23 results on '"van Werkhoven H"'
Search Results
2. The Automation Plans of the Music Library of the Nederlandse Omroep Stichting (Dutch Broadcasting Foundation)
- Author
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VAN WERKHOVEN, H. B. M.
- Published
- 1977
3. The Effect of Different Weight Plate Widths (Bumper vs. Standard) on the Biomechanics of the Bench Press.
- Author
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Fiedler MJ, Triplett NT, Hamilton KC, Needle AR, and van Werkhoven H
- Subjects
- Humans, Biomechanical Phenomena, Pectoralis Muscles physiology, Electromyography, Weight Lifting physiology, Muscle Strength physiology, Muscle, Skeletal physiology, Resistance Training
- Abstract
Abstract: Fiedler, MJ, Triplett, NT, Hamilton, KC, Needle, AR, and van Werkhoven, H. The effect of different weight plate widths (bumper vs. standard) on the biomechanics of the bench press. J Strength Cond Res 38(4): e143-e149, 2024-Anecdotal evidence suggests that bumper plates impact lifts in powerlifting and weightlifting differently than standard cast iron plates, but whether biomechanical differences exist between lifts using bumper versus standard plates has not been investigated. Eleven resistance-trained subjects performed the bench press at 70, 80, and 90% of their 1 repetition maximum (1RM) while being blinded to whether they were lifting with bumper or standard plates. Motion data were captured by an 8-camera motion capture system, and electromyography (EMG) data were recorded for the anterior deltoid, pectoralis major, and triceps brachii. Repeated-measures analysis of variances showed a significant main weight effect for time under tension (p < 0.001), total work (p < 0.001), and muscle activity through EMG (across all muscles; p < 0.001) and a significant weight × joint interaction effect for average joint moment (p < 0.001) and peak joint moment (p < 0.001). However, there were no significant differences observed between the different weight plates for any of the measures. The main finding of the study suggests that there are no biomechanical differences between using bumper plates compared with standard plates during the bench press lift., (Copyright © 2023 National Strength and Conditioning Association.)
- Published
- 2024
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4. Effects of COVID-19 vaccination and previous infection on Omicron SARS-CoV-2 infection and relation with serology.
- Author
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de Gier B, Huiberts AJ, Hoeve CE, den Hartog G, van Werkhoven H, van Binnendijk R, Hahné SJM, de Melker HE, van den Hof S, and Knol MJ
- Subjects
- Adult, Humans, COVID-19 Vaccines, Cohort Studies, Prospective Studies, SARS-CoV-2, Vaccination, COVID-19 prevention & control
- Abstract
An increasing proportion of the population has acquired immunity through COVID-19 vaccination and previous SARS-CoV-2 infection, i.e., hybrid immunity, possibly affecting the risk of new infection. We aim to estimate the protective effect of previous infections and vaccinations on SARS-CoV-2 Omicron infection, using data from 43,257 adult participants in a prospective community-based cohort study in the Netherlands, collected between 10 January 2022 and 1 September 2022. Our results show that, for participants with 2, 3 or 4 prior immunizing events (vaccination or previous infection), hybrid immunity is more protective against infection with SARS-CoV-2 Omicron than vaccine-induced immunity, up to at least 30 weeks after the last immunizing event. Differences in risk of infection are partly explained by differences in anti-Spike RBD (S) antibody concentration, which is associated with risk of infection in a dose-response manner. Among participants with hybrid immunity, with one previous pre-Omicron infection, we do not observe a relevant difference in risk of Omicron infection by sequence of vaccination(s) and infection. Additional immunizing events increase the protection against infection, but not above the level of the first weeks after the previous event., (© 2023. Springer Nature Limited.)
- Published
- 2023
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5. Muva physical activity intervention to improve social functioning in people with a severe mental illness: study protocol of a pragmatic stepped wedge cluster randomized trial.
