Article
Biology
Anthony J. Blazevich, Jared R. Fletcher
Summary: The long, distal tendons, such as the Achilles, allow for muscle power amplification and reduction of locomotor energy cost. These tendons evolved to reduce energy cost and have additional advantages such as reducing muscle force requirement, attenuating vibrations, reducing muscle heat production, and preventing muscle damage. Overall, these benefits reduce fatigue and sense of effort, allowing humans to move at faster speeds for longer.
BIOLOGICAL REVIEWS
(2023)
Article
Biotechnology & Applied Microbiology
Matej Tomc, Zlatko Matjacic
Summary: A novel rehabilitation device AN-EXTRA-Push was proposed, utilizing a brake and an elastic tendon to assist push-off by harnessing energy during stance phase and releasing it during push-off. The feasibility of the device was studied, with key parameters of brake engagement timing and elastic tendon stiffness determining the level of exoskeleton assistance. Insights from the study highlight the importance of timing in assistive torque, particularly the assistance termination determined by brake disengagement timing.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2022)
Article
Neurosciences
Bettina Sommer, Andreas Hollenstein, Eveline Graf
Summary: Different orthopedic boots (Vacoped, Kuenzli, and Orthotech) used for walking treatment of Achilles tendon injuries have distinct impacts on lower extremity biomechanical parameters, indicating significant differences between boot types.
Article
Sport Sciences
Katie A. Conway, Keyaira L. Crudup, Michael D. Lewek, Jason R. Franz
Summary: The study showed that utilizing horizontal impeding forces in older adults can enhance their muscle strength and walking speed, leading to improved push-off intensity during walking.
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
(2021)
Article
Multidisciplinary Sciences
Michael Esposito, John W. Wannop, Darren J. Stefanyshyn
Summary: The study aimed to investigate the impact of footwear midsole material on running performance and found that changes in midsole stiffness can improve performance by increasing energy return from the Achilles tendon. These findings suggest that increasing energy return from the Achilles could be a valid mechanism for improving running performance.
SCIENTIFIC REPORTS
(2022)
Review
Orthopedics
Choon Chiet Hong, Susanne Olesen Schaarup, James Calder
Summary: This paper describes a novel technique for treating push-off weakness by selectively shortening the gastrocnemius. It improves the differential elongation between the gastrocnemius and the soleus.
KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY
(2023)
Article
Physiology
Benjamin Staeudle, Olivier Seynnes, Guido Laps, Gert-Peter Brueggemann, Kirsten Albracht
Summary: Achilles tendon rupture (ATR) can lead to functional limitations, but the remodeled muscle-tendon unit (MTU) has limited impact on walking gait.
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Biology
Andrea Monte, Paolo Tecchio, Francesca Nardello, Paola Zamparo
Summary: This study investigated the mechanical determinants of the walk-to-run transition, focusing on ankle joint functional indexes and Achilles tendon mechanical behavior. The results showed that walking at speeds faster than the transition speed could impair the mechanical behavior of the Achilles tendon and the spring-like function of the ankle joint. These findings provide insights into the mechanical factors involved in the walk-to-run transition.
Article
Orthopedics
Anna Nordenholm, Eric Hamrin Senorski, Katarina Nilsson Helander, Michael Moller, Roland Zugner
Summary: The purpose of this study was to investigate the relationships between calf muscle function, tendon length and gait biomechanics in patients who underwent surgical treatment for chronic Achilles tendon rupture. The findings showed that better performance in the heel-rise endurance test was associated with faster walking speed, greater peak ankle power, shorter stance phase, and less peak ankle dorsiflexion angle during gait. In addition, greater Achilles Tendon Resting Angle (ATRA) was correlated with longer stance time, greater peak ankle dorsiflexion angle, fewer repetitions in the heel-rise test, and lower total work. These results suggest that greater calf muscle endurance is moderately correlated with better ankle biomechanics during gait in patients surgically treated for chronic Achilles tendon rupture.
KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY
(2022)
Article
Orthopedics
Kristine Rask Andreasen, Maria Swennergren Hansen, Jesper Bencke, Per Holmich, Kristoffer Weisskirchner Barfod
Summary: The heel-rise work test using the heel as a surrogate for center of body mass overestimates the total work by 21.0-24.7%, but is able to precisely detect relative differences between limbs.
KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY
(2021)
Article
Orthopedics
Susanna Aufwerber, Josefine E. Naili, Karin Gravare Silbernagel, Paul W. Ackermann
Summary: This study compared the recovery of gait patterns in patients treated with early functional mobilization (EFM) or standard treatment (ST) after Achilles tendon rupture repair. There were no significant differences in gait patterns between the two treatment groups, and no correlations were found between gait deviations and tendon elongation or muscle atrophy.
