A body-fixed-sensor based analysis of compensatory trunk movements during unconstrained walking

Area of Science:

• Biomechanics
• Gait Analysis
• Wearable Sensors

Background:

• Compensatory trunk movements are crucial indicators of gait dysfunction, particularly in patients with hip arthroplasty.
• Objective quantification of these movements is essential for accurate clinical assessment and monitoring.
• Existing methods may be limited in unconstrained walking scenarios.

Purpose of the Study:

• To present and validate a body-fixed-sensor (BFS) based approach for quantifying compensatory trunk movements during unconstrained walking.
• To assess the accuracy of the BFS method by comparing it to a high-accuracy camera system.
• To evaluate the BFS method's ability to differentiate between hip arthroplasty patients with and without compensatory trunk movements.

Main Methods:

• Utilized a sensor fusion technique combining low-pass filtered accelerometer data and high-pass filtered gyroscope data to determine trunk segment orientation.
• Validated the accuracy of the BFS method by comparing frontal plane pelvic angular movements to a gold-standard camera system under various treadmill conditions.
• Applied the validated BFS method to assess trunk movements in hip arthroplasty patients and healthy controls during overground walking.

Main Results:

• The BFS method demonstrated high accuracy, with mean differences within 0.31 degrees and standard deviations of differences within 1.4 degrees compared to the camera system.
• Error percentages were below 17.7%, and correlations ranged from 0.87 to 0.99, indicating strong agreement.
• The BFS method successfully discriminated between patient groups, showing significantly larger peak-to-peak trunk movement amplitudes in patients with compensatory movements (13.5-26.3 degrees) compared to those without (7.4-13.8 degrees) and healthy controls (5.7-7.9 degrees).

Conclusions:

• The body-fixed-sensor (BFS) based approach provides an accurate and reliable method for quantifying compensatory trunk movements during unconstrained walking.
• This technique can effectively differentiate gait patterns in hip arthroplasty patients, identifying those with compensatory trunk movements.
• The BFS approach offers a valuable tool for objective assessment and monitoring of gait function in clinical settings, particularly for hip arthroplasty rehabilitation.