Ronald F. Zernicke's research while affiliated with University of Michigan and other places
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Publications (194)
Background:
A mismatch between organizational priorities and system-level policies can negatively impact implementation and sustainment of classroom-based physical activity (PA) interventions. The purpose of this study was twofold: (1) present methods to systematically identify organization- and system-level implementation barriers, and (2) align...
The purpose of the current study was twofold: (1) to evaluate the strength and comprehensiveness of district wellness policies in one central Michigan intermediate school district (ISD; 16 districts), and (2) to pilot a novel policy alignment and enhancement process in one district within the ISD to improve sustainment of district-wide physical act...
Our objective was to systematically adapt Interrupting Prolonged sitting with ACTivity (InPACT), a classroom-based physical activity intervention, for home delivery to equitably increase access to structured youth physical activity opportunities during the COVID-19 pandemic. Key steps in the rapid-cycle research adaptation process included: (Step 1...
Objective
The purpose of this study was to identify patterns of clustering of the 10 health consequences identified in the Relative Energy Deficiency in Sport (RED-S) framework among collegiate female Cross-Country runners. We also assessed risk characteristics associated with each cluster.
Methods
This randomly sampled population included 211 cur...
Human evolution required adaptation to the boundary conditions of Earth, including 1 g gravity. The bipedal mobility of Homo sapiens in that gravitational field causes ground reaction force (GRF) loading of their lower extremities, influencing the integrity of the tissues of those extremities. However, humans usually experience such loading during...
Common in-lab, marker-based gait analyses may not represent daily, real-world gait. Real-world gait analyses may be feasible using inertial measurement units (IMUs), especially with recent advancements in open-source methods (e.g., OpenSense). Before using OpenSense to study real-world gait, we must determine whether these methods: (1) estimate joi...
![The estimates of the multiplicative effects [95% Wald CIs] were drawn...](profile/Sigrid-Olthof/publication/357062310/figure/tbl2/AS:1101348506480642@1639593354820/The-estimates-of-the-multiplicative-effects-95-Wald-CIs-were-drawn-from-the-Poisson_Q320.jpg)
Basketball games and training sessions are characterized by quick actions and many scoring attempts, which pose biomechanical loads on the bodies of the players. Inertial Measurement Units (IMUs) capture these biomechanical loads as PlayerLoad and Inertial Movement Analysis (IMA) and teams collect those data to monitor adaptations to training sched...
Quantifying player training loads allows football coaching staff to make informed adjustments to the volume and intensity of training. Physical workload intensity in American football practices have not been extensively quantified. The current study examined physical workload intensities across positions in American collegiate football during train...
Background:
The coronavirus disease 2019 (COVID-19) pandemic triggered a seismic shift in education, to online learning. With nearly 20 million students enrolled in colleges across the U.S., the long-simmering mental health crisis in college students was likely further exacerbated by the pandemic.
Objective:
This study leveraged mobile health (m...
BACKGROUND
The coronavirus disease 2019 (COVID-19) pandemic triggered a seismic shift in education, to online learning. With nearly 20 million students enrolled in colleges across the U.S., the long-simmering mental health crisis in college students was likely further exacerbated by the pandemic.
OBJECTIVE
This study leveraged mobile health (mHeal...
Running dynamical analyses typically approximate a runner's stance velocity as the average stride cycle velocity (the average running speed). That approximation necessarily overestimates stance velocity and biases subsequent results. Stance velocities are crucial in kinetic spring-mass analyses of running, where approximation of a runner's impact a...
Elite middle distance runners present as a unique population in which to explore biomechanical phenomena in relation to running speed, as their training and racing spans a broad spectrum of paces. However, there have been no comprehensive investigations of running mechanics across speeds within this population. Here, we used the spring-mass model o...
Background
Neuromuscular changes that occur with aging or joint pathology likely alter the coordinative strategies that adults use to walk and to recover from perturbations during gait. Differences in coordination patterns or in how coordination changes in response to a challenge may provide insight into neuromuscular targets for falls prevention i...
