classified 343 of 361 freeze episodes when each freezing participant was tested separately.

02A model trained to predict freezing of gait correctly identified 79.9% of periods defined as pre-freeze or freeze, and 76.3% of periods that were not.

03The detection model mistook standing for freezing: 65.3% of data labelled as standing were false positives.

STILL TO COME

How it was doneWhat they foundWhat it means for PTs

Read the rest of this summary

You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.

Already have one?

What it does not show

Only 11 male participants were tested, and only 7 froze; Participant 7 contributed 221 of 362 freeze episodes. The study was a single laboratory session with added cognitive and motor tasks to provoke freezes, not a real-world assessment. The reported outcomes were model classification metrics, not patient outcomes such as falls, mobility, or independence. The model misclassified many standing periods as freezes: 65.3% of standing data were false positives. Prediction used a binary setup that grouped pre-freeze and freeze together, so it did not test a separate pre-freeze warning class. Freeze labels were identified by study authors, with a second rater consulted only if uncertain. The insoles used were wired, single-use laboratory sensors, not a finished wearable product.

Declared interests

Funded by Microsoft Canada, Waterloo Artificial Intelligence Institute, Network for Aging Research, University of Waterloo, and Natural Sciences and Engineering Research Council of Canada. No author conflicts-of-interest declaration is provided in the supplied article text.

The easy way to misread this

Do not conclude that plantar-pressure insoles can detect freezing of gait reliably in clinics. The model detected 343 of 361 lab freeze episodes in only seven participants, and 65.3% of standing data were false positives, so it is not ready for patient care.

Read it on PubMed →