Anterior Cruciate Ligament ReconstructionSyncGaitNCT07243535
Fractal vs Isochronous Cueing in Athletes After ACL Reconstruction
A study testing Fractal Cueing and Isochronous Cueing in people with Anterior Cruciate Ligament Reconstruction and Anterior Cruciate Ligament Reconstruction Rehabilitation, run by Egas Moniz - Cooperativa de Ensino Superior, CRL at 1 site in Portugal.
Trial summary
Anterior cruciate ligament (ACL) injuries are among the most prevalent and functionally limiting knee injuries in sports, particularly those that involve pivoting movements. Despite advancements in surgical reconstruction and physical rehabilitation, many athletes continue to exhibit persistent motor control deficits… Read more about this study
- Who is it for?
- Ages 15 to 35 years
- Conditions the study is for
- Anterior Cruciate Ligament Reconstruction, Anterior Cruciate Ligament Reconstruction Rehabilitation, Athlete
- What is being tested?
- Fractal Cueing and Isochronous Cueing
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 sitePortugal
- Study dates
- 3 Oct 2025to Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 15 to 35 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Undergone unilateral ACL reconstruction less than 2 years ago;
- Have medical release for the full load on the injury limb for at least 2 weeks;
- Be independently pain-free walking;
- Being sports athletes according to an athlete description: Training regularly to improve performance, actively participating in competitions or formally registering in a sports federation or association;
- Must be able to understand and perform the requested task.
Who cannot join
- Participants with previous surgery on either knee;
- Those with more than 3 months between ACL injury and surgery;
- More than 2 weeks between surgery and the start of physical therapy;
- Had another musculoskeletal injury in the lower limb within the past 6 months;
- Another musculoskeletal surgery within the past 18 months;
- Participants with a history of movement system pathologies, such as nervous system, cardiovascular, pulmonary, integumentary, or endocrine conditions;
- Participants with vestibular or somatosensory system pathologies or visual impairments limiting their ability to see the metronome required for the task;
- Use of medications that could affect locomotion and balance.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Portugal1 site, 1 recruiting
- Recruiting
Egas Moniz School of Health & Science
Almada, Monte de Caparica, 2829-511
Inês Gomes, rso.cieem@egasmoniz.edu.pt
About this study
Official title: Comparison Between a Session of Walking Synchronized to Fractal- VS Isochronous-Based Cues on Gait Variability and Corticospinal Measures in Athletes With a Reconstructed Anterior Cruciate Ligament: A Crossover Randomized Controlled Trial
Anterior cruciate ligament (ACL) injuries are among the most prevalent and functionally limiting knee injuries in sports, particularly those that involve pivoting movements. Despite advancements in surgical reconstruction and physical rehabilitation, many athletes continue to exhibit persistent motor control deficits and increased gait variability, both of which are closely linked to a heightened risk of re-injury and long-term joint degeneration. These deficits arise from biomechanical impairments and disrupt proprioceptive input that requires cortical reorganization, contributing to maladaptive neuroplasticity. However, conventional rehabilitation strategies often overlook this neural dimension. Recent findings emphasize the importance of fostering motor variability and promoting neuroplasticity through external focus strategies, including sensorimotor synchronization. While isochronous cues, an invariant stimulus, are commonly used, they do not reflect the natural fluctuations of healthy gait and may reduce its complexity. Fractal-based cues, in contrast, introduce structured variability resembling the natural dynamics of locomotion and have been shown to restore gait complexity in clinical populations. However, no study has yet explored their acute effects on gait variability and corticospinal function following ACL reconstruction (ACLR). This crossover randomized controlled trial aims to compare the acute effects of a single session of treadmill walking synchronized to either fractal or isochronous-based visual cues on gait variability and corticospinal measures in athletes with ACLR. The investigators hypothesize that fractal-based cueing will acutely restore gait variability and enhance corticospinal excitability, evidenced by increased corticospinal excitability and intracortical facilitation, and reduced short-interval intracortical inhibition, thus promoting adaptive neuroplasticity. Conversely, isochronous cueing is expected to maintain or decrease gait complexity without improving corticospinal measures. This study may provide insights that could be highly valuable as a way to promote neuroplasticity and optimize gait rehabilitation after ACLR, also allowing an objective quantification and aiming to restore variability to levels close to those observed in healthy individuals, thus contributing to reducing the re-injury rate.
