Article
Multidisciplinary Sciences
Elisabetta Brunello, Lorenzo Marcucci, Malcolm Irving, Luca Fusi
Summary: The contraction of skeletal muscle is initiated by an increase in intracellular calcium concentration, causing a change in the structure of actin-containing thin filaments that allows binding of myosin motors from the thick filaments. The release of folded motors is triggered by thick filament stress, suggesting a positive feedback loop. This study reveals the coordination of thin and thick filament activation mechanisms and the coupling of these mechanisms through positive feedback loops, achieving rapid cooperative activation of skeletal muscle.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Neurosciences
Cameron Hill, Elisabetta Brunello, Luca Fusi, Jesus Garcia Ovejero, Malcolm Irving
Summary: In this study, the activation of myosin filaments in muscle contraction was found to be mainly influenced by filament stress. A switch-like change in myosin motor conformation at the start of force development was also observed, along with the involvement of filament zonal dynamics in activation.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Article
Cell Biology
Alexander Sonne, Lorenzo Peverelli, Aurelio Hernandez-Lain, Cristina Dominguez-Gonzalez, Jesper L. Andersen, Margherita Milone, Alan H. Beggs, Julien Ochala
Summary: In this study, we investigated the effects of MYH2 truncating mutations on the presence and post-translational modifications of myosin heavy chains, as well as the functionality of myosin molecules. We found that these mutations resulted in the presence of type IIa myosin heavy chains with an additional acetylated lysine in patients, accompanied by increased ATP demand, faster actomyosin kinetics, and reduced muscle fiber force.
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
(2023)
Article
Biology
Axel J. Fenwick, David C. Lin, Bertrand C. W. Tanner
Summary: Muscle contraction results from force-generating interactions between myosin and actin, with factors influencing cross-bridge kinetics at the molecular level propagating through tissues to modulate whole-muscle function. Researchers found that cross-bridge kinetics vary with whole-muscle length during intact, isometric contraction, suggesting a feedback pathway between muscle function and cross-bridge activity. The study highlights the complexity of muscle contraction and the potential impact of length-dependent cross-bridge kinetics on force generation and energetics.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2021)
Article
Multidisciplinary Sciences
Atsuki Fukutani, Shiho Kunimatsu, Tadao Isaka
Summary: This study examined the influence of caffeine on cross-bridge dynamics and found that the effect of caffeine on cross-bridge dynamics is negligible. The ergogenic effect of caffeine is primarily achieved through facilitating Ca2+ release.
SCIENTIFIC REPORTS
(2022)
Review
Biochemistry & Molecular Biology
Gabryela Kuhnen, Tiago Guedes Russomanno, Marta Murgia, Nicolas J. Pillon, Martin Schoenfelder, Henning Wackerhage
Summary: Adult skeletal muscle fibres can be classified into different types based on the expression of specific genes. The proportions of these muscle fibre types can be altered through gene gain or loss-of-function. In particular, transcriptional regulators play a significant role in regulating the expression of muscle fibre-specific genes. After exercise, the expression of certain genes increases or decreases, suggesting their involvement in muscle fibre adaptation. DNA sequence variants of muscle fibre genes may contribute to the variation in muscle fibre type proportions in the human population.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Review
Physiology
Christopher T. A. Lewis, Julien Ochala
Summary: After extensive research, it is clear that myosin molecules play a vital role in muscle contraction. However, they also have important functions in cardiac and skeletal muscle. This review provides an overview of myosin heavy chain states and their influence on ATP consumption, as well as the involvement of partner proteins in modulating ATP demand. It also discusses experimental drugs targeting myosin ATP consumption for the treatment of muscle diseases.
Article
Cell Biology
Koichi Ojima, Masahiro Kigaki, Emi Ichimura, Takahiro Suzuki, Ken Kobayashi, Susumu Muroya, Takanori Nishimura
Summary: The dynamics of different isoforms of myosin in skeletal muscle have been studied using a mouse model expressing fluorescently tagged slow and fast myosin. The results showed that the response to protein turnover disturbance varied between slow and fast myofibers. These findings highlight the importance of studying endogenous myosin dynamics in different muscle fiber types.
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
(2022)
Review
Biochemistry & Molecular Biology
R. John Solaro
Summary: This article discusses the significant contributions of Michael B'ar'any and his colleagues in understanding myosin motors, with two of their papers being highly cited. The impact of these papers on the current understanding of myosin ATPase activity regulation is summarized, particularly in the context of cardiac homeostasis and diseases.
