scholarly journals The Force-Velocity Relationship in Older People: Reliability and Validity of a Systematic Procedure

2017 ◽  
Vol 38 (14) ◽  
pp. 1097-1104 ◽  
Author(s):  
Julian Alcazar ◽  
Carlos Rodriguez-Lopez ◽  
Ignacio Ara ◽  
Ana Alfaro-Acha ◽  
Asier Mañas-Bote ◽  
...  
Keyword(s):  
Older Adults ◽  
Muscle Power ◽  
Reliability And Validity ◽  
Maximal Power ◽  
Mean Values ◽  
Multiple Loads ◽  
Velocity Relationship ◽  
Force Velocity ◽  
The Mean ◽  
Older Men And Women

AbstractThis study compared the reliability and validity of different protocols evaluating the force-velocity (F-V) relationship and muscle power in older adults. Thirty-one older men and women (75.8±4.7 years) underwent two F-V tests by collecting the mean and peak force and velocity data exerted against increasing loads until one repetition maximum (1RM) was achieved in the leg press exercise. Two attempts per load were performed, with a third attempt when F-V points deviated from the linear F-V regression equation. Then, the subjects performed 2×3 repetitions at 60% 1RM to compare purely concentric and eccentric-concentric repetitions. The Short Physical Performance Battery was conducted to assess the validity of the different protocols. Significant differences were found in maximal power (Pmax) between mean and peak values and between protocols differing in the number of attempts per load (p<0.01). Registering mean values, a third attempt, and multiple loads (>3), was significantly more reliable (Pmax: CV=2.6%; ICC=0.99) than the other alternatives. Mean values were also observed to be more associated with physical function than peak values (R2=0.34 and 0.15, respectively; p<0.05). No significant differences were observed between concentric and eccentric-concentric repetitions. Thus, collecting mean force and velocity values against multiple loads, while monitoring the linearity of the F-V relationship, seemed to be the more adequate procedure to assess the F-V profile and muscle power in older adults.

scholarly journals Force-Velocity Relationship in the Countermovement Jump Exercise Assessed by Different Measurement Methods

2019 ◽  
Vol 67 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Amador García-Ramos ◽  
Alejandro Pérez-Castilla ◽  
Antonio J. Morales-Artacho ◽  
Filipa Almeida ◽  
Paulino Padial ◽  
...  
Keyword(s):  
Maximum Velocity ◽  
Measurement Methods ◽  
Loading Conditions ◽  
Countermovement Jump ◽  
Mean Values ◽  
Velocity Transducer ◽  
Jump Exercise ◽  
Velocity Relationship ◽  
Force Velocity ◽  
The Mean

AbstractThis study aimed to compare force, velocity, and power output collected under different loads, as well as the force-velocity (F-V) relationship between three measurement methods. Thirteen male judokas were tested under four loading conditions (20, 40, 60, and 80 kg) in the countermovement jump (CMJ) exercise, while mechanical output data were collected by three measurement methods: the Samozino's method (SAM), a force platform (FP), and a linear velocity transducer (LVT). The variables of the linear F-V relationship (maximum force [F0], maximum velocity [V0], F-V slope, and maximum power [P0]) were determined. The results revealed that (1) the LVT overestimated the mechanical output as compared to the SAM and FP methods, especially under light loading conditions, (2) the SAM provided the lowest magnitude for all mechanical output, (3) the F-V relationships were highly linear either for the SAM (r = 0.99), FP (r = 0.97), and LVT (r = 0.96) methods, (4) the F-V slope obtained by the LVT differed with respect to the other methods due to a larger V0 (5.28 ± 1.48 m·s-1) compared to the SAM (2.98 ± 0.64 m·s-1) and FP (3.06 ± 0.42 m·s-1), and (5) the methods were significantly correlated for F0 and P0, but not for V0 or F-V slope. These results only support the accuracy of the SAM and FP to determine the F-V relationship during the CMJ exercise. The very large correlations of the SAM and LVT methods with respect to the FP (presumed gold-standard) for the mean values of force, velocity and power support their concurrent validity for the assessment of mechanical output under individual loads.

scholarly journals Effects of cross-bridge compliance on the force-velocity relationship and muscle power output

