Jonathan B Dingwell

Jonathan B Dingwell
Pennsylvania State University | Penn State · Department of Kinesiology

Ph.D.

About

145
Publications
25,409
Reads
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7,371
Citations
Citations since 2017
22 Research Items
3453 Citations
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20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600
Introduction
Our lab works to understand the biomechanics and neuromuscular control of complex adaptive human movements. We conduct both basic science and clinically relevant research on: - Maintaining dynamic stability during human locomotion - Determining how humans exploit redundancy and neuronal noise to control repetitive movements We address these questions using both experimental and modeling approaches derived primarily from the analysis of nonlinear dynamical systems and statistical mechanics.
Additional affiliations
January 2009 - December 2011
University of Rhode Island
Position
  • Collaborator
January 2007 - August 2017
Brooke Army Medical Center
Position
  • Collaborator
January 2006 - April 2008
University of Illinois at Chicago
Position
  • Collaborator

Publications

Publications (145)
Article
Full-text available
To successfully traverse their environment, humans often perform maneuvers to achieve desired task goals while simultaneously maintaining balance. Humans accomplish these tasks primarily by modulating their foot placements. As humans are more unstable laterally, we must better understand how humans modulate lateral foot placement. We previously dev...
Article
Derived from inverted pendulum dynamics, mediolateral Margin of Stability (MoSML) is a mechanically-grounded measure of instantaneous stability. However, average MoSML measures yield paradoxical results. Gait pathologies or perturbations often induce larger (supposedly “more stable”) average MoSML, despite clearly destabilizing factors. However, pe...
Article
Full-text available
Walking humans display great versatility when achieving task goals, like avoiding obstacles or walking alongside others, but the relevance of this to fall avoidance remains unknown. We recently demonstrated a functional connection between the motor regulation needed to achieve task goals (e.g., maintaining walking speed) and a simple walker’s abili...
Preprint
Full-text available
To successfully traverse their environment, humans often perform maneuvers to achieve desired task goals while simultaneously maintaining balance. Humans accomplish these tasks primarily by modulating their foot placements. As humans are more unstable laterally, we must better understand how humans modulate lateral foot placement. We previously dev...
Preprint
Full-text available
Humans display great versatility when performing goal-directed tasks while walking. However, the extent to which such versatility helps with fall avoidance remains unclear. We recently demonstrated a functional connection between the motor regulation needed to achieve task goals (e.g. maintaining walking speed) and a simple walker's ability to reje...
Preprint
Full-text available
Maintaining frontal-plane stability is a major objective of human walking. Derived from inverted pendulum dynamics, the mediolateral Margin of Stability ( MoS ML ) is frequently used to measure people's frontal-plane stability on average . However, typical MoS ML -based analyses deliver paradoxical interpretations of stability status. To address me...
Article
Background Daily walking paths exhibit varying environment features and require continuous adjustments to locomotor trajectories. Humans maintain lateral balance while navigating paths by modifying stepping in accordance with changing side-to-side path limitations (i.e. path width, lateral location). These processes are influenced by one’s actual p...
Article
People walk in complex environments where they must adapt their steps to maintain balance and satisfy changing task goals. How people do this is not well understood. We recently developed computational models of lateral stepping, based on Goal Equivalent Manifolds that serve as motor regulation templates, to identify how people regulate walking mov...
Article
Full-text available
Dual-task research is limited in its transferability to authentic contexts because laboratory conditions do not replicate real-world physical activity and decision-making scenarios. Creating valid, reliable methodologies to assess physiological and behavioral responses under varying physical and cognitive demands using virtual reality (VR) environm...
Article
Background Persons with lower limb amputation often experience decreased physical capacity, difficulty walking, and increased fall risk. To either prevent or recover from a loss of balance, one must effectively regulate their stepping movements. It is therefore critical to identify how well persons with amputation regulate stepping. Here, we used a...
Article
Much remains unknown about how considerations such as stability and energy minimization shape the way humans walk. While active neuromotor control keeps humans upright, they also need to choose from multiple stepping regulation strategies to achieve one or more task goals, such as maintaining a desired speed or direction. Experiments on human tread...
Article
Gait variability is generally associated with falls, but specific connections remain disputed. To reduce falls, we must first understand how older adults maintain lateral balance while walking, particularly when their stability is challenged. We recently developed computational models of lateral stepping, based on Goal Equivalent Manifolds, that se...
Article
Experimental studies of human walking have shown that within an individual step, variations in the center of mass (CoM) state can predict corresponding variations in the next foot placement. This has been interpreted by some to indicate the existence of active control in which the nervous system uses the CoM state at or near mid-stance to regulate...
