The Influence of Biological Maturity and Competitive Level on Isometric Force-Time Curve Variables and Vaulting Performance in Young Female Gymnasts

Abstract Purpose This cross-sectional study investigated dynamic force–time variables and vaulting performance in young female gymnasts of different maturity status. Methods 120 gymnasts aged 5–14 years were sub-divided into maturity groupings using percent of predicted adult height (%PAH) attained. Participants performed three jumping protocols, the squat jump (SJ), countermovement jump (CMJ) and drop jump (DJ), before completing straight jump vaults that were recorded using two-dimensional video. Results Jumping performance improved with biological maturity evidenced by the most mature gymnasts’ producing significantly more absolute force (P < 0.05; all d > 0.78), impulse (P < 0.05; all d > 0.75) and power (P < 0.05; all d > 0.91) than the least mature group, resulting in the greater jump heights (P < 0.05; all d > 0.70). While, no significant differences were observed in relative peak force across multiple tests, measures of relative peak power did significantly increase with maturity. Based upon regression analyses, maturation was found to influence vertical take-off velocity during vaulting, explaining 41% of the variance in each jumping protocol. Across all tests, the DJ was found to have the highest predictive ability of vaulting vertical take-off velocity, explaining 55% of the total variance. Conclusion Biological maturation impacts jump height and underpinning mechanical variables in young female gymnasts. Vaulting vertical take-off velocity appears to be influenced by maturation and various dynamic force–time variables, particularly those during DJ, which had the highest explained total variance.

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The Relationship Between Isometric Force-Time Curve Characteristics and Club Head Speed in Recreational Golfers

The Journal of Strength and Conditioning Research ◽

10.1519/jsc.0b013e31826791bf ◽

2012 ◽

Vol 26 (10) ◽

pp. 2685-2697 ◽

Cited By ~ 26

Author(s):

Brian K. Leary ◽

Jason Statler ◽

Britton Hopkins ◽

Rachael Fitzwater ◽

Tucker Kesling ◽

...

Keyword(s):

Isometric Force ◽

Time Curve ◽

Club Head ◽

Force Time ◽

The Relationship ◽

Recreational Golfers

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Reliability of Isometric Force-time Curve Parameters for Men Aged 20 to 79 Years

The Journal of Strength and Conditioning Research ◽

10.1519/1533-4287(1992)006<0158:roiftc>2.3.co;2 ◽

1992 ◽

Vol 6 (3) ◽

pp. 158

Author(s):

Michael G. Bemben ◽

Benjamin H. Massey ◽

Richard A. Boileau ◽

James E. Misner

Keyword(s):

Isometric Force ◽

Time Curve ◽

Force Time

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The Influence of Biological Maturity on Sprint Speed, Standing Long Jump, and Vaulting Performance in Young Female Gymnasts

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2020-0505 ◽

2020 ◽

pp. 1-8

Author(s):

Sylvia Moeskops ◽

Jon L. Oliver ◽

Paul J. Read ◽

Gregory D. Myer ◽

Rhodri S. Lloyd

Keyword(s):

Adult Height ◽

Velocity Ratio ◽

Young Female ◽

Regression Analyses ◽

Standing Long Jump ◽

Long Jump ◽

Biological Maturity ◽

Female Gymnasts ◽

Peak Speed ◽

Separate Regression

Purpose: To quantify speed, peak momentum, standing long jump (SLJ), and the ratio of vertical to horizontal take-off velocity (Ratiovert–hori TOV) in young female gymnasts of different maturity status and their influence on vaulting vertical TOV. Methods: One hundred twenty gymnasts age 5–14 years were subdivided into maturity groupings using percentage of predicted adult height. Participants performed three 20-m sprints, SLJ, and straight jump vaults that were recorded using 2-dimensional video and analyzed using digitizing software. Results: All speed intervals, peak speed, peak momentum, SLJ distance, vault height, and vertical TOV increased between the early prepubertal and late prepubertal (P < .001; d = 0.65–1.10) and early prepubertal and pubertal (P < .001; d = 0.75–1.00) groups. No differences between these metrics were observed between the 2 most mature groups (d = 0.01–0.55). Multiple regression analyses revealed peak speed had the strongest association with vertical TOV (R2 = 59%) and also identified the Ratiovert–hori as a secondary determinant (R2 = 12%). A separate regression model indicated that maturity status (percentage of predicted adult height) moderately influences vertical TOV during vaulting (R2 = 41%). Conclusion: Speed and SLJ performance increase between the early prepubertal and late prepubertal years in young female gymnasts. However, given that peak speed and Ratiovert–hori combined to explain 71% of the total variance in vaulting vertical TOV, in order to increase aerial time for more advanced vaulting, practitioners should attempt to enhance peak speed alongside takeoff technique to develop gymnasts’ ability to transfer linear speed to vertical TOV.

