Eccentric Training Effects on Hamstrings Structure, Strength, and Sprint Performance

University of Wisconsin (UW)

Status: Completed

Conditions: Healthy; Exercise Training; Ultrasound Imaging; Sport; Elastography; Running

Treatments: Other: Maximal 60 m Sprint; Other: Romanian Deadlift; Other: Hamstring Eccentric Strength Testing; Diagnostic Test: Ultrasound imaging; Other: Nordic hamstring exercise

Study type: Interventional

Funder types: Other

Identifiers

NCT05455346

A176000 (Other Identifier)

2022-0763

Protocol Version 2/27/2023 (Other Identifier)

Details and patient eligibility

About

The overall goal of this study is to investigate the effects of a 6-week training program between two hamstring exercises-the Romanian deadlift (RDL) and the Nordic hamstring exercise (NHE)-on hamstring strain injury risk factors and sprint performance.

Full description

Prior to the intervention, participants will report to the lab on one occasion for baseline assessments. During the baseline visit, a) regional measures of biceps femoris long head fascicle length, pennation angle, muscle thickness, and anatomical cross-sectional area will be determined using ultrasound, b) baseline NHE strength and 3RM for the RDL will be determined, and c) maximal 60 m sprint performance will be measured.

Participants will be randomly assigned to either the RDL or NHE. After randomization, each participant will undergo the 6 week intervention program based upon their group allocation. Exercises will be performed using a 6 second eccentric (i.e., lowering) contraction.

Following the 6 week intervention, participants would return to the lab for post-intervention assessments of regional hamstring morphology and architecture and sprint testing, which would be carried out in the same manner as baseline assessments. Since fascicle length changes are known to return to baseline values within 2 weeks after the cessation of eccentric training, participants will be asked to return to the lab following a 2 week detraining period where final imaging, strength, and sprint performance assessments will be determined.

Enrollment: 32 patients

Sex: All

Ages: 18 to 25 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• 18-25 years of age
• Have >6 months experience in resistance training

Exclusion criteria

• History of hamstring strain injury within the last 12 months
• History of lower extremity surgery
• Current musculoskeletal injury to the lower extremity
• Females who are currently pregnant
• Individuals who indicate they are unwilling to refrain from novel outside training activities
• Individuals who do not complete 75% (9 out of 12) of the training sessions

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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32 participants in 2 patient groups

Romanian Deadlift

Experimental group

Description:

The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. The RDL will be performed with a 6 second eccentric component with the athlete returning to the start position with a maximal concentric hip extension.

Treatment:

Other: Hamstring Eccentric Strength Testing

Other: Maximal 60 m Sprint

Other: Romanian Deadlift

Diagnostic Test: Ultrasound imaging

Nordic Hamstring Exercise

Active Comparator group

Description:

The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. During the acclimatization period, the relative intensity will be lower compared to the 4-week progressive training to ensure each participant performs the exercise with proper technique. During the subsequent progressive training weeks, the participants will perform the NHE without the bands.

Treatment:

Other: Hamstring Eccentric Strength Testing

Other: Maximal 60 m Sprint

Other: Nordic hamstring exercise

Diagnostic Test: Ultrasound imaging