The aquatic environment represents an adequate and safe alternative for children with overweight to exercise. However, the magnitude of the vertical ground reaction force (Fz) during these exercises ...is unknown in this population. Therefore, our study aimed to compare the Fz during the stationary running exercise between the aquatic and land environments in children with overweight or obesity. The study is characterized as a cross-over study. Seven children, two with overweight and five with obesity (4 boys and 3 girls; 9.7 ± 0.8 years), performed two experimental sessions, one on land and another in the aquatic environment. In both conditions, each participant performed 15 repetitions of the stationary running exercise at three different cadences (60, 80, and 100 b min−1) in a randomized order. Their apparent weight was reduced by 72.1 ± 10.4% on average at the xiphoid process depth. The peak Fz, impulse, and loading rate were lower in the aquatic environment than on land (p < 0.001). Peak Fz was also lower at 80 b min−1 compared to 100 b min−1 (p = 0.005) and loading rate was higher at 100 b min−1 compared to 80 b min−1 (p = 0.003) and 60 b min−1 (p < 0.001) in the aquatic environment, whereas impulse was significantly reduced (p < 0.001) with the increasing cadence in both environments. It can be concluded that the aquatic environment reduces all the Fz outcomes investigated during stationary running and that exercise intensity seems to influence all these outcomes in the aquatic environment.
Reliability and case-control injury study.
To determine if a novel device designed to measure eccentric knee flexor strength via the Nordic hamstring exercise displays acceptable test-retest ...reliability; to determine normative values for eccentric knee flexor strength derived from the device in individuals without a history of hamstring strain injury (HSI); and to determine if the device can detect weakness in elite athletes with a previous history of unilateral HSI.
HSI and reinjury are the most common cause of lost playing time in a number of sports. Eccentric knee flexor weakness is a major modifiable risk factor for future HSI. However, at present, there is a lack of easily accessible equipment to assess eccentric knee flexor strength.
Thirty recreationally active males without a history of HSI completed the Nordic hamstring exercise on the device on 2 separate occasions. Intraclass correlation coefficients, typical error, typical error as a coefficient of variation, and minimal detectable change at a 95% confidence level were calculated. Normative strength data were determined using the most reliable measurement. An additional 20 elite athletes with a unilateral history of HSI within the previous 12 months performed the Nordic hamstring exercise on the device to determine if residual eccentric muscle weakness existed in the previously injured limb.
The device displayed high to moderate reliability (intraclass correlation coefficient = 0.83-0.90; typical error, 21.7-27.5 N; typical error as a coefficient of variation, 5.8%-8.5%; minimal detectable change at a 95% confidence level, 60.1-76.2 N). Mean ± SD normative eccentric flexor strength in the uninjured group was 344.7 ± 61.1 N for the left and 361.2 ± 65.1 N for the right side. The previously injured limb was 15% weaker than the contralateral uninjured limb (mean difference, 50.3 N; 95% confidence interval: 25.7, 74.9; P<.01), 15% weaker than the normative left limb (mean difference, 50.0 N; 95% confidence interval: 1.4, 98.5; P = .04), and 18% weaker than the normative right limb (mean difference, 66.5 N; 95% confidence interval: 18.0, 115.1; P<.01).
The experimental device offers a reliable method to measure eccentric knee flexor strength and strength asymmetry and to detect residual weakness in previously injured elite athletes.
The aim of this review is to evaluate existing isokinetic testing protocols for the shoulder in tactical occupations, document their shoulder strength profiles, and determine any associations to ...shoulder injury. Four electronic databases were searched (Medline/Pubmed, Ovid/Emcare, CINAHL/Ebsco and Embase) using the keywords police OR law enforcement, firefighter, military, AND isokinetic. Articles were eligible if they had at least one cohort of a tactical population and included isokinetic testing of the glenohumeral joint. The search yielded 275 articles. After screening for duplicates and inclusion criteria, 19 articles remained for review, six of which assessed injury correlation. 17 articles evaluated military personnel and two examined firefighters. Articles were categorized by study design, population, isokinetic protocols, strength outcome measures and statistical measures. Concentric internal rotation (IR) and external rotation (ER) strength at 60 degrees/second were reported most frequently (84% of cases). There was a paucity of testing speeds, repetition ranges and contraction types evaluated when compared to existing literature in other populations with high shoulder injury occurrence such as overhead and collision athletes. Outside of military cohorts, there is limited data available to characterise the isokinetic strength profile of the shoulder in tactical occupations. Meta-analysis for injury association was unable to be performed due to independent variable and statistical heterogeneity. However, a best evidence synthesis suggested conflicting evidence to support the association of injury with isokinetic strength testing in tactical populations. Future studies should prioritise prospective designs utilising variable speeds, repetition schemes and contraction types to better capture the dynamic occupational demands in tactical groups.
