scholarly journals The validity of using one force platform to quantify whole-body forces, velocities, and power during a plyometric push-up

Author(s):  
Zhanxin Sha ◽  
Boyi Dai

Abstract Background Previous studies have typically measured velocity and power parameters during the push-up, either using one or two force platforms. The purpose of the study was to compare the force, velocity, and power parameters between the one-force-platform method and the two-force-platform method during plyometric push-ups. Methods Thirty-four physically active young adults participated in the study to perform the plyometric push-up. For the two-force-platform calculation method, the forces applied to the feet and hands were both measured. For the one-force-platform calculation method, the forces applied to the feet were assumed to be constant, while the forces applied to hands were measured by one force platform. Whole-body linear velocities were calculated based on the impulse and momentum theorem. Whole-body power was calculated as the product of the whole-body forces and velocities. Results The one-force-platform method overestimated the whole-body velocities and power compared with the two-force-platform method (1.39 ± 0.37 m/s vs. 0.90 ± 0.23 m/s, Cohen’s d = 1.59, p < 0.05; 1.63 ± 0.47 W/body weight vs. 1.03 ± 0.29 W/body weight, Cohen’s d = 1.49, p < 0.05). These differences were caused by the decreased forces applied to the feet compared to the initial value throughout most of the push-up phase. Large to perfect correlations (r = 0.55 – 0.99) were found for most variables between the two-force-platform and one-force-platform methods. Previous findings of push-up velocities and power using the two-force-platform and one-force-platform methods should be compared with caution. While the two-force-platform method is recommended, linear regression equations may be used to predict velocities and power parameters obtained from one force platform. Conclusions For those professionals who need to accurately quantify kinetic variables during the plyometric push-up, the two-force-platform method should be considered.

Nutrients ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1248 ◽  
Author(s):  
Jeremy McAdam ◽  
Kaitlin McGinnis ◽  
Darren Beck ◽  
Cody Haun ◽  
Matthew Romero ◽  
...  

We investigated the effects of whey protein (WP) supplementation on body composition and physical performance in soldiers participating in Army Initial Entry Training (IET). Sixty-nine, male United States Army soldiers volunteered for supplementation with either twice daily whey protein (WP, 77 g/day protein, ~580 kcal/day; n = 34, age = 19 ± 1 year, height = 173 ± 6 cm, weight = 73.4 ± 12.7 kg) or energy-matched carbohydrate (CHO) drinks (CHO, 127 g/day carbohydrate, ~580 kcal/day; n = 35, age = 19 ± 1 year, height = 173 ± 5 cm, weight = 72.3 ± 10.9 kg) for eight weeks during IET. Physical performance was evaluated using the Army Physical Fitness Test during weeks two and eight. Body composition was assessed using 7-site skinfold assessment during weeks one and nine. Post-testing push-up performance averaged 7 repetitions higher in the WP compared to the CHO group (F = 10.1, p < 0.001) when controlling for baseline. There was a significant decrease in fat mass at post-training (F = 4.63, p = 0.04), but no significant change in run performance (F = 3.50, p = 0.065) or fat-free mass (F = 0.70, p = 0.41). Effect sizes for fat-free mass gains were large for both the WP (Cohen’s d = 0.44) and CHO (Cohen’s d = 0.42) groups. WP had a large effect on fat mass (FM) loss (Cohen’s d = −0.67), while CHO had a medium effect (Cohen’s d = −0.40). Twice daily supplementation with WP improved push-up performance and potentiated reductions in fat mass during IET training in comparison to CHO supplementation.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259989
Author(s):  
Mario Lucchini ◽  
Tiziano Gerosa ◽  
Marta Pancheva ◽  
Maurizio Pisati ◽  
Chiara Respi ◽  
...  

This study used a subsample of a household panel study in Italy to track changes in mental health before the onset of COVID-19 and into the first lockdown period, from late April to early September 2020. The results of the random-effects regression analyses fitted on a sample of respondents aged 16 years and older (N = 897) proved that there was a substantial and statistically significant short-term deterioration in mental health (from 78,5 to 67,9; β = -10.5, p < .001; Cohen’s d -.445), as measured by a composite index derived from the mental component of the 12-item Short-Form Health Survey (SF-12). The findings also showed heterogeneity in the COVID-related effects. On the one hand, evidence has emerged that the pandemic acted as a great leveller of pre-existing differences in mental health across people of different ages: the decrease was most pronounced among those aged 16–34 (from 84,2 to 66,5; β = -17.7, p < .001; Cohen’s d -.744); however, the magnitude of change reduced as age increased and turned to be non-significant among individuals aged 70 and over. On the other hand, the COVID-19 emergency widened the mental health gender gap and created new inequalities, based on the age of the youngest child being taken care of within the household.


