Triaxial accelerometer gait dataset: foot and lower back motion during normal and metronome walking

File Naming Scheme

Each file is in CSV (Comma-Separated Values) format and adheres to the following structure: 

[SubjectID]_[AccelerometerLocation]_[Condition]_[Direction].csv.

The components of the file name are as follows:

• Subject ID: A three-digit identifier unique to each participant (e.g., 001, 002, ...).
• Accelerometer Location: Indicates the accelerometer's placement during data collection.
  • FO: Foot accelerometer.
  • LB: Low back (lumbar region) accelerometer.
• Condition: Specifies the walking condition under which the data were recorded.
  • N: Normal walking at the participant's preferred pace.
  • M: Walking synchronized to a metronome.
  • E: External or outdoor walking, without the corridor's constraints.
• Direction (applicable only for corridor walking): Indicates the segment of the indoor walking test.
  • O: Outbound (the first half of the corridor walk).
  • R: Return (the second half of the corridor walk).

Examples

• 001_FO_M_O.csv: Subject 001, data from the foot accelerometer, metronome walking condition, outbound segment of the corridor walk.
• 002_LB_N_R.csv: Subject 002, data from the low back accelerometer, normal walking condition, return segment of the corridor walk.
• 003_LB_E.csv: Subject 003, data from the low back accelerometer, external (outdoor) walking condition.

Data Format

The dataset is presented in CSV (Comma-Separated Values) format, a standard text file format that uses a comma (,) as a delimiter to separate individual values. 

Columns Description

Each CSV file consists of three columns, corresponding to the three axes of the accelerometer used for the measurements. The orientation of these axes differs depending on the location of the accelerometer:

• Low Back Accelerometer (Lumbar Region):
  • First Column: Anteroposterior Axis - This axis aligns with the forward and backward direction relative to the body's anatomical position.
  • Second Column: Vertical Axis - Represents the up and down movement, perpendicular to the ground.
  • Third Column: Mediolateral Axis - Corresponds to the side-to-side movement, parallel to the ground but perpendicular to the body's forward direction.
• Foot Accelerometer: The axes for the foot accelerometer are not aligned with specific anatomical directions. Instead, they represent the accelerometer's internal coordinate system, marked as X, Y, and Z.
  • First Column (X-Axis): Represents the accelerometer's first axis, which varies depending on its orientation on the foot.
  • Second Column (Y-Axis): Corresponds to the accelerometer's second axis, orthogonal to the X-axis.
  • Third Column (Z-Axis): Aligns with the accelerometer's third axis, orthogonal to both the X and Y axes.

The data represented in each column consist of raw acceleration measurements expressed in Earth's gravitational units (g), captured at a sampling rate of 256 Hz

Description of the Participant Information Files (_data_old.csv and _data_young.csv)

The dataset includes two CSV file, named _data_old.csv and _data_young.csv, which contain detailed demographic and experimental data for each participant. The file is structured with each row representing an individual participant and columns detailing specific attributes:

1. ID: Participant Identification Number - A unique numeric identifier assigned to each participant.
2. age: Age in years - The participant's age at the time of the study, expressed in full years.
3. sex: Sex of the participant - Coded as 1 for male and 2 for female.
4. mass: Body mass in kilograms (kg) - The weight of the participant.
5. height: Body height in centimeters (cm) - The height of the participant.
6. speed_N_O: Walking speed under normal condition, outbound lap - This column records the walking speed (measured in meters per second, m/s) during the outbound lap of the corridor walk under normal conditions.
7. speed_N_R: Walking speed under normal condition, return lap - Similar to the previous, this column documents the walking speed during the return lap of the corridor walk under normal condition.
8. speed_M_O: Walking speed under metronome condition, outbound lap - Here, the walking speed is recorded for the outbound lap under the metronome walking condition.
9. speed_M_R: Walking speed under metronome condition, return Lap - This column contains the walking speed data for the return lap during the metronome walking condition.

Any missing data in the columns are indicated as 'NaN' (Not a Number), 

Ethical considerations

The  protocol for this study was submitted to the ethics committee ("commission cantonale d'éthique de la recherche sur l'être humain du canton de Vaud", project ID 2021-01937) in October 2021 and received approval in November 2021. The procedures of the study were conducted in strict accordance with the Declaration of Helsinki and in compliance with the Swiss Human Research Act. All participants were informed of the objectives and procedures of the study and provided signed informed consent. They agreed that their data would be anonymized and made publicly available to ensure both the transparency of the research and their privacy.