PLoS ONE ◽  
2017 ◽  
Vol 12 (12) ◽  
pp. e0190335 ◽  
Author(s):  
Axel J. Fenwick ◽  
Alexander M. Wood ◽  
Bertrand C. W. Tanner
Keyword(s):  
Power Output ◽  
Muscle Power ◽  
Cross Bridge ◽  
Velocity Relationship ◽  
Force Velocity ◽  
Muscle Power Output

scholarly journals Association between Nutritional Status Determined By Mini Nutritional Assessment and Serum Marker Levels in Older Adults at Eldercare Facilities

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Angel G Hilerio Lopez
Keyword(s):  
Older Adults ◽  
At Risk ◽  
Nutritional Status ◽  
Nutritional Assessment ◽  
Mini Nutritional Assessment ◽  
Serum Marker ◽  
Cross Sectional ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean

Malnutrition in the older adult is an ongoing situation in Mexico and is most apparent in individuals that reside in hospitals, nursing homes, and retirement homes. For that reason, it is necessary to evaluate the nutritional status of these adults by means of the Mini Nutritional Assessment (MNA) and levels of three serum indicators that are commonly ordered when making malnutrition diagnosis. An analytical cross-sectional study was carried out on 100 older adults residing in eldercare facilities. Nutritional status was evaluated by means of the MNA and three serum indicators (albumin, ferritin, and hemoglobin). Descriptive statistics were used to analyze sociodemographic characteristics, and a Student’s t test, based on gender and reference values, was used to compare mean values of the three serum indicators.  A Chi-square test was used to compare proportions in individuals, based on gender, who had normal nutritional status or were malnourished, and who were at-risk of malnutrition.  A One-way ANOVA with Scheffé post hoc test was used to identify the association between serum indicators and nutritional status of older adults. Of the 100 older adults studied, 53% were men and 47% were women. The mean age was 85±0.7 years. According to the MNA, 20% had normal nutritional status, 55% were at-risk of malnutrition, and 25% were malnourished. The mean indicator values were: albumin 4.7±0.04 g/dL, ferritin 74.2±8.7 ng/mL, and hemoglobin 13.0±0.1 g/dL. No significant association was found between serum indicators and each MNA classification; however, when the same indicators were compared between the sexes, hemoglobin showed a significant difference (P=0.037). Women had lower values but those values did not extend beyond the established physiological range for this population. There was a 55% prevalence of risk of malnutrition in the nutritional status of older adults living in Mexican eldercare facilities in a Mexican province and it was even more frequent in women. 

Force-velocity relationship of expiratory muscles in normal subjects

1982 ◽  
Vol 52 (4) ◽  
pp. 930-938 ◽  
Author(s):  
Y. Kikuchi ◽  
H. Sasaki ◽  
K. Sekizawa ◽  
K. Aihara ◽  
T. Takishima
Keyword(s):  
Respiratory Muscles ◽  
Normal Subjects ◽  
Contractile Element ◽  
Shortening Velocity ◽  
Mean Values ◽  
Significant Difference ◽  
Velocity Relationship ◽  
Force Velocity ◽  
Expiratory Muscles ◽  
Relationship Of

We examined the force-velocity relationship of the respiratory muscles in normal subjects under nearly isotonic conditions, taking into consideration the pleural pressure (Ppl) changes during maximum forced expirations (MFE). We used an electromagnetic valve (EMV) to select the Ppl value at the onset of mouth flow; and both a pressure reservoir and a variable resistance to control the Ppl changes after the opening of the EMV during MFE. To simulate isotonic conditions and to obtain the shortening velocity of the contractile element (CE), we mathematically corrected the velocity of the series elastic component (SEC), using a modified version of Hill's equation. Although the maximum tension at total lung capacity (TLC) [1,156 +/- 215 (SD) g/cm] was larger than that at functional residual capacity (FRC) (782 +/- 97 g/cm) there was no significant difference in the maximum shortening velocity, 3.4 +/- 1.0 and 3.2 +/- 0.8 circumference/s at TLC and FRC, respectively. The mean values of k (slope) for the SEC at TLC and FRC were 19 +/- 4 and 18 +/- 5 circumference-1, respectively, and they were not significantly different. We concluded that the force-velocity relationship of the expiratory muscles exhibited the same mechanical properties as that of the other skeletal muscles.