Author(s):  
Urška Čeklić ◽  
Nejc Šarabon ◽  
Žiga Kozinc

The purpose of this study was twofold: (a) to compare postural control between a group of young female gymnasts (n = 15; age: 11.2 ± 1.9 years) and non-trained peers (n = 15; age: 10.9 ± 2.0 years), and (b) to investigate the effect of an 8-week whole body exercise intervention program on postural control in young female gymnasts. Postural control was assessed by recording center of pressure (CoP) movements during unipedal quiet stance. Velocity and amplitude of CoP movement in anterior-posterior (AP) and medial-lateral (ML) directions were considered. In addition to common trial-averaged CoP outcomes, we also considered the transient behavior of CoP movements, by calculating relative differences between the 1st and 2nd, and the 1st and 3rd 10-s intervals within the whole trial (DIF_21 and DIF_31, respectively). The gymnast group had lower total CoP velocity (Cohen’s d = 0.97) and AP amplitude (Cohen’s d = 0.85), compared to their non-trained peers. The gymnasts also had lower CoP AP amplitude DIF21 (Cohen’s d = 0.73), with almost constant values across all intervals. After the training ML CoP velocity was reduced for 13.12% (Cohen’s d = 0.60), while ML CoP amplitude increased (Cohen’s d = −0.89).


2013 ◽  
Vol 2 (4) ◽  
pp. 199-215 ◽  
Author(s):  
Maria Klatte ◽  
Claudia Steinbrink ◽  
Kirstin Bergström ◽  
Thomas Lachmann

Defizite in der phonologischen Informationsverarbeitung werden heute als Kernsymptom der Lese-Rechtschreibstörung betrachtet. In Trainingsstudien mit betroffenen Kindern erwiesen sich Phonemwahrnehmungsfähigkeiten als trainierbar, und Programme, in denen Aufgaben zur phonologischen Bewusstheit mit der systematischen Vermittlung von Phonem-Graphem-Zuordnungen kombiniert wurden, zeigten Transfereffekte auf Lese- und Rechtschreibleistungen. Ausgehend von diesen Erkenntnissen wurde ein computerbasiertes Trainingsprogramm zur Förderung der Phonemwahrnehmung, der phonologischen Bewusstheit und der Graphem-Phonem-Zuordnungen für deutschsprachige Grundschulkinder mit Lese-Rechtschreibstörung entwickelt. Aufgrund der besonderen Relevanz der Vokallänge für die deutsche Orthographie enthält das Programm neben Aufgaben, die auf Konsonanten fokussieren, auch Vokallängenaufgaben. Bei der Konzipierung des Programms wurden etablierte, ursprünglich für andere Sprachen entwickelte Aufgaben an die deutsche Phonologie angepasst und in ein computerbasiertes Format übersetzt. Im Rahmen der vorliegenden Studie sollte überprüft werden, ob die konstruierten Trainingsaufgaben die spezifischen Defizite von Kindern mit Lese-Rechtschreibstörung wie intendiert abbilden. Hierzu wurden leseschwache Dritt- und Viertklässler (n = 35) mit mindestens durchschnittlichen Lesern derselben Klassenstufen (n = 75; Kontrollgruppe) hinsichtlich ihrer Leistungen in den Aufgaben verglichen. Die leseschwachen Kinder zeigten in allen Aufgaben schlechtere Leistungen als die Kontrollgruppe. Die Effektstärken der Gruppenunterschiede (Cohen's d) lagen im mittleren bis hohen Bereich (0.50 – 2.19). Die Ergebnisse bestätigen, dass die Aufgaben des Trainingsprogramms die spezifischen Defizite leseschwacher Kinder abbilden. Ein Training mit diesen Aufgaben erscheint daher grundsätzlich sinnvoll. Die Wirkungen eines solchen Trainings auf die schriftsprachlichen Leistungen von Kindern mit Lese-Rechtschreibstörung werden in zukünftigen Studien überprüft.


1973 ◽  
Vol 30 (01) ◽  
pp. 114-122
Author(s):  
C.R.M Prentice ◽  
K.M Rogers ◽  
G.P McNicol

SummaryThe pharmacological effect of a new preparation of urokinase (Leo) has been studied, both in vitro and in six patients suffering from thrombo-embolic disorders. It was a non-toxic, effective fibrinolytic agent if given in sufficient dosage. A regimen consisting of an initial dose of 7,200 ploug units per kg body weight, followed by hourly maintenance therapy with 3,600 ploug units per kg intravenously, gave satisfactory evidence of whole body fibrinolytic activity. The preparation had minor but insignificant thromboplastic activity both when assayed in the laboratory and when given to patients.