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
(2022)
Review
Biophysics
Joseph D. Powers, Sage A. Malingen, Michael Regnier, Thomas L. Daniel
Summary: The study of muscle physiology, starting from the sliding filament theory in 1954, aims to understand the multiscale processes that govern muscle function. This understanding has significant consequences for various applications, but connecting structural and functional properties across different scales remains a challenge.
ANNUAL REVIEW OF BIOPHYSICS, VOL 50, 2021
(2021)
Article
Chemistry, Multidisciplinary
Xinpeng Hu, Xiaodan Zhao, Iong Ying Loh, Jie Yan, Zhisong Wang
Summary: This study demonstrates the sustained force generation capability of an artificial molecular motor at the single-molecule level, showcasing its autonomous chemically fueled operation and self-directed walking. The results suggest a reasonably efficient chemomechanical conversion of the motor compared to biomotors, with implications for similar force-demanding applications.
Article
Neurosciences
Natasha Ranu, Jenni Laitila, Hannah F. Dugdale, Jennifer Mariano, Justin S. Kolb, Carina Wallgren-Pettersson, Nanna Witting, John Vissing, Juan Jesus Vilchez, Chiara Fiorillo, Edmar Zanoteli, Mari Auranen, Manu Jokela, Giorgio Tasca, Kristl G. Claeys, Nicol C. Voermans, Johanna Palmio, Sanna Huovinen, Maurizio Moggio, Thomas Nyegaard Beck, Aikaterini Kontrogianni-Konstantopoulos, Henk Granzier, Julien Ochala
Summary: Nemaline myopathy (NM) is a common genetic muscle disorder associated with mutations in the NEB gene. This study revealed that the myosin stabilizing state, known as super-relaxed state, is impaired in NM patients, leading to increased energy consumption in resting muscle fibers. Proteomics analysis also showed metabolic changes in a nebulin-deficient mouse model. These findings provide insights into the pathophysiology of NM and suggest potential therapeutic targets for NEB-NM.
ACTA NEUROPATHOLOGICA COMMUNICATIONS
(2022)
Article
Physiology
Masataka Kawai, Robert Stehle, Gabriele Pfitzer, Bogdan Iorga
Summary: This study aimed to investigate the role of inorganic phosphate (P-i) in the production of oscillatory work and cross-bridge kinetics in striated muscle. The research found that P-i competitively inhibits ATP binding to cross-bridges and rebinds to affect the production of oscillatory work. Additionally, the study showed that the sinusoidal waveform of tension is distorted by second harmonics, indicating a nonlinear force generation mechanism in muscle fibers.
JOURNAL OF GENERAL PHYSIOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Keisuke Hitachi, Yuri Kiyofuji, Hisateru Yamaguchi, Masashi Nakatani, Masafumi Inui, Kunihiro Tsuchida
Summary: This study investigated the effects of the loss of MyHC-IIb and MyHC-IIx on skeletal muscle function using a mouse model. The results showed that the simultaneous loss of IIb and IIx led to severe muscle hypoplasia after 2 weeks of age in mice. Increased expression of other MyHCs was observed in 3-week-old mice, but it was not sufficient to compensate for the loss of IIb and IIx. Aberrant sarcomere structure and altered expression of sarcomere components were also observed. These findings contribute to the understanding of molecular mechanisms underlying skeletal muscle wasting disorders caused by the loss of skeletal muscle MyHCs.
Article
Biochemistry & Molecular Biology
Keitaro Minato, Yuki Yoshimoto, Tamaki Kurosawa, Kei Watanabe, Hiroyuki Kawashima, Madoka Ikemoto-Uezumi, Akiyoshi Uezumi
Summary: Skeletal muscles generate force through myofiber contraction, which is transmitted to tendons. Studies on age-related changes in mouse muscles showed an increased dependence on longitudinal force transmission and a decreased efficiency in lateral force transmission in older muscles. There was an increase in connective tissue volume in the old muscles, but no significant change in dystrophin expression.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Orthopedics
Jaqueline Lourdes Rios, David A. Hart, Raylene A. Reimer, Walter Herzog
Summary: The study found that aerobic exercise or prebiotic fiber supplementation, either alone or in combination, improved certain markers of metabolic disturbance but did not have a significant impact on knee joint damage. It is important to note that chow-fed rats showed similar knee osteoarthritis-like damage as the high-fat/high-sucrose-fed rats.
Article
Engineering, Biomedical
Scott C. Sibole, Eng Kuan Moo, Salvatore Federico, Walter Herzog
Summary: PCM asymmetry may play an important role in cartilage development, pathology, and engineering. The changes in PCM geometry can affect the cellular mechanical environment and the surface strains on cells.
