Does Gait with an Ankle Foot Orthosis Improve or Compromise Minimum Foot Clearance?

Pedro Fonseca,Manoela Vieira Sousa,Filipa Sousa,Cristina P Santos,Leandro Machado,Joana Figueiredo,João Paulo Vilas-Boas,Ricardo Sebastião

doi:10.3390/s21238089

Pedro Fonseca, Manoela Vieira Sousa + Show 6 more

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https://doi.org/10.3390/s21238089

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Abstract

The purpose of this study was to investigate if the use of an ankle foot orthosis in passive mode (without actuation) could modify minimum foot clearance, and if there are any compensatory mechanisms to enable these changes during treadmill gait at a constant speed. Eight participants walked on an instrumented treadmill without and with an ankle foot orthosis on the dominant limb at speeds of 0.8, 1.2, and 1.6 km/h. For each gait cycle, the minimum foot clearance and some gait linear kinematic parameters were calculated by an inertial motion capture system. Additionally, maximum hip and knee flexion and maximum ankle plantar flexion were calculated. There were no significant differences in the minimum foot clearance between gait conditions and lower limbs. However, differences were found in the swing, stance and step times between gait conditions, as well as between limbs during gait with orthosis (p < 0.05). An increase in hip flexion during gait with orthosis was observed for all speeds, and different ankle ranges of motion were observed according to speed (p < 0.05). Thus, the use of an ankle foot orthosis in passive mode does not significantly hinder minimum foot clearance, but can change gait linear and angular parameters in non-pathological individuals.

Highlights

Published: 3 December 2021Human locomotion on land is performed mainly by walking in an erect position, which is enabled by the successive advance of the lower limbs, while keeping a dynamic control of balance
The Ankle foot orthoses (AFOs) used in this study was kept on a passive setting, it was designed to operate as an active assistive device, supporting and enabling dorsal and plantar flexion of the ankle during gait
The use of an AFO on passive mode does not significantly hinder minimum foot clearance (MFC) on the dominant lower limb in healthy young individuals at low gait speeds. It may change the temporal distribution of the stance, swing, and step times of both limbs, as well as the hip flexion

Summary

Introduction

Human locomotion on land is performed mainly by walking in an erect position, which is enabled by the successive advance of the lower limbs, while keeping a dynamic control of balance This coordination ability reflects a complex combination of actions of the musculoskeletal system [1,2], which may be impaired by age-related degeneration or pathological alterations [3]. Motor disabilities resulting from pathologies, such as stroke, palsy or multiple sclerosis, may cause a significant toll on an individual’s ability to walk and their daily living These difficulties may result in falls [4], which may lead to additional side effects, with the potential to increase motor impairment. In older adults, tripping is a leading cause of accidental falls [5,6], and many causes may be related to fall occurrence, the minimum foot clearance (MFC) has been associated with an increased risk of falling [2,7].

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