- Author
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Koomen LEM, van de Meent IHT, Deenik J, van Dellen E, Schnack HG, van Werkhoven H, Swildens WE, van Meijel B, Staal W, Jörg F, Scheepers F, and Cahn W
- Subjects
- Humans, Social Interaction, Exercise, Life Style, Randomized Controlled Trials as Topic, Quality of Life, Mental Disorders therapy, Mental Disorders psychology
- Abstract
Background: People with severe mental illness (SMI) often suffer from long-lasting symptoms that negatively influence their social functioning, their ability to live a meaningful life, and participation in society. Interventions aimed at increasing physical activity can improve social functioning, but people with SMI experience multiple barriers to becoming physically active. Besides, the implementation of physical activity interventions in day-to-day practice is difficult. In this study, we aim to evaluate the effectiveness and implementation of a physical activity intervention to improve social functioning, mental and physical health., Methods: In this pragmatic stepped wedge cluster randomized controlled trial we aim to include 100 people with SMI and their mental health workers from a supported housing organization. The intervention focuses on increasing physical activity by implementing group sports activities, active guidance meetings, and a serious game to set physical activity goals. We aim to decrease barriers to physical activity through active involvement of the mental health workers, lifestyle courses, and a medication review. Participating locations will be divided into four clusters and randomization will decide the start of the intervention. The primary outcome is social functioning. Secondary outcomes are quality of life, symptom severity, physical activity, cardiometabolic risk factors, cardiorespiratory fitness, and movement disturbances with specific attention to postural adjustment and movement sequencing in gait. In addition, we will assess the implementation by conducting semi-structured interviews with location managers and mental health workers and analyze them by direct content analysis., Discussion: This trial is innovative since it aims to improve social functioning in people with SMI through a physical activity intervention which aims to lower barriers to becoming physically active in a real-life setting. The strength of this trial is that we will also evaluate the implementation of the intervention. Limitations of this study are the risk of poor implementation of the intervention, and bias due to the inclusion of a medication review in the intervention that might impact outcomes., Trial Registration: This trial was registered prospectively in The Netherlands Trial Register (NTR) as NTR NL9163 on December 20, 2020. As the The Netherlands Trial Register is no longer available, the trial can now be found in the International Clinical Trial Registry Platform via: https://trialsearch.who.int/Trial2.aspx?TrialID=NL9163 ., (© 2022. The Author(s).)
- Published
- 2022
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6. Can Foot Anthropometry Predict Vertical Jump Performance?
- Author
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Hawley VS, Gurchiek RD, and van Werkhoven H
- Subjects
- Adult, Anthropometry, Female, Foot, Humans, Male, Muscle Strength, Young Adult, Athletic Performance, Sports
- Abstract
Abstract: Hawley, VS, Gurchiek, RD, and van Werkhoven, H. Can foot anthropometry predict vertical jump performance? J Strength Cond Res 36(7): 1860-1865, 2022-Vertical jumping is an important element of many sporting activities, and whether anthropometric adaptations can predict jumping performance is of interest. Few studies have specifically considered anthropometric measures of the foot and its link to performance. Furthermore, previous studies have mainly focused on a male subject pool, and whether relationships are consistent across sexes is unclear. The purpose of this study was to investigate relationships between common anthropometric measures, as well as specific foot measures, and jump performance in men and women. Anthropometric measures of 21 men (age: 22.0 ± 1.5 years; stature: 181.4 ± 6.3 cm; body mass: 85.6 ± 9.4 kg) and 21 women (age: 21.2 ± 1.8 years; stature: 166.1 ± 7.5 cm; body mass: 61.4 ± 11.4 kg) were taken before performing 3 maximal countermovement jumps (CMJs). Correlational analysis was used to determine relationships between anthropometric measures and CMJ height (a priori significance set at p≤ 0.05, effect size: small >0.1; medium >0.3; large >0.5). There was no significant correlation between anthropometric variables and CMJ height for men, whereas for women, mass (r = -0.585, p = 0.005, large effect), foot length (r = -0.533, p = 0.013, large effect), and toe length (r = -0.604, p = 0.004, large effect) showed significant negative correlations with CMJ height. The unexpected result that smaller feet and toes predicted higher jumps for women warrants further investigation. Furthermore, these results highlight the need to incorporate diverse subject pools, and a need for caution when generalizing across sexes., (Copyright © 2020 National Strength and Conditioning Association.)
- Published
- 2022
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7. The effects of 72 h of dynamic ankle immobilization on neural excitability and lower extremity kinematics.
- Author
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Cash JJ, van Werkhoven H, Cole KJ, and Needle AR
- Subjects
- Ankle Joint physiology, Biomechanical Phenomena, Cross-Over Studies, Humans, Lower Extremity physiology, Muscle, Skeletal physiology, Ankle, Motor Cortex
- Abstract
Background: Ankle injuries can foster maladaptive changes in nervous system function that predisposes patients to subsequent injury. Patients are often placed in a dynamic boot immobilizer (BI) following injury; however, little is known about the effects of this treatment on neuromechanical function., Research Question: We aimed to determine the effect of 72 h of BI-use on neural excitability and lower extremity joint motion in a healthy cohort., Methods: Twelve uninjured individuals (20.8 ± 1.4 yrs, 1.7 ± 0.1 m, 75.2 ± 9.9 kg) participated in this crossover study. Neural excitability and lower extremity kinematics were assessed before and after 72 h of BI or compression sock (CS) use. Neural excitability was assessed via the Hoffmann (H) reflex and transcranial magnetic stimulation of the motor cortex by measuring muscle activation at the tibialis anterior, peroneus longus, and soleus of the immobilized extremity. Three-dimensional lower extremity joint angles were assessed while participants walked on a treadmill. Repeated-measures analyses of variance detected changes in neural excitability and peak joint angles across time-points and testing conditions, while statistical parametric mapping (SPM) was implemented to determine continuous joint angle changes (α = 0.05)., Results: Pre-BI to post-BI, H
Max :MMax ratio (F = 6.496; p = 0.031) significantly decreased. The BI did not alter resting motor threshold (F = 0.601; p = 0.468), or motor evoked potential amplitudes (F > 2.82; p > 0.608). Significant changes in peak knee and hip angles in the frontal and transverse planes were observed (p < 0.05), with no changes at the ankle. SPM analyses revealed significant hip and knee changes in range of motion (p < 0.05)., Significance: Decreased measures of reflex but not corticospinal excitability suggest that BI-use for 72 h unloaded the joint enough to generate peripheral changes, but not the CNS, as has been described in casting models. Further, kinematic changes were observed in proximal lower extremity joints, likely due to swing-phase adaptations while wearing the BI., (Copyright © 2022 Elsevier B.V. All rights reserved.)- Published
- 2022
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8. Continuous Tracking of Foot Strike Pattern during a Maximal 800-Meter Run.