2019 ◽  
Author(s):  
Jan G. Voelkel ◽  
Dongning Ren ◽  
Mark John Brandt

The political divide is characterized by liberals and conservatives who hold strong prejudice against each other. Here we introduce one possible strategy for reducing political prejudice: political inclusion. We define political inclusion as receiving a fair chance to voice one’s opinions in a discussion of political topics with political outgroup members. This strategy may reduce political prejudice by inducing perceptions of the political outgroup as fair and respectful; however, such a strategy may also highlight conflicting attitudes and worldviews, thereby further exacerbating prejudice. In three preregistered studies (total N = 799), we test if political inclusion reduces or increases prejudice toward the political outgroup. Specifically, political inclusion was manipulated with either an imagined scenario (Study 1) or a concurrent experience in an ostensible online political discussion (Studies 2 &amp; 3). Across all studies, participants who were politically included by political outgroup members reported reduced prejudice toward their outgroup compared to participants in a neutral control condition (Cohen’s d [-0.27, -0.50]). This effect was mediated by perceptions of the political outgroup as fairer and less dissimilar in their worldviews. Our results indicate that political discussions that are politically inclusive do not cause additional prejudice via worldview conflict, but instead give others a feeling of being heard. It is a promising strategy to reduce political prejudice.


Author(s):  
Roxana Steliana Miclaus ◽  
Nadinne Roman ◽  
Ramona Henter ◽  
Silviu Caloian

More innovative technologies are used worldwide in patient’s rehabilitation after stroke, as it represents a significant cause of disability. The majority of the studies use a single type of therapy in therapeutic protocols. We aimed to identify if the association of virtual reality (VR) therapy and mirror therapy (MT) exercises have better outcomes in lower extremity rehabilitation in post-stroke patients compared to standard physiotherapy. Fifty-nine inpatients from 76 initially identified were included in the research. One experimental group (n = 31) received VR therapy and MT, while the control group (n = 28) received standard physiotherapy. Each group performed seventy minutes of therapy per day for ten days. Statistical analysis was performed with nonparametric tests. Wilcoxon Signed-Rank test showed that both groups registered significant differences between pre-and post-therapy clinical status for the range of motion and muscle strength (p < 0.001 and Cohen’s d between 0.324 and 0.645). Motor Fugl Meyer Lower Extremity Assessment also suggested significant differences pre-and post-therapy for both groups (p < 0.05 and Cohen’s d 0.254 for the control group and 0.685 for the experimental group). Mann-Whitney results suggested that VR and MT as a therapeutic intervention have better outcomes than standard physiotherapy in range of motion (p < 0.05, Cohen’s d 0.693), muscle strength (p < 0.05, Cohen’s d 0.924), lower extremity functionality (p < 0.05, Cohen’s d 0.984) and postural balance (p < 0.05, Cohen’s d 0.936). Our research suggests that VR therapy associated with MT may successfully substitute classic physiotherapy in lower extremity rehabilitation after stroke.


Author(s):  
Jieling Chen ◽  
Cho Lee Wong ◽  
Bernard Man Hin Law ◽  
Winnie Kwok Wei So ◽  
Doris Yin Ping Leung ◽  
...  

Summary Pneumoconiosis is a common occupational lung disease among construction workers. Educational interventions targeting specific ethnic groups of construction workers are of benefit for pneumoconiosis prevention. The aim of this study was to develop a multimedia educational intervention for pneumoconiosis prevention for South Asian construction workers, and to evaluate its feasibility, acceptability and effectiveness in increasing knowledge of pneumoconiosis, modifying beliefs about pneumoconiosis, and enhancing intention to implement measures for its prevention among the workers. This evaluation was performed using the Reach-Effectiveness-Adoption-Implementation-Maintenance framework. A one-group design was adopted and intervention mapping was used to guide the process of intervention development, while the Health Belief Model guided the development of intervention content. The intervention was delivered at construction sites, ethnic minority associations and South Asian community centres. Data were collected via surveys completed at pre-intervention, post-intervention and 3 months after the intervention. A total of 1002 South Asian construction workers participated in the intervention. The participants reported a moderate-to-large increase in knowledge, perceived susceptibility, perceived severity, perceived benefits, cues to action and self-efficacy (Cohen’s d: 0.37–0.89), a small reduction in perceived barriers (Cohen’s d = 0.12) and a moderate improvement in attitudes and intention to practice (Cohen’s d: 0.45, 0.51) at post-intervention. A follow-up survey of 121 participants found that the implementation of preventive measures appeared to increase. Overall, the findings demonstrate that the implementation of a culturally adapted multimedia educational intervention could be an effective approach to improving knowledge, self-efficacy and intention regarding pneumoconiosis prevention among South Asian construction workers.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Monika S. Mellem ◽  
Matt Kollada ◽  
Jane Tiller ◽  
Thomas Lauritzen