ANNALS OF BIOMEDICAL ENGINEERING
(2022)
Article
Biophysics
Atsuki Fukutani, Walter Herzog
Summary: This study found that very quick stretches can affect the magnitude of residual force enhancement, although there was no significant difference between muscles. This can help explain the key mechanism for inducing residual force enhancement.
JOURNAL OF BIOMECHANICS
(2022)
Article
Biology
Shuyue Liu, Venus Joumaa, Walter Herzog
Summary: The steady-state isometric force of a muscle after active stretching is greater than that of a purely isometric contraction at the same length and activation level, a phenomenon known as residual force enhancement (rFE). The role of cross-bridge cycling in rFE was investigated, and it was found that fast stretching, which causes cross-bridge slipping, is associated with a loss of rFE.
JOURNAL OF EXPERIMENTAL BIOLOGY
(2022)
Review
Physiology
Walter Herzog
Summary: This article introduces the methods, applications, advantages, and disadvantages of single sarcomere/myofibril research, emphasizing its importance in uncovering the mechanisms of muscle contraction.
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Health Care Sciences & Services
Walter Herzog, Peter Kevorkian, Brent Russell, Joel Alcantara
Summary: The objective of this study was to quantify the forces exerted by a single chiropractor on children and adults during high-velocity, low-amplitude spinal manipulations and evaluate the correlation of forces to age. The results showed that most outcome variables increased with the age of the patient. This study demonstrated the feasibility of measuring the forces used by a chiropractor in clinical practice on patients of different ages.
JOURNAL OF MANIPULATIVE AND PHYSIOLOGICAL THERAPEUTICS
(2022)
Article
Engineering, Biomedical
Faruk Ortes, Azim Jinha, Walter Herzog, Yunus Ziya Arslan
Summary: Muscle models based on the cross-bridge theory can represent the dynamic and nonlinear characteristics of muscle forces. Sensitivity analysis of a Huxley model showed that changes in detachment rate had the greatest effect on muscle forces during lengthening contractions, while changes in attachment rate and binding distance had the greatest effect on forces during shortening contractions. These results highlight the asymmetry between shortening and lengthening contractions and the challenges of accurately predicting forces using a single cross-bridge model.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART H-JOURNAL OF ENGINEERING IN MEDICINE
(2022)
Article
Rehabilitation
Lindsay M. Gorrell, Andrew Sawatsky, W. Brent Edwards, Walter Herzog
Summary: This study measured the length changes of the vertebral artery during cervical spine manipulation and found that the artery elongated but was not stretched. However, further research is needed to assess the safety of cervical spine manipulation from a mechanical perspective.
JOURNAL OF MANUAL & MANIPULATIVE THERAPY
(2023)
Article
Sport Sciences
Matthew Zukowski, Walter Herzog, Matthew J. Jordan
Summary: This study examined the intraday reliability of two novel unilateral loaded jump protocols designed for long track speed skaters and correlated them with performance in speed skating. The results showed that unilateral loaded jump tests are reliable in speed skating athletes and can be used to diagnose and monitor lower-limb maximal muscle power capacity.
JOURNAL OF STRENGTH AND CONDITIONING RESEARCH
(2023)
Editorial Material
Biophysics
Heiliane de Brito Fontana, Taylor J. M. Dick, Seong-won Han, Walter Herzog
JOURNAL OF BIOMECHANICS
(2023)
Article
Engineering, Biomedical
Philippe Pouletaut, Yoann Tatarenko, Mashhour K. Chakouch, Meng Li, Venus Joumaa, John R. Hawse, Walter Herzog, Simon Chatelin, Sabine F. Bensamoun
Summary: The study aimed to compare the passive mechanical properties of soleus and extensor digitorum longus muscles at different scales in a mouse model. Results showed significant differences in passive mechanical properties at the macroscopic scale, highlighting the importance of scale in tissue characterization. This research contributes referent data for future studies on multiscale passive mechanical properties of muscles.
Article
Health Care Sciences & Services
Lindsay M. Gorrell, Philip J. Conway, Franziska Onasch, Walter Herzog
Summary: This study systematically investigated the electromyographic responses associated with manual high-velocity, low-amplitude spinal manipulation in individuals with mild neck disability. The results showed that cervical spinal manipulation resulted in the highest rate of electromyographic responses in muscles of the cervical spine, while responses in back muscles were highest after upper thoracic manipulations.