JOURNAL OF ORTHOPAEDIC RESEARCH
(2022)
Article
Neurosciences
Anahid Ebrahimi, Robyn L. Kuchler, Robin L. Pomeroy, Isaac F. Loegering, Jack A. Martin, Darryl G. Thelen
Summary: This study is the first to utilize shear wave tensiometry to characterize Achilles and patellar tendon loading during gait in children. Achilles tendon loading closely aligns with peak ankle plantarflexor moment during push-off, while patellar tendon loading increases with walking speed and matches peak knee extension moment timings.
Article
Multidisciplinary Sciences
Jian Jin, Jaap H. van Dieen, Dinant Kistemaker, Andreas Daffertshofer, Sjoerd M. Bruijn
Summary: Understanding the mechanisms humans use to stabilize walking is crucial for predicting falls in the elderly. Two potential mechanisms, foot placement control and ankle push-off control, have been identified to stabilize gait in the anterior-posterior direction. It is unknown whether the latter mechanism is employed in steady-state walking. This study found that foot placement errors in steady-state walking were correlated to ankle push-off torque, suggesting that humans use a push-off strategy to correct foot placement errors.
Article
Orthopedics
Maria Swennergren Hansen, Jesper Bencke, Morten Tange Kristensen, Thomas Kallemose, Per Holmich, Kristoffer Weisskirchner Barfod
Summary: This study aimed to investigate if treatment selection using the individualized treatment algorithm CARTA differs from usual treatment in terms of gait dynamics and tendon elongation. The results indicated no statistically significant differences between the intervention group and the control groups.
FOOT AND ANKLE SURGERY
(2023)
Article
Orthopedics
Anahid Ebrahimi, Michael H. Schwartz, Jack A. Martin, Tom F. Novacheck, Darryl G. Thelen
Summary: The purpose of this study was to evaluate the mechanical behavior of the Achilles tendon during gait in children with cerebral palsy (CP) using a noninvasive sensor. The results showed that children with CP had significantly reduced Achilles tendon work compared to typically developing children. The work loop patterns in CP children were different from those in the control group, indicating a different muscle-tendon behavior.
JOURNAL OF ORTHOPAEDIC RESEARCH
(2022)
Article
Multidisciplinary Sciences
Daniel B. Kowalsky, John R. Rebula, Lauro V. Ojeda, Peter G. Adamczyk, Arthur D. Kuo
Summary: This study quantified the effects of different outdoor terrains on foot motion and net metabolic rate in healthy adults, showing that energy expenditure increased significantly on terrains such as Sidewalk, Dirt, Gravel, Grass, and Woodchips, with Woodchips being 27% costlier than Sidewalk. Terrain type also influenced measures such as stride variability and virtual foot clearance.
Article
Chemistry, Analytical
Jennifer K. Leestma, Katherine Heidi Fehr, Peter G. Adamczyk
Summary: The study found positive linear sensitivity of DMAMA to stiffness on ramps and level ground. Additionally, there was a positive linear sensitivity of DMAMA to ground slope in the low- and medium-stiffness conditions and a negative interaction effect between slope and stiffness. Considerable variability suggests that applications of DMAMA as a control input should look at the running average over several strides.
Article
Chemistry, Analytical
Sara E. Harper, Dylan G. Schmitz, Peter G. Adamczyk, Darryl G. Thelen
Summary: This study combines kinetic and kinematic measures to establish a wearable system for estimating work and power output from the soleus and gastrocnemius muscles during outdoor locomotion. Results show that gastrocnemius work is relatively insensitive to incline, while soleus work scales with incline.
Article
Multidisciplinary Sciences
R. C. Riddick, A. D. Kuo
Summary: This study investigates the metabolic cost of human running and the active versus passive work performed by muscles. The research indicates that despite some work being done passively, active muscle work still contributes significantly to the overall energetic cost, with passive elasticity playing a role in reducing the active work cost.
SCIENTIFIC REPORTS
(2022)
Article
Biology
Osman Darici, Arthur D. Kuo
Summary: This study reveals the anticipatory speed adjustment pattern of humans when walking up a curb, which is predicted by an optimized control model. Experimental results show that humans ascend and descend the curb according to the predicted trajectory, maintaining the overall walking speed. This finding is important for understanding the dynamics and control mechanisms of human walking.