Read the detailed description
This study will test a laboratory-based intervention using gait trials with sensorimotor synchronization, a common approach in gait rehabilitation aimed at restoring or acutely modifying gait variability. The intervention, called SyncGait, consists of treadmill walking synchronized with visual cues. Following a crossover design, each participant will complete two sessions, one with fractal cueing (FRC) and one with isochronous cueing (ISO), with the order randomized. Each cued trial will last 12 minutes and will be preceded and followed by uncued walking trials. The visual cues will be presented as a moving bar on a screen positioned in front of the treadmill. For the FRC condition, the cues will be individualized to each participant's stride time variability, generated through a fractal algorithm and validated using detrended fluctuation analysis. For the ISO condition, cues will match each participant's average stride time without variability. Participants will be instructed to synchronize heel strikes of the reconstructed limb with the top of the moving bar. The treadmill (Bertec Inc., USA) will record gait data at 1000 Hz. Each session will be conducted individually, supervised by at least two trained team members. A sample size of 36 participants was determined to ensure adequate power (90%) to detect a moderate effect size (ηp² = 0.25) at a 5% significance level, accounting for an anticipated 20% dropout rate. To encourage participation and retention, participants will receive a personalized evaluation report and a free isokinetic assessment within 12 months. Data collection will include both gait and corticospinal outcomes. Gait variability will be analyzed from treadmill force data, focusing on stride intervals and synchronization performance. Corticospinal outcomes will be assessed using transcranial magnetic stimulation (TMS) with a BiStim2 stimulator (Magstim®, UK). Electromyography (Delsys Trigno, AD Instruments, NZ) will be recorded from quadriceps and hamstrings, while knee strength will be assessed with an isokinetic dynamometer (Humac Norm, USA). Standardized electrode placement and contraction protocols will ensure reproducibility. During testing, single- and paired-pulse TMS protocols will be applied at 10% of maximal voluntary contraction. Ten stimuli per condition will be collected, providing reliable estimates of excitability and inhibition. Visual feedback will help participants maintain the required contraction level throughout assessments. Statistical analysis will begin with normality testing (Shapiro-Wilk). Linear mixed models (Time × Cue condition) will be used for primary and secondary outcomes. Post-hoc comparisons will use Bonferroni corrections. Synchronization accuracy will be compared with paired t-tests. Statistical significance will be set at p < 0.05, and analyses will be performed using Jamovi software. This protocol is designed to rigorously test whether fractal cueing can restore healthy gait variability patterns and enhance corticospinal excitability in athletes with ACL reconstruction, compared with conventional isochronous cueing.
- Conditions
- Anterior Cruciate Ligament Reconstruction, Anterior Cruciate Ligament Reconstruction Rehabilitation, Athlete
- Being tested
- Fractal Cueing, Isochronous Cueing
- Keywords
- Complexity, Excitability, Metronome, Neuroplasticity, Rehabilitation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Fractal CueingDevice
Walking synchronized to a visual fractal metronome.
Isochronous CueingDevice
Walking synchronized to a visual Isochronous metronome.
| Study group | Role | What they receive |
|---|---|---|
| Fractal Cueing, Then Isochronous Cueing | Experimental | Participants exposed to 12-minute treadmill walking synchronized to a visual fractal metronome individualized to stride time variability. After a washout period of 1 week, participants will be exposed to 12-minute treadmill walking synchronized to a visual isochronous metronome with fixed stride time. Receives: Device: Fractal Cueing; Device: Isochronous Cueing |
| Isochronous Cueing, then Fractal cueing | Experimental | Participants exposed to 12-minute treadmill walking synchronized to a visual isochronous metronome with fixed stride time. After a washout period of 1 week, participants will be exposed to 12-minute treadmill walking synchronized to a visual fractal metronome individualized to stride time variability. Receives: Device: Fractal Cueing; Device: Isochronous Cueing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Gait Variability Measured by Fractal Scaling Exponent of inter-stride intervals
The fractal-scaling exponent, α, of inter-stride intervals (α-ISIs) will be determine by calculating the time between two consecutive heel strikes of the same foot. First, the investigators will identify the heel strike events of the dominant foot. To improve the identification of this event, the signals will be filtered using a 2nd order, zero lag low-pass Butterworth filter with a cutoff frequency of 20 Hz. Then, Detrended Fluctuation Analysis (DFA) will be used to determine the fractal-scaling, an index of complexity. The DFA is a modified random-walk analysis that makes use of a long-range correlated time series. The long-range correlation can be mapped to self-similar calculations through simple integration.