- Author
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Farina KA, Needle AR, and van Werkhoven H
- Subjects
- Biomechanical Phenomena, Female, Foot, Gait, Humans, Male, Running
- Abstract
(1) Background: Research into foot strike patterns (FSP) has increased due to its potential influence on performance and injury reduction. The purpose of this study was to evaluate changes in FSP throughout a maximal 800-m run using a conformable inertial measurement unit attached to the foot; (2) Methods: Twenty-one subjects (14 female, 7 male; 23.86 ± 4.25 y) completed a maximal 800-m run while foot strike characteristics were continually assessed. Two measures were assessed across 100-m intervals: the percentage of rearfoot strikes (FSP
%RF ), and foot strike angle (FSA). The level of significance was set to p ≤ 0.05; (3) Results: There were no differences in FSP%RF throughout the run. Significant differences were seen between curve and straight intervals for FSAAVE (F [1, 20] = 18.663, p < 0.001, ηp 2 = 0.483); (4) Conclusions: Participants displayed decreased FSA, likely indicating increased plantarflexion, on the curve compared to straight intervals. The analyses of continuous variables, such as FSA, allow for the detection of subtle changes in foot strike characteristics, which is not possible with discrete classifiers, such as FSP%RF .- Published
- 2021
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9. The Effects of Transcranial Direct Current Stimulation on Chronic Ankle Instability.
- Author
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Bruce AS, Howard JS, VAN Werkhoven H, McBride JM, and Needle AR
- Subjects
- Chronic Disease, Combined Modality Therapy, Evoked Potentials, Motor physiology, Feasibility Studies, Female, Humans, Male, Muscle Strength physiology, Patient Reported Outcome Measures, Postural Balance physiology, Single-Blind Method, Young Adult, Ankle physiopathology, Exercise Therapy methods, Joint Instability physiopathology, Joint Instability therapy, Motor Cortex physiology, Resistance Training, Transcranial Direct Current Stimulation
- Abstract
Purpose: Given maladaptive neuroplasticity after musculoskeletal injury, interventions capable of restoring corticospinal excitability should be considered. We therefore aimed to determine if a 4-wk intervention of anodal transcranial direct current stimulation (aTDCS) with eccentric exercise would improve neural excitability, functional performance, and patient-reported function in individuals with chronic ankle instability (CAI)., Methods: Twenty-six individuals with CAI were recruited to undergo 4 wk of eccentric evertor strengthening. Subjects were randomized into aTDCS (n = 13) and sham (n = 13) groups, where the aTDCS group received 18 min of aTDCS (1.5 mA) over the primary motor cortex. Participants were assessed for cortical excitability, dynamic balance, muscle activation, functional performance, strength, and patient-reported function at baseline, week 2, week 4, and week 6., Results: Twenty-two subjects completed the training and test sessions. Cortical excitability (resting motor threshold) to peroneus longus in aTDCS increased from baseline (36.92 ± 11.53) to week 6 (32.91 ± 12.33, P = 0.024), whereas sham increased excitability from baseline (36.67 ± 12.74) to week 2 (27.86 ± 14.69, P = 0.007), but decreased at week 4 (35.63 ± 13.10, P = 0.022) and week 6 (35.99 ± 13.52, P = 0.006). Dynamic balance and muscle activation also improved in the aTDCS group from baseline to week 6 (P = 0.034). Functional performance on a side-hop test increased in all participants from baseline to week 2 (P = 0.003). The aTDCS group had decreased perceived disablement from week 2 (18.09 ± 6.41) to week 4 (15.55 ± 4.82, P = 0.046), whereas the sham group reported increased disablement from baseline (17.91 ± 4.59) to week 2 (21.00 ± 8.52, P = 0.047)., Conclusions: Our results provide preliminary evidence that 4 wk of eccentric training with aTDCS improves cortical excitability, functional performance, and patient-reported function in individuals with CAI. These data are the first to show the efficacy of noninvasive brain stimulation therapies in patients with musculoskeletal injury, and demonstrate the link between improved neural excitability and functional outcomes.
- Published
- 2020
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10. Using A Soft Conformable Foot Sensor to Measure Changes in Foot Strike Angle During Running.