Force–Velocity Relationship of Upper Body Muscles: Traditional Versus Ballistic Bench Press

2016 ◽  
Vol 32 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Amador García-Ramos ◽  
Slobodan Jaric ◽  
Paulino Padial ◽  
Belén Feriche
Keyword(s):  
Bench Press ◽  
Maximum Velocity ◽  
Maximum Force ◽  
Upper Body ◽  
Strongly Correlated ◽  
Mean Values ◽  
Repetition Maximum ◽  
Velocity Relationship ◽  
Force Velocity ◽  
Relationship Of

This study aimed to (1) evaluate the linearity of the force–velocity relationship, as well as the reliability of maximum force (F0), maximum velocity (V0), slope (a), and maximum power (P0); (2) compare these parameters between the traditional and ballistic bench press (BP); and (3) determine the correlation of F0 with the directly measured BP 1-repetition maximum (1RM). Thirty-two men randomly performed 2 sessions of traditional BP and 2 sessions of ballistic BP during 2 consecutive weeks. Both the maximum and mean values of force and velocity were recorded when loaded by 20–70% of 1RM. All force–velocity relationships were strongly linear (r > .99). While F0 and P0 were highly reliable (ICC: 0.91–0.96, CV: 3.8–5.1%), lower reliability was observed for V0 and a (ICC: 0.49–0.81, CV: 6.6–11.8%). Trivial differences between exercises were found for F0 (ES: < 0.2), however the a was higher for the traditional BP (ES: 0.68–0.94), and V0 (ES: 1.04–1.48) and P0 (ES: 0.65–0.72) for the ballistic BP. The F0 strongly correlated with BP 1RM (r: 0.915–0.938). The force–velocity relationship is useful to assess the upper body maximal capabilities to generate force, velocity, and power.

Effects of cluster training sets on muscle power and force–velocity relationship in postmenopausal women

2019 ◽  
Vol 16 (2) ◽  
pp. 257-265
Author(s):  
Marcelo A. S. Carneiro ◽  
Gersiel N. de Oliveira Júnior ◽  
Jairo F. R. de Sousa ◽  
Samarita B. Santagnello ◽  
Markus V. C. Souza ◽  
...  
Keyword(s):  
Postmenopausal Women ◽  
Muscle Power ◽  
Velocity Relationship ◽  
Force Velocity ◽  
Training Sets

Dissecting muscle power output

1999 ◽  
Vol 202 (23) ◽  
pp. 3369-3375 ◽  
Author(s):  
R.K. Josephson
Keyword(s):  
Time Course ◽  
Muscle Activation ◽  
Muscle Force ◽  
Muscle Power ◽  
Muscle Length ◽  
Velocity Relationship ◽  
Shortening Deactivation ◽  
Force Velocity ◽  
Work Done ◽  
Kinetics Of

The primary determinants of muscle force throughout a shortening-lengthening cycle, and therefore of the net work done during the cycle, are (1) the shortening or lengthening velocity of the muscle and the force-velocity relationship for the muscle, (2) muscle length and the length-tension relationship for the muscle, and (3) the pattern of stimulation and the time course of muscle activation following stimulation. In addition to these primary factors, there are what are termed secondary determinants of force and work output, which arise from interactions between the primary determinants. The secondary determinants are length-dependent changes in the kinetics of muscle activation, and shortening deactivation, the extent of which depends on the work that has been done during the preceding shortening. The primary and secondary determinants of muscle force and work are illustrated with examples drawn from studies of crustacean muscles.

“The Whole is More than the Sum of its Parts”: The Effects of Grouping and Randomizing Items on the Reliability and Validity of Questionnaires

1997 ◽  
Vol 13 (2) ◽  
pp. 67-74 ◽  
Author(s):  
Gabriele Helga Franke
Keyword(s):  
University Students ◽  
Group Testing ◽  
Reliability And Validity ◽  
Nursing School ◽  
Self Report ◽  
School Students ◽  
Application Study ◽  
Mean Values ◽  
The Mean ◽  
Item Presentation