Measured: Pre- (40 minutes before) and Post- (40 minutes after) -Intervention
Corticospinal Excitability Measured by Motor Evoked Potential Amplitude
Conducted using Spike2 software (version 10; Cambridge Electronic Design, Cambridge, United Kingdom) and subsequently exported to, MATLAB R2018a (The MathWorks, Natick, Massachusetts, United States) for processing and analysis. Corticospinal Excitability will be quantified as the peak-to-peak amplitude of MEPs elicited by a single-pulse TMS stimulus, with values averaged across 10 trials per participant.
Measured: Baseline (Pre) and immediately after the intervention (Post)
Cortical Silent Period (SP) Duration
Silent period will be calculated as the time from MEP onset to the resumption of voluntary EMG activity, expressed as SP = resumption of voluntary EMG time - MEP onset (58), and averaged across all 10 stimuli.
Measured: Baseline (Pre) and immediately after the intervention (Post)
Intracortical Facilitation (ICF)
ICF will be determined using the same calculation method but with an interstimulus interval of 12 ms (ICF = conditioned MEP / control MEP).
Measured: Baseline (Pre) and immediately after the intervention (Post)
Short-Interval Intracortical Inhibition (SICI)
SICI will be calculated as the ratio between the conditioned MEP elicited with a paired-pulse TMS protocol (interstimulus interval: 3 ms) and a control MEP obtained from AMT assessment, expressed as SICI = conditioned MEP / control MEP.
Measured: Baseline (Pre) and immediately after the intervention (Post)
Secondary outcomes (2)
Magnitude of variability
Calculate the coefficient of variation of inter-stride intervals, representing the magnitude of variability.
Measured: Pre- (40 minutes before) and Post- (40 minutes after) -Intervention
Synchronization Accuracy
Asynchronies (ASYNC), i.e., the time difference between the heel strikes and the cues, expressed in milliseconds. This will be used to ensure that differences at the primary outcome are not the result of different synchronization performances. A negative value of ASYNC indicates that the heel strike occurred before the cue. The ASYNC provides information regarding the strategies used and the performance of the synching processes, serving as a control parameter to reliably interpret our results in terms of gait complex.
Measured: During Intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Nov 2025
- Study start3 Oct 2025
- Primary completionNov 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Anterior Cruciate Ligament ReconstructionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This study is a crossover randomized controlled trial, comprising two sessions. Each session will take approximately 2 hours, and the sessions will be separated from 7 to 10 days. Both sessions will be held at the same period of the day to avoid the circadian effect on our primary outcome. The two sessions will be similar. At the beginning of the first session, however, three questionnaires will be administered to collect the demographic and baseline characteristics of the participants. Following the completion of these questionnaires, a randomization process through a fixed block method will be conducted by the study's supervisor to determine the order in which the intervention will be presented across the two sessions. The participants will be asked to complete three 12-minute gait trials in each session: one cued trial and two uncued trials. A minimum of 20 minutes of rest will be taken between each trial while collecting the cortical drive assessment, PRE and POST the cued trial.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 36 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Egas Moniz - Cooperativa de Ensino Superior, CRL
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- João R Vaz, PhD, Study director, Egas Moniz school of Health & Science
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07243535
- Sponsor's protocol ID
- SyncGait-5725
- Acronym
- SyncGait
- Status last verified
- Sep 2026
- First submitted
- 16 Sep 2025
- Last updated
- 11 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All raw data will be stored in the supervisor's institutional personal Microsoft 365 account for five years, after which it will be permanently deleted. Data will be recorded anonymously using a unique coded numerical ID, known only to the supervisor. The database will be in Excel format. The encoded dataset may be shared with the rest of the research team and the journal where the study will be published, which may, in turn, make the data available to the scientific community for one year following publication.
