Healthy RunnersNCT06988709
Examining the Most Effective Method to Reduce Running Ground Contact Time
A study testing Real-time Visual Feedback, Real-time Auditory Feedback and Real-time Verbal Feedback in people with Healthy Runners, run by Keller Army Community Hospital at 1 site in United States.
Trial summary
The purpose of our study is to establish the most effective running retraining technique to decrease ground contact time. This will be investigated by applying three running retraining conditions and assessing the change in ground contact time and other biomechanical variables between the runner's baseline running and… Read more about this study
- Who is it for?
- Ages 17 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Runners
- What is being tested?
- Real-time Visual Feedback, Real-time Auditory Feedback and Real-time Verbal Feedback
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jul 2025to 1 Dec 2025
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 17 to 60 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Military Service Member or USMA cadet between the ages of 17-60
- Run at least 2 miles three times per week for the past 3 months
- Able to run for at least 15 continuous minutes at a self-selected speed
- Fluent in the English language to read and provide informed consent and follow study instructions
Who cannot join
- Lower extremity or low back pain in the previous 3 months
- Lower extremity or low back surgery in the previous 6 months
- Self-reported pregnancy or given birth within the last 6 months
- Currently on a profile that restricts or limits running
Trial locations and contacts
1 site in 1 country.
United States1 site
Keller Army Community Hospital
West Point, New York, 10996
About this study
The purpose of our study is to establish the most effective running retraining technique to decrease ground contact time. This will be investigated by applying three running retraining conditions and assessing the change in ground contact time and other biomechanical variables between the runner's baseline running and each retraining technique.
Read the detailed description
The purpose of our study is to establish the most effective running retraining technique to decrease ground contact time utilizing three common running retraining methods in healthy runners.
The first aim will be to apply three running retraining conditions and assess the change in ground contact time and other spatiotemporal and biomechanical variables between the runner's baseline running and each retraining condition.
The three running conditions will be at the participant's self-selected speed corresponding to "a comfortable run for 30 minutes". The conditions will be, condition 1: a verbal cue to "pull your foot off the ground as quickly as you can," condition 2: a metronome set to 10% above their preferred cadence found during the baseline run, and condition 3: visual feedback to reduce their ground contact time through observing that number in real time provided by a commercial IMU. The participant will attempt to lower that to 5% below their baseline run ground contact time by being given that target number on a sheet of paper.
The second aim will be to examine the effect of the 3 running conditions on the runner's level of exertion and difficulty using the Omni Rate of Perceived Exertional Scale, the Rate of Perceived Difficulty, and ranking the techniques from 1 to 3 on which they felt was most natural.
We hypothesize that each method will reduce ground contact time, but condition 3 providing continuous visual feedback will result in the most consistent decrease to ground contact time across the runners and will be perceived as the easiest to perform.
Overall, this study will provide clinicians with a running retraining intervention that has been objectively shown to decrease ground contact time and provide researchers with a method to further investigate its effect on running injuries.
- Conditions
- Healthy Runners
- Being tested
- Real-time Visual Feedback, Real-time Auditory Feedback, Real-time Verbal Feedback
- Keywords
- running, ground, gait, retraining, contact, time
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Real-time Visual FeedbackOther
Runners will visualize their real-time ground contact time (GCT) measured by the RunScribe on a TV screen. They will be instructed to run with a goal of matching their target GCT. Their target GCT will be 5% less than their baseline.
Real-time Auditory FeedbackOther
Runners will be instructed to match their step rate to a target step rate, 10% above their baseline step rate. A metronome will be played over a speaker to provide real-time auditory feedback of the target step rate.
