Lower-Limb Biomechanical Characteristics Associated with Unplanned Gait Termination Under Different Walking Speeds

Summary

This study compared the biomechanical characteristics of the lower extremity during unplanned gait termination under different walking speeds. The lower-limb kinematic and kinetic data from fifteen subjects with normal and fast walking speeds were collected using a motion analysis system and plantar pressure platform.

Abstract

Gait termination caused by unexpected stimulus is a common occurrence in everyday life. This study presents a protocol to investigate the lower-limb biomechanical changes that occur during unplanned gait termination (UGT) under different walking speeds. Fifteen male participants were asked to perform UGT on a walkway at normal walking speed (NWS) and fast walking speed (FWS), respectively. A motion analysis system and plantar pressure platform were applied to collect lower-limb kinematic and plantar pressure data. Paired-sampled T-test was used to examine the differences in lower-limb kinematics and plantar pressure data between two walking speeds. The results showed larger range of motion in the hip, knee, and ankle joints in the sagittal plane as well as plantar pressure in forefoot and heel regions during UGT at FWS when compared with NWS. With the increase in walking speed, subjects exhibited different lower-limb biomechanical characteristics that show FWS associated with greater potential injury risks.

Introduction

Human locomotion is considered to be an extremely complex process that needs to be described by multidisciplinary methods^1,2. The most representative aspect is the gait analysis by biomechanical approaches. Human gait aims to sustain progression from initiation to termination, and the dynamic balance should be maintained in position movement. Although gait termination (GT) has been extensively studied as a sub-task of gait, it has received less attention. Sparrow and Tirosh³ defined GT in their review as motor control period when both feet stop moving either forward or backward based on....

Protocol

The Human Ethics Committee of Ningbo University approved this experiment. All written informed consent was obtained from all subjects after they were told about the goal, requirements, and experimental procedures of the UGT experiment.

1. Laboratory preparation for gait

1. Kinematics: Motion capture system
   1. When calibrating the system, turn off the incandescent lights and remove any possible reflective objects that can be mistaken for passive retro-reflective markers. Ensure that eight infrared cameras are properly aimed and have a clear and reasonable view.
   2. Plug the appropriate USB dongle into the PC’s ....

Results

Mean & SD values of NWS and FWS of 15 subjects were 1.33 ± 0.07m/s and 1.62 ± 0.11m/s, respectively.

Figure 3 shows the mean ROM of the hip, knee, and ankle joints in the sagittal plane during UGT at NWS and FWS. Compared with NWS, the ROM of three joints increased significantly at FWS (p<0.05). In detail, the ROM of hip, knee and ankle joints increased from 22.26 ± 3.03, 29.72 ± 5.14 and 24.92 ± 4.17 to 25.98 ± 2.94, 31.61 &#.......

Discussion

Most previous studies that analyze gait biomechanics during UGT omit the importance of walking speed in their biomechanical assessment. Thus, this study investigated the lower-limb biomechanical changes that occur in UGT at NWS and FWS with the aim to reveal the speed-related effects.

Significant differences have been found on the ROM of the hip, knee, and ankle joints in the sagittal plane during UGT at NWS and FWS. Our findings showed greater ROMs of the 3 joints in the sagittal plane during.......

Materials

Name	Company	Catalog Number	Comments
14 mm Diameter Passive Retro-reflective Marker	Oxford Metrics Ltd., Oxford, UK	n=16
Double Adhesive Tape	Minnesota Mining and Manufacturing Corporation, Minnesota, USA	For fixing markers to skin
Motion Tracking Cameras	Oxford Metrics Ltd., Oxford, UK	n= 8
T-Frame	Oxford Metrics Ltd., Oxford, UK	-
Valid Dongle	Oxford Metrics Ltd., Oxford, UK	Vicon Nexus 1.4.116
Vicon Datastation ADC	Oxford Metrics Ltd., Oxford, UK	-
Pressure platform	RSscan International, Olen, Belgium	-