Publications
Grooms DR, Page SJ, Nichols-Larsen DS, Chaudhari AM, White SE, Onate JA. Neuroplasticity Associated With Anterior Cruciate Ligament Reconstruction. J Orthop Sports Phys Ther. 2017 Mar;47(3):180-189. doi: 10.2519/jospt.2017.7003. Epub 2016 Nov 5.
PubMed 27817301Bodkin SG, Bruce AS, Hertel J, Diduch DR, Saliba SA, Novicoff WM, Hart JM. Visuomotor therapy modulates corticospinal excitability in patients following anterior cruciate ligament reconstruction: A randomized crossover trial. Clin Biomech (Bristol). 2021 Jan;81:105238. doi: 10.1016/j.clinbiomech.2020.105238. Epub 2020 Nov 20.
PubMed 33234323Moraiti CO, Stergiou N, Vasiliadis HS, Motsis E, Georgoulis A. Anterior cruciate ligament reconstruction results in alterations in gait variability. Gait Posture. 2010 Jun;32(2):169-75. doi: 10.1016/j.gaitpost.2010.04.008. Epub 2010 Jun 29.
PubMed 20591671Vaz JR, Groff BR, Rowen DA, Knarr BA, Stergiou N. Synchronization dynamics modulates stride-to-stride fluctuations when walking to an invariant but not to a fractal-like stimulus. Neurosci Lett. 2019 Jun 21;704:28-35. doi: 10.1016/j.neulet.2019.03.040. Epub 2019 Mar 25.
PubMed 30922850Vaz JR, Knarr BA, Stergiou N. Gait complexity is acutely restored in older adults when walking to a fractal-like visual stimulus. Hum Mov Sci. 2020 Dec;74:102677. doi: 10.1016/j.humov.2020.102677. Epub 2020 Oct 15.
PubMed 33069099
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison Between a Session of Walking Synchronized to Fractal- VS Isochronous-Based Cues on Gait Variability and Corticospinal Measures in Athletes With a Reconstructed Anterior Cruciate Ligament: A Crossover Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07243535
- Acronym / sponsor ID
- SyncGait / SyncGait-5725
- Conditions
- Anterior Cruciate Ligament Reconstruction, Anterior Cruciate Ligament Reconstruction Rehabilitation, Athlete
- Keywords
- Complexity, Excitability, Metronome, Neuroplasticity, Rehabilitation
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 36 participants (estimated)
- Lead sponsor
- Egas Moniz - Cooperativa de Ensino Superior, CRLUniversity, hospital or other
- Study start
- 3 Oct 2025 (actual)
- Primary completion
- Nov 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 24 Nov 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Anterior cruciate ligament (ACL) injuries are among the most prevalent and functionally limiting knee injuries in sports, particularly those that involve pivoting movements. Despite advancements in surgical reconstruction and physical rehabilitation, many athletes continue to exhibit persistent motor control deficits and increased gait variability, both of which are closely linked to a heightened risk of re-injury and long-term joint degeneration. These deficits arise from biomechanical impairments and disrupt proprioceptive input that requires cortical reorganization, contributing to maladaptive neuroplasticity. However, conventional rehabilitation strategies often overlook this neural dimension. Recent findings emphasize the importance of fostering motor variability and promoting neuroplasticity through external focus strategies, including sensorimotor synchronization. While isochronous cues, an invariant stimulus, are commonly used, they do not reflect the natural fluctuations of healthy gait and may reduce its complexity. Fractal-based cues, in contrast, introduce structured variability resembling the natural dynamics of locomotion and have been shown to restore gait complexity in clinical populations. However, no study has yet explored their acute effects on gait variability and corticospinal function following ACL reconstruction (ACLR). This crossover randomized controlled trial aims to compare the acute effects of a single session of treadmill walking synchronized to either fractal or isochronous-based visual cues on gait variability and corticospinal measures in athletes with ACLR. The investigators hypothesize that fractal-based cueing will acutely restore gait variability and enhance corticospinal excitability, evidenced by increased corticospinal excitability and intracortical facilitation, and reduced short-interval intracortical inhibition, thus promoting adaptive neuroplasticity. Conversely, isochronous cueing is expected to maintain or decrease gait complexity without improving corticospinal measures. This study may provide insights that could be highly valuable as a way to promote neuroplasticity and optimize gait rehabilitation after ACLR, also allowing an objective quantification and aiming to restore variability to levels close to those observed in healthy individuals, thus contributing to reducing the re-injury rate.