Article
Full-text available
A fundamental question in human motor neuroscience is to determine how the nervous system generates goal-directed movements despite inherent physiological noise and redundancy. Walking exhibits considerable variability and equifinality of task solutions. Existing models of bipedal walking do not yet achieve both continuous dynamic balance control a...
Data
Uni‐objective models: Results of parameter sensitivity analyses. (PDF)
Data
Multi‐objective models: Results of parameter sensitivity analyses. (PDF)
Article
Full-text available
Cell phone related pedestrian injuries are increasing, but the underlying causes remain unclear. Here, we studied how cell phone use directly affected obstacle avoidance ability. Thirty healthy adults participated. Cognitive capacity was quantified using standard tests. Participants walked on a treadmill in a virtual reality environment with and wi...
Article
As humans walk or run, external (environmental) and internal (physiological) disturbances induce variability. How humans regulate this variability from stride-to-stride can be critical to maintaining balance. One cannot infer what is "controlled" based on analyses of variability alone. Assessing control requires quantifying how deviations are corre...
Article
Humans use visual optic flow to regulate average walking speed. Among many possible strategies available, healthy humans walking on motorized treadmills allow fluctuations in stride length (Ln) and stride time (Tn) to persist across multiple consecutive strides, but rapidly correct deviations in stride speed (Sn = Ln/Tn) at each successive stride,...
Article
Older adults exhibit increased gait variability that is associated with fall history and predicts future falls. It is not known to what extent this increased variability results from increased physiological noise versus a decreased ability to regulate walking movements. To “walk”, a person must move a finite distance in finite time, making stride l...
Article
Full-text available
Author During the repeated execution of precision movement tasks, humans face two formidable challenges from the motor system itself: dimensionality and noise. Human motor performance involves biomechanical, neuromotor, and perceptual degrees of freedom far in excess of those theoretically needed to prescribe typical goal-directed tasks. At the sa...
Data
A compressed folder containing all data and software used for this study. (ZIP)
Article
Full-text available
Age-related gait changes may be due to the loss of complexity in the neuromuscular system. This theory is disputed due to inconsistent results from single-scale analyses. Also, behavioral adaptations may confound these changes. We examined whether EMG dynamics during gait is less complex in older adults over a range of timescales using the multisca...
Article
Background and purpose: Roughly 50% of individuals with lower limb amputation report a fear of falling and fall at least once a year. Perturbation based gait training and the use of virtual environments have been shown independently to be effective at improving walking stability in patient populations. We developed an intervention combining the st...
Article
Humans continually adapt their movements as they walk on different surfaces, avoid obstacles, etc. External (environmental) and internal (physiological) noise-like disturbances, and the responses that correct for them, each contribute to locomotor variability. This variability may sometimes be detrimental (perhaps increasing fall risk), or sometime...
Article
Full-text available
Temporal-spatial, kinematic variability, and dynamic stability measures collected during perturbation-based assessment paradigms are often used to identify dysfunction associated with gait instability. However, it remains unclear which measures are most reliable for detecting and tracking responses to perturbations. This study systematically determ...
Article
Full-text available
Variability is ubiquitous in human movement, arising from internal and external noise, inherent biological redundancy, and from the neurophysiological control actions that help regulate movement fluctuations. Increased walking variability can lead to increased energetic cost and/or increased fall risk. Conversely, biological noise may be beneficial...
Article
Over 50% of individuals with lower limb amputation fall at least once each year. These individuals also exhibit reduced ability to effectively respond to challenges to frontal plane stability. The range of whole body angular momentum has been correlated with stability and fall risk. This study determined how lateral walking surface perturbations af...
Chapter
Using the concept of task manifolds, a number of data analysis methods have been used to explain how redundancy influences the structure of variability observed during repeated motor performance. Here we describe investigations that integrate the task manifold perspective with the analysis of Inter-Trial task dynamics. Goal equivalent manifolds (GE...
Article
Full-text available
Repetitive movements can cause muscle fatigue, leading to motor reorganization, performance deficits, and/or possible injury. The effects of fatigue may depend on the type of fatigue task employed, however. The purpose of this study was to determine how local fatigue of a specific muscle group versus widespread fatigue of various muscle groups affe...
Article
Interestingly, young and highly active people with lower limb amputation appear to maintain a similar trunk and upper body stability during walking as able-bodied individuals. Understanding the mechanisms underlying how this stability is achieved after lower-leg amputation is important to improve training regimens for improving walking function in...
Presentation
Full-text available
Error Correction Alone Does Not Capture Behavior in a Virtual Shuffleboard Experiment
Conference Paper
Full-text available
The analysis of fluctuations in the performance of repeated, skilled movement tasks has long been used to study the underlying motor control system, as well as to reveal pathologies. One method for analyzing these fluctuations is the goal equivalent manifold (GEM) framework [1, 2]. This approach defines a goal function that relates the body states to...
