Mental Fatigue Effects on Posture and Spinal Reflexes
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Mental Fatigue Induction, Control Condition.
- Who it may be relevant to
- Registry conditions: Mental Fatigue. Basic parameters: 18 years — 35 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Belgium
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Effects of Mental Fatigue on Posture and Spinal Reflexes Modulations
Overview
This randomized crossover study investigates the effects of mental fatigue on postural control and spinal reflex excitability in healthy physically active adults aged 18-35 years. Participants will complete two experimental conditions: a mentally fatiguing Stroop task and a control condition involving passive documentary watching, separated by at least 48 hours. Postural control will be assessed using force plate measures of center of pressure displacement during bipedal and unipedal stance, with and without concurrent cognitive dual-tasking. In parallel, spinal reflex excitability will be evaluated using H-reflex recordings from the triceps surae muscles across sitting and standing postures. The primary aim is to determine whether mental fatigue increases postural sway, particularly in more challenging balance conditions such as single-leg stance. The secondary aim is to examine whether mental fatigue alters the normal modulation of spinal reflex excitability across progressively demanding postural tasks. Additional biomechanical and neuromuscular measures, including EMG activity and hip kinematics, will be recorded to provide insight into underlying control mechanisms. The study will include approximately 26 participants, with each serving as their own control. Data will contribute to understanding how cognitive fatigue influences balance control and spinal-level neuromuscular regulation.
Interventions
- Behavioral Mental Fatigue Induction
Participants complete a 60-minute computerized Stroop color-word task designed to induce mental fatigue. The task consists of repeated incongruent stimuli requiring rapid and accurate responses, with difficulty individualized based on a prior maximal Stroop performance test. Performance (reaction time and accuracy) is continuously recorded. Subjective mental fatigue is assessed intermittently during the task using a visual analogue scale. - Behavioral Control Condition
Participants watch a 60-minute neutral documentary of their choice. This condition is designed to match the mental fatigue intervention in duration and general sensory engagement without inducing cognitive fatigue. No cognitive task performance is required. Subjective mental fatigue is assessed at equivalent time points using a visual analogue scale.
Primary outcome measures
- Center of Pressure (CoP) Displacement (Postural Sway) [Time frame: Pre-intervention and immediately post-intervention (each experimental session)]
- Subjective Mental Fatigue [Time frame: During intervention (every 15 minutes) and immediately post-intervention]
Secondary outcome measures (3)
- Spinal Reflex Excitability (H-reflex Modulation) [Time frame: Pre-intervention and immediately post-intervention across sitting, bipedal stance, and unipedal stance conditions]
- Surface Electromyography (EMG) Activity of Postural Muscles [Time frame: Continuous recording during postural tasks, pre-intervention and immediately post-intervention (each condition)]
- Hip / Leg Movement (IMU Angular Velocity) [Time frame: Pre-intervention and immediately post-intervention during bipedal and unipedal stance]
Eligibility criteria
Inclusion criteria
- Healthy participants aged between 18 and 35 years
- Recreational active
Exclusion criteria
- Previous major lower limb injury (last 6 months)
- Present neurological or musculoskeletal disorders
- Involvement in another concurrent physical or cognitive intervention study
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Crossover
- Masking
- Single blind
- Primary purpose
- Basic science
Study locations
Belgium · 1 center
- Vrije Universiteit Brussel — Brussels
Identifiers
NCT: NCT07650903 · MFspinal