Detailed description
This study will test a laboratory-based intervention using gait trials with sensorimotor synchronization, a common approach in gait rehabilitation aimed at restoring or acutely modifying gait variability. The intervention, called SyncGait, consists of treadmill walking synchronized with visual cues. Following a crossover design, each participant will complete two sessions, one with fractal cueing (FRC) and one with isochronous cueing (ISO), with the order randomized. Each cued trial will last 12 minutes and will be preceded and followed by uncued walking trials. The visual cues will be presented as a moving bar on a screen positioned in front of the treadmill. For the FRC condition, the cues will be individualized to each participant's stride time variability, generated through a fractal algorithm and validated using detrended fluctuation analysis. For the ISO condition, cues will match each participant's average stride time without variability. Participants will be instructed to synchronize heel strikes of the reconstructed limb with the top of the moving bar. The treadmill (Bertec Inc., USA) will record gait data at 1000 Hz. Each session will be conducted individually, supervised by at least two trained team members. A sample size of 36 participants was determined to ensure adequate power (90%) to detect a moderate effect size (ηp² = 0.25) at a 5% significance level, accounting for an anticipated 20% dropout rate. To encourage participation and retention, participants will receive a personalized evaluation report and a free isokinetic assessment within 12 months. Data collection will include both gait and corticospinal outcomes. Gait variability will be analyzed from treadmill force data, focusing on stride intervals and synchronization performance. Corticospinal outcomes will be assessed using transcranial magnetic stimulation (TMS) with a BiStim2 stimulator (Magstim®, UK). Electromyography (Delsys Trigno, AD Instruments, NZ) will be recorded from quadriceps and hamstrings, while knee strength will be assessed with an isokinetic dynamometer (Humac Norm, USA). Standardized electrode placement and contraction protocols will ensure reproducibility. During testing, single- and paired-pulse TMS protocols will be applied at 10% of maximal voluntary contraction. Ten stimuli per condition will be collected, providing reliable estimates of excitability and inhibition. Visual feedback will help participants maintain the required contraction level throughout assessments. Statistical analysis will begin with normality testing (Shapiro-Wilk). Linear mixed models (Time × Cue condition) will be used for primary and secondary outcomes. Post-hoc comparisons will use Bonferroni corrections. Synchronization accuracy will be compared with paired t-tests. Statistical significance will be set at p < 0.05, and analyses will be performed using Jamovi software. This protocol is designed to rigorously test whether fractal cueing can restore healthy gait variability patterns and enhance corticospinal excitability in athletes with ACL reconstruction, compared with conventional isochronous cueing.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- This study is a crossover randomized controlled trial, comprising two sessions. Each session will take approximately 2 hours, and the sessions will be separated from 7 to 10 days. Both sessions will be held at the same period of the day to avoid the circadian effect on our primary outcome. The two sessions will be similar. At the beginning of the first session, however, three questionnaires will be administered to collect the demographic and baseline characteristics of the participants. Following the completion of these questionnaires, a randomization process through a fixed block method will be conducted by the study's supervisor to determine the order in which the intervention will be presented across the two sessions. The participants will be asked to complete three 12-minute gait trials in each session: one cued trial and two uncued trials. A minimum of 20 minutes of rest will be taken between each trial while collecting the cortical drive assessment, PRE and POST the cued trial.
