scholarly journals Mechanical demands of the two-handed hardstyle kettlebell swing performed by an RKC-certified Instructor

2021 ◽  
Author(s):  
Neil J. Meigh ◽  
Wayne A. Hing ◽  
Ben J. Schram ◽  
Justin W.L. Keogh
Keyword(s):  
Ground Reaction Force ◽  
Pearson Correlation ◽  
Reaction Force ◽  
Peak Force ◽  
Vertical Force ◽  
Strong Positive Correlation ◽  
Male Body ◽  
Positive Correlation ◽  
Force Peak ◽  
Force Time

Background: The effects of hardstyle kettlebell training are frequently discussed in the strength and conditioning field, yet reference data from a proficient swing is scarce. The aim of this study was to profile the mechanical demands of a two-handed hardstyle swing performed by a Russian Kettlebell Challenge (RKC) Instructor. Methods: The subject is a 44-year-old male, body mass 75.6 kg, height 173.5 cm, with 6 years of regular hardstyle kettlebell training since attaining certification in 2013. Two-handed hardstyle swings were performed with a series of incremental weight (8-68 kg) kettlebells. Ground reaction forces (GRFs) were obtained from a floor-mounted force platform. Force-time curves (FTCs), peak force, forward force relative to vertical force, rate of force development (RFD) and swing cadence were investigated. Results: Data revealed the FTC of a proficient swing were highly consistent (mean SD = 47 N) and dominated by a single force peak, with a profile that remained largely unchanged with 8-24 kg kettlebells. Pearson correlation analyses revealed a very strong positive correlation in peak force with kettlebell weight (r = 0.95), which increased disproportionately from the lightest to heaviest kettlebells; peak net force increasing from 8.36 ± 0.75 N.kg-1 (0.85 x BW) to 12.82 ± 0.39 N.kg-1 (1.3x BW). There was a strong negative correlation between RFD and kettlebell weight (r = 0.82) decreasing from 39.2 N.s-1.kg-1 to 21.5 N.s-1.kg-1. There was a very strong positive correlation in forward ground reaction force with kettlebell weight (r = 0.99), expressed as a ratio of vertical ground reaction, increasing from 0.092 (9.2%) to 0.205 (20.5%). Swing cadence exceeded 40 swings per minute (SPM) at all weights. Conclusion: Our findings challenge some of the popular beliefs of the hardstyle kettlebell swing. Consistent with hardstyle practice and previous kinematic analysis of expert and novice, force-time curves show a characteristic single large force peak, differentiating passive from active shoulder flexion. Ground reaction force did not increase proportionate to bell weight, with a magnitude of forward force smaller than described in practice. These results could be useful for coaches and trainers using kettlebells with the intent to improve athletic performance, and healthcare providers using the kettlebell swing for therapeutic purposes. Findings from this study were used to inform the BELL Trial, a pragmatic clinical trial of kettlebell training with older adults. www.anzctr.org.au ACTRN12619001177145.

Use of Ground Reaction Force Parameters in Predicting Peak Tibial Accelerations in Running

1993 ◽  
Vol 9 (4) ◽  
pp. 306-314 ◽  
Author(s):  
Ewald M. Hennig ◽  
Thomas L. Milani ◽  
Mario A. Lafortune
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
The Body ◽  
Force Platform ◽  
Good Prediction ◽  
Vertical Force ◽  
Force Peak ◽  
Power Frequency ◽  
Initial Force ◽  
Force Data

Ground reaction force data and tibial accelerations from a skin-mounted transducer were collected during rearfoot running at 3.3 m/s across a force platform. Five repetitive trials from 27 subjects in each of 19 different footwear conditions were evaluated. Ground reaction force as well as tibial acceleration parameters were found to be useful for the evaluation of the cushioning properties of different athletic footwear. The good prediction of tibial accelerations by the maximum vertical force rate toward the initial force peak (r2 = .95) suggests that the use of a force platform is sufficient for the estimation of shock-absorbing properties of sport shoes. If an even higher prediction accuracy is required a regression equation with two variables (maximum force rate, median power frequency) may be used (r2 = .97). To evaluate the influence of footwear on the shock traveling through the body, a good prediction of peak tibial accelerations can be achieved from force platform measurements.

scholarly journals Estimates of Running Ground Reaction Force Parameters from Motion Analysis

2017 ◽  
Vol 33 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Gaspare Pavei ◽  
Elena Seminati ◽  
Jorge L.L. Storniolo ◽  
Leonardo A. Peyré-Tartaruga
Keyword(s):  
Motion Analysis ◽  
Ground Reaction Force ◽  
Center Of Mass ◽  
Reaction Force ◽  
The Body ◽  
Vertical Force ◽  
Vertical Stiffness ◽  
Leg Stiffness ◽  
Force Peak ◽  
Body Center

