Hamstring InjuryNCT05343052
Hamstring Injury (HAMIR) Index
An observational study of Hamstring Injury, run by University of Wisconsin, Madison at 5 sites in United States.
Trial summary
The investigators will combine state-of-the-art quantitative imaging, on-field biomechanics, and computational analytics into the largest-of-its-kind study to assess hamstring strain injury (HSI) risk and recovery in elite collegiate football players. Read more about this study
- Who is it for?
- Ages 18 to 26 yearsHealthy volunteers can take part
- Conditions the study is for
- Hamstring Injury
- What is being tested?
- Patient Reported Outcomes Surveys, Clinical Assessments and Biomechanical and Neuromuscular Assessments
- Type of treatment
- Medical device
- How many people
- 699 participants
- Where
- 5 sitesUnited States
- Study dates
- 25 Apr 2022to 5 Jun 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
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 18 to 26 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Student-athlete rostered on the varsity football team of participating institutions between 5/1/2022-6/30/2025 (study period)
Who may be able to join
- Student-athlete rostered on the varsity football team of participating institutions between 5/1/2022-6/30/2025 (study period)
Who cannot join
- History of malignant disease
- Contraindication to MRI
Trial locations and contacts
5 sites in 1 country.
5 sites in 1 country
United States5 sites
Indiana University
Bloomington, Indiana, 47405
University of North Carolina - Chapel Hill
Chapel Hill, North Carolina, 27514
University of Wisconsin - Madison
Madison, Wisconsin, 53705
Notre Dame University
Notre Dame, Indiana, 46556
Brigham Young University
Provo, Utah, 84602
About this study
Official title: Hamstring Injury (HAMIR) Index: A Framework for Injury Mitigations Strategies Through Innovative Imaging, Biomechanics, and Data Analytics
The investigators will combine state-of-the-art quantitative imaging, on-field biomechanics, and computational analytics into the largest-of-its-kind study to assess hamstring strain injury (HSI) risk and recovery in elite collegiate football players. The study will take place over 3 years and enroll up to 560 student athletes from Division I (D1) teams: University of Wisconsin-Madison, Brigham Young University and the University of North Carolina-Chapel Hill.
Read the detailed description
The current approach to assess hamstring strain injury (HSI) risk and recovery is suboptimal. Many player-games are lost in American Football due to the lack of a clear understanding of the risk factors for HSI and the absence of effective methods to minimize re-injury.
The investigators propose that the key issues are: 1) every athlete is unique; therefore, a "one-size-fits-all" approach to HSI risk assessment will not work; 2) clinicians have limited relevant information on the potential injury risk for a specific athlete; 3) current methods to assess the extent of injury in a specific athlete are largely qualitative, limiting the ability to determine re-injury risk; and 4) current use of biologic injections is common, yet studies to quantify their effects are lacking. In this study, the investigators will address these four critical barriers by combining state-of-the-art quantitative imaging, on-field biomechanics, and computational analytics into the largest-of-its-kind study of elite collegiate football players.
The study will be conducted in 4 Division I collegiate men's football teams over a 3-year period. All student-athletes enrolled in this study will complete preseason hamstring strength testing, inertial measurement units (IMU)-based sprinting biomechanics, and undergo baseline magnetic resonance imaging (MRI). Student-athletes will be monitored by athletic trainers throughout the school year, who will record injuries and participation (e.g., time in practice, game).
Student-athletes who sustain an HSI will undergo a clinical assessment at the time of injury along with an MRI examination. Following completion of a rehabilitation program, hamstring strength will be re-evaluated and imaging will be repeated, along with performance measurements.
This study will provide the most detailed understanding of the physiological causes and effects of HSI, advancing our understanding of the processes affecting muscle function and improving our ability to evaluate, treat, and prevent HSI. This study represents what will be the largest, most quantitative prospective cohort study ever into HSI. Data gathered as part of this study will be used to develop a quantitative Hamstring Injury (HAMIR) index such that the medical and scientific communities can identify an individual athlete's propensity for HSI, and, more importantly, identify targets for injury mitigation, thereby reducing the global burden of HSI.
Aim 1. Develop a risk prediction model for HSI based on morphological, architectural, biomechanical and clinical factors in National Collegiate Athletic Association (NCAA) D1 college football players. The goal is to test the predictive capacity of innovative measures of risk for initial HSI in the largest prospective cohort study ever conducted in HSI. The outcome will be the establishment of a quantitative HAMIR index that is based on multiple athlete-specific measures. This aim will also identify potential future targets for injury risk mitigation and prophylactic strategies.