| Arm | Type | Receives |
|---|---|---|
| Fractal Cueing, Then Isochronous Cueing | Experimental | Device: Fractal Cueing, Device: Isochronous CueingParticipants exposed to 12-minute treadmill walking synchronized to a visual fractal metronome individualized to stride time variability. After a washout period of 1 week, participants will be exposed to 12-minute treadmill walking synchronized to a visual isochronous metronome with fixed stride time. |
| Isochronous Cueing, then Fractal cueing | Experimental | Device: Fractal Cueing, Device: Isochronous CueingParticipants exposed to 12-minute treadmill walking synchronized to a visual isochronous metronome with fixed stride time. After a washout period of 1 week, participants will be exposed to 12-minute treadmill walking synchronized to a visual fractal metronome individualized to stride time variability. |
Who may qualify
- Ages
- 15 to 35 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (5 listed)
- Undergone unilateral ACL reconstruction less than 2 years ago;
- Have medical release for the full load on the injury limb for at least 2 weeks;
- Be independently pain-free walking;
- Being sports athletes according to an athlete description: Training regularly to improve performance, actively participating in competitions or formally registering in a sports federation or association;
- Must be able to understand and perform the requested task.
Key exclusion criteria (8 listed)
- Participants with previous surgery on either knee;
- Those with more than 3 months between ACL injury and surgery;
- More than 2 weeks between surgery and the start of physical therapy;
- Had another musculoskeletal injury in the lower limb within the past 6 months;
- Another musculoskeletal surgery within the past 18 months;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Fractal CueingWalking synchronized to a visual fractal metronome. | Device | Fractal Cueing, Then Isochronous Cueing, Isochronous Cueing, then Fractal cueing |
| Isochronous CueingWalking synchronized to a visual Isochronous metronome. | Device | Fractal Cueing, Then Isochronous Cueing, Isochronous Cueing, then Fractal cueing |
Primary outcome
Gait Variability Measured by Fractal Scaling Exponent of inter-stride intervals
Time frame: Pre- (40 minutes before) and Post- (40 minutes after) -Intervention
The fractal-scaling exponent, α, of inter-stride intervals (α-ISIs) will be determine by calculating the time between two consecutive heel strikes of the same foot. First, the investigators will identify the heel strike events of the dominant foot. To improve the identification of this event, the signals will be filtered using a 2nd order, zero lag low-pass Butterworth filter with a cutoff frequency of 20 Hz. Then, Detrended Fluctuation Analysis (DFA) will be used to determine the fractal-scaling, an index of complexity. The DFA is a modified random-walk analysis that makes use of a long-range correlated time series. The long-range correlation can be mapped to self-similar calculations through simple integration.
Corticospinal Excitability Measured by Motor Evoked Potential Amplitude
Time frame: Baseline (Pre) and immediately after the intervention (Post)
Conducted using Spike2 software (version 10; Cambridge Electronic Design, Cambridge, United Kingdom) and subsequently exported to, MATLAB R2018a (The MathWorks, Natick, Massachusetts, United States) for processing and analysis. Corticospinal Excitability will be quantified as the peak-to-peak amplitude of MEPs elicited by a single-pulse TMS stimulus, with values averaged across 10 trials per participant.
Cortical Silent Period (SP) Duration
Time frame: Baseline (Pre) and immediately after the intervention (Post)
Silent period will be calculated as the time from MEP onset to the resumption of voluntary EMG activity, expressed as SP = resumption of voluntary EMG time - MEP onset (58), and averaged across all 10 stimuli.
Intracortical Facilitation (ICF)
Time frame: Baseline (Pre) and immediately after the intervention (Post)
ICF will be determined using the same calculation method but with an interstimulus interval of 12 ms (ICF = conditioned MEP / control MEP).
Short-Interval Intracortical Inhibition (SICI)
Time frame: Baseline (Pre) and immediately after the intervention (Post)
SICI will be calculated as the ratio between the conditioned MEP elicited with a paired-pulse TMS protocol (interstimulus interval: 3 ms) and a control MEP obtained from AMT assessment, expressed as SICI = conditioned MEP / control MEP.