Article
Orthopedics
Joshua M. Caputo, Evan Dvorak, Kate Shipley, Mary Ann Miknevich, Peter G. Adamczyk, Steven H. Collins
Summary: This study proposes an evidence-based and personalized approach to the design and selection of lower-limb prosthetic devices, and demonstrates its feasibility through two experiments. The first experiment shows that optimal prosthetic foot parameters vary across different subjects, walking conditions, and outcome measures. The second experiment presents a quick and effective manual tuning procedure for identifying preferred parameters. These results motivate further clinical studies on the validity, efficacy, and economics of this approach.
JOURNAL OF PROSTHETICS AND ORTHOTICS
(2022)
Article
Multidisciplinary Sciences
Tim J. van der Zee, Arthur D. Kuo
Summary: An algorithm for accurately estimating geometric features of pennate muscle from ultrasound images without drift sensitivity was proposed. Experiments on healthy subjects showed that the algorithm outperformed existing algorithms in terms of accuracy and processing speed.
Article
Biophysics
Kieran M. Nichols, Peter G. Adamczyk
Summary: This paper investigates the effects of adjusting stiffness on knee and ankle mechanics using the Variable Stiffness Foot (VSF) for prosthetic users. The results show that a stiffer VSF leads to decreased ankle dorsiflexion angle, increased ankle plantarflexor moment, increased knee extension, increased knee flexor moment, and decreased prosthetic energy storage, energy return, and power. These findings suggest that a less stiff VSF can reduce joint moments and increase joint range of motion, which may be advantageous for persons using lower-limb prostheses. Modulating the VSF stiffness can help overcome gait deviations associated with different slopes, terrain characteristics, or footwear.
JOURNAL OF BIOMECHANICS
(2023)
Article
Chemistry, Analytical
Dilruba Mahmud, Sean T. T. Bennett, Zhenhua Zhu, Peter G. G. Adamczyk, Michael Wehner, Dharmaraj Veeramani, Fei Dai
Summary: Exoskeletons and exosuits have the potential to reduce the risk of work-related musculoskeletal disorders in construction workplaces. However, the knowledge required for the acceptance and application of this technology is still lacking. This research aims to identify the facilitators, barriers, and corresponding solutions to foster the adoption of exoskeletons in construction workplaces.
Article
Multidisciplinary Sciences
Tim J. van der Zee, Emily M. Mundinger, Arthur D. Kuo
Summary: This study presents an open biomechanics dataset of human walking under various step lengths and speeds, providing valuable information for describing and determining the mechanics of locomotion.
Article
Biology
Rebecca Elizabeth Carlisle, Arthur D. Kuo
Summary: Humans choose their walking speed and duration based on minimizing energy expenditure per distance, but actual walking bouts involve time-varying trajectories influenced by task urgency and movement vigor. A computational model and human experiment demonstrate that walking speed and duration can be explained better by minimizing Energy and Time, with speed vs. time trajectories following inverted U shapes. Short bouts are unsteady due to acceleration, while longer bouts are steadier and faster. Individual-dependent vigor is characterized by the energy one is willing to spend to save time, resulting in similar-shaped walking trajectories.
Article
Construction & Building Technology
Sean T. Bennett, Wei Han, Dilruba Mahmud, Peter G. Adamczyk, Fei Dai, Michael Wehner, Dharmaraj Veeramani, Zhenhua Zhu
Summary: The labor-intensive construction industry puts workers at risk of musculoskeletal injuries due to physically demanding manual work. Exoskeletons and exosuits, known as EXOs, are designed to reduce exertion and muscle fatigue in order to protect workers. However, the usability of EXOs in construction remains unclear.
Article
Engineering, Biomedical
Ava D. Segal, Peter G. Adamczyk, Andrew J. Petruska, Anne K. Silverman
Summary: Providing engaging, at-home balance therapy for aging adults is crucial for long-term adherence to unsupervised training and fostering independence. This study developed a portable interactive balance training system that uses wobble board tilt angles to control a robotic car platform, providing real-world visual cues on balance performance. The findings demonstrate the feasibility of implementing goal-directed robotic balance training with mobile tracking of balance performance in home environments.
IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING
(2022)
Proceedings Paper
Computer Science, Cybernetics
Patrick Dills, Alexander Dawson-Elli, Kreg Gruben, Peter Adamczyk, Michael Zinn
Summary: This study presents a stability and rendering range analysis of how parallel hybrid actuation increases the stable rendering range of virtual stiffness.
2022 IEEE HAPTICS SYMPOSIUM (HAPTICS)
(2022)
Article
Engineering, Biomedical
Michael A. McGeehan, Peter G. Adamczyk, Kieran M. Nichols, Michael E. Hahn
Summary: This study modeled and simulated the dynamics of the residual limb-socket interface and evaluated the effects of varied prosthesis stiffness on interface dynamics during gait. The results showed that increased stiffness led to greater normal pressure and shear stress. These methods can provide insights into the effects of prosthesis design parameters and gait conditions on residual limb-socket interface dynamics, aiding experimental studies.
