Wearable Mid-Activity Measurement of Lower Limb Electrical Bioimpedance Estimates Vertical Ground Reaction Force...

Area of Science:

• Biomechanics
• Wearable Technology
• Biomedical Engineering

Background:

• Wearable electrical bioimpedance (EBI) sensing non-invasively monitors joint edema during activity.
• Previous work demonstrated physiological origins of EBI changes, but waveform patterns during activity remained unexplored.

Purpose of the Study:

• To develop a novel approach for extracting EBI waveform features during gait.
• To estimate changes in vertical ground reaction forces (vGRF) associated with fatigue using EBI.

Main Methods:

• Collected wearable EBI and vGRF data from six healthy subjects during an asymmetric fatiguing protocol.
• Analyzed changes in vGRF parameters (first peak, loading rate) for exercised and control legs.
• Correlated multi-frequency EBI features with vGRF parameters across 15 walking sessions.

Main Results:

• The exercised leg showed a significant decrease in the first peak vGRF and a significant increase in loading rate.
• No significant changes in these vGRF parameters were observed in the control leg.
• Strong correlations were found between EBI features and vGRF parameters (Pearson's r=0.81 for first peak, r=0.777 for loading rate).

Conclusions:

• This proof-of-concept study demonstrates the feasibility of estimating biomechanical parameters during activity using wearable EBI.
• The system enables convenient tracking of vGRF changes during daily activities.
• Potential for remote patient monitoring by physiotherapists and doctors to track progress and adherence, reducing clinical visits.