- Author
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van Werkhoven H, Farina KA, and Langley MH
- Abstract
The potential association between running foot strike analysis and performance and injury metrics has created the need for reliable methods to quantify foot strike pattern outside the laboratory. Small, wireless inertial measurement units (IMUs) allow for unrestricted movement of the participants. Current IMU methods to measure foot strike pattern places small, rigid accelerometers and/or gyroscopes on the heel cap or on the instep of the shoe. The purpose of this study was to validate a thin, conformable IMU sensor placed directly on the dorsal foot surface to determine foot strike angles and pattern. Participants (n = 12) ran on a treadmill with different foot strike patterns while videography and sensor data were captured. Sensor measures were compared against traditional 2D video analysis techniques and the results showed that the sensor was able to accurately (92.2% success) distinguish between rearfoot and non-rearfoot foot strikes using an angular velocity cut-off value of 0°/s. There was also a strong and significant correlation between sensor determined foot strike angle and foot strike angle determined from videography analysis ( r = 0.868, p < 0.001), although linear regression analysis showed that the sensor underestimated the foot strike angle. Conformable sensors with the ability to attach directly to the human skin could improve the tracking of human dynamics and should be further explored.
- Published
- 2019
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11. Fosfomycin-trometamol for Urinary Tract Infections in Kidney Transplant Recipients.
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Ten Doesschate T, van Werkhoven H, Meijvis S, Stalenhoef J, van Zuilen A, de Vries A, and Bonten M
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- Aged, Anti-Bacterial Agents adverse effects, Drug Resistance, Bacterial, Female, Fosfomycin adverse effects, Humans, Immunocompromised Host, Male, Middle Aged, Netherlands, Opportunistic Infections immunology, Opportunistic Infections microbiology, Recurrence, Remission Induction, Retrospective Studies, Time Factors, Treatment Outcome, Urinary Tract Infections immunology, Urinary Tract Infections microbiology, Anti-Bacterial Agents therapeutic use, Fosfomycin therapeutic use, Kidney Transplantation adverse effects, Opportunistic Infections drug therapy, Urinary Tract Infections drug therapy
- Abstract
Background: The treatment of urinary tract infections (UTIs) in kidney transplant recipients (KTRs) with oral antibiotics is complicated by increasing resistance to trimethoprim-sulfamethoxazole, amoxicillin/clavulanic acid, and ciprofloxacin. Fosfomycin-trometamol (FT) could be an alternative, but evidence on clinical effectiveness is scarce. We evaluated the use, effectiveness and safety of FT for UTI in KTRs., Methods: Data were retrospectively collected in 2 Dutch transplant hospitals from adult KTRs that were treated with FT as initial treatment for lower UTI or asymptomatic bacteriuria (ASB) or as stepdown treatment for upper UTI after initial intravenous antibiotics. Exclusion criteria were in vitro resistance to FT or concomitant antibiotic treatment. Endpoints were clinical cure within 14 days and severe clinical failure, microbiological cure, relapse, recurrence, and acquired resistance within 90 days postend of treatment., Results: Fifty-three episodes in 40 KTRs were included (ASB, n = 15; lower UTI, n = 33; upper UTI, n = 5). Fosfomycin-trometamol was used for a median short duration in a heterogeneous gift interval. Fosfomycin-trometamol resulted in microbiological cure in 25%, 28%, and 100% of ASB, lower UTI and upper UTI with initial positive culture and follow-up culture performed, respectively. Clinical cure rates were 67% for lower UTI and 80% for upper UTI. Relapses or recurrences occurred in 31% and 24% of symptomatic UTI episodes, without severe clinical failure. Acquired resistance to fosfomycin was observed in 6 episodes., Conclusions: Fosfomycin-trometamol has a reasonable effectiveness as last-resort oral treatment for lower UTI and stepdown treatment for upper UTI in KTRs. Randomized controlled trials with optimal dosage regimens are warranted. Use of FT is not recommended for ASB.
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- 2019
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12. Sprint Assessment Using Machine Learning and a Wearable Accelerometer.
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Gurchiek RD, Rupasinghe Arachchige Don HS, Pelawa Watagoda LCR, McGinnis RS, van Werkhoven H, Needle AR, McBride JM, and Arnholt AT
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- Adolescent, Biomechanical Phenomena, Female, Humans, Linear Models, Male, Young Adult, Accelerometry, Athletic Performance, Machine Learning, Running, Wearable Electronic Devices
- Abstract
Field-based sprint performance assessments rely on metrics derived from a simple model of sprinting dynamics parameterized by 2 constants, v
0 and τ, which indicate a sprinter's maximal theoretical velocity and the time it takes to approach v0 , respectively. This study aims to automate sprint assessment by estimating v0 and τ using machine learning and accelerometer data. To this end, photocells recorded 10-m split times of 28 subjects for three 40-m sprints while wearing an accelerometer around the waist. Features extracted from the accelerometer data were used to train a classifier to identify the sprint start and regression models to estimate the sprint model parameters. Estimates of v0 , τ, and 30-m sprint time (t30 ) were compared between the proposed method and a photocell method using root mean square error and Bland-Altman analysis. The root mean square error of the sprint start estimate was .22 seconds and ranged from .52 to .93 m/s for v0 , .14 to .17 seconds for τ, and .23 to .34 seconds for t30 . Model-derived sprint performance metrics from most regression models were significantly (P < .01) correlated with t30 . Comparison of the proposed method and a physics-based method suggests pursuit of a combined approach because their strengths appear to complement each other.- Published
- 2019
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13. Lower Leg Morphology and Stretch-Shortening Cycle Performance of Dancers.