Article
Lower limb amputation substantially disrupts motor and proprioceptive function. People with lower limb amputation experience considerable impairments in walking ability, including increased fall risk. Understanding the biomechanical aspects of the gait of these patients is crucial to improving their gait function and their quality of life. In the p...
Article
Understanding how lower-limb amputation affects walking stability, specifically in destabilizing environments, is essential for developing effective interventions to prevent falls. This study quantified mediolateral margins of stability (MOS) and MOS sub-components in young individuals with traumatic unilateral transtibial amputation (TTA) and youn...
Article
Fluctuations in the repeated performance of human movements have been the subject of intense scrutiny because they are generally believed to contain important information about the function and health of the neuromotor system. A variety of approaches has been brought to bear to study these fluctuations. However it is frequently difficult to underst...
Article
Falls are common in older adults. The most common cause of falls is tripping while walking. Simulation studies demonstrated that older adults may be restricted by lower limb strength and movement speed to regain balance after a trip. This review examines how modeling approaches can be used to determine how different measures predict actual fall ris...
Article
Older adults and those with increased fall risk tend to walk slower. They may do this voluntarily to reduce their fall risk. However, both slower and faster walking speeds can predict increased risk of different types of falls. The mechanisms that contribute to fall risk across speeds are not well known. Faster walking requires greater forward prop...
Article
Full-text available
Background Due to increased interest in treadmill gait training, recent research has focused on the similarities and differences between treadmill and overground walking. Most of these studies have tested healthy, young subjects rather than impaired populations that might benefit from such training. These studies also do not include optic flow, whi...
Data
Full-text available
Table S1. Mean and standard deviation of the temporal-spatial parameters during overground (OG) and treadmill walking in a CAREN (CA). Significant differences between conditions are highlighted. Significant p-values (p < 0.05) are in bold.
Article
If humans exploit task redundancies as a general strategy, they should do so even if the redundancy is de-coupled from the physical implementation of the task itself. Here, we derived a family of goal functions that explicitly defined infinite possible redundancies between distance (D) and time (T) for unidirectional reaching. All [T, D] combinatio...
Article
Determining how the human nervous system contends with neuro-motor noise is vital to understanding how humans achieve accurate goal-directed movements. Experimentally, people learning skilled tasks tend to reduce variability in distal joint movements more than in proximal joint movements. This suggests that they might be imposing greater control ov...
Article
Falls during walking are a major contributor to accidental deaths and injuries that can result in debilitating hospitalization costs, lost productivity, and diminished quality of life. To reduce these losses, we must develop a more profound understanding of the characteristic responses to perturbations similar to those encountered in daily life. Th...
Article
"Cautious" gait is generally characterized by wider and shorter steps. However, we do not clearly understand the relationship between step characteristics and individuals' stability. Here, we examined the effects of voluntarily altering step width (SW) and step length (SL) on individuals' margins of stability. Fourteen participants completed three...
Article
Individuals with transtibial amputation (TTA) have a high incidence of falls during walking. Environmental factors, such as uneven ground, often play a contributing role in these falls. The purpose of this study was to quantify the adaptations TTA made when walking on a destabilizing loose rock surface. In this study, 13 young TTA walked over a roc...
Article
Understanding how humans maintain stability when walking, particularly when exposed to perturbations, is key to preventing falls. Here, we quantified how imposing continuous, pseudorandom anterior-posterior (AP) and mediolateral (ML) oscillations affected the control of dynamic walking stability. Twelve subjects completed five 3-minute walking tria...
Article
Changes in step width (SW), step length (SL), and/or the variability of these parameters have been prospectively related to risk of falling. However, it is unknown how voluntary changes in SW and SL directly alter variability and/or dynamic stability of walking. Here, we quantified how variability and dynamic stability of human walking changed when...
Article
It is important to understand how people adapt their gait when walking in real-world conditions with variable surface characteristics. This study quantified lower-extremity joint kinematics, estimated whole body center of mass height (COM(VT)), and minimum toe clearance (MTC) while 15 healthy, young subjects walked on level ground (LG) and a destab...
Article
Full-text available
Tracking or predicting physiological fatigue is important for developing more robust training protocols and better energy supplements and/or reducing muscle injuries. Current methodologies are usually impractical and/or invasive and may not be realizable outside of laboratory settings. It was recently demonstrated that smooth orthogonal decompositi...
Article
Measures that can predict risk of falling are essential for enrollment of older adults into fall prevention programs. Local and orbital stability directly quantify responses to very small perturbations and are therefore putative candidates for predicting fall risk. However, research to date is not conclusive on whether and how these measures relate...
Article
Understanding how humans remain stable during challenging locomotor activities is critical to developing effective tests to diagnose patients with increased fall risk. This study determined if different continuous low-amplitude perturbations would induce specific measureable changes in measures of dynamic stability during walking. We applied contin...