We compared running mechanics parameters determined from ground reaction force (GRF) measurements with estimated forces obtained from double differentiation of kinematic (K) data from motion analysis in a broad spectrum of running speeds (1.94–5.56 m⋅s–1). Data were collected through a force-instrumented treadmill and compared at different sampling frequencies (900 and 300 Hz for GRF, 300 and 100 Hz for K). Vertical force peak, shape, and impulse were similar between K methods and GRF. Contact time, flight time, and vertical stiffness (kvert) obtained from K showed the same trend as GRF with differences < 5%, whereas leg stiffness (kleg) was not correctly computed by kinematics. The results revealed that the main vertical GRF parameters can be computed by the double differentiation of the body center of mass properly calculated by motion analysis. The present model provides an alternative accessible method for determining temporal and kinetic parameters of running without an instrumented treadmill.

Relationships between Ground Reaction Force and Tibial Bone Acceleration Parameters

1991 ◽  
Vol 7 (3) ◽  
pp. 303-309 ◽  
Author(s):  
Ewald M. Hennig ◽  
Mario A. Lafortune
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Time Shift ◽  
Vertical Force ◽  
Time To Peak ◽  
Axial Acceleration ◽  
Force Peak ◽  
Tibial Acceleration ◽  
Using Data ◽  
Force Data

Using data from six male subjects, this study compared ground reaction force and tibial acceleration parameters for running. A bone-mounted triaxial accelerometer and a force platform were employed for data collection. Low peak values were found for the axial acceleration, and a time shift toward the occurrence of the first peak in the vertical force data was present. The time to peak axial acceleration differed significantly from the time to the first force peak, and the peak values of force and acceleration demonstrated only a moderate correlation. However, a high negative correlation was found for the comparison of the peak axial acceleration with the time to peak vertical force. Employing a multiple regression analysis, the peak tibial acceleration could be well estimated using vertical force loading rate and peak horizontal ground reaction force as predictors.

scholarly journals Change in force profile of the hardstyle kettlebell swing in older adults is small following 16 weeks of training and may not be required to improve physical function: findings from the BELL trial

2021 ◽  
Author(s):  
Neil J Meigh ◽  
Justin W.L. Keogh ◽  
Evelyne N. Rathbone ◽  
Wayne Hing
Keyword(s):  
Older Adults ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Healthcare Providers ◽  
High Volume ◽  
Minimum Clinically Important Difference ◽  
Vertical Force ◽  
Time Curve ◽  
Force Profile ◽  
Force Time

Background. Hardstyle kettlebell training is characterised by the ballistic two-handed kettlebell swing with outcomes believed to be strongly influenced by swing proficiency. This study examines the effect of four months hardstyle kettlebell training on the force profile of the two-handed kettlebell swing, and peak ground reaction force during a kettlebell deadlift in older adults. These data will help inform healthcare providers and coaches about the use and prescription of kettlebell exercises with older adults. Methods. Five males and five females <70 years of age who participated in the BELL trial were recruited. Two-handed hardstyle swings were performed with 8-16 kg, and deadlifts with 8-32 kg. Ground reaction force (GRF) was obtained from a floor-mounted force platform. Force-time curves (FTCs), peak force, forward force relative to vertical force, rate of force development (RFD), and swing cadence were investigated. Results were compared with the same data variables collected from the participants in an exploratory pre-intervention study, conducted approximately seven months before the present study. Participants completed approximately 90 kettlebell training sessions during a four-month training intervention. Results. Participants used kettlebells to perform 3779 ± 802 swings, 923 ± 251 cleans, 825 ± 309 snatches and 744 ± 178 deadlifts during group-training sessions. Peak ground reaction force during kettlebell swings did not significantly change with any kettlebell weight. There was a significant 3% increase in the magnitude of forward force during 8 kg swings, and a significant 3% decrease in forward force during 16 kg swings. There were large significant improvements in swing cadence with a mean increase of three swings per minute and a small non-significant increase in RFD. Change in kettlebell swing force-time curve profiles were small. Change in peak ground reaction force during deadlifts were moderate to large. All participants increased in grip strength following training, with the magnitude of change greater than the minimum clinically important difference for seven participants. All participants had significant increases in multiple secondary outcomes. Conclusion. Group-based and online kettlebell training is likely to be ineffective for improving the force profile of the hardstyle kettlebell swing in older adults. Insufficiently active older adults engaged in high-volume kettlebell training performed 3-5 times weekly, can however expect to see clinically meaningful improvements in health-related physical fitness irrespective of swing proficiency, and have increased confidence with heavy lifting tasks. Results of this study suggest that beyond safe and competent performance, striving to optimise hardstyle swing technique may provide no additional benefit to clinical outcomes in older adults.

scholarly journals Running ground reaction forces across footwear conditions are predicted from the motion of two body mass components

2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
Andrew B. Udofa ◽  
Kenneth P. Clark ◽  
Laurence J. Ryan ◽  
Peter G. Weyand
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Time Patterns ◽  
Foot Strike ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Force Time

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error  = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.