- Author
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Rice PE, van Werkhoven H, Merritt EK, and McBride JM
- Subjects
- Adaptation, Physiological, Adolescent, Ankle Joint physiology, Bone Density, Case-Control Studies, Female, Humans, Muscle Strength, Stress, Mechanical, Young Adult, Dancing physiology, Leg physiology, Movement, Muscle Contraction
- Abstract
Greater levels of bone ultimate fracture load, bone stress-strain index, muscle cross-sectional area, and maximal voluntary isometric plantarflexion (MVIP) strength of the lower leg may be adaptations from chronic exposure to stretch-shortening cycle (SSC) actions. Dancers, a population that habitually performs SSC movements primarily about the ankle joint, may serve as a novel population to gain broader understanding of SSC function. A total of 10 female collegiate dancers and 10 untrained controls underwent peripheral quantitative computed tomography scans of both lower legs and performed MVIPs, countermovement hops, and drop hops at 20, 30, and 40 cm on a custom-made inclined sled. Dancers had greater right and left ultimate fracture load values and significantly (P ≤ .05) greater left leg stress-strain index than controls. Dancers had significantly larger right and left muscle cross-sectional area and MVIP values and hopped significantly higher during all hopping conditions in comparison with controls. Average force-time and power-time curves revealed significantly greater relative force and power measurements during the concentric phase for all hopping conditions in dancers when compared with controls. This investigation provides evidence that dance may be a stimulus for positive muscle and bone adaptations, strength levels, and enhanced SSC capabilities.
- Published
- 2018
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14. Gastrocnemius fascicle and achilles tendon length at the end of the eccentric phase in a single and multiple countermovement hop.
- Author
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Lidstone DE, van Werkhoven H, Needle AR, Rice PE, and McBride JM
- Subjects
- Adolescent, Adult, Humans, Male, Muscle Contraction, Achilles Tendon physiology, Movement, Muscle, Skeletal physiology
- Abstract
The purpose of this investigation was to compare fascicle and tendon length of the gastrocnemius at the end of the eccentric phase during a hop utilizing a single countermovement (sCM) versus multiple countermovement (mCM1, mCM2, mCM3) strategy. Seventeen healthy males performed nine hopping trials of sCM and nine trials of mCM. Ankle and knee joint angle and lower leg length from videography and muscle ultrasound were used to calculate muscle-tendon unit (MTU), fascicle and tendon length. Sacral marker data was used to determine hopping height. Force- and displacement-time curves were utilized to calculate work. Muscle activity of the lateral and medial gastrocnemius was also measured. Fascicle length was significantly shorter (mCM3: 6.2 ± 1.5 cm, sCM: 7.3 ± 2.0 cm) and tendon length was significantly longer (mCM3: 36.5 ± 3.6 cm, sCM: 35.5 ± 3.8 cm) at the end of the eccentric phase in mCM3 in comparison to sCM. Maximal hopping height (mCM: 14.6 ± 3.1 cm, sCM: 13.1 ± 2.5 cm), eccentric phase gastrocnemius muscle activity (mCM medial gastrocnemius: 0.10 ± 0.03 mV, mCM lateral gastrocnemius: 0.08 ± 0.04 mV, sCM medial gastrocnemius: 0.07 ± 0.03 mV, sCM lateral gastrocnemius: 0.05 ± 0.04 mV), and both eccentric (mCM3: 46.6 ± 19.4 J, sCM: 38.5 ± 15.9 J) and concentric work (mCM3: 87.6 ± 26.5 J, sCM: 80.9 ± 27.6 J) were significantly higher for mCM3 compared to sCM. The results indicate that a multiple countermovement hop strategy results in shorter fascicle length and longer tendon length at the end of the eccentric phase. In addition, greater eccentric phase muscle activity during the third countermovement (mCM3) in comparison to a single countermovement hop (sCM) was observed. A multiple countermovement strategy appears to result in higher hopping height and greater work done in both the eccentric and concentric phase indicating possible contribution of stored-elastic energy from the tendon., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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15. A Comparison of Musculo-Articular Stiffness and Maximal Isometric Plantar Flexion and Knee Extension Force in Dancers and Untrained Individuals.
