Healthy subjects will be invited to fill out a questionnaire regarding falls and balance skills followed by normal walking trials on a treadmill at 9 different speeds (0.28-1.4 m/s). Key gait parameters for the normative database will be collected. During the perturbation trials, the subjects will walk at a constant speed (1.2 m/s). The treadmill belts are ac, - or decelerated during the perturbations according to three different perturbation algorithms with varying perturbation onset. Movements will be analyzed by 3D motion capture, force plates, surface electromyography and IMU sensors. All methods are non-invasive and commonly used in the field of biomechanics.
Study Type
OBSERVATIONAL
Enrollment
43
Acceleration or deacceleration of one treadmill gait belt.
Balgrist Campus
Zurich, Canton of Zurich, Switzerland
Calculation of Margins of Stability (MoS) in anterior-posterior direction at foot contact
Difference between base of support and interpolated center of mass (mm), based on 3D motion capture.
Time frame: Once during visit 1
Step length at baseline, before (Pre) and after (Recovery step 1-10) perturbation
Time frame: Once during visit 1
Step width at foot contact of baseline, before (Pre) and Recovery steps 1-10
Time frame: Once during visit 1
Calculation of Margin of stability medial-lateral direction at foot contact of baseline, before (Pre) and Recovery steps 1-10
Difference between base of support and interpolated center of mass (mm), based on 3D motion capture.
Time frame: Once during visit 1
Maximal trunk velocity during gait cycle at of baseline, before (Pre) and Recovery steps 1-10 to detect fast trunk movement to gain balance
Optical markers are placed on the upper body of the subjects and will be used for calculation (distance over time) of the trunk velocity.
Time frame: Once during visit 1
3D kinematic gait profiles to analyze detailed movement patterns/strategies
The optical markers are placed according to the Plug-in gait marker set in Vicon Nexus (motion capture system). Hip, knee, ankle and trunk angles are calculated from this marker set.
Time frame: Once during visit 1
EMG analysis to detect reaction time and activity patterns of different leg muscles
Time frame: Once during visit 1
Questionnaire regarding the incidence of falls in the last six months
Contains questions how often und the reason why the subject falls
Time frame: Once during visit 1
Activities specific Balance Confidence scale (ABC scale)
Contains 16 questions rating the balance confidence between 0-100%. 100% means absolutely confident in doing some activity
Time frame: Once during visit 1
Questionnaire regarding the perceived intensities of the three perturbation algorithms
Judging the three pertubation algorithms according to their intensity, inconvenience and how realistic the slipping felt. Scale ranges from 0-10, whereas 10 is the most intense
Time frame: Once during visit 1
Functional Gait Assessment (FGA) as a clinical balance test
Assess the dynamic stability during different walking tasks. In total, 30 points are possible, at 22 points is the cut off score to classify the fall risk in older adults in predicting falls.
Time frame: Once during visit 1
A set of kinematic parameters
Measurement of hip, knee, ankle and spine angles during walking in degrees (°).
Time frame: Once during visit 1
A set of kinetic parameters
Ground reaction forces measured by force plates in Newton (N).
Time frame: Once during visit 1
A set of spatiotemporal parameters
Stance time, double stance time in seconds (s).
Time frame: Once during visit 1
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