JOURNAL OF MANIPULATIVE AND PHYSIOLOGICAL THERAPEUTICS
(2022)
Article
Sport Sciences
Matthew J. Jordan, Nathaniel Morris, Sophia Nimphius, Per Aagaard, Walter Herzog
Summary: A retrospective analysis on routine countermovement jump testing in female elite alpine skiers revealed that ACL-reconstructed skiers may experience impaired SSC function for up to 5 years post-surgery, although limb-specific asymmetry decreases over time.
FRONTIERS IN SPORTS AND ACTIVE LIVING
(2022)
Article
Rehabilitation
Rafael Fortuna, Andrew Sawatsky, John C. Fuller, Walter Herzog
Summary: The study found that while HMB did not completely prevent muscle mass and strength loss induced by BoNT-A injection, it did reduce the loss of contractile material in the injected muscles and prevented strength loss in the contralateral non-injected muscles.
JOURNAL OF REHABILITATION MEDICINE
(2021)
Article
Sport Sciences
Nathaniel Morris, Matthew J. Jordan, Shailah Sumar, Bram Adrichem, Mark Heard, Walter Herzog
Summary: The study analyzed the effects of ACL reconstruction using the semitendinosus tendon autograft technique on knee flexor maximal torque and rate of torque development in athletes who had returned to competition. It found deficits in torque and rate of torque development in the ACLR limb compared to the contralateral limb, and lower semitendinosus muscle cross-sectional area in the ACLR limb. The results suggest the importance of preserving semitendinosus muscle architecture following ACL reconstruction and considering specific strength requirements of the athlete's sport when choosing a graft.
TRANSLATIONAL SPORTS MEDICINE
(2021)
Article
Biophysics
Nathan D. Camarillo, Rafael Jimenez-Silva, Frances T. Sheehan
Summary: This article discusses the statistical dependence between multiple measurements from the same participant and provides recommendations for using these measurements when they are not independent.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
J. Huet, A. -S. Boureau, A. Sarcher, C. Cornu, A. Nordez
Summary: Standard compression in freehand 3D ultrasound induces a bias in volume calculations, but minimal compression and gel pad methods have similar results. With a trained examiner and precautions, the bias can be minimized and become acceptable in clinical applications.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
C. Lariviere, A. H. Eskandari, H. Mecheri, F. Ghezelbash, D. Gagnon, A. Shirazi-Adl
Summary: Recent developments in musculoskeletal modeling have focused on model customization. Personalization of the spine profile may affect estimates of spinal loading and stability. This study investigates the biomechanical consequences of changes in the spinal profile and finds that personalizing the spine profile has medium to large effects on trunk muscle forces and negligible to small effects on spinal loading and stability.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Luke T. Mattar, Arash B. Mahboobin, Adam J. Popchak, William J. Anderst, Volker Musahl, James J. Irrgang, Richard E. Debski
Summary: Exercise therapy fails in about 25.0% of cases for individuals with rotator cuff tears, and one reason for this failure may be the inability to strengthen and balance the muscle forces that keep the humeral head in the correct position. This study developed computational musculoskeletal models to compare the net muscle force before and after exercise therapy between successfully and unsuccessfully treated patients. The study found that unsuccessfully treated patients had less inferiorly oriented net muscle forces, which may increase the risk of impingement.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Natsuki Sado, Takeshi Edagawa, Toshihide Fujimori, Shogo Hashimoto, Yoshikazu Okamoto, Takahito Nakajima
Summary: The existing methods for predicting hip and lumbosacral joint centres in Japanese adults are biased and differ between sexes. We propose new regression equations that consider soft-tissue thickness, sex differences, and a height-directional measure, and validate them using leave-one-out cross-validation.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Peimin Yu, Xuanzhen Cen, Qichang Mei, Alan Wang, Yaodong Gu, Justin Fernandez
Summary: This study aimed to explore the intra-foot biomechanical differences among individuals with chronic ankle instability (CAI), copers, and healthy individuals during dynamic tasks. The study found that copers and CAI individuals had smaller dorsiflexion angles and copers presented a more eversion position compared to healthy participants. Copers also had greater dorsiflexion angles in the metatarsophalangeal joint and more inversion moments in the subtalar joint during certain tasks. These findings can help in designing interventions to restore ankle joint functions in CAI individuals.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Jon Skovgaard Jensen, Anders Holsgaard-Larsen, Anders Stengaard Sorensen, Per Aagaard, Jens Bojsen-Moller
Summary: This study investigates the biomechanical effects of robot-assisted body weight unloading (BWU) on gait patterns in healthy young adults. The results show that dynamic robot-assisted BWU enables reduced kinetic requirements without distorting biomechanically normal gait patterns during overground walking.
JOURNAL OF BIOMECHANICS
(2024)