Proof-of-concept of a Robotic Knee Exoskeleton in Healthy Subjects and Hemiparetic Patients During Gait.

Summary

Hemiparetic gait is characterized by strong asymmetries that could severely affect the quality of life of stroke survivors. This asymmetry is due to motor deficits in the paretic leg and the resulting compensations in the non-paretic limb.

In this study, the investigators aim to evaluate the effect of actively promoting gait symmetry in hemiparetic patients by assessing the behavior of both paretic and non-paretic lower limbs. To this end, the investigators use a unilateral active Knee-Ankle-Foot Orthosis able to assist the paretic limb of hemiparetic patients during gait.

The system is able to synchronize its action with the movement of the unassisted joints, promoting a natural and intuitive interaction. The device generate the assistance according to two differents strategies: (1) Replicating the movement of the helathy leg or (2) Inducing a healthy gait pattern on the paretic leg.

The hypothesis is that a proper and natural interaction between the user and the exoskeleton would enable the patients to consider the robot action as a part of their own gait capability, improving their gait quality as consequence. Hemiparetic asymmetry is not only due to impairments in the affected limb, but also it is the consequence of biomechanical compensatory mechanisms that might arose in the non-paretic leg. We aim to assess the adaptation process of the subject to the exoskeleton assistance, and to evaluate the effects of such human-robot interaction in both paretic and non-paretic legs.

Conditions

• Hemiparesis/Hemiplegia (One Sided Weakness/Paralysis)

Interventions

DEVICE

Exoskeleton assisted gait on a treadmill

Subjects were instructed to walk on a treadmill at a constant speed during trials of 5 minutes. All subjects carried out four trials: (1) NoExo: subjects only wore the sensors to acquire their basal motion; (2) Free: subjects wore the exoskeleton although the actuator was mechanically decoupled, so it enabled the free movement of the knee; (3) Echo: the device provided gait assistance following the Echo-control strategy; and (4) Pattern: the device provided gait assistance following the Pattern strategy. During trials, patients wore a safety harness that did not support any weight. Previously to the execution of the trials, the gait velocity was self-selected by the subjects to a comfortable level. Subjects rested between trials for five minutes. Healthy subjects also performed a previous trial under variable gait speed. They walked over the treadmill as in the NoExo condition, although the gait speed randomly varies from 1km/h to 3km/h in 0.2km/h steps for 15 seconds at least.

Sponsors & Collaborators

• Hospital Beata María Ana

  collaborator OTHER

• Spanish National Research Council

  lead OTHER_GOV

Principal Investigators

• Julio S. Lora-Millan · Spanish National Research Council

Study Design

Allocation

NA

Purpose

DEVICE_FEASIBILITY

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

85 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2021-02-15

Primary Completion

2021-04-20

Completion

2021-04-20

Countries

• Spain

Study Locations