Impacts and Mechanisms of Age and Muscle Fatigue on Postural Control and Force Control
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- Enrollment
- 140
- Locations
- 2
- Primary Endpoint
- Maximal force
Study Overview
Brief Summary
Muscle fatigue is one of the clinical symptoms in elderly people and demonstrates task dependency and muscle dependency. Muscle fatigue has been shown to negatively impact postural control, physical activity, and quality of life. However, the evidence for the influence of muscle fatigue on postural control is limited and inconsistent in elderly people. Therefore, this study aims to investigate the impacts of aging and muscle fatigue on postural control and gait performance with fatiguing exercises of upper and lower extremities.
Detailed Description
This study aims to investigate the effects of muscle fatigue on postural control and gait performance in healthy older adults (≥65 years) and young adults (20-40 years). Neuromuscular fatigue has been associated with postural instability, but its influence on gait and potential age-related differences remain unclear. Therefore, this study will compare fatigue-induced changes in motor performance between age groups and examine whether fatigue of the upper and lower extremities produces similar functional effects.
Healthy older adults and young adults will be recruited from the community. Eligible participants must be in good health, able to walk independently, demonstrate normal cognitive function, and provide informed consent. Individuals with neurological, cardiovascular, musculoskeletal, or other conditions that may affect motor performance will be excluded.
A repeated-measures design will be used. The study will involve two laboratory sessions separated by at least one week. Participants will undergo pre-test assessments, a fatiguing exercise protocol, and post-test assessments. Motor outcomes-including maximal voluntary isometric contraction, postural control, and gait performance-will be measured before and after the fatiguing exercises. Fatiguing exercises will consist of repeated cycles of maximal contractions with rest periods, while heart rate and perceived exertion are monitored to ensure safety. The protocol will terminate if exertion reaches a predefined threshold or heart rate exceeds the age-predicted maximum.
Surface electromyography and electrical stimulation will be used to assess neuromuscular function. Postural control will be evaluated using a force plate under multiple standing conditions, and gait parameters will be measured while participants walk at comfortable and fast speeds. Statistical analyses will use repeated-measures mixed-model ANOVAs to examine the effects of age group and fatigue on motor outcomes.
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Cross Sectional
Eligibility Criteria
- Ages
- 20 Years to 85 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •20 to 40 years (young), and 60-85 years (old)
- •walk independently
- •able to follow commands (Mini Mental Status Exam (MMSE) scores greater than 21
- •able and willing to provide informed consent.
Exclusion Criteria
- •pregnancy
- •neurologic, psychiatric, cardiac, vascular, pulmonary, musculoskeletal, immune, integumentary disease or disorder which might influence this study
- •any current loss of sensation in the arms, wrists, hands, fingers, hips, knees, ankles or toes
- •any pain at the time of testing
- •any restriction in range of motion of lower extremity.
Arms & Interventions
Healthy people
General healthy people aged 20-40 and 60-85 years.
Intervention: Age (Other)
Healthy people
General healthy people aged 20-40 and 60-85 years.
Intervention: Muscle fatigue (Other)
Outcomes
Primary Outcomes
Maximal force
Time Frame: Baseline (pre-fatigue protocol) and immediately after the fatigue protocol
The maximal force of upper and lower extremity muscles
Walking speed
Time Frame: Baseline (pre-fatigue protocol) and immediately after the fatigue protocol
The time taken by participants to walk a standardized distance
Step Length
Time Frame: Baseline (pre-fatigue protocol) and immediately after the fatigue protocol
The linear distance between the two ankles, typically expressed in centimeter(cm).
Cadence
Time Frame: Baseline (pre-fatigue protocol) and immediately after the fatigue protocol
The number of steps taken per minute (SPM)
Single Support Time
Time Frame: Baseline (pre-fatigue protocol) and immediately after the fatigue protocol
The duration within the gait cycle when only one foot is in contact with the ground, typically measured in seconds or as a percentage of the total gait cycle.
Double Support Time
Time Frame: Baseline (pre-fatigue protocol) and immediately after the fatigue protocol
The portion of the gait cycle where both feet are in contact with the ground, indicating the transition phase between steps, expressed as a percentage of the gait cycle or in seconds.
Swing Time
Time Frame: Baseline (pre-fatigue protocol) and immediately after the fatigue protocol
The portion of the gait cycle where the foot is not in contact with the ground, moving forward to the next step. It is usually expressed as a percentage of the total gait cycle or in seconds.
COP Velocity in Balance Tasks
Time Frame: Baseline (pre-fatigue protocol) and immediately after the fatigue protocol
The speed at which the COP moves, calculated over the duration of the balance task. Higher velocities may reflect more dynamic balance adjustments or instability. Unit：millimeter per second(mm/s)
COP Area in Balance Tasks
Time Frame: Baseline (pre-fatigue protocol) and immediately after the fatigue protocol
The area covered by the COP trajectory during the balance task, providing an estimate of the sway envelope. A larger area might indicate poorer balance control. Unit：square millimeter(mm\^2)
Secondary Outcomes
- Oxygenated hemoglobin(Baseline (pre-fatigue protocol), during the fatigue protocol, and immediately after the fatigue protocol.)
- Total hemoglobin(Baseline (pre-fatigue protocol), during the fatigue protocol, and immediately after the fatigue protocol.)
- Deoxygenated hemoglobin(Baseline (pre-fatigue protocol), during the fatigue protocol, and immediately after the fatigue protocol.)
Investigators
Chu-Ling Yen
Assistant professor
Chang Gung University