Runners are commonly modeled as spring-mass systems, but the traditional calculations of these models rely on discrete observations during the gait cycle (e.g., maximal vertical force) and simplifying assumptions (e.g., leg length), challenging the predicative capacity and generalizability of observations. We present a method to model runners as sp...
Objective
We aimed to describe current and former National Collegiate Athletic Association (NCAA) Division One (DI) female distance runners’ experiences of perceived norms of body image and disordered eating in their sport, as well as the emergence and influence of coach–athlete power dynamics.
This manuscript reports a qualitative research study (...
Lower propulsive joint powers, particularly at the ankle, are often observed in older compared to young adults. Interventions to increase joint powers often require labs with motion capture and force treadmill technology. Translating these interventions out of the lab requires identifying portable measures that track (i.e., strongly correlate with)...
It is widely acknowledged that achieving and maintaining a healthier lifestyle can be enhanced through regular participation in sport and physical activity. Coevally, a growing number of health professionals regard exercise as a legitimate intervention strategy for those who have lost their health. Exercise has been shown to be effective for overwe...
Differences in gait with age or knee osteoarthritis have been demonstrated in laboratory studies using optical motion capture (MoCap). While MoCap is accurate and reliable, it is impractical for assessment outside the laboratory. Inertial measurement units (IMUs) may be useful in these situations. Before IMUs are used as a surrogate for MoCap, meth...
This study explored whether player position in baseball influenced countermovement jumping strategies and their resultant force-time profiles. Subjects performed a series of three countermovement jumps on a force platform. Eccentric rate of force development (RFD), peak concentric force, countermovement depth and jump time variables were extracted...
This study explored whether player position in baseball influenced countermovement jumping strategies and their resultant force-time profiles. Subjects performed a series of three countermovement jumps on a force platform. Eccentric rate of force development (RFD), peak concentric force, countermovement depth and jump time variables were extracted...
Running is a popular activity that results in high rates of overuse injury, with less-experienced runners becoming injured at higher rates than their more-experienced peers. Although measures of joint kinematics and kinetics and ground reaction forces have been associated with overuse running injuries, similar differences across levels of running e...
Research question:
The current study investigated stride-to-stride fluctuations of step rate and contact time in response to enforced step frequency perturbations as well as adaptation and de-adaptation behavior.
Methods:
Forty distance runners ran at a self-selected speed and were asked to match five different enforced step frequencies (150, 16...
Forefoot strike is increasingly being adopted by runners because it can better attenuate impact than rearfoot strike. However, forefoot strike may overload the plantar fascia and alter the plantar fascia elasticity. This study aimed to use ultrasound elastography to investigate and compare shear wave elasticity of the plantar fascia between rearfoo...
Movement is essential to the human experience, and efficient biomechanics facilitate effective action across the breadth of tasks one encounters in life. The concept of movement efficiency has been investigated and explored through a variety of means including biomechanical modeling, simulation, and experimental manipulation. Observations of elite...
Step frequency (SF) in running has received substantial interest from researchers, coaches, therapists, and runners. It has been widely studied in controlled settings, but no published study has measured it continuously in elite-level competition. The present study used wrist-based accelerometers in consumer-grade watches to monitor SF and SF varia...
Ground reaction force measurements are a fundamental element of kinetic analyses of locomotion, yet they are traditionally constrained to laboratory settings or stationary frames. This study assessed the validity and reliability of a new wireless in-shoe system (Novel Loadsol/Pedoped) for field-based ground reaction force measurement in hopping, wa...
Biomechanical response to running footwear has been studied with regard to traditional shoes and, more recently, minimalist (MIN) shoes. Maximalist (MAX) shoes have grown in popularity as a highly-cushioned counterpoint to MIN shoes. However, little is known about the influence of MAX shoes on running biomechanics alone or in comparison to a MIN sh...