Aim 2. Develop a risk prediction model for recurrent HSI based on morphological, architectural, biomechanical and clinical factors (identified in Aim 1) in NCAA D1 college football players by completing the largest ever analysis of re-injury data. The investigators will track players who sustain an HSI, both immediately after injury and longitudinally. Quantification of injury metrics (e.g., volume of initial edema and volume, shape and location of long-term scar) will be incorporated into the analytics framework to develop a new "re-injury" HAMIR index. Similar to Aim 1, this aim will identify potential future targets for re-injury risk mitigation and prophylactic approaches.
- Conditions
- Hamstring Injury
- Being tested
- Patient Reported Outcomes Surveys, Clinical Assessments, Biomechanical and Neuromuscular Assessments, Conventional MRI
- Keywords
- football, athlete
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Patient Reported Outcomes SurveysOther
Also called HaOS, FASH
- Oslo Sports Trauma Research Center Hamstring Injury Screening Questionnaire (HaOS) at baseline
- Functional Assessment Scale for Acute Hamstring Injuries (FASH) within 7 days of injury and within 7 days of return to sport (RTS)
Clinical AssessmentsOther
- Injury History at baseline, within 7 days of injury, within 7 days of RTS
- Pain and Function Assessments within 7 days of injury, within 7 days of RTS
Biomechanical and Neuromuscular AssessmentsOther
- Eccentric Strength measure at baseline and within 7 days of RTS
- Sprinting Biomechanics at baseline and within 7 days of RTS
Conventional MRIDevice
Also called Magnetic Resonance Imaging (MRI)
at baseline, within 7 days of injury, and within 7 days of RTS
| Study group | Role | What they receive |
|---|---|---|
| Student Athlete | Student-athlete rostered on the varsity football team of participating institutions between 5/1/2022-6/30/2025 (study period) Receives: Other: Patient Reported Outcomes Surveys; Other: Clinical Assessments; Other: Biomechanical and Neuromuscular Assessments; Device: Conventional MRI |
What is being measured
The primary outcome is the main question the study is designed to answer.
Aim 1: Initial Hamstring Strain Injury (HSI)
The outcome will be occurrence of an index HSI, measured at the athlete level. Athlete characteristics will be used to develop the quantitative HAMIR index to predict those at greatest risk of HSI. This aim will also identify potential future targets for injury risk mitigation and prophylactic strategies.
HSI defined as an acute injury to the posterior thigh that limits full, unrestricted sports participation and includes two or more of the following symptoms: palpable pain along the hamstring muscles, posterior thigh pain without radicular symptoms, weakness and/or pain with resisted knee flexion, and pain with running.
Measured: up to 3 years
Aim 2: Recurrent Hamstring Strain Injury (HSI)
The outcome will be the occurrence of a recurrent, or secondary, HSI measured at the athlete level. The investigators will use quantification of injury metrics (e.g., volume of initial edema and volume, shape and location of long-term scar) and incorporate these into the analytics framework to develop a new "re-injury" HAMIR index. Similar to Aim 1, this aim will identify potential future targets for re-injury risk mitigation and prophylactic approaches.
Re-injury will be defined as an acute HSI that occurs to either limb within 6 months of an index HSI.
Measured: up to 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Apr 2022
- Study start25 Apr 2022
- Primary completion5 Jun 2025
- Study completion5 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Hamstring InjuryStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 699 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Wisconsin, Madison
- Sponsor type
- University, hospital or other
- Collaborators
- National Football League
- Responsible party
- Sponsor
- Investigators
- Bryan Heiderscheit, PT, PhD, FAPTA, Principal investigator, UW School of Medicine and Public HealthDavid Opar, PhD, Principal investigator, Australian Catholic UniversitySilvia Blemker, PhD, Principal investigator, Springbok Analytics
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05343052
- Sponsor's protocol ID
- 2021-1420
- Other IDs
- A536130, Protocol Version 6/15/2023
- Status last verified
- Jun 2025
- First submitted
- 15 Apr 2022
- Last updated
- 11 Jun 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Wilwand M, VanderAkker J, Guymon I, Mortensen BB, Johnson AW. Normalized Eccentric Hamstring Strength in Collegiate American Football: Position-Based Norms and Longitudinal Patterns. J Strength Cond Res. 2026 Jul 27. doi: 10.1519/JSC.0000000000005632. Online ahead of print.
PubMed 42506958Hulm S, Lin YC, Maniar N, Timmins RG, Hickey JT, Heiderscheit BC, Blemker SS, Opar DA. Impact of Prior Hamstring Strain Injury on Muscle Morphology and Sprinting Biomechanics in Collegiate American Football Athletes. Scand J Med Sci Sports. 2026 Jun;36(6):e70317. doi: 10.1111/sms.70317.