Objective. To study the relationship between the specific strength in handball, assessed with Functional Electromechanical Dynamometer (FEMD), and throwing velocity. Methods. Thirteen Spanish elite ...handball players were evaluated (28.77 ± 4.81 years, 90.19 ± 13.07 kg y 1.86 ± 0.10 m) during the preseason. A day of familiarization with the throwing velocity and strength test with FEMD was performed. One week later, the assessment of specific strength, including the upper and lower body (unilateral pullover test and step forward test) and throwing velocity was conducted by the subjects. Results. Significant correlations were found between (i) throwing velocity peak and isometric strength mean in unilateral pullover test with the dominant hand (r = 0.548, p = 0.05), and (ii) between throwing velocity peak and step forward test with the dominant leg (r = 0.628, p = 0.02). Conclusion. Training exercises closer to real game situations are positively related to performance enhancement in handball players. Therefore, the use of devices that allow the assessment and training at the same time in specific situations, should be extended in the sport coaches and researches.
Objetivo. Estudiar la relación entre la fuerza de dos ejercicios específicos de balonmano (test del martillo y test de un paso) y la velocidad de lanzamiento en apoyo. Métodos. Trece jugadores españoles de balonmano de élite fueron evaluados (28.77 ± 4.81 años, 90.19 ± 13.07 kg y 1.86 ± 0.10 m) durante la pretemporada. Se realizó un día de familiarización con los test de lanzamiento y de fuerza con Dinamometría Electromecánica Funcional (DEMF). Una semana después, se realizaron las evaluaciones de fuerza específica de tren superior e inferior (test del martillo y test de un paso) y de velocidad de lanzamiento. Resultados. Se encontraron (i) relaciones significativas entre la velocidad máxima de lanzamiento y la fuerza isométrica media del ejercicio de martillo unilateral con el brazo dominante (r = 0.548, p = 0.05), y (ii) relaciones significativas entre la velocidad máxima de lanzamiento y el paso con la pierna dominante (r = 0.628, p = 0.02). Conclusión. El entrenamiento con situaciones cercanas a las condiciones reales del juego se relaciona positivamente en el proceso de mejora del rendimiento del jugador de balonmano. Por lo tanto, utilizar dispositivos que permitan evaluar y entrenar a la vez en situaciones específicas es algo que debería extenderse entre los profesionales del deporte.
Influencia del sobrepeso y la obesidad sobre la fuerza en la infancia Fernández-García, José Carlos; Castillo-Rodríguez, Alfonso; Onetti-Onetti, Wanesa
Nutrición hospitalaria : organo oficial de la Sociedad Española de Nutrición Parenteral y Enteral,
10/2019, Volume:
36, Issue:
5
Journal Article
Open access
Resumen Introducción: el sobrepeso y la obesidad alcanzan una alta prevalencia desde la infancia en España. Objetivo: describir el efecto del sobrepeso y la obesidad en niños escolares de once años ...de edad, en pruebas que valoran la fuerza, tanto de las extremidades inferiores como de las superiores, así como la velocidad. Método: participaron en el estudio 423 escolares de once años de edad. Se obtuvieron características básicas antropométricas y desarrollaron diversos test de la batería EUROFIT. Resultados: los niños y niñas que se encuentran en normopeso poseen mejores puntuaciones en las pruebas de condición física en general. De este modo, los saltos verticales y horizontales, suspensión en barra y abdominales son superiores en los participantes con normopeso (p < 0,05). Además, recorren en menos tiempo un circuito de velocidad en ambos sexos (p < 0,001); sin embargo, en la fuerza isométrica manual, en el grupo de niñas poseen mejores resultados aquellas que se encuentran en sobrepeso u obesidad (p < 0,01). Conclusiones: los niños de once años con sobrepeso y obesidad muestran una menor prestación muscular, salvo en el caso de la fuerza isométrica manual. También se han determinado diversas ecuaciones de predicción de resultados de las pruebas físicas llevadas a cabo, como saltos, dinamometría y velocidad, a través del sexo e índice de masa corporal (IMC).
