Biomedical Sciences
Mohit Prashar, n/a
Research Assistant
KITE Research Institute, University Health Network
Brampton, Ontario, Canada
Abdullah Zafar, MSc
PhD Student
Université de Montréal – Department of Biomedical Sciences
Montréal, Quebec, Canada
Karl Zabjek, PhD
Associate Professor
University of Toronto – Temerty Faculty of Medicine, Department of Physical Therapy
Toronto, Ontario, Canada
Beverley Craven, MD, MSc, FRCPC
Professor
University of Toronto – Temerty Faculty of Medicine, Department of Medicine
Toronto, Ontario, Canada
Thomas Walden, PhD
Postdoctoral Research Fellow
KITE Research Institute, University Health Network
Toronto, Ontario, Canada
Sixteen adults completed three stance configurations (standing unsupported, tandem stance (left and right), and one-leg stance (left and right) for 20-seconds each with an IMU positioned at the C7 spinous process. Net acceleration (X, Y, Z-axes) was filtered using 4th-order Butterworth filters (low-pass < 0.7 Hz; bandpass 1-20 Hz) to isolate low- and high-frequency components. Peak detection algorithm identified low-frequency peaks (≥1s apart, prominence ≥0.02m/s²) and high-frequency peaks (120–300ms apart), including amplitude measures (max, min, mean). Pearson correlation examined the relationship between stance difficulty and event rates across frequency bands.
Results:
In the unsupported stance, low-frequency analysis detected 5-13 peaks per trial (mean amplitude = 8.47 m/s²), while high-frequency analysis detected 117-226 peaks (mean amplitude (0.025 m/s²). In tandem stance, low-frequency peaks increased to 10-25 per trial (mean = 8.35 m/s²), and high-frequency peaks ranged 79-195 (mean = 0.043 m/s²). In the one-leg stance, low-frequency peaks reached 8-28 per trial (mean = 8.61 m/s²), whereas high-frequency peaks decreased to 60-212 (mean = 0.066 m/s²). As stance difficulty increased, low-frequency event rates increased (r = 0.53) and high-frequency rates decreased (r = -0.33).
Conclusion:
This proof-of-concept demonstrates the feasibility of using a cervical-mounted IMU to quantify frequency-specific postural adjustments across varying stance demands. The observed relationship between task difficulty and peak frequencies indicates a shift from fast, fine-tuned corrections to slower, larger postural adjustments.