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Upper-Limb Force–Time Characteristics Determine Serve Velocity in Competition Tennis Players

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2021-0254 ◽

2021 ◽

pp. 1-9

Author(s):

Ernest Baiget ◽

Joshua Colomar ◽

Francisco Corbi

Keyword(s):

Upper Limb ◽

High Performance ◽

Isometric Force ◽

External Rotation ◽

Stepwise Multiple Regression ◽

Kinetic Chain ◽

Time Intervals ◽

Time Curve ◽

Tennis Players ◽

Force Time

Purpose: (1) To analyze the associations between serve velocity (SV) and various single-joint upper-limb isometric force–time curve parameters, (2) to develop a prediction model based on the relationship between these variables, and (3) to determine whether these factors are capable of discriminating between tennis players with different SV performances. Method: A total of 17 high-performance tennis players performed 8 isometric tests of joints and movements included in the serve kinetic chain (wrist and elbow flexion [EF] and extension; shoulder flexion [SHF] and extension [SHE], internal [SHIR] and external rotation). Isometric force (IF), rate of force development (RFD), and impulse (IMP) at different time intervals (0–250 ms) were obtained for analysis. Results: Significant (P < .05 to P < .01) and moderate to very large correlations were found between SV and isometric force (IF), RFD and impulse (IMP) at different time intervals in all joint positions tested (except for the EF). Stepwise multiple regression analysis highlighted the importance of RFD in the SHIR from 0 to 50 milliseconds and isometric force (IF) in the SHF at 250 milliseconds on SV performance. Moreover, the discriminant analyses established SHIR RFD from 0 to 30 milliseconds as the most important factor discriminating players with different serve performances. Conclusions: Force–time parameters in upper-limb joints involved in the serve moderate to very largely influence SV. Findings suggest that the capability to develop force in short periods of time (<250 ms), especially in the shoulder joint, seems relevant to develop high SV in competition tennis players.

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The Effect of Static Stretching on Maximal Voluntary Contraction and Force-Time Curve Characteristics

Journal of Sport Rehabilitation ◽

10.1123/jsr.15.3.185 ◽

2006 ◽

Vol 15 (3) ◽

pp. 185-194 ◽

Cited By ~ 7

Author(s):

Christos Papadopoulos ◽

Vasilios I. Kalapotharakos ◽

Georgios Noussios ◽

Konstantinos Meliggas ◽

Evangelia Gantiraga

Keyword(s):

Maximal Voluntary Contraction ◽

Isometric Force ◽

Rectus Femoris ◽

Biceps Femoris ◽

Voluntary Contraction ◽

Emg Activity ◽

Static Stretching ◽

Time Curve ◽

Significant Difference ◽

Force Time

Objective:To examine the effect of static stretching on maximal voluntary contraction (MVC) and isometric force-time curve characteristics of leg extensor muscles and EMG activity of rectus femoris (RF), biceps femoris (BF), and gastrocnemius (GA).Design:A within subjects experimental design.Participants:Ten healthy students were tested after a jogging and a jogging/stretch protocol.Intervention:The stretching protocol involved a 10 min jog and seven static stretching exercises.Main Outcomes:Measurements included MVC, time achieved to MVC (TMVC), force at 100ms (F100), index of relative force (IRF), index of rate of force development (IRFD), and average integrated EMG activity (AEMG).Results:There were slight but no significant changes in MVC (1%), TMVC(4.8%), F100(7.8%), IRF (1%), and IRFD(3.5%) between measurement. A significant difference (21%;P< 0.05) in AEMG of RF was found.Conclusions:The present study indicated that a moderate volume of static stretching did not alter significantly the MVC and the isometric force-time curve characteristics. Neural inhibition, as it is reflected from AEMG of RF, did not alter MVC and isometric force-time curve characteristics.

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INDICATORS OF NEUROMUSCULAR FATIGUE IN LEG PRESS EXERCISE IN MEN AND WOMEN

Revista Brasileira de Medicina do Esporte ◽

10.1590/1517-869220202603216124 ◽

2020 ◽

Vol 26 (3) ◽

pp. 243-247

Author(s):

Camila Brasileiro Azevedo Barros ◽

Manoel da Cunha Costa ◽

Antônio Gonçalves dos Santos Neto ◽

José Hildemar Teles Gadelha ◽

Brendha Stephany Rodrigues da Silva ◽

...

