Ground reaction force estimates from ActiGraph GT3X+ hip accelerations.

Area of Science:

• Biomechanics
• Human Movement Analysis
• Wearable Technology

Background:

• Quantifying daily ground reaction forces (GRFs) outside laboratory settings is crucial for understanding biomechanical loading on the body.
• Existing methods often require specialized equipment, limiting real-world application.
• Activity monitors offer a potential solution for accessible GRF estimation.

Purpose of the Study:

• To develop and validate statistically based models for estimating peak vertical GRF (pGRFvert) and peak braking GRF (pGRFbrake).
• To utilize raw hip-worn activity monitor (AM) acceleration data for these estimations.
• To enable GRF quantification during both walking and running activities.

Main Methods:

• 19 males and 20 females completed walking and running trials wearing an ActiGraph GT3X+ AM on their hip.
• Raw acceleration data (ACCvert, ACCbrake) and GRF data were collected during the stance phase of gait.
• Generalized regression equations were developed using a training dataset (30 subjects) and tested on a holdout dataset (9 subjects).

Main Results:

• Developed generalized equations incorporated acceleration data, body mass, and locomotion type (walk/run).
• The models achieved an average absolute percent difference of 8.3% for pGRFvert and 17.8% for pGRFbrake on the test dataset.
• These equations accurately predict GRFs, demonstrating the utility of AMs for biomechanical analysis.

Conclusions:

• Repeated measures generalized regression equations can effectively predict pGRFvert and pGRFbrake from hip AM acceleration data in young adults.
• This approach provides a feasible method for estimating GRFs during daily activities without the need for force plates.
• The findings support the use of wearable sensors for non-laboratory-based biomechanical assessments.