Real-time Verbal FeedbackOther
The clinician will provide real-time verbal feedback to runner to "pull your foot off the ground as quickly as you can," every 15 seconds during the retraining condition.
| Study group | Role | What they receive |
|---|---|---|
| Run Retraining Conditions | Experimental | Single-arm, within subject, repeated measures design. All participants will run at baseline and then under 3 different running conditions. Receives: Other: Real-time Visual Feedback; Other: Real-time Auditory Feedback; Other: Real-time Verbal Feedback |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ground Contact Time
The amount of time in seconds (s) that the foot remains in contact with the ground while running. Data were collected over a 10-second window at the conclusion of each 2-minute running intervention.
Measured: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Secondary outcomes (6)
Step Rate
The number of steps per minute (SPM) that the participant takes while running. Data were collected over a 10-second window at the conclusion of each 2-minute running intervention and extrapolated to steps per minute
Measured: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Average Vertical Loading Rate (AVLR)
Average vertical loading rate (AVLR) was calculated as the slope of the vertical ground reaction force (vGRF) curve between 20% and 80% of the magnitude of the vertical impact peak (VIP), normalized to body mass and measured in Newtons per kilogram-second (N/kg*s). When a distinct VIP was not present, the force value at 13% of stance was used to define the loading region. Data were collected over a 10-second window at the conclusion of each 2-minute running intervention.
Measured: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Braking Impulse
Total posterior-directed impulse applied during the braking phase of running, calculated as the time integral of the posterior ground reaction force (GRF) during stance (Kliethermes et al., 2021). The stance phase was determined using a vertical GRF threshold of 50 Newtons (N) to identify foot strike and toe-off. Data were normalized to body mass and reported in Newton-seconds per kilogram (N·s·kg-¹). Data were collected over a 10-second window at the conclusion of each 2-minute running intervention.
Measured: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Step Length
The longitudinal distance, measured in meters (m), from the foot strike of one foot to the consecutive foot strike of the opposite foot while running. Data were collected over a 10-second window at the conclusion of each 2-minute running intervention.
Measured: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Vertical Oscillation
The peak-to-peak vertical displacement of the runner's center of mass (CoM) during a stride, measured in centimeters (cm). Data were collected over a 10-second window at the conclusion of each 2-minute running intervention.
Measured: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Duty Factor
The duty factor of running, calculated as the ratio of ground contact (stance) time to the total stride time (dimensionless ratio). Data were collected over a 10-second window at the conclusion of each 2-minute running intervention.
Measured: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 May 2025
- Study start1 Jul 2025
- Primary completion1 Dec 2025
- Study completion1 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Healthy RunnersStudies 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
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Within-subjects, repeated measures design completed in a single session
- Masking
- None (open label)
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- Keller Army Community Hospital
- Sponsor type
- US federal agency
- Responsible party
- Principal investigator, Jennah Bulen, Keller Army Community Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06988709
- Sponsor's protocol ID
- KACH.2025.0009
- Other IDs
- 24KACH008
- Status last verified
- Aug 2026
- First submitted
- 18 Apr 2025
- Last updated
- 24 Sep 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: We do not have a data sharing agreement or plan to share IDP as part of our IRB protocol.
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Examining the Most Effective Method to Reduce Running Ground Contact Time
- ClinicalTrials.gov ID
- NCT06988709
- Acronym / sponsor ID
- KACH.2025.0009
- Conditions
- Healthy Runners
- Keywords
- running, ground, gait, retraining, contact, time
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- Keller Army Community HospitalUS federal agency
- Study start
- 1 Jul 2025 (actual)
- Primary completion
- 1 Dec 2025 (actual)
- Study completion
- 1 Dec 2025 (actual)
- First posted
- 25 May 2025 (actual)
- Results
- Posted 24 Sep 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of our study is to establish the most effective running retraining technique to decrease ground contact time. This will be investigated by applying three running retraining conditions and assessing the change in ground contact time and other biomechanical variables between the runner's baseline running and each retraining technique.
Detailed description
The purpose of our study is to establish the most effective running retraining technique to decrease ground contact time utilizing three common running retraining methods in healthy runners.