PubMed 42261806Heiderscheit BC, Blemker SS, Opar D, Stiffler-Joachim MR, Bedi A, Hart J, Mortensen B, Kliethermes SA; HAMIR Study Group. The development of a HAMstring InjuRy (HAMIR) index to mitigate injury risk through innovative imaging, biomechanics, and data analytics: protocol for an observational cohort study. BMC Sports Sci Med Rehabil. 2022 Jul 15;14(1):128. doi: 10.1186/s13102-022-00520-3.
PubMed 35841053
Study at a glance
From the registry record, last updated by the sponsor on 11 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hamstring Injury (HAMIR) Index: A Framework for Injury Mitigations Strategies Through Innovative Imaging, Biomechanics, and Data Analytics
- ClinicalTrials.gov ID
- NCT05343052
- Acronym / sponsor ID
- 2021-1420
- Conditions
- Hamstring Injury
- Keywords
- football, athlete
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 699 participants (actual)
- Lead sponsor
- University of Wisconsin, MadisonUniversity, hospital or other
- Collaborators
- National Football League
- Study start
- 25 Apr 2022 (actual)
- Primary completion
- 5 Jun 2025 (actual)
- Study completion
- 5 Jun 2025 (actual)
- First posted
- 25 Apr 2022 (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.
The investigators will combine state-of-the-art quantitative imaging, on-field biomechanics, and computational analytics into the largest-of-its-kind study to assess hamstring strain injury (HSI) risk and recovery in elite collegiate football players. The study will take place over 3 years and enroll up to 560 student athletes from Division I (D1) teams: University of Wisconsin-Madison, Brigham Young University and the University of North Carolina-Chapel Hill.
Detailed description
The current approach to assess hamstring strain injury (HSI) risk and recovery is suboptimal. Many player-games are lost in American Football due to the lack of a clear understanding of the risk factors for HSI and the absence of effective methods to minimize re-injury.
The investigators propose that the key issues are: 1) every athlete is unique; therefore, a "one-size-fits-all" approach to HSI risk assessment will not work; 2) clinicians have limited relevant information on the potential injury risk for a specific athlete; 3) current methods to assess the extent of injury in a specific athlete are largely qualitative, limiting the ability to determine re-injury risk; and 4) current use of biologic injections is common, yet studies to quantify their effects are lacking. In this study, the investigators will address these four critical barriers by combining state-of-the-art quantitative imaging, on-field biomechanics, and computational analytics into the largest-of-its-kind study of elite collegiate football players.
The study will be conducted in 4 Division I collegiate men's football teams over a 3-year period. All student-athletes enrolled in this study will complete preseason hamstring strength testing, inertial measurement units (IMU)-based sprinting biomechanics, and undergo baseline magnetic resonance imaging (MRI). Student-athletes will be monitored by athletic trainers throughout the school year, who will record injuries and participation (e.g., time in practice, game).
Student-athletes who sustain an HSI will undergo a clinical assessment at the time of injury along with an MRI examination. Following completion of a rehabilitation program, hamstring strength will be re-evaluated and imaging will be repeated, along with performance measurements.
This study will provide the most detailed understanding of the physiological causes and effects of HSI, advancing our understanding of the processes affecting muscle function and improving our ability to evaluate, treat, and prevent HSI. This study represents what will be the largest, most quantitative prospective cohort study ever into HSI. Data gathered as part of this study will be used to develop a quantitative Hamstring Injury (HAMIR) index such that the medical and scientific communities can identify an individual athlete's propensity for HSI, and, more importantly, identify targets for injury mitigation, thereby reducing the global burden of HSI.
Aim 1. Develop a risk prediction model for HSI based on morphological, architectural, biomechanical and clinical factors in National Collegiate Athletic Association (NCAA) D1 college football players. The goal is to test the predictive capacity of innovative measures of risk for initial HSI in the largest prospective cohort study ever conducted in HSI. The outcome will be the establishment of a quantitative HAMIR index that is based on multiple athlete-specific measures. This aim will also identify potential future targets for injury risk mitigation and prophylactic strategies.
