Inertial measurement unit-based real-time feedback gait immediately changes gait parameters in older inpatients: a pilot study

Abstract

The effect of gait feedback training for older people remains unclear, and such training methods have not been adapted in clinical settings. This study aimed to examine whether inertial measurement unit (IMU)-based real-time feedback gait for older inpatients immediately changes gait parameters. Seven older inpatients (mean age: 76.0 years) performed three types of 60-s gait trials with real-time feedback in each of the following categories: walking spontaneously (no feedback trial); focused on increasing the ankle plantarflexion angle during late stance (ankle trial); and focused on increasing the leg extension angle, which is defined by the location of the ankle joint relative to the hip joint in the sagittal plane, during late stance (leg trial). Tilt angles and accelerations of the pelvis and lower limb segments were measured using seven IMUs in pre- and post-feedback trials. To examine the immediate effects of IMU-based real-time feedback gait, multiple comparisons of the change in gait parameters were conducted. Real-time feedback increased gait speed, but it did not significantly differ in the control (p = 0.176), ankle (p = 0.237), and leg trials (p = 0.398). Step length was significantly increased after the ankle trial (p = 0.043, r = 0.77: large effect size). Regarding changes in gait kinematics, the leg trial increased leg extension angle compared to the no feedback trial (p = 0.048, r = 0.77: large effect size). IMU-based real-time feedback gait changed gait kinematics immediately, and this suggests the feasibility of a clinical application for overground gait training in older people.

Keywords: clinical application; gait analysis; gait training; propulsion; wearable sensor.

FIGURE 1

Experimental protocol of the IMU-based real-time feedback gait. At pre-gait (spontaneous gait) and post-gait (replicate gait without feedback) measurements, gait parameters were measured using IMUs. Pre-gait measurements also determined the threshold of feedback. During the feedback trials, participants modified gait in response to the beep sound when the participant’s current joint angle (solid line) reached the threshold angle (dot line). The threshold was set at a 20% increase in the peak values of each joint angle during spontaneous gait. IMUs: inertial measurement units.

FIGURE 2

Comparisons of the changes in gait parameters. (A) Gait speed, (B) cadence, (C) step length, (D) maximum leg extension angle at late stance, (E) maximum ankle plantarflexion angle at late stance, and (F) increment of velocity at late stance. *: p < 0.05.