Application of knee robotic orthosis to improve the walking performance of the people with poliomyelitis: The case study

Abstract Description

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Authors (including presenting author) :

Ng CK (1), Ng YK (1), Chan KL (1), Wong KF (2), Ng SW (1), Yu KP (1), Tong KY (3)

Affiliation :

(1) Community Rehabilitation Service Support Centre, Queen Elizabeth Hospital, (2) Prosthetic and Orthotic Department, Kowloon Hospital, (3) Department of Biomedical Engineering, The Chinese University of Hong Kong.

Introduction :

Poliomyelitis has been a statutory notifiable infectious disease in Hong Kong since 1948. About 15% to 80% of the persons with a history of an acute paralytic poliomyelitis infection perceive new or increased impairments after a stable period of at least 15 years, referred to as late effects of polio’ or ‘postpolio syndrome’ (PPS) (Winberg, 2014). Previous studies using a stance-control knee joint in a Knee-Ankle-Foot-Orthosis (KAFO) appeared to improve gait biomechanics and improved energy efficiency compared with a locked knee. (Hebert & Liggins, 2005).

Objectives :

The objective of this study is to evaluate the effectiveness of adopting a knee robotic orthosis in people with poliomyelitis to improve walking ability.

Methodology :

The robotic knee orthosis consists of a pressure sensor-driven microprocessor controlling the locking and unlocking movement of the motorized knee hinge. Subjects using traditional lower limb orthosis with single lower limb paralysis caused by poliomyelitis at their early age during childhood are recruited. The gait performances of using traditional lower limb orthosis and using the robotic knee orthosis are measured and compared. The kinematics gait parameters are measured in the laboratory using a twelve-carmera motion capture system (ViconNexus, Oxford Metrics) and the GaitRite mat.

Result & Outcome :

2 subject were completed up to 2018. The kinematics data are normalized to 100% gait cycle and averaged among five steps, peak to peak value are considered. The antero-posterior (AP) trunk swaying movement, lateral trunk swaying movement and the shoulder tilting movement during gait cycle are measured and found reduced by 32.8% to 49.8%, 21.0% to 24.8% and 55.8% to 56.7% respectively when participating subjects are using the robotic knee orthosis in comparing with that using the traditional KAFO. Both subjects show the ability to execute knee flexion movement on the affected leg when walking on level ground as well as walking up across kerb with the use of the robotic knee orthosis.