Assessment of an Assistive Control Approach Applied in an Active Knee Orthosis Plus Walker for Post-Stroke Gait Rehabilitation

Abstract

The goal of this study is the assessment of an assistive control approach applied to an active knee orthosis plus a walker for gait rehabilitation. The study evaluates post-stroke patients and healthy subjects (control group) in terms of kinematics, kinetics, and muscle activity. Muscle and gait information of interest were acquired from their lower limbs and trunk, and a comparison was conducted between patients and control group. Signals from plantar pressure, gait phase, and knee angle and torque were acquired during gait, which allowed us to verify that the stance control strategy proposed here was efficient at improving the patients’ gaits (comparing their results to the control group), without the necessity of imposing a fixed knee trajectory. An innovative evaluation of trunk muscles related to the maintenance of dynamic postural equilibrium during gait assisted by our active knee orthosis plus walker was also conducted through inertial sensors. An increase in gait cycle (stance phase) was also observed when comparing the results of this study to our previous work. Regarding the kinematics, the maximum knee torque was lower for patients when compared to the control group, which implies that our orthosis did not demand from the patients a knee torque greater than that for healthy subjects. Through surface electromyography (sEMG) analysis, a significant reduction in trunk muscle activation and fatigability, before and during the use of our orthosis by patients, was also observed. This suggest that our orthosis, together with the assistive control approach proposed here, is promising and could be considered to complement post-stroke patient gait rehabilitation.

Effects of control strategies on gait in robot-assisted post-stroke lower limb rehabilitation: a systematic review

“…For what concerns the study design, only three were RCTs [ 25 – 27 ] and one CT [ 28 ], corresponding to the four papers with the higher numbers of patients included. Of these papers, only Villa-Parra et al [ 28 ] distinguished experimental and control groups among post-stroke patients and healthy subjects, whilst in the remaining three [ 25 ]–[ 27 ] the two groups were distinguished on the treatment type. Thus, among the 247 post-stroke participants, 194 actually performed robotic treatment.…”

“…Among the devices offering direct assistance on one joint only, four devices involved the hip, aiding only in the sagittal plane in two cases [ 26 , 27 ] and both in the frontal and sagittal plane in the other two devices working toward the restoration of balance and gait symmetry [ 38 , 43 ]. Villa-Parra et al [ 28 ], Quintana et al [ 34 ] and Hirano et al [ 36 ] provided assistance on the knee only, whilst the remaining nine studies focussed on the ankle.…”

Atypical Gait Cycles in Parkinson’s Disease

“…Furthermore, it is advisable to adopt gait partitioning methods that do not require pathology-specific templates, or the a-priori definition of the number of gait phases. Even if the most common approach is based on the four-phase model, models with a different number of gait phases are also used [ 58 , 59 , 60 ].…”

Use of Pressure-Measuring Insoles to Characterize Gait Parameters in Simulated Reduced-Gravity Conditions

“…It was suggested that the assessment of plantar pressure could be an appropriate substitute for measuring foot trauma. In addition, COP path length and width have also been examined to determine preventative fall risk strategies, typically among geriatric and clinical populations [ 22 , 23 ]. Currently, pressure mats and force platforms are typically used to measure COP [ 19 ].…”