JOURNAL OF REHABILITATION AND ASSISTIVE TECHNOLOGIES ENGINEERING
(2022)
Article
Biology
Iain Hunter, Raz Leib
Summary: Natural movement is related to health, but it is difficult to measure. Existing methods cannot capture the full range of natural movement. Comparing movement across different species helps identify common biomechanical and computational principles. Developing a system to quantify movement in freely moving animals in natural environments and relating it to life quality is crucial. This study proposes a theoretical framework based on movement ability and validates it in Drosophila.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Andy Gardner
Summary: Fisher's geometric model is a useful tool for predicting key properties of Darwinian adaptation, and here it is applied to predict differences between the evolution of altruistic versus nonsocial phenotypes. The results suggest that the effect size maximizing probability of fixation is smaller in the context of altruism and larger in the context of nonsocial phenotypes, leading to lower overall probability of fixation for altruism and higher overall probability of fixation for nonsocial phenotypes.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Thomas F. Pak, Joe Pitt-Francis, Ruth E. Baker
Summary: Cell competition is a process where cells interact in multicellular organisms to determine a winner or loser status, with loser cells being eliminated through programmed cell death. The winner cells then populate the tissue. The outcome of cell competition is context-dependent, as the same cell type can win or lose depending on the competing cell type. This paper proposes a mathematical framework to study the emergence of winner or loser status, highlighting the role of active cell death and identifying the factors that drive cell competition in a cell-based modeling context.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Haruto Tomizuka, Yuuya Tachiki
Summary: Batesian mimicry is a strategy in which palatable prey species resemble unpalatable prey species to avoid predation. The evolution of this mimicry plays a crucial role in protecting the unpalatable species from extinction.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Jason W. Olejarz, Martin A. Nowak
Summary: Gene drive technology shows potential for population control, but its release may have unpredictable consequences. The study suggests that the failure of suppression is a natural outcome, and there are complex dynamics among wild populations.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Hamid Ravaee, Mohammad Hossein Manshaei, Mehran Safayani, Javad Salimi Sartakhti
Summary: Gene expression analysis is valuable for cancer classification and phenotype identification. IP3G, based on Generative Adversarial Networks, enhances gene expression data and discovers phenotypes in an unsupervised manner. By converting gene expression profiles into images and utilizing IP3G, new phenotype profiles can be generated, improving classification accuracy.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Beatrix Rahnsch, Leila Taghizadeh
Summary: This study forecasts the evolution of the COVID-19 pandemic in Germany using a network-based inference method and compares it with other approaches. The results show that the network-inference based approach outperforms other methods in short-to mid-term predictions, even with limited information about the new disease. Furthermore, predictions based on the estimation of the reproduction number in Germany can yield more reliable results with increasing data availability, but still cannot surpass the network-inference based algorithm.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Rongsheng Huang, Qiaojun Situ, Jinzhi Lei
Summary: Maintaining tissue homeostasis requires appropriate regulation of stem cell differentiation. Random inheritance of epigenetic states plays a pivotal role in stem cell differentiation. This computational model provides valuable insights into the intricate mechanism governing stem cell differentiation and cell reprogramming, offering a promising path for enhancing the field of regenerative medicine.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Patrick Vincent N. Lubenia, Eduardo R. Mendoza, Angelyn R. Lao
Summary: This study compares insulin signaling in healthy and type 2 diabetes states using reaction network analysis. The results show similarities and differences between the two conditions, providing insights into the mechanisms of insulin resistance, including the involvement of other complexes, less restrictive interplay between species, and loss of concentration robustness in GLUT4.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Nuverah Mohsin, Heiko Enderling, Renee Brady-Nicholls, Mohammad U. Zahid
Summary: Mathematical modeling is crucial in understanding radiobiology and designing treatment approaches in radiotherapy for cancer. This study compares three tumor volume dynamics models and analyzes the implications of model selection. A new metric, the point of maximum reduction of tumor volume (MRV), is introduced to quantify the impact of radiotherapy. The results emphasize the importance of caution in selecting models of response to radiotherapy due to the artifacts imposed by each model.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Armindo Salvador
Summary: Michael Savageau's Biochemical Systems Analysis papers have had a significant impact on Systems Biology, generating core concepts and tools. This article provides a brief summary of these papers and discusses the most relevant developments in Biochemical Systems Theory since their publication.
JOURNAL OF THEORETICAL BIOLOGY
(2024)