Evaluating Methods to Replicate Stumbles and Slips During Walking

Primary outcomes

1. Effectiveness of Gait Perturbation Methods in Inducing Stumble or Fall Events

   Time frame: For each gait perturbation method, events are assessed during its application within a single testing session (approximately 30-60 minutes); multiple methods may be tested per session.

   This measure evaluates the effectiveness of various gait perturbation methodologies in successfully inducing perturbation events that result in stumbles or falls. Data will be collected on the number of perturbation events, with a particular focus on those leading to stumbles or falls. The incidence rate will be calculated as the number of perturbation events resulting in stumbles or falls per total number of perturbations. The target outcome is for at least 80% of perturbations to create an event that results in a stumble or fall. Descriptive statistics will be used to summarize the findings and assess the overall effectiveness of the perturbation methods.

2. Subjective Evaluation of Gait Perturbation Methodologies

   Time frame: Participant feedback is collected immediately after each gait perturbation method within a single testing session (approximately 30-60 minutes); multiple methods may be evaluated per session.

   This measure focuses on assessing participant feedback regarding the effectiveness and realism of different gait perturbation methodologies. Participants will provide ratings based on a questionnaire, excluding safety-related questions, to capture their experiences and perceptions. The goal is for all subjects to rate the methodologies as at least neutral or safe. Descriptive statistics will be employed to analyze the ratings, offering valuable insights into user experiences and perceptions of the perturbation methods.

3. Safety Perception of Gait Perturbation Methodologies

   Time frame: Participant feedback is collected immediately after each gait perturbation method within a single testing session (approximately 30-60 minutes); multiple methods may be evaluated per session.

   This measure evaluates participants' perceptions of safety regarding the gait perturbation methodologies used in the study. Participants will provide ratings based on a specific safety question from a questionnaire. The aim is for all subjects to rate the safety of the methods as at least neutral or safe. Descriptive statistics will be used to summarize the feedback, ensuring that the perturbation methods are perceived as minimizing the risk of injury and maintaining participant safety.

4. Unpredictability of Gait Perturbation Methodologies

   Time frame: Participant feedback is collected immediately after each gait perturbation method within a single testing session (approximately 30-60 minutes); multiple methods may be evaluated per session.

   This measure assesses the extent to which gait perturbation events are unnoticed and unexpected by participants. Feedback will be collected after each perturbation event, using a yes/no question to determine whether participants anticipated the perturbation. The objective is for at least 90% of perturbations to be perceived as unnoticed and unexpected. Descriptive statistics will be utilized to analyze the data, providing insights into the effectiveness of the methodologies in creating genuinely unpredictable perturbation events.

5. Consistency of Gait Perturbation Incidence Rates Over Time

   Time frame: For each gait perturbation method, events are assessed during its application within a single testing session (approximately 30-60 minutes); multiple methods may be tested per session.

   This measure evaluates the consistency of incidence rates for perturbation events among able-bodied subjects over time. The focus is on comparing the incidence rates of stumbles or falls from the first two perturbations to the last two perturbations. The goal is to ensure that the methodologies lead to a similar number of incidents throughout the study, with no more than a 10% difference observed between these two sets of perturbations. Descriptive statistics will be used to assess the data, ensuring stability and reliability in the perturbation methodologies across the duration of the study.