Observer Reactivity During Gait Measurements in a Clinical Setting

Observer reactivity, also known as the 'Hawthorne effect', can roughly be described as the alteration of behaviour as a consequence of observation or awareness of measurement. Although researchers are aware of a potential observation effect during measurements, observer reactivity may also influence assessments that are performed as part of clinical care. Previous research on observer reactivity during gait measurements has resulted in contradicting outcomes and most studies examined the effects of participation in research rather than the clinical measurement of gait in a gait lab setting or the observation by professionals. Therefore, the aim of this study is to examine the differences in gait pattern between unobserved walking, observed walking, and observed walking combined with awareness of measurement, in a within-subjects repeated measures design.

Study Overview

• Status: Completed
• Conditions: Stroke
• Intervention / Treatment: Behavioral: Unobserved; Behavioral: Observed; Radiation: Unobserved & Measured

Detailed Description

Observer reactivity, also known as the 'Hawthorne effect', can roughly be described as the alteration in behaviour as a consequence of observation or awareness of measurement. It is believed that this could influence research outcomes in prospective experimental and observational studies. However, as described in a recent systematic review, the extend of the effect on research outcomes is still debated. The available studies on observer reactivity with various populations and tasks generate contradicting findings and conclusions. Especially within the health sciences, more research is necessary as observer reactivity may confound study results in the direction of better health outcomes.

Previous research on observer reactivity during gait measurements has resulted in contradicting outcomes. For example, some studies showed a higher walking velocity and better gait symmetry under observation, while others showed an opposite effect. This may be caused by the variation in diagnosis group between the studies or small sample sizes. Because of these mixed results and the low number of studies available on this topic, there is yet no consensus on a generalizable effect of observation during gait measurements. Furthermore, most studies examine the effects of participation in research rather than the clinical measurement of gait in a gait lab setting or the observation by professionals.

For clinical decision making, it is essential to investigate whether gait measurements are representative for the actual gait pattern of the patient. Therefore, the aim of this study is to examine the differences in gait pattern between unobserved walking, observed walking by a researcher, and observed walking combined with awareness of measurement by sensors.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Gelderland
    • Ubbergen, Gelderland, Netherlands, 6574 NA
      • Sint Maartenskliniek

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Subacute or chronic stroke (>3 months ago)

Exclusion Criteria:

• Not able to walk 50 meters without resting.
• Not able to understand instructions given by the researcher.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Gait measurement; Use of four accellerometers/sensors (1 on each foot, one on the lumbar area and one on the sternum) that measure gait parameters during walking.

Behavioral: Unobserved; Participants walk a distance of 40 meters wearing the sensors, unobserved by the researcher.; Behavioral: Observed; Participants walk a distance of 40 meters wearing the sensors, observed by the researcher.; Radiation: Unobserved & Measured; Participants walk a distance of 40 meters wearing the sensors, unobserved by the researcher and aware of the gait measurement by the sensors.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gait velocity	Mean walking speed (meters/second)	5 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Swing time symmetry	Symmetry in swing time between paretic and non-paretic leg	5 minutes
Stride length	Mean stride length (meters)	5 minutes
Cadance	Cadance (steps/minute)	5 minutes
Stance time symmetry	Symmetry in stance time between paretic and non-paretic leg	5 minutes
percent single leg stance	percent single leg stance of the total gait cycle of the paretic leg	5 minutes
percent single leg stance symmetry	Symmetry in percent single leg stance between paretic and non-paretic leg	5 minutes
Stride length variability	Variability in stride length	5 minutes
Swing time variability	Variability in swing time of the paretic leg	5 minutes

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fugl Meyer Assessment of Lower Extremities	Stages 3 and 4, both ranging from minimum 0 to maximum 4 points, with a higher score meaning a better outcome	2 minutes

Collaborators and Investigators

• Sponsor: Sint Maartenskliniek
• Investigators: Principal Investigator: Noël LW Keijsers, PhD, Sint Maartenskliniek

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2023
• Primary Completion (Actual): May 1, 2023
• Study Completion (Actual): May 1, 2023

Study Registration Dates

• First Submitted: December 21, 2022
• First Submitted That Met QC Criteria: December 21, 2022
• First Posted (Actual): January 6, 2023

Study Record Updates

• Last Update Posted (Estimated): December 13, 2023
• Last Update Submitted That Met QC Criteria: December 6, 2023
• Last Verified: December 1, 2022

More Information

Terms related to this study

• Other Study ID Numbers: 1042_TZO_Observer Reactivity

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No