Abstract Background Heterogeneity among patients’ responses to treatment is prevalent in psychiatric disorders. Personalized medicine approaches—which involve parsing patients into subgroups better indicated for a particular treatment—could therefore improve patient outcomes and serve as a powerful tool in patient selection within clinical trials. Machine learning approaches can identify patient subgroups but are often not “explainable” due to the use of complex algorithms that do not mirror clinicians’ natural decision-making processes. Methods Here we combine two analytical approaches—Personalized Advantage Index and Bayesian Rule Lists—to identify paliperidone-indicated schizophrenia patients in a way that emphasizes model explainability. We apply these approaches retrospectively to randomized, placebo-controlled clinical trial data to identify a paliperidone-indicated subgroup of schizophrenia patients who demonstrate a larger treatment effect (outcome on treatment superior than on placebo) than that of the full randomized sample as assessed with Cohen’s d. For this study, the outcome corresponded to a reduction in the Positive and Negative Syndrome Scale (PANSS) total score which measures positive (e.g., hallucinations, delusions), negative (e.g., blunted affect, emotional withdrawal), and general psychopathological (e.g., disturbance of volition, uncooperativeness) symptoms in schizophrenia. Results Using our combined explainable AI approach to identify a subgroup more responsive to paliperidone than placebo, the treatment effect increased significantly over that of the full sample (p < 0.0001 for a one-sample t-test comparing the full sample Cohen’s d = 0.82 and a generated distribution of subgroup Cohen’s d’s with mean d = 1.22, std d = 0.09). In addition, our modeling approach produces simple logical statements (if–then-else), termed a “rule list”, to ease interpretability for clinicians. A majority of the rule lists generated from cross-validation found two general psychopathology symptoms, disturbance of volition and uncooperativeness, to predict membership in the paliperidone-indicated subgroup. Conclusions These results help to technically validate our explainable AI approach to patient selection for a clinical trial by identifying a subgroup with an improved treatment effect. With these data, the explainable rule lists also suggest that paliperidone may provide an improved therapeutic benefit for the treatment of schizophrenia patients with either of the symptoms of high disturbance of volition or high uncooperativeness. Trial Registration: clincialtrials.gov identifier: NCT 00,083,668; prospectively registered May 28, 2004


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 58-58
Author(s):  
Katherine Kirsch ◽  
Catherine Lemieux ◽  
Laura Ainsworth ◽  
Sarah Choate ◽  
Ashleigh Borgmeyer ◽  
...  

Abstract A recent Alzheimer’s Association report noted that by year 2050, the number of Americans diagnosed with Alzheimer’s disease and related dementias (ADRD) will triple to over 15 million. The report referred to primary care as the front line for meeting this demand, yet the nation faces a severe shortage of ADRD trained, primary care professionals (PCPs). Louisiana Geriatric Workforce Enhancement Program (LA-GWEP) addresses this demand. The purpose of this study was to examine preliminary data respective to LA-GWEP effectiveness with interdisciplinary education and training seminars, primarily aimed at medical, nursing, and social work PCPs. Three seminars were conducted in south Louisiana: Seminars 1 and 2 addressed effective communication, verbal and nonverbal, among persons with ADRD and caregivers; Seminar 3 offered basic overview of dementia symptomology, stages, and behaviors. Pre- and post-training session data were collected on-site. Participants completed questionnaires that included a 10-item knowledge assessment and 20-item Dementia Attitudes Scale (DAS). These measures contained Likert response formats; higher scores indicating greater levels of ADRD knowledge, in patient and caregiver contexts. Paired sample t-tests were conducted to observe any significant pre-to-post improvement, Cohen’s d for effect size. Seminar 1 revealed no significant pre-to-post difference: t = -1.019, p = 0.320. Adjusting content from audience feedback, Seminar 2 revealed significant pre-to-post difference: t = -7.516, p &lt; .001, Cohen’s d = 1.2. Seminar 3 yielded significant improvement on DAS scores: t = -2.96, p &lt; .01, Cohen’s d = 0.34. Implications for seminars in future years of LA-GWEP are discussed.


Sign in / Sign up

Export Citation Format

Share Document