- Author
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Rice PE, van Werkhoven H, Dejournette DJ, Gurchiek RD, Mackall JW, and McBride JM
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- Biomechanical Phenomena, Exercise physiology, Female, Humans, Range of Motion, Articular physiology, Reflex, Stretch physiology, Young Adult, Dancing physiology, Isometric Contraction physiology, Muscle Contraction physiology, Muscle, Skeletal physiology
- Abstract
Dance involves a high volume of aesthetic, stretch-shortening cycle (SSC) actions, which may cause unique adaptations to performance. The strength dancers possess to withstand such frequency of SSCs remains elusive. The extensive training that dancers experience from a young age, however, yields anatomical and strength development that may contrast with that of untrained individuals. Therefore, the purpose of this study was to investigate differences in musculo-articular stiffness and maximal isometric plantar flexion and knee extension force between dancers and untrained individuals. A total of 16 females volunteered to participate in the study (N = 8 dancers; N = 8 untrained individuals). Dancers had a minimum of 10 years of dance experience and were currently training at the collegiate dance level three or more times per week. Untrained individuals had no dance background, nor were they currently involved in any form of regularized physical activity. All subjects completed a series of lower leg measurements and strength tests. This included a musculo-articular stiffness measurement using a free-oscillation technique, along with maximal isometric plantar flexion (MIP) and maximal isometric knee extension (MIKE) testing. The data indicate that dancers had a significantly greater rate of force development and peak force during MIP and rate of force development during MIKE in comparison to untrained individuals. Dancers also possessed significantly greater musculo-articular stiffness. Hence, the data provide some evidence that involvement in dance can result in greater muscle force generating capacity and musculo-articular stiffness due to the SSC mechanisms involved in dance movements.
- Published
- 2017
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16. Does Foot Anthropometry Predict Metabolic Cost During Running?
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van Werkhoven H and Piazza SJ
- Subjects
- Achilles Tendon anatomy & histology, Achilles Tendon physiology, Biomechanical Phenomena, Body Weight physiology, Humans, Male, Oxygen Consumption physiology, Predictive Value of Tests, Young Adult, Ankle Joint anatomy & histology, Ankle Joint physiology, Anthropometry methods, Energy Metabolism physiology, Foot anatomy & histology, Foot physiology, Running physiology
- Abstract
Several recent investigations have linked running economy to heel length, with shorter heels being associated with less metabolic energy consumption. It has been hypothesized that shorter heels require larger plantar flexor muscle forces, thus increasing tendon energy storage and reducing metabolic cost. The goal of this study was to investigate this possible mechanism for metabolic cost reduction. Fifteen male subjects ran at 16 km⋅h
-1 on a treadmill and subsequently on a force-plate instrumented runway. Measurements of oxygen consumption, kinematics, and ground reaction forces were collected. Correlational analyses were performed between oxygen consumption and anthropometric and kinetic variables associated with the ankle and foot. Correlations were also computed between kinetic variables (peak joint moment and peak tendon force) and heel length. Estimated peak Achilles tendon force normalized to body weight was found to be strongly correlated with heel length normalized to body height (r = -.751, p = .003). Neither heel length nor any other measured or calculated variable were correlated with oxygen consumption, however. Subjects with shorter heels experienced larger Achilles tendon forces, but these forces were not associated with reduced metabolic cost. No other anthropometric and kinetic variables considered explained the variance in metabolic cost across individuals.- Published
- 2017
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17. The use of a single inertial sensor to estimate 3-dimensional ground reaction force during accelerative running tasks.
- Author
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Gurchiek RD, McGinnis RS, Needle AR, McBride JM, and van Werkhoven H
- Subjects
- Accelerometry, Adult, Algorithms, Biomechanical Phenomena, Female, Humans, Male, Posture, Young Adult, Running physiology
- Abstract
The purpose of this investigation was to determine the feasibility of using a single inertial measurement unit (IMU) placed on the sacrum to estimate 3-dimensional ground reaction force (F) during linear acceleration and change of direction tasks. Force plate measurements of F and estimates from the proposed IMU method were collected while subjects (n=15) performed a standing sprint start (SS) and a 45° change of direction task (COD). Error in the IMU estimate of step-averaged component and resultant F was quantified by comparison to estimates from the force plate using Bland-Altman 95% limits of agreement (LOA), root mean square error (RMSE), Pearson's product-moment correlation coefficient (r), and the effect size (ES) of the differences between the two systems. RMSE of the IMU estimate of step-average F ranged from 37.70 N to 77.05 N with ES between 0.04 and 0.47 for SS while for COD, RMSE was between 54.19 N to 182.92 N with ES between 0.08 and 1.69. Correlation coefficients between the IMU and force plate measurements were significant (p≤0.05) for all values (r=0.53 to 0.95) except the medio-lateral component of step-average F. The average angular error in the IMU estimate of the orientation of step-average F was ≤10° for all tasks. The results of this study suggest the proposed IMU method may be used to estimate sagittal plane components and magnitude of step-average F during a linear standing sprint start as well as the vertical component and magnitude of step-average F during a 45° change of direction task., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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18. Physiological and Biomechanical Responses to Prolonged Heavy Load Carriage During Level Treadmill Walking in Females.
