There are no known studies on the changes in walking ability in patients with transfemoral amputations returning to daily activities after prosthetic gait training. The ability to walk after discharge may vary depending on an individual’s physical, psychological, and social factors. This study compared spatiotemporal variables and lower limb coordination ability at the end of training and one year after the end of training in seven unilateral transfemoral amputees and analyzed the factors affecting walking ability. The study results confirmed that there was no significant difference in spatiotemporal parameters such as walking speed and lower limb coordination ability after one year of training, and walking ability was well maintained after training. Five out of seven (71.4%) participants in this study returned to work, and there was a strong correlation between employment and gait improvement (r = 0.806, p < .05). In conclusion, activities such as social participation, employment, and exercise were very important factors in maintaining and improving an individual’s walking ability. The findings are intended to be used as basic data to provide guidelines for maintaining the health of lower limb amputees.

The understanding of impaired neural control of gait after stroke is important to evaluate mobility impairments focused on improving walking function. Previous studies have shown that the central nervous system may control gait via muscle synergies, which modularly organizes multiple muscles. However, there are insufficient studies to evaluate mobility impairments, using muscle synergy during walking in post-stroke patients. Thus, the purpose of this study was to determine if the variability of muscle synergies during gait reflects impaired motor performance. Electromyography (EMG) signals were collected from five persons with post-stroke hemiparesis and five similarly age healthy persons, as they walked on a treadmill at a comfortable speed. EMG signals were decomposed using non-negative matrix factorization and the variability of muscle synergies was calculated using a synergy stability index (SSI). We also investigated correlation between the SSI and Fugl-Meyer assessment and Berg Balance Scale, which are clinical evaluation indicators. Post-stroke patients were found to have variable muscle synergies. We also observed a positive proportional relation, between SSI and clinical motor impair evaluation indicators. These results could yield a quantitative assessment of gait after stroke, and provide a causal relationship between internal neuromuscular mechanisms and functional performance.

In this study, an insole-type ground reaction force (GRF) measurement system using a load cell was manufactured and configured as a system that can measure joint angle and GRF, when walking in conjunction with a commercialized inertial sensor. The data acquisition device was used to acquire synchronized data, between the inertial measurement unit (IMU) sensor and the load cell insole. A three-dimensional motion analysis system comprising six infrared cameras and two ground reaction forces, was used to check the accuracy of the gait measurement system, comprising an inertial sensor and a load cell insole. The motion and force data were acquired while performing five times six-meter walking test by five young adult male subjects (Age: 26.0±1.8, Height: 171.4±6.8 cm, Weight: 62.2±10.8 kg). It was measured and as a result of comparing the calculated sagittal joint angle with the vertical GRF, the sagittal lower extremity joint angle correlation coefficient (Pearson’s r) was 0.40 to 0.94, and the vertical GRF to be 0.98 to 0.99. It is necessary to upgrade the joint angle calculation algorithm through future research. Additionally, the possibility of clinical application for actual stroke patients will be reviewed.

This study presented a mechanism overview of a novel modular knee exoskeleton, ACE-Knee, and the analysis of the design requirements by observing human knee-motion characteristics. The ACE-Knee exoskeleton consists of 1) base frame at waist, 2) a 3-DOF (degrees of freedom) passive spherical hip, and 3) a knee driving mechanism. The passive hip is designed based on a 3R spherical serial chain such that it has RCM (remote center of motion) capability. For designing a compact and efficient knee driving mechanism, it is realized by two crank-slider linkages where two sliders are coupled with a linear spring. The proposed kinematic structure enables the driving concept of the passive support by the linear spring and the active following by an actuator. In order to setup design requirements, gait experiments were performed for level walking and ascending/descending stairs. From the analysis of experimental results, unique motion and quasi-stiffness characteristics of human knee were identified.

Gait analysis is the best objective measurement tool for monitoring rehabilitation. However, it has limitations to evaluate gait recovery. Previous studies have evaluated the effect of gait training using continuous relative phase. The objective of this study was to determine the effect of gait recovery by rehabilitation gait training on lower limb coordination. We analyzed spatio-temporal parameters and CRP values of hip and knee joints based on gait analysis data obtained by 3D motion analysis system at 15 days intervals in 24 uni-lateral transfemoral amputees participated in IRP. Our results revealed that walking velocity of uni-lateral transfemoral amputees who participated in the program during a mean of 107.1 days was 49.2% faster than that at initial stage. The walking velocity showed a 46% increase at the end of 30 days after training. In gait coordination, values of CRP-RMS and CRP-SD were increased and maintained in-phase pattern. CRP showed symmetry in both limbs at the end of 90 days after training. Therefore, CRP is a significant factor in the gait recovery process. Effects of various rehabilitation training methods can be determined through CRP analysis.