To determine the reliability, responsiveness, validity, and agreement of handheld dynamometry, relative to electromechanical dynamometry, for assessing quadriceps strength surrounding total knee ...arthroplasty.
Fifty-six patients (48% female) undergoing total knee arthroplasty were assessed prior to surgery and at 2 and 6 weeks following surgery. Maximum isometric quadriceps force was assessed at each time point by handheld dynamometry and electromechanical dynamometry. Within-session test-retest reliability was determined by intraclass correlation coefficient (ICC). Standard error of measurement and relative standard error (RSE) values were calculated. Standardized response means were used to describe responsiveness. Pearson's correlations examined construct validity. Agreement was assessed by the Bland-Altman method.
Both handheld dynamometry and electromechanical dynamometry demonstrated excellent test-retest reliability (ICC >0.90) and RSE (<15%). Both methods were responsive, with large postoperative standardized response means of 1.57 (handheld dynamometry) and 1.37 (electromechanical dynamometry). Pearson's correlations were moderate to strong. The Bland-Altman analysis revealed underestimation of force by handheld dynamometry, although this effect was diminished in the early postoperative period.
Our results suggest handheld dynamometry is a promising tool for monitoring quadriceps strength in patients pre- and post-total knee arthroplasty.
IMPLICATIONS FOR REHABILITATION
This study provides evidence of high reliability and responsiveness of handheld dynamometry for assessing quadriceps strength throughout a clinically relevant time frame for patients with total knee arthroplasty.
There is construct validity of handheld dynamometry for measuring quadriceps strength, with moderate to high correlations between handheld dynamometry and electromechanical dynamometry, both pre- and post-total knee arthroplasty.
Rehabilitation professionals should be aware that handheld dynamometry and electromechanical dynamometry do not agree in terms of the force measurement itself; particularly at higher force values, handheld dynamometry underestimates force output relative to electromechanical dynamometry.
Overall, this study supports the use of handheld dynamometry for monitoring quadriceps strength in clinical settings for patient with total knee arthroplasty.
This study was aimed to set reference values of hand-grip strength by age and sex and validate cut points for risk of functional limitation and mortality in older Chileans.
This was a pooled analysis ...of four studies including 6,426 people ≥60 years of nondependent community-dwelling Chileans. After exclusion criteria, the final sample included 5,250 subjects, from whom 2,193 were followed to study all-cause mortality associated with low hand-grip strength. Face-to-face interviews registering sociodemographic characteristics, self-reported chronic diseases, and functional limitations were conducted. Anthropometric measurements and observed mobility were performed by trained professionals. Hand-grip strength was measured with a hand dynamometer T-18 (Country Technology, Inc.) before 2008 or with JAMAR brand from 2008 onwards. Percentiles were calculated through descriptive analysis and quantile regression models for specific groups of age and sex. Adjusted Cox regression hazard models for mortality risk according to low dynamometry condition and covariates were developed.
We deliver reference values of hand-grip strength for older Chileans proposing the 25th percentile as the cut-off point for low dynamometry risk: men ≤27 kg, women ≤15 kg. Low hand-grip strength was associated with Instrumental Activities of Daily Living limitations (
=0.001), and altered physical performance evaluated through the Timed Up and Go test (
=0.0001), grasping (
=0.001), bending (
<0.0001), and lifting (
<0.0001). After Cox proportional hazard regression models were assessed with a median follow-up of 9.2 years, the adjusted risk of all-cause mortality associated with a hand-grip strength lower than the 25th percentile in older Chileans showed a hazard ratio of 1.39 (95% confidence interval: 1.13-1.71).
The cut-off points of dynamometry validated for the older Chileans allow the incorporation in the geriatric evaluation in primary health care of an easy-to-use, inexpensive indicator to identify older adults at risk of sarcopenia, frailty, and dismobility. In addition this also helps to optimize the evaluation of intervention strategies focused on the maintenance of functionality.
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