Inflammation can arise in response to a variety of stimuli, including infectious agents, tissue injury, autoimmune diseases, and obesity. Some of these responses are acute and resolve, while others become chronic and exert a sustained impact on the host, systemically, or locally. Obesity is now recognized as a chronic low-grade, systemic inflammato...
Purpose:
Increased running experience and more time spent running appears to be advantageous in reducing injury risk, although the reason behind this is unclear. It is plausible that more experience results in better running mechanics leading to less injuries. Running mechanics are often screened during clinical assessments and targeted for correc...
Background:
Ulnar collateral ligament (UCL) reconstruction surgeries in Major League Baseball (MLB) have increased significantly in recent decades. Although several risk factors have been proposed, a scientific consensus is yet to be reached, providing challenges to those tasked with preventing UCL injuries.
Purpose:
To identify significant pred...
This study aimed to quantify how ball flight kinematics (i.e., ball speed and movement), release location and variations therein relate to pitching success in Major League Baseball (MLB). 190 starting MLB pitchers met the inclusion criteria for this study. Ball trajectory information was collected for 76,000 pitches and inserted into a forward step...
With a view to informing in-game decision making as it relates to strategy and pitcher health, this study examined changes in pitching performance characteristics across nine innings of professional (MLB) baseball games.
129 starting MLB pitchers met the inclusion criteria for this study. Pitch type, speed, ball movement, release location, and stri...
Femoroacetabular impingement (FAI) is particularly prevalent in ice hockey. The butterfly goalie technique is thought to involve extreme ranges of hip motion that may predispose goaltenders to FAI.
To quantify hip mechanics during 3 common goaltender movements and interpret their relevance to the development of FAI.
Descriptive laboratory study.
Fo...
Although inter-and intra-tester reliability has been a common theme in Functional Movement Screen (FMS) research, the criterion validity of manual grading is yet to be comprehensively examined. This study aimed to compare the FMS scores assigned by a certified FMS tester to those measured by an objective inertial-based motion capture system (IMU)....
Background: Femoroacetabular impingement is a debilitating hip condition commonly affecting American football athletes. Femoroacetabular impingement is associated with reduced hip range of motion; however, little is known about the range-of-motion demands of football athletes. This knowledge is critical to effective management of this condition.
Pu...
Following an ankle injury, many patients have functional ankle instability (FAI) with an increased predisposition to reinjury. The purpose of this study was to assess the effects of FAI on ankle kinematics and muscle activity during a lateral hop movement.
Cross-sectional and observational study; all data collection for each subject was performed o...
Leptin signaling deficient rodents have emerged as models of obesity/insulin resistance syndrome. Altered leptin signaling, however, can affect axial and appendicular bone geometrical properties differently, and, thus, we hypothesized that leptin-deficiency would differentially influence mechanical properties of vertebrae and tibiae compared to lea...
Total hip replacement (THR) and total knee replacement (TKR) (arthroplasty) surgery for end-stage osteoarthritis (OA) are ideal candidates for optimization through an algorithmic care pathway. Using a comparative effectiveness study design, we compared the effectiveness of a new clinical pathway (NCP) featuring central intake clinics, dedicated inp...
High-frequency, low-magnitude vibration enhances bone formation ostensibly by mimicking normal postural muscle activity. We tested this hypothesis by examining whether daily exposure to low-magnitude vibration (VIB) would maintain bone in a muscle disuse model with botulinum toxin type A (BTX). Female 16-18 wk old BALB/c mice (N = 36) were assigned...
Ankle function is frequently measured using static or dynamic tasks in normal and injured patients. The purpose of this study was to develop a novel task to quantify ankle dynamics and muscle activity in normal subjects. Twelve subjects with no prior ankle injuries participated. Video motion analysis cameras, force platforms, and an EMG system were...
We previously showed that skim milk powder (SMP) prevents weight gain more so than casein or whey alone. Dairy foods and changes in body mass can affect bone architecture; therefore, our objective was to examine the effect of dairy proteins on bone structure in the tibia of dietary-induced obese rats.
