Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2025 Aug 1;57(8):1799-1809.
doi: 10.1249/MSS.0000000000003701. Epub 2025 May 14.

Hamstrings Muscle Architecture and Morphology Following 6 wk of an Eccentrically Biased Romanian Deadlift or Nordic Hamstring Exercise Intervention

Scott K Crawford, Caleb Sandberg  1 , Jessica Vlisides  1 , Quinlan Thompson  1 , Samuel J Mosiman  2 , Bryan C Heiderscheit, Jack T Hickey
Affiliations
Randomized Controlled Trial

Hamstrings Muscle Architecture and Morphology Following 6 wk of an Eccentrically Biased Romanian Deadlift or Nordic Hamstring Exercise Intervention

Scott K Crawford et al. Med Sci Sports Exerc. .

Abstract

Purpose: This study investigated the effects of a 6-wk eccentrically biased training intervention between Romanian deadlift (RDL) and Nordic hamstring exercises (NHE) on regional hamstring muscle architecture and morphology.

Methods: Participants were randomly allocated to an RDL or NHE intervention group and trained twice per week for 6 wk followed by a 2-wk detraining period. Biceps femoris long head (BFlh) architecture (fascicle length (FL) and pennation angle (PA)) and muscle thickness (MT) were measured using extended-field-of-view ultrasound. Anatomical cross-sectional areas (ACSA) of BFlh, semimembranosus, and semitendinosus were also assessed via ultrasound. Muscle architecture and morphology were measured proximally, in the middle, and distally along the thigh. Separate linear mixed-effects models were run for each outcome.

Results: Thirty-two healthy participants (15 females, 17 males) aged 20.8 (0.9) yr were enrolled and allocated to RDL ( n = 16) or NHE ( n = 16) groups. Following the intervention, BFlh FL increased (0.80 (0.6-1.0) cm (9%), P < 0.001), whereas PA decreased uniformly across all regions (-1.2° (-1.5° to -0.9°) (10%), P < 0.001) and MT did not change ( P = 0.29). Both BFlh FL and PA returned to baseline after detraining. No differences were observed between groups for changes in FL ( P = 0.55), PA ( P = 0.74), or MT ( P = 0.48). Hamstrings ACSA increased after the intervention (0.78 cm 2 (0.45-1.11 cm 2 ) (10%), P < 0.001) and remained elevated after detraining. There were no significant differences in ACSA between groups after the intervention ( P = 0.60).

Conclusions: Changes in FL, PA, and ACSA are consistent between an eccentrically biased RDL and NHE intervention. These findings provide practitioners choice in exercise selection for eliciting adaptations relevant to hamstring injury prevention.

Trial registration: ClinicalTrials.gov NCT05455346.

Keywords: BICEPS FEMORIS; CROSS-SECTIONAL AREA; FASCICLE LENGTH; PENNATION ANGLE; RESISTANCE TRAINING; ULTRASOUND.

PubMed Disclaimer

References

    1. Boltz AJ, Hooper N, Satalich J, et al. Epidemiology of hamstring tears in national collegiate athletic association athletes: findings from the National Collegiate Athletic Association Injury Surveillance Program between 2014/2015 and 2018/2019. Clin J Sport Med . 2024;34(5):444–53.
    1. Magistrali M, Stefanini L, Abate M, et al. Epidemiology of non-contact muscle injuries in the Italian male elite under-19 football (soccer) championship. Sports Med Open . 2024;10(1):75.
    1. Mack CD, Kent RW, Coughlin MJ, et al. Incidence of lower extremity injury in the National Football League: 2015 to 2018. Am J Sports Med . 2020;48(9):2287–94.
    1. Brooks JHM, Fuller CW, Kemp SPT, Reddin DB. Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union. Am J Sports Med . 2006;34(8):1297–306.
    1. Hägglund M, Waldén M, Magnusson H, Kristenson K, Bengtsson H, Ekstrand J. Injuries affect team performance negatively in professional football: an 11-year follow-up of the UEFA champions league injury study. Br J Sports Med . 2013;47(12):738–42.

Publication types

Associated data

LinkOut - more resources