This investigation was concerned with the widely spread practice to extract subscales from extensive psychodiagnostic inventories and to present their items in questionnaires as homogeneous item-blocks. By way of examining the effects of the mode of item-presentation on the reliability and validity, the frequently used and validated SCL-90-R was analyzed as a prototype of multidimensional symptom self-report inventories. Two studies were conducted in different contexts of application (study I: controlled group testing, study II: non-controlled individual testing) and involved different groups of subjects (study I: 130 nursing school students, study II: 134 university students). In both studies the standard item-arrangement was contrasted with the item-block presentation, which groups together items measuring the same dimension. The results revealed significant effects of item-blocking on the mean values, on the reliability, and the validity of the questionnaire. The findings seriously call into question the admissibility of subscale-extraction for self-report inventories. We conclude that the Gestalt paradigm, “The whole is more than the sum of its parts,” is valid for multidimensional psychodiagnostic inventories.

scholarly journals Power-Velocity Characteristics and Jumping Abilities in Male Combat Athletes

2016 ◽  
Vol 17 (3) ◽  
Author(s):  
Krzysztof Buśko
Keyword(s):  
External Force ◽  
Cycle Ergometer ◽  
Centre Of Mass ◽  
Maximal Power ◽  
Counter Movement Jump ◽  
Significant Difference ◽  
Ergometer Exercise ◽  
Velocity Relationship ◽  
Force Velocity ◽  
External Loads

AbstractThe aim of the study was to examine differences in power-velocity characteristics, and the maximal power and height of rise of the body’s centre of mass, measured in the counter-movement jump (CMJ) and the spike jump (SPJ), between judoists, boxers and taekwondo athletes.The study involved 7 judoists, 6 boxers, and 6 taekwondo athletes. The maximal power and height of jump were measured at CMJ and SPJ jumps. Force-velocity and power-velocity relations were determined on the basis of 5 maximal cycle ergometer exercise bouts at increasing external loads of 2.5, 5.0, 7.5, 10.0, and 12.5% of body weight (BW).The absolute and relative power and velocity recorded for an external force-velocity relationship were similar in the groups. A significant difference was only observed between taekwondo athletes and judoists for absolute power at the external load of 2.5% BW (In martial arts, training and competition should affect physical characteristics, including jumping and power. The power and velocity recorded for an external force-velocity relationship were similar in the groups. Judoists and boxers did not differ in terms of power or height of the jumps. Taekwondo athletes developed the biggest power and height of the jumps. This is consistent with the discipline characteristics.

scholarly journals Operating length and velocity of human M. vastus lateralis fascicles during vertical jumping

2017 ◽  
Vol 4 (5) ◽  
pp. 170185 ◽  
Author(s):  
Maria Elissavet Nikolaidou ◽  
Robert Marzilger ◽  
Sebastian Bohm ◽  
Falk Mersmann ◽  
Adamantios Arampatzis
Keyword(s):  
Velocity Potential ◽  
Vastus Lateralis ◽  
Power Production ◽  
Velocity Curve ◽  
Mechanical Power ◽  
Jump Height ◽  
Velocity Relationship ◽  
Force Velocity ◽  
The Mean ◽  
Force Potential

Humans achieve greater jump height during a counter-movement jump (CMJ) than in a squat jump (SJ). However, the crucial difference is the mean mechanical power output during the propulsion phase, which could be determined by intrinsic neuro-muscular mechanisms for power production. We measured M. vastus lateralis (VL) fascicle length changes and activation patterns and assessed the force–length, force–velocity and power–velocity potentials during the jumps. Compared with the SJ, the VL fascicles operated on a more favourable portion of the force–length curve (7% greater force potential, i.e. fraction of VL maximum force according to the force–length relationship) and more disadvantageous portion of the force–velocity curve (11% lower force potential, i.e. fraction of VL maximum force according to the force–velocity relationship) in the CMJ, indicating a reciprocal effect of force–length and force–velocity potentials for force generation. The higher muscle activation (15%) could therefore explain the moderately greater jump height (5%) in the CMJ. The mean fascicle-shortening velocity in the CMJ was closer to the plateau of the power–velocity curve, which resulted in a greater (15%) power–velocity potential (i.e. fraction of VL maximum power according to the power–velocity relationship). Our findings provide evidence for a cumulative effect of three different mechanisms—i.e. greater force–length potential, greater power–velocity potential and greater muscle activity—for an advantaged power production in the CMJ contributing to the marked difference in mean mechanical power (56%) compared with SJ.

Sign in / Sign up

Export Citation Format

Share Document