2 secondary outcomes
Magnitude of variability
Time frame: Pre- (40 minutes before) and Post- (40 minutes after) -Intervention
Synchronization Accuracy
Time frame: During Intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2026.
- Background: PubMed 27817301Grooms DR, Page SJ, Nichols-Larsen DS, Chaudhari AM, White SE, Onate JA. Neuroplasticity Associated With Anterior Cruciate Ligament Reconstruction. J Orthop Sports Phys Ther. 2017 Mar;47(3):180-189. doi: 10.2519/jospt.2017.7003. Epub 2016 Nov 5.
- Background: PubMed 33234323Bodkin SG, Bruce AS, Hertel J, Diduch DR, Saliba SA, Novicoff WM, Hart JM. Visuomotor therapy modulates corticospinal excitability in patients following anterior cruciate ligament reconstruction: A randomized crossover trial. Clin Biomech (Bristol). 2021 Jan;81:105238. doi: 10.1016/j.clinbiomech.2020.105238. Epub 2020 Nov 20.
- Background: PubMed 20591671Moraiti CO, Stergiou N, Vasiliadis HS, Motsis E, Georgoulis A. Anterior cruciate ligament reconstruction results in alterations in gait variability. Gait Posture. 2010 Jun;32(2):169-75. doi: 10.1016/j.gaitpost.2010.04.008. Epub 2010 Jun 29.
- Background: PubMed 30922850Vaz JR, Groff BR, Rowen DA, Knarr BA, Stergiou N. Synchronization dynamics modulates stride-to-stride fluctuations when walking to an invariant but not to a fractal-like stimulus. Neurosci Lett. 2019 Jun 21;704:28-35. doi: 10.1016/j.neulet.2019.03.040. Epub 2019 Mar 25.
- Background: PubMed 33069099Vaz JR, Knarr BA, Stergiou N. Gait complexity is acutely restored in older adults when walking to a fractal-like visual stimulus. Hum Mov Sci. 2020 Dec;74:102677. doi: 10.1016/j.humov.2020.102677. Epub 2020 Oct 15.
- Individual participant dataSharing planned: Yes. All raw data will be stored in the supervisor's institutional personal Microsoft 365 account for five years, after which it will be permanently deleted. Data will be recorded anonymously using a unique coded numerical ID, known only to the supervisor. The database will be in Excel format. The encoded dataset may be shared with the rest of the research team and the journal where the study will be published, which may, in turn, make the data available to the scientific community for one year following publication.
Related trials for Anterior Cruciate Ligament Reconstruction
Not yet recruiting
Stair Biomechanics and Vibration Study After ACLR
Anterior Cruciate Ligament Reconstruction (ACLR), Anterior Cruciate Ligament Injury
Not yet recruiting
Nerve Block of the Vastus Medialis and Anterior Obturator Branch in Anterior Cruciate Ligament Reconstruction With DIDT Graft
Anterior Cruciate Ligament (ACL) Reconstruction Surgery
Not yet recruiting
Supporting Athletes' Return to Sports After ACL Reconstruction: A Study of a Psychological Readiness Program
Anterior Cruciate Ligament Reconstruction, Anterior Cruciate Ligament Injuries
Recruiting
Interventions to Enhance Quadriceps Output After ACLR
ACL
Recruiting
Graded Exposure and Mindfulness Meditation for Patients Post-ACL Reconstruction
Anterior Cruciate Ligament Injuries
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
João R Vaz, PhD study director
Egas Moniz school of Health & Science
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Fractal Cueing and Isochronous Cueing in people with Anterior Cruciate Ligament Reconstruction and Anterior Cruciate Ligament Reconstruction Rehabilitation, run by Egas Moniz - Cooperativa de Ensino Superior, CRL at 1 site in Portugal.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Portugal. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Inês D Ribeiro, MSC Student ((+351) 964 544 607, 115360@alunos.egasmoniz.edu.pt), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Gait Variability Measured by Fractal Scaling Exponent of inter-stride intervals (time frame: Pre- (40 minutes before) and Post- (40 minutes after) -Intervention). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07243535, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Sep 2026.