Publications
Acute fatigue-induced alterations in hamstring muscle properties after repeated Nordic hamstring exercises
Authors: Podczarska-Glowacka Magdalena 1, Bogdanski Bartlomiej 2, Trybulski Robert 3, 4, Smoter Malgorzata 1, Wang Hsing-Kuo 5, 6, Klich Sebastian 7
Affiliations:
- Department of Basic Physiotherapy, Gdansk University of Physical Education and Sport, Gdansk, Poland
- Doctoral School, Gdansk University of Physical Education and Sport, Gdansk, Poland
- ProvitaZory Medical Center, Zory, Poland
- Department of Medical Sciences, The Wojciech Korfanty Upper Silesian Academy, Katowice, Poland
- School and Graduate Institute of Physical Therapy, National Taiwan University, Taipei, Taiwan
- Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan
- Department of Paralympic Sport, Wroclaw University of Health and Sport Sciences, Wroclaw, Poland
Journal: Science Progress - April 2024, Volume 107, Issue 2, Pages 1-17 (DOI: 10.1177/00368504241242934)
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Field & Applications:
- Sport
- Fatigue / Overtraining
- Muscle development / Performance
This study aimed to investigate the impact of the Nordic hamstring exercises (NHE) on acute fatigue-induced alterations in the mechanical and morphological properties of hamstring muscles. The second aim was to define the blood flow and perfusion after NHE in recreational active volunteers.
Twenty-two individuals volunteered to participate in the study. This study investigated fatigue outcomes: rate of perceived exertion (RPE) scale and average force generated during NHE; mechanical properties (stiffness); morphological properties (thickness, pennation angle, and fascicle length), and vascularity index (VI) of the semitendinosus (ST) and biceps femoris long head (BFLH) at baseline, immediately post-exercise and 1-h post-exercise. The NHE fatigue procedure consisted of six bouts of five repetitions.
The results showed an increase in thickness and pennation angle of BFLH and ST immediately post-exercise and a decrease in thickness and pennation angle of BFLH and ST 1-h post-exercise. While the fascicle length of BFLH and ST decreased immediately post-exercise and increased 1-h post-exercise. The VI for two muscles increased immediately post-exercise and after 1-h post-exercise. Moreover, we found a relationship between RPE and average force, that is, as RPE increased during NHE, average force decreased.
In conclusion, eccentric NHE exercises significantly and acutely affect BFLH and ST. The NHE fatigue protocol significantly affected the mechanical and morphological properties of BFLH and ST muscles, changing their thickness, fascicle length, pennation angle, and VI.
Keywords: fatigue, stiffness, thickness, fascicle length, vascularity index, pennation angle
In conclusion, this study showed that eccentric NHE significantly affected acute BFLH and ST muscle fatigue, resulting in a decrease in average muscle strength during the procedure. The NHE fatigue protocol significantly affected the mechanical and morphological properties of BFLH and ST muscles, changing their thickness, fascicle length, pennation angle, and VI.