Validation of Muscle Ultrasound Speckle Tracking and the Effect of Nordic Hamstring Exercise on Biceps Femoris Displacement

Chun-Yu Chou; Wei-Ning Lee; Kun-Lin Hung; Yi-Ju Tsai; Ming-Wei Wang; Adam Kawczyński; Sebastian Klich; Peemongkon Wattananon; Hsing-Kuo Wang

doi:10.1016/j.ultrasmedbio.2025.01.005

Validation of Muscle Ultrasound Speckle Tracking and the Effect of Nordic Hamstring Exercise on Biceps Femoris Displacement

Ultrasound Med Biol. 2025 Jan 24:S0301-5629(25)00005-5. doi: 10.1016/j.ultrasmedbio.2025.01.005. Online ahead of print.

Authors

Chun-Yu Chou¹, Wei-Ning Lee², Kun-Lin Hung³, Yi-Ju Tsai⁴, Ming-Wei Wang³, Adam Kawczyński⁵, Sebastian Klich⁶, Peemongkon Wattananon⁷, Hsing-Kuo Wang⁸

Affiliations

¹ School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan ROC; Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan ROC.
² Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China; Medical Engineering Programme, The University of Hong Kong, Hong Kong SAR, China.
³ School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan ROC.
⁴ Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan ROC; Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan ROC.
⁵ Department of Biomechanics and Sport Engineering, Gdansk University of Physical Education and Sport, Gdansk, Poland.
⁶ Department of Sport Didactics, Wrocław University of Health and Sport Sciences, Wrocław, Poland.
⁷ Faculty of Physical Therapy, Mahidol University, Bangkok, Thailand.
⁸ School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan ROC; Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan ROC. Electronic address: hkwang@ntu.edu.tw.

PMID: 39863448
DOI: 10.1016/j.ultrasmedbio.2025.01.005

Abstract

Objective: This study aimed to validate the ultrasound speckle tracking (UST) algorithm, determine the optimal probe location by comparing normalized cross-correlation (NCC) values of muscle displacement at two locations (proximal vs. middle) of the biceps femoris long head (BFlh) using the UST, and investigate the effects of Nordic hamstring curl exercise (NHE) training on BFlh displacement.

Methods: UST efficacy was verified with ex vivo uniaxial testing of porcine leg muscles. Ten participants (mean age 23.4 y) were recruited for comparison of NCC values between the proximal and middle BFlh during maximal knee flexor eccentric contraction using an ultrasound device and isokinetic dynamometer. Using the above devices, electromyography and shear wave elastography, the effects of an 8-wk NHE program on the morphomechanical profiles, displacement and activation of the middle BFlh and eccentric torque of the knee flexor were investigated in 20 males (mean age 23.5 y).

Results: The validity of UST was confirmed by comparing UST and ex vivo test results (r = 0.99). The NCC values of the middle BFlh were greater than those of the proximal BFlh. The caudal-direction displacements of the BFlh in the dominant leg were reduced after the NHE training (from 3.98 ± 3.84 to 1.50 ± 4.17 mm, p < 0.05). The magnitude of reduction was associated with improved eccentric strength of the knee flexor muscle in the dominant leg (r = 0.63).

Conclusions: UST is a validated tool for measuring muscle displacement. NHE training decreased caudal-direction muscle displacement in the BFlh and increased eccentric strength.

Keywords: Nordic exercise; Speckle tracking; Ultrasound; hamstring.