Gate Speed

We are designing products for seniors and we have a wearable that has an accelerometer. Need to calculate the gate speed (walking speed) of a person using 3 axis accelerometer data. The accelerometer just streams raw g-force data that it senses on the x y and z axes. We need to convert the data to meters per second. We need someone that understand Physics, Firmware and Math

This is a discussion of what we need
https://www.researchgate.net/post/Calculating_Speed_and_Distance_from_a_3-axis_accelerometer

This is our accelerometer
https://www.st.com/resource/en/datasheet/lis2dh.pdf

Thank You