Twelve-week-old diet-induced obese Sprague-Dawl...
The effectiveness of clinical measures to predict scoliotic progression is unclear. The objective of this study was to identify potential prognostic factors affecting scoliosis progression. Consecutive measurements (181) from 35 non-instrumented adolescent idiopathic scoliosis patients with at least two follow-up assessments were studied. Potential...
We examined changes in weight-bearing ability in mice after injection with botulinum toxin type A (BTX) to determine whether BTX can be used to isolate the effects of muscle on bone. As ambulation patterns were previously shown to improve within two weeks post-injection, we hypothesized that BTX injection to the posterior hindlimb would not signifi...
The sections in this article are:
As a field, biomechanics comprises research from the molecular and cellular levels, to tissues, to organs, to organisms and their movements. In the past 50 years, the impact of biomechanics research on society has been amplified dramatically. Here, we provide five brief summaries of exemplar biomechanics results that have had substantial impact on...
Scoliosis causes an abnormal three dimensional curvature of the spine that is often treated by an orthotic device called brace. The objective of this research was to develop a new approach to automatically identify the optimal design of custom-built brace, based on clinical and patient evaluations. In this approach, torso geometry of the scoliosis...
Adolescent idiopathic scoliosis (AIS) progression is clinically monitored by a series of full spinal X-rays. To decrease radiation exposure, an artificial progression surface (APS) is proposed to predict progression. Fifty-six acquisitions (posteroanterior radiographs, 0° and 20°) were obtained from 11 AIS patients (29.8 ± 9.6° Cobb angle). Three-d...
Studies to date have assumed that botulinum toxin type A (BTX) affects bone indirectly, through its action on muscle. We hypothesized that BTX has no discernable effect on bone morphometry, independent of its effect on muscle. Therefore, we investigated whether BTX had an additional effect on bone when combined with tenotomy compared to tenotomy in...
To determine whether treatment with an antiresorptive drug in combination with an antiinflammatory drug reduces periarticular bone and soft tissue adaptations associated with the progression of posttraumatic secondary osteoarthritis (OA).
We used in vivo microfocal computed tomography (micro-CT) to map bony adaptations and in vivo micro–magnetic re...
The purpose of this study was to determine whether a mineral-rich extract derived from the red marine algae Lithothamnion calcareum could be used as a dietary supplement for prevention of bone mineral loss. Sixty C57BL/6 mice were divided into three groups based on diet: the first group received a high-fat Western-style diet (HFWD), the second grou...
Exposure to diets high in fat and sucrose can induce hyperinsulinaemia, affect Ca and Mg metabolism, and alter bone mineralisation and mechanical properties. The present study assessed morphological and mechanical changes in a murine model exposed to a high-fat/sucrose (HFS) diet, as well as corresponding molecular and endocrine markers of bone tur...
If muscle force is a primary source for triggering bone adaptation, with disuse and reloading, bone changes should follow muscle changes. We examined the timing and magnitude of changes in muscle cross-sectional area (MCSA) and bone architecture in response to muscle inactivity following botulinum toxin (BTX) injection. We hypothesized that MCSA wo...
Each year, more than 30 million children and adolescents participate in organized sports in the United States (US), and more than 4.3 million nonfatal sports- and recreation-related injuries are treated in US hospital emergency departments. Two types of activity-related injuries, in particular, that we study in the Bone and Joint Injury Prevention...
A poroelastic lacunocanalicular model was developed for the quantification of physiologically relevant parameters related to bone fluid flow. The canalicular and lacunar microstructures were explicitly represented by a dual-continuum poroelastic model. Effective material properties were calculated using the theory of composite materials. Porosity a...
This study investigated the delivery of a model therapeutic protein, namely, osteoprotegerin (OPG), to bone sites in an animal model of osteoarthritis. The OPG was chemically conjugated to a "bone seeking" thiol-bisphosphonate (thiolBP) via a disulfide linkage. The BP conjugates of OPG were shown to display a higher hydroxyapatite affinity in vitro...