Article
Full-text available
Performing repetitive manual tasks can lead to muscle fatigue, which may induce changes in motor coordination, movement stability, and kinematic variability. In particular, movements performed at or above shoulder height have been associated with increased shoulder injury risk. The purpose of this study was to determine the effects of repetitive mo...
Article
People at risk of falling exhibit increased gait variability, which may predict future falls. However, the causal mechanisms underlying these correlations are not well known. Increased neuronal noise associated with aging likely leads to increased gait variability, which could in turn lead to increased fall risk. This paper presents a model of how...
Data
Full-text available
Extended description of the construction of Figure 1. (0.30 MB PDF)
Data
Full-text available
Additional surrogate data analyses and results. (0.44 MB PDF)
Data
Full-text available
Extended description of the detrended fluctuation analysis algorithm. (0.27 MB PDF)
Data
Derivation of the GEM-based inter-stride optimal controller for treadmill walking. (0.26 MB PDF)
Article
Full-text available
It is widely accepted that humans and animals minimize energetic cost while walking. While such principles predict average behavior, they do not explain the variability observed in walking. For robust performance, walking movements must adapt at each step, not just on average. Here, we propose an analytical framework that reconciles issues of optim...
Article
Full-text available
Detrended fluctuation analyses (DFA) have been widely used to quantify stride-to-stride temporal correlations in human walking. However, significant questions remain about how to properly interpret these statistical properties physiologically. Here, we propose a simpler and more parsimonious interpretation than previously suggested. Seventeen young...
Article
Walking on uneven surfaces or while undergoing perturbations has been associated with increased gait variability in both modeling and human studies. Previous gait research involving continuous perturbations has focused on sinusoidal oscillations, which can result in individuals predicting the perturbation and/or entraining to it. Therefore, we exam...
Conference Paper
Full-text available
Identifying physiological fatigue is important for the development of more robust training protocols, better energy supplements, and/or reduction of muscle injuries. Current fatigue measurement technologies are usually invasive and/or impractical, and may not be realizable in out of laboratory settings. A fatigue identification methodology that onl...
Article
Muscle fatigue alters neuromuscular responses. This may lead to increased sensitivity to perturbations and possibly to subsequent injury risk. We studied the effects of muscle fatigue on movement stability during a repetitive upper extremity task. Twenty healthy young subjects performed a repetitive work task, similar to sawing, synchronized with a...
Article
Full-text available
To facilitate stable walking, humans must generate appropriate motor patterns and effective corrective responses to perturbations. Yet most EMG analyses do not address the continuous nature of muscle activation dynamics over multiple strides. We compared muscle activation dynamics in young and older adults by defining a multivariate state space for...
Article
Active control of trunk motion is believed to enable humans to maintain stability during walking, suggesting that stability of the trunk is prioritized over other segments by the nervous system. We investigated if superior segments are more stable than inferior segments during walking and if age-related differences are more prominent in any particu...
Article
Measures of local dynamic stability, such as the local divergence exponent (lambda*(s)) quantify how quickly small perturbations deviate from an attractor that defines the motion. When the governing equations of motion are unknown, an attractor can be reconstructed by defining an appropriate state space. However, state space definitions are not uni...
Article
Full-text available
The ability to identify physiologic fatigue and related changes in kinematics can provide an important tool for diagnosing fatigue-related injuries. This study examined an exhaustive cycling task to demonstrate how changes in movement kinematics and variability reflect underlying changes in local muscle states. Motion kinematics data were used to c...
Conference Paper
Full-text available
Both for civilian and military applications, tracking and identifying muscle fatigue—usually caused by continuous, repetitive motion over a finite period of time—is of great importance. The muscle fatigue process is very difficult to track due to its hidden nature. Invasive procedures are often needed to measure fatigue. Here, easily obtainable non...
Conference Paper
Full-text available
Both athletes and soldiers subject their body to extensive prolonged movements at the price of completing their tasks. The purpose of his study is to show that phase space warping (PSW) concept and smooth orthogonal decomposition (SOD) can be used to extract muscle fatigue related information from easily obtainable and noninvasive movement kinemati...
Article
Full-text available
Muscle fatigue may alter kinematics and contribute to repetitive strain injuries. This study quantified how both localized muscle fatigue and movement kinematics change over time during exhaustive cycling. Seven highly trained cyclists rode a stationary bicycle ergometer at 100% of their maximum oxygen consumption (VO(2) max) until voluntary exhaus...
Article
Falls pose a tremendous risk to those over 65 and most falls occur during locomotion. Older adults commonly walk slower, which many believe helps improve walking stability. While increased gait variability predicts future fall risk, increased variability is also caused by walking slower. Thus, we need to better understand how differences in age and...