The first aim will be to apply three running retraining conditions and assess the change in ground contact time and other spatiotemporal and biomechanical variables between the runner's baseline running and each retraining condition.
The three running conditions will be at the participant's self-selected speed corresponding to "a comfortable run for 30 minutes". The conditions will be, condition 1: a verbal cue to "pull your foot off the ground as quickly as you can," condition 2: a metronome set to 10% above their preferred cadence found during the baseline run, and condition 3: visual feedback to reduce their ground contact time through observing that number in real time provided by a commercial IMU. The participant will attempt to lower that to 5% below their baseline run ground contact time by being given that target number on a sheet of paper.
The second aim will be to examine the effect of the 3 running conditions on the runner's level of exertion and difficulty using the Omni Rate of Perceived Exertional Scale, the Rate of Perceived Difficulty, and ranking the techniques from 1 to 3 on which they felt was most natural.
We hypothesize that each method will reduce ground contact time, but condition 3 providing continuous visual feedback will result in the most consistent decrease to ground contact time across the runners and will be perceived as the easiest to perform.
Overall, this study will provide clinicians with a running retraining intervention that has been objectively shown to decrease ground contact time and provide researchers with a method to further investigate its effect on running injuries.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Within-subjects, repeated measures design completed in a single session
| Arm | Type | Receives |
|---|---|---|
| Run Retraining Conditions | Experimental | Other: Real-time Visual Feedback, Other: Real-time Auditory Feedback, Other: Real-time Verbal FeedbackSingle-arm, within subject, repeated measures design. All participants will run at baseline and then under 3 different running conditions. |
Who may qualify
- Ages
- 17 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (4 listed)
- Military Service Member or USMA cadet between the ages of 17-60
- Run at least 2 miles three times per week for the past 3 months
- Able to run for at least 15 continuous minutes at a self-selected speed
- Fluent in the English language to read and provide informed consent and follow study instructions
Key exclusion criteria (4 listed)
- Lower extremity or low back pain in the previous 3 months
- Lower extremity or low back surgery in the previous 6 months
- Self-reported pregnancy or given birth within the last 6 months
- Currently on a profile that restricts or limits running
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 |
|---|---|---|
| Real-time Visual FeedbackRunners will visualize their real-time ground contact time (GCT) measured by the RunScribe on a TV screen. They will be instructed to run with a goal of matching their target GCT. Their target GCT will be 5% less than their baseline. | Other | Run Retraining Conditions |
| Real-time Auditory FeedbackRunners will be instructed to match their step rate to a target step rate, 10% above their baseline step rate. A metronome will be played over a speaker to provide real-time auditory feedback of the target step rate. | Other | Run Retraining Conditions |
| Real-time Verbal FeedbackThe clinician will provide real-time verbal feedback to runner to "pull your foot off the ground as quickly as you can," every 15 seconds during the retraining condition. | Other | Run Retraining Conditions |
Primary outcome
Ground Contact Time
Time frame: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
The amount of time in seconds (s) that the foot remains in contact with the ground while running. Data were collected over a 10-second window at the conclusion of each 2-minute running intervention.
6 secondary outcomes
Step Rate
Time frame: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Average Vertical Loading Rate (AVLR)
Time frame: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Braking Impulse
Time frame: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Step Length
Time frame: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Vertical Oscillation
Time frame: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Duty Factor
Time frame: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Sep 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No. We do not have a data sharing agreement or plan to share IDP as part of our IRB protocol.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Real-time Visual Feedback, Real-time Auditory Feedback and Real-time Verbal Feedback in people with Healthy Runners, run by Keller Army Community Hospital at 1 site in United States.
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 4 inclusion and 4 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: finished, as of the sponsor's last update on 24 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 United States. 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?
Yes. Results are posted in the registry (first posted 24 Sep 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Ground Contact Time (time frame: Within a single session: pre-intervention baseline, and at the end of each 2-minute running intervention period.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 24 Sep 2026.