The Alberta Hip and Knee Replacement Project developed a new evidence-based clinical pathway (NCP) for total hip (THR) and knee (TKR) replacement. The aim was to facilitate the delivery of services in a timely and cost-effective manner while achieving the highest quality of care for the patient across the full continuum of care from patient referra...
This study examined the effects of caloric restriction on structural and material properties of tibiae and sixth lumbar vertebrae in F344BN male rats. Rats were divided into two dietary groups, ad libitum or calorie restricted. Caloric restriction commenced at 14 weeks of age, with 40% restriction and micronutrient supplementation by 16 weeks maint...
Compliant surfaces are used to challenge postural stability, but assessments are frequently limited to summary measures of center of pressure that do not provide insights into the temporal dynamics of motor coordination. Here, we measured center-of-pressure changes on three surfaces (solid, foam, and air-filled disc) and quantified the relative tim...
The purpose of this study was to investigate the preparation process of bone morphogenetic protein-2 (BMP-2) containing bovine serum albumin (BSA) nanoparticles (NPs), and to assess the bioactivity of BMP-2 encapsulated in such NPs.
The NPs were prepared by a coacervation method, and the effects of process parameters on NP size and polydispersity w...
By applying the principles and methods of mechanics to the musculoskeletal system, new insights can be discovered about control of human limb dynamics both in adults and infants. Here, we first provide a basic primer about biomechanics—its historical context, terminology, and analytical techniques. Next we review research with animals and human adu...
IntroductionBiomechanical ConceptsMechanisms of Upper-Extremity Injuries in AthletesSummaryReferences
Bone changes in experimental post-traumatic osteoarthritis occur early after transection of the anterior cruciate. The purpose of this study was to determine whether antiresorptive bisphosphonate therapy could slow or arrest the periarticular bone architecture and mechanical properties in a post-traumatic model of knee osteoarthritis.
Skeletally ma...
Load-induced fluid flow is a key factor in triggering bone modeling and remodeling processes that maintain bone mass and architecture. To provide an enhanced understanding of fluid flow in bone, unique computational models of a tibial section were developed. The purpose of the study was to examine the effects of incorporating vascular porosity on p...
BoneTendons and ligamentsMeniscusConcluding commentsReferences
Safety or comfort? Can you truly have one without the other? Is it feasible to have both? Although by no means the only factor, a deep understanding of biomechanics plays a leading role in the design of work and workplaces that are both pain and injury free. Standing firmly on the foundation built by the previous edition, the second edition of Biom...
This study aimed to estimate the reliability of 3-D trunk surface measurements for the characterization of external asymmetry associated with scoliosis. Repeated trunk surface acquisitions using the Inspeck system (Inspeck Inc., Montreal, Canada), with two different postures A (anatomical position) and B (''clavicle'' position), were obtained from...
Creatine kinase, found in osteoblasts, is an enzyme that is upregulated in response to interventions that enhance bone mass accretion. Creatine monohydrate supplementation can increase fat-free mass in young healthy men and women and can reduce markers of bone breakdown in boys with Duchenne muscular dystrophy.
The objective of this study was to de...
Basic fibroblast growth factor (bFGF) is a potent mitogen that exhibits stimulatory effects on bone tissue regeneration. To gain further insight into the potential of bFGF for systemic therapy in osteoporosis, we investigated the responsiveness of bone marrow stromal cells (BMSCs) explanted from 7-month-old normal and ovariectomized (OVX) rats that...
Exercise-induced mechanical loading can have potent effects on skeletal form and health. Both intrinsic and extrinsic factors contribute to bone structure and function. Mechanical simuli (e.g., strain magnitude, frequency, rate, and gradients, as well as fluid flow and shear stress) have potent influences on bone-cell cytoskeleton and associated si...