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Lidstone DE, Stewart JA, Gurchiek R, Needle AR, van Werkhoven H, and McBride JM
- Subjects
- Absorptiometry, Photon, Anthropometry methods, Exercise Test, Female, Heart Rate physiology, Humans, Muscle Fatigue physiology, Oxygen Consumption physiology, Young Adult, Biomechanical Phenomena physiology, Walking physiology, Weight-Bearing physiology
- Abstract
Heavy load carriage has been identified as a main contributing factor to the high incidence of overuse injuries in soldiers. Peak vertical ground reaction force (VGRF
MAX ) and maximal vertical loading rates (VLRMAX ) may increase during heavy prolonged load carriage with the development of muscular fatigue and reduced shock attenuation capabilities. The objectives of the current study were (1) to examine physiological and biomechanical changes that occur during a prolonged heavy load carriage task, and (2) to examine if this task induces neuromuscular fatigue and changes in muscle architecture. Eight inexperienced female participants walked on an instrumented treadmill carrying operational loads for 60 minutes at 5.4 km·h-1 . Oxygen consumption ( V ˙ O 2 ), heart rate, rating of perceived exertion (RPE), trunk lean angle, and ground reaction forces were recorded continuously during task. Maximal force and in-vivo muscle architecture were assessed pre- and posttask. Significant increases were observed for VGRFMAX , VLRMAX , trunk lean angle, [Formula: see text], heart rate, and RPE during the task. Increased vastus lateralis fascicle length and decreased maximal force production were also observed posttask. Prolonged heavy load carriage, in an inexperienced population carrying operational loads, results in progressive increases in ground reaction force parameters that have been associated with overuse injury.- Published
- 2017
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19. Foot structure is correlated with performance in a single-joint jumping task.
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van Werkhoven H and Piazza SJ
- Subjects
- Adult, Body Weights and Measures, Humans, Male, Young Adult, Foot anatomy & histology, Foot physiology, Movement physiology
- Abstract
Variability in musculoskeletal structure has the potential to influence locomotor function. It has been shown, for example, that sprinters have smaller Achilles tendon moment arms and longer toes than non-sprinters, and toe length has been found to correlate with toe flexor work in running humans. These findings suggest that interindividual variation in human foot structure allows for function that is adapted to various motor tasks. The purpose of this study was to test for correlations between foot anthropometry and single-joint maximal-height jumping performance. Ten male subjects performed static jumps using only their ankles for propulsion. Several anthropometric measures were taken. Bivariate correlation analyses were performed between all anthropometric variables and the average jump height for each subject. Results showed that the best jumpers had longer lateral heel lengths (r=0.871; p=0.001) and longer toes (r=0.712; p=0.021). None of the other anthropometric variables (stature, mass, lower extremity lengths) measured were found to correlate significantly with jump height. A factor analysis was performed to investigate whether some underlying feature related to body stature could explain jumping performance. Taller subjects did not necessarily jump higher. Specific variations in foot structure, unrelated to other general stature measures, were associated with performance in this single-joint jumping task., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
20. Medial gastrocnemius muscle-tendon interaction and architecture change during exhaustive hopping exercise.
- Author
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Lidstone DE, van Werkhoven H, Stewart JA, Gurchiek R, Burris M, Rice P, Feimster G, and McBride JM
- Subjects
- Adaptation, Physiological physiology, Adult, Electromyography methods, Energy Metabolism physiology, Humans, Male, Movement physiology, Muscle Contraction physiology, Muscle Fatigue physiology, Young Adult, Exercise physiology, Muscle, Skeletal diagnostic imaging, Muscle, Skeletal physiology, Plyometric Exercise methods, Tendons diagnostic imaging, Tendons physiology
- Abstract
Background: Previous literature has shown in vivo changes in muscle-tendon interaction during exhaustive stretch-shortening cycle (SSC) exercise. It is unclear whether these changes in muscle-tendon length during exhaustive SSC exercise are associated with changes in mechanical efficiency (ME). The purpose of the study was to investigate whether changes in platarflexor contractile component (CC) length, tendon length, and changes in plantarflexor muscle activity could explain reduction in ME during exhaustive SSC exercise., Methods: Eight males participated in an exhaustive hopping task to fatigue. Mechanical work and energy expenditure were calculated at different time-points during the hopping task. Furthermore, hopping kinetics and kinematics, medial gastrocnemius (MG) muscle activity, and in vivo ultrasound of the MG were also collected at different time-points throughout the hopping task., Results: ME did not change during the hopping protocol despite shorter tendon and longer CC lengths as subjects approached exhaustion. Percent decreases in pennation angle and muscle thickness were most strongly correlated to time to exhaustion (r=0.94, p⩽0.05; r=0.87, p⩽0.05; respectively). Percent changes in CC length change and pennation angle were strongly correlated to percent decrease in maximal voluntary isometric plantarflexion (MVIP) force (r=-0.71, p⩽0.04; r=0.70, p⩽0.05; respectively). Braking/push-off EMG ratio increased from initial pre-fatigue values to all other time points showing neuromuscular adaptations to altered muscle lengths., Conclusion: Findings from the current study suggest that changes in CC and tendon lengths occur during repetitive hopping to exhaustion, with the amount change strongly related to time to exhaustion. ME of hopping remained unchanged in the presence of altered CC and tendon lengths., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