Keyword(s):

Muscle Activation ◽

Isometric Force ◽

Maximum Voluntary Contraction ◽

Voluntary Contraction ◽

Level Of Evidence ◽

Similar Reduction ◽

Time Curve ◽

Men And Women ◽

Leg Press ◽

Force Time

ABSTRACT Introduction Muscle fatigue is characterized by reduced ability to produce maximum strength or power, and may differ between men and women. Changes in velocity of movement during exercise, and in the ability to produce strength after exercise, may help when comparing fatigue in men and women. Objective To analyze the differences between men and women in relation to number of repetitions, kinetics, kinematics and isometric force-time curve performance, and their respective muscle activation in horizontal leg press exercises. Methods Fifteen men and fifteen women underwent isometric force-time curve (Cf-t) and electromyographic (EMG) assessments before and after performing horizontal leg press exercises. The exercises were performed in three sets until voluntary exhaustion, at 70% maximal repetition. During the exercises, kinetic and kinematic variables were obtained by means of two force transducers, a linear position potentiometer and accelerometer adapted for the horizontal leg press and synchronized by a signal conditioning plate. Results The mean propulsive velocity significantly reduced between the first and last repetition of each series, with a similar reduction for men (-12.4 to -29.2%) and women (-29.2 to -35.6%). The same pattern was observed for the other kinetic and kinematic variables. The maximum voluntary contraction and peak force development rate also decreased for both men (-15.1 ± 8.7% and -26.9 ± 21.2%, respectively) and women (-13.9 ± 10.4% and -28.2 ± 11.5%, respectively). Conclusion Based on the different variables used to quantify the effect of fatigue during and after horizontal leg press exercises, the research found practically no differences between men and women. Level of evidence II; Comparative prospective study.

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Reliability of Isometric Force-time Curve Parameters for Men Aged 20 to 79 Years

The Journal of Strength and Conditioning Research ◽

10.1519/00124278-199208000-00006 ◽

1992 ◽

Vol 6 (3) ◽

pp. 158-164

Author(s):

Michael G. Bemben ◽

Benjamin H. Massey ◽

Richard A. Boileau ◽

James E. Misner

Keyword(s):

Isometric Force ◽

Time Curve ◽

Force Time

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Relationship Between Strength Characteristics and Unweighted and Weighted Vertical Jump Height

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.4.4.461 ◽

2009 ◽

Vol 4 (4) ◽

pp. 461-473 ◽

Cited By ~ 96

Author(s):

Jenna M. Kraska ◽

Michael W. Ramsey ◽

G. Gregory Haff ◽

Nate Fethke ◽

William A. Sands ◽

...

Keyword(s):

Body Mass ◽

Isometric Force ◽

Vertical Jump ◽

Force Plate ◽

Collegiate Athletes ◽

Practical Method ◽

Relative Strength ◽

Jump Height ◽

Time Curve ◽

Force Time

Purpose:To investigate the relationship between maximum strength and differences in jump height during weighted and unweighted (body weight) static (SJ) and countermovement jumps (CMJ).Methods:Sixty-three collegiate athletes (mean ± SD; age= 19.9 ± 1.3 y; body mass = 72.9 ± 19.6 kg; height = 172.8 ± 7.7 cm) performed two trials of the SJ and CMJ with 0 kg and 20 kg on a force plate; and two trials of mid-thigh isometric clean pulls in a custom rack over a force plate (1000-Hz sampling). Jump height (JH) was calculated from fight time. Force-time curve analyses determined the following: isometric peak force (IPF), isometric force (IF) at 50, 90, and 250 ms, and isometric rates of force development (IRFD). Absolute and allometric scaled forces, [absolute force/(body mass0.67)], were used in correlations.Results:IPF, IRFD, F50a, F50, F90, and F250 showed moderate/strong correlations with SJ and CMJ height percent decrease from 0 to 20 kg. IPFa and F250a showed weak/moderate correlations with percent height decrease. Comparing strongest (n = 6) to weakest (n = 6): t tests revealed that stronger athletes (IPFa) performed superior to weaker athletes.Conclusion:Data indicate the ability to produce higher peak and instantaneous forces and IRFD is related to JH and to smaller differences between weighted and unweighted jump heights. Stronger athletes jump higher and show smaller decrements in JH with load. A weighted jump may be a practical method of assessing relative strength levels.

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