Assessment of walking, running, and jumping movement features by using the inertial measurement unit

• Uniaxial acceleration or angular velocity can be used to identify the locomotion and intensity.
• The plantar/dorsiflexion movement in each locomotion exhibited a regular sequence.
• The combination of shoes and IMU sensor is a practical way to determine intensity and locomotion.

PurposeTo observe various modes of lower limb locomotion, an inertial measurement unit (IMU) was used. Digital signals were used to identify signal characteristics that help to distinguish among locomotion modes and intensity levels.MethodsA wireless IMU was installed on the outside of shoes and three forms of locomotion (walking, running, and jumping) were assessed at two intensity levels (low and high) to observe the acceleration, foot angular velocity variations, and characteristics of the curve variations in the anteroposterior, mediolateral, and superior–inferior directions.ResultsMost interactions between intensity and locomotion were statistically significant, except for the acceleration in the anteroposterior direction and on the horizontal plane. In addition, as the intensity increased, the values of all the parameters increased. Thus, both the acceleration values and range of angular velocity variation can be used to distinguish the intensity levels. Moreover, the results indicated that the angular velocity in the frontal axis, which is the sequence of the plantar/dorsiflexion movements, can also be used to identify different locomotion.ConclusionsUniaxial acceleration or the range of angular velocity variation could be used to identify locomotion intensities, whereas the characteristics of the uniaxial angular velocity curve could be used to identify the locomotion modes.