21. Adding Stiffness to the Foot Modulates Soleus Force-Velocity Behaviour during Human Walking.
- Author
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Takahashi KZ, Gross MT, van Werkhoven H, Piazza SJ, and Sawicki GS
- Subjects
- Ankle physiology, Gait physiology, Humans, Biomechanical Phenomena physiology, Foot physiology, Muscle, Skeletal physiology, Walking physiology
- Abstract
Previous studies of human locomotion indicate that foot and ankle structures can interact in complex ways. The structure of the foot defines the input and output lever arms that influences the force-generating capacity of the ankle plantar flexors during push-off. At the same time, deformation of the foot may dissipate some of the mechanical energy generated by the plantar flexors during push-off. We investigated this foot-ankle interplay during walking by adding stiffness to the foot through shoes and insoles, and characterized the resulting changes in in vivo soleus muscle-tendon mechanics using ultrasonography. Added stiffness decreased energy dissipation at the foot (p < 0.001) and increased the gear ratio (i.e., ratio of ground reaction force and plantar flexor muscle lever arms) (p < 0.001). Added foot stiffness also altered soleus muscle behaviour, leading to greater peak force (p < 0.001) and reduced fascicle shortening speed (p < 0.001). Despite this shift in force-velocity behaviour, the whole-body metabolic cost during walking increased with added foot stiffness (p < 0.001). This increased metabolic cost is likely due to the added force demand on the plantar flexors, as walking on a more rigid foot/shoe surface compromises the plantar flexors' mechanical advantage.
- Published
- 2016
- Full Text
- View/download PDF
22. Computational model of maximal-height single-joint jumping predicts bouncing as an optimal strategy.
- Author
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van Werkhoven H and Piazza SJ
- Subjects
- Adult, Biomechanical Phenomena, Computer Simulation, Humans, Male, Young Adult, Ankle Joint physiology, Models, Biological, Movement physiology, Muscle, Skeletal physiology
- Abstract
Maximal-height single-joint jumping, in which only the ankle muscles are used for propulsion, is a useful paradigm for joint-specific investigation of the mechanisms underlying optimal performance. In this study, we used a combination of computational modeling and experiments to determine the optimal strategy for this task. We hypothesized that our computer simulation and subjects would use a countermovement in order to maximize jump height. Our model was actuated by only a lumped plantarflexor and a lumped dorsiflexor, and we simulated maximal-height jumping using parameter optimization to determine the control excitations driving these muscles. Experimental data were collected from eight subjects who wore braces to limit knee motion during jumps. The model did not jump as high as the subjects did, but its jump height (12.8 cm) was similar to that found for subjects, 16.3±4.6 cm. The model jumped highest when it "bounced" by executing several countermovements in succession. Four of the subjects jumped highest when they also bounced; these subjects were also the highest jumpers and they bounced at 2.53±0.47 Hz, a value similar to that employed by the computational model, 2.78 Hz. The other four subjects, who failed to jump highest when bouncing, bounced at only 1.46±0.45 Hz when they attempted to do so. Simulation results indicated that subjects who used a bouncing strategy to record their highest jump made use of mechanical resonance to facilitate elastic energy storage in the Achilles tendon. Simulation results also showed that multiple bounces allowed the model to reach an optimal state in which potential energy was maximized prior to the final pushoff., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
23. Ankle joint mechanics and foot proportions differ between human sprinters and non-sprinters.
- Author
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Baxter JR, Novack TA, Van Werkhoven H, Pennell DR, and Piazza SJ
- Subjects
- Biomechanical Phenomena, Computer Simulation, Foot anatomy & histology, Humans, Magnetic Resonance Imaging, Male, Muscle Contraction, Muscle, Skeletal anatomy & histology, Muscle, Skeletal physiology, Ankle Joint physiology, Foot physiology, Running
- Abstract
Recent studies of sprinters and distance runners have suggested that variations in human foot proportions and plantarflexor muscle moment arm correspond to the level of sprint performance or running economy. Less clear, however, is whether differences in muscle moment arm are mediated by altered tendon paths or by variation in the centre of ankle joint rotation. Previous measurements of these differences have relied upon assumed joint centres and measurements of bone geometry made externally, such that they would be affected by the thickness of the overlying soft tissue. Using magnetic resonance imaging, we found that trained sprinters have shorter plantarflexor moment arms (p = 0.011) and longer forefoot bones (p = 0.019) than non-sprinters. The shorter moment arms of sprinters are attributable to differences in the location of the centre of rotation (p < 0.001) rather than to differences in the path of the Achilles tendon. A simple computer model suggests that increasing the ratio of forefoot to rearfoot length permits more plantarflexor muscle work during plantarflexion that occurs at rates expected during the acceleration phase following the sprint start.
- Published
- 2012
- Full Text
- View/download PDF
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