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Hamstring Strain in High School Athletes

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03248011
Recruitment Status : Enrolling by invitation
First Posted : August 14, 2017
Last Update Posted : January 27, 2020
General Electric
TRIA Orthopaedic Center
Information provided by (Responsible Party):
Nathaniel (Nate) A. Bates, Mayo Clinic

Brief Summary:
The purpose of the current study is, 1) Determine the effectiveness of injury prevention programs for prevention of hamstring muscle strains, 2) Identify how these programs impact athletes' flexibility, muscle stiffness, strength, and power, and 3) Determine the ability of a state-of-the-art imaging technology, shear wave elastography to predict future hamstring muscle strain injury.

Condition or disease Intervention/treatment Phase
Strains Thigh Other: Stretching Other: Strengthening Other: Neuromuscular Not Applicable

Detailed Description:

Hamstring strains are a significant problem for basketball athletes across levels of play for both sexes. The impact of hamstring muscle strains (HSMS) is significant. Injuries typically result in persistent symptoms and lengthy recovery periods which limit the athlete's practice and play time. Even more significantly, HSMS have high rates of reinjury. It is estimated that approximately one-third of hamstring strains are recurrent. Given the high incidence of HSMS and the substantial tendency for injuries to recur, it has been advocated the greatest impact may be achieved by the development of improved techniques for prevention of initial injury.

Multiple risk factors for HSMS have been identified. Perhaps the strongest modifiable risk factor associated with HSMS is an imbalance between quadriceps and hamstring strength, specifically the eccentric hamstrings and concentric quadriceps strength ratio. The rationale is that sufficient eccentric capacity of the hamstring muscles is necessary to offset the concentric quadriceps contraction during the terminal swing phase of running. Not surprisingly, prevention programs that emphasize eccentric hamstring strengthening have been effective in reduction of HSMS injury rates.Prospective studies have demonstrated mixed results regarding the relationship between hamstring flexibility and hamstring injury, and the effectiveness of a flexibility program for reduction of the incidence of HSMS remains controversial. Stretching duration, frequency, timing of stretching relative to sports activities and the type of stretch being performed have been suggested as important factors in the effectiveness of a flexibility program at reducing injury occurrence. In addition, reduced hip flexor and quadriceps flexibility has been identified as a risk factor for HSMS. Further investigation is necessary to determine if a flexibility program that addresses both anterior and posterior thigh musculature reduces injury risk. The role of neuromuscular (NM) deficits as a risk factor in HSMS injuries is unclear. Inclusion of NM exercises in a six week training period improved lower extremity control and movement discrimination, which has been suggested to contribute to HSMS injury prevention. However, the impact of a NM injury prevention program on HSMS rates has not been established.

Sheer wave elastography (SWE) represents an emerging imaging technology. This real-time imaging technique evaluates the local mechanical properties of muscles. Thus, SWE has the potential to provide more sensitive insight into muscle stiffness than flexibility assessment. Recent studies have utilized this technique to evaluate the effect of lower extremity positioning on hamstring stiffness. The relationship between stiffness measures obtained using SWE and HSMS has not, however, been established.

Key gaps in knowledge regarding HSMS injury prevention programs remain. Most critically, the effectiveness of HSMS prevention programs among basketball athletes is unknown. Furthermore, the comparative effectiveness of eccentric, flexibility, and NM training for reduction of HSMS injuries is also unknown. Assessment of lower extremity strength, rate of power production, flexibility, and stiffness (captured with SWE) may elucidate the mechanisms underlying the effectiveness of injury prevention training, and aid in enhancement of injury prevention programs. Thus, the potential impact of this proposal is profound as our investigative team aims to fill these gaps in knowledge. Ultimately, the results of this study have the potential to 1) reduce injuries among basketball athletes and consequently enhance and lengthen athletic careers, 2) provide scientific rationale underlying the effects of HSMS injury prevention training, and 3) determine if a novel ultrasound imaging technique may be effective in determining risk for HSMS.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 1000 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: This is a prospective, randomized, repeated measures single- blind clinical trial.
Masking: Single (Investigator)
Masking Description: Group assignment will be masked to investigator.
Primary Purpose: Prevention
Official Title: Comparative Effectiveness of Hamstring Muscle Strain Injury Prevention Programs
Actual Study Start Date : September 27, 2017
Estimated Primary Completion Date : July 2021
Estimated Study Completion Date : July 2021

Arm Intervention/treatment
Experimental: Flexibility
Stretching exercise
Other: Stretching
Lower extremity flexibility exercises will be performed

Experimental: Strength
Eccentric hamstring strengthening exercise
Other: Strengthening
Eccentric hamstring strengthening exercises will be performed

Experimental: Neuromuscular
Balance exercise
Other: Neuromuscular
Dynamic lower extremity balance and movement control exercises will be performed

No Intervention: Control
No exercise

Primary Outcome Measures :
  1. Number of subjects who sustain a hamstring strain [ Time Frame: Duration of school basketball season, approximately 4 months ]
    Physician based diagnosis

Secondary Outcome Measures :
  1. Change in thigh strength [ Time Frame: Baseline and post school basketball season, approximately 4 months ]
    This will be measured using an isokinetic dynamometer

  2. Change in hamstring stiffness [ Time Frame: Baseline, post school basketball season, approximately 4 months ]
    This will be measured using sheer wave elastography

  3. Change in lower extremity power [ Time Frame: Baseline, post school basketball season, approximately 4 months ]
    This will be measured using force plates

  4. Change in lower extremity hamstring flexibility [ Time Frame: Baseline, post school basketball season, approximately 4 months ]
    Measured using a goniometer

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   14 Years to 18 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion criteria:

  • member of high school basketball team
  • school agreement to participate in study

Exclusion criteria:

  • inability to ambulate independently
  • lower extremity or back surgery within 1 year of study enrollment
  • presence of neurological disease

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03248011

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United States, Minnesota
Mayo Clinic in Rochester
Rochester, Minnesota, United States, 55405
Sponsors and Collaborators
Mayo Clinic
General Electric
TRIA Orthopaedic Center
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Principal Investigator: Nathaniel Bates, PhD Mayo Clinic
Additional Information:
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Responsible Party: Nathaniel (Nate) A. Bates, Principal Investigator, Mayo Clinic Identifier: NCT03248011    
Other Study ID Numbers: 17-003905
First Posted: August 14, 2017    Key Record Dates
Last Update Posted: January 27, 2020
Last Verified: January 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Plan Description: Subject identification (ID) and study data (test results, injuries) will be shared with study co-investigators at TRIA Orthopaedics
Supporting Materials: Study Protocol
Informed Consent Form (ICF)
Clinical Study Report (CSR)
Time Frame: Co-Investigators will have access to the data as it is collected, for the duration of the study.
Access Criteria: Secured file transfer protocols will be utilized to transfer files between investigators. Only study co-investigators may access study data.

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Nathaniel (Nate) A. Bates, Mayo Clinic:
Additional relevant MeSH terms:
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Sprains and Strains
Wounds and Injuries