Aim 2. Develop a risk prediction model for recurrent HSI based on morphological, architectural, biomechanical and clinical factors (identified in Aim 1) in NCAA D1 college football players by completing the largest ever analysis of re-injury data. The investigators will track players who sustain an HSI, both immediately after injury and longitudinally. Quantification of injury metrics (e.g., volume of initial edema and volume, shape and location of long-term scar) will be incorporated into the analytics framework to develop a new "re-injury" HAMIR index. Similar to Aim 1, this aim will identify potential future targets for re-injury risk mitigation and prophylactic approaches.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Student Athlete | – | Other: Patient Reported Outcomes Surveys, Other: Clinical Assessments, Other: Biomechanical and Neuromuscular Assessments, Device: Conventional MRIStudent-athlete rostered on the varsity football team of participating institutions between 5/1/2022-6/30/2025 (study period) |
Who may qualify
- Ages
- 18 to 26 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Student-athlete rostered on the varsity football team of participating institutions between 5/1/2022-6/30/2025 (study period)
Key inclusion criteria (1 listed)
- Student-athlete rostered on the varsity football team of participating institutions between 5/1/2022-6/30/2025 (study period)
Key exclusion criteria (2 listed)
- History of malignant disease
- Contraindication to MRI
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 |
|---|---|---|
| Patient Reported Outcomes SurveysAlso: HaOS, FASH* Oslo Sports Trauma Research Center Hamstring Injury Screening Questionnaire (HaOS) at baseline * Functional Assessment Scale for Acute Hamstring Injuries (FASH) within 7 days of injury and within 7 days of return to sport (RTS) | Other | Student Athlete |
| Clinical Assessments* Injury History at baseline, within 7 days of injury, within 7 days of RTS * Pain and Function Assessments within 7 days of injury, within 7 days of RTS | Other | Student Athlete |
| Biomechanical and Neuromuscular Assessments* Eccentric Strength measure at baseline and within 7 days of RTS * Sprinting Biomechanics at baseline and within 7 days of RTS | Other | Student Athlete |
| Conventional MRIAlso: Magnetic Resonance Imaging (MRI)at baseline, within 7 days of injury, and within 7 days of RTS | Device | Student Athlete |
Primary outcome
Aim 1: Initial Hamstring Strain Injury (HSI)
Time frame: up to 3 years
The outcome will be occurrence of an index HSI, measured at the athlete level. Athlete characteristics will be used to develop the quantitative HAMIR index to predict those at greatest risk of HSI. This aim will also identify potential future targets for injury risk mitigation and prophylactic strategies. HSI defined as an acute injury to the posterior thigh that limits full, unrestricted sports participation and includes two or more of the following symptoms: palpable pain along the hamstring muscles, posterior thigh pain without radicular symptoms, weakness and/or pain with resisted knee flexion, and pain with running.
Aim 2: Recurrent Hamstring Strain Injury (HSI)
Time frame: up to 3 years
The outcome will be the occurrence of a recurrent, or secondary, HSI measured at the athlete level. The investigators will use quantification of injury metrics (e.g., volume of initial edema and volume, shape and location of long-term scar) and incorporate these into the analytics framework to develop a new "re-injury" HAMIR index. Similar to Aim 1, this aim will identify potential future targets for re-injury risk mitigation and prophylactic approaches. Re-injury will be defined as an acute HSI that occurs to either limb within 6 months of an index HSI.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jun 2025.
- Derived from this study: PubMed 42506958Wilwand M, VanderAkker J, Guymon I, Mortensen BB, Johnson AW. Normalized Eccentric Hamstring Strength in Collegiate American Football: Position-Based Norms and Longitudinal Patterns. J Strength Cond Res. 2026 Jul 27. doi: 10.1519/JSC.0000000000005632. Online ahead of print.
- Derived from this study: PubMed 42261806Hulm S, Lin YC, Maniar N, Timmins RG, Hickey JT, Heiderscheit BC, Blemker SS, Opar DA. Impact of Prior Hamstring Strain Injury on Muscle Morphology and Sprinting Biomechanics in Collegiate American Football Athletes. Scand J Med Sci Sports. 2026 Jun;36(6):e70317. doi: 10.1111/sms.70317.
- Derived from this study: PubMed 35841053Heiderscheit BC, Blemker SS, Opar D, Stiffler-Joachim MR, Bedi A, Hart J, Mortensen B, Kliethermes SA; HAMIR Study Group. The development of a HAMstring InjuRy (HAMIR) index to mitigate injury risk through innovative imaging, biomechanics, and data analytics: protocol for an observational cohort study. BMC Sports Sci Med Rehabil. 2022 Jul 15;14(1):128. doi: 10.1186/s13102-022-00520-3.
- Individual participant dataSharing planned: No
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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.
Bryan Heiderscheit, PT, PhD, FAPTA principal investigator
UW School of Medicine and Public Health
David Opar, PhD principal investigator
Australian Catholic University
Silvia Blemker, PhD principal investigator
Springbok Analytics
5 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Hamstring Injury, run by University of Wisconsin, Madison at 5 sites 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 1 inclusion and 2 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 11 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 sites 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Aim 1: Initial Hamstring Strain Injury (HSI) (time frame: up to 3 years). The study lists 2 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 NCT05343052, which also lists 3 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 Jun 2025.