Phase-Specific Force and Time Predictors of Standing Long Jump Distance

2021 ◽  
pp. 1-8
Author(s):  
John R. Harry ◽  
John Krzyszkowski ◽  
Luke D. Chowning ◽  
Kristof Kipp
Keyword(s):  
National Collegiate Athletic Association ◽  
Reaction Force ◽  
Vertical Force ◽  
Jump Height ◽  
Strength Index ◽  
Phase Duration ◽  
Standing Long Jump ◽  
Jump Distance ◽  
Long Jump ◽  
Force Time

This study sought to identify potential predictors of standing long jump (SLJ) performance using force–time strategy metrics within the unloading, eccentric yielding, eccentric braking, and concentric phases. Fifteen National Collegiate Athletic Association division 1 male soccer players (19 [1] y, 1.81 [0.94] m, 80.3 [22.4] kg) performed 3 maximum-effort SLJs, while 3-dimensional ground reaction force (GRF) data were obtained. Regularized regression models were used to investigate associations between force–time strategy metrics and 2 metrics of SLJ performance (ie, jump distance and modified reactive strength index). Jump height and eccentric yielding time were the only predictors of jump distance that also demonstrated large correlations to jump distance. Anterior–posterior unloading yank, average concentric vertical force, and concentric phase duration were the only predictors of modified reactive strength index that also demonstrated large correlations to modified reactive strength index. To maximize SLJ distance in high-level soccer athletes, human performance practitioners could design interventions to drive changes in strategy to increase jump height and decrease eccentric yielding time. To improve SLJ explosiveness, interventions to drive changes in unloading and concentric force application and decrease concentric time could be emphasized. Importantly, unique variable combinations can be targeted when training for SLJ distance and explosiveness adaptations.

scholarly journals Ground reaction force in basketball cutting maneuvers with and without ankle bracing and taping

2006 ◽  
Vol 124 (5) ◽  
pp. 245-252 ◽  
Author(s):  
Isabel de Camargo Neves Sacco ◽  
Henrique Yuji Takahasi ◽  
Eneida Yuri Suda ◽  
Linamara Rizzo Battistella ◽  
Cristianne Akie Kavamoto ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Repeated Measurements ◽  
Medical Rehabilitation ◽  
Time Interval ◽  
Peak Time ◽  
Ankle Sprains ◽  
Vertical Force ◽  
Sport Shoe ◽  
Ankle Bracing

CONTEXT AND OBJECTIVE: In basketball, the most common injuries are ankle sprains. For this reason, players frequently use external ankle devices or taping as prophylactic and rehabilitation measures. The purpose of this study was to evaluate ground reaction force (GRF) responses in basketball players while performing typical cutting maneuvers with and without ankle bracing and ankle taping. DESIGN AND SETTING: Comparative study with experimental design of single-group repeated measurements, at Medical Rehabilitation Division, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo. METHODS: Vertical (Fy) and medial-lateral (Fz) GRF measurements were made under three conditions (taping, Aircast-type orthosis and basketball shoes alone), with analysis of peak forces at foot contact (Fymax1, Fzmax1, Fymax2 and Fzmax2), growth gradient (peak/time) (GG Fymax1, GG Fzmax1, GG Fymax2 and GG Fzmax2) and impulse after foot contact. RESULTS: Bracing significantly reduced Fymax2 and GG Fymax2. GG Fzmax1 was significantly higher for the sport shoe condition than for the taping condition. Taping increased Fy in relation to the sport shoe at foot contact, but over a longer time interval, without increasing excessive ankle loading. Fz reached a peak in less time, which might generate greater inversion/eversion loading on a player's foot. The Aircast exerted better shock-absorbing effect than did the other two conditions, since it generated less vertical force over longer time intervals and smaller medial-lateral forces in relation to taping. CONCLUSIONS: Ankle bracing and ankle taping action mechanisms are still unclear and therefore should be carefully prescribed. More studies are needed to clarify taping and bracing effects on sporting activities.

scholarly journals The Short Communication: Polymorphism of myostatin gene and its association with body weight traits in a hybrid of GAMA chicken (Gallus gallus domesticus Linn. 1758)

2019 ◽  
Vol 20 (11) ◽  
Author(s):  
ARDO TANJUNG ◽  
H.T.S.S.G. SARAGIH ◽  
TRIJOKO ◽  
H.P. SOENARWAN ◽  
S. WIDIANTO ◽  
...  
Keyword(s):  
Body Weight ◽  
Pearson Correlation ◽  
Negative Relationship ◽  
Gallus Gallus ◽  
Gallus Domesticus ◽  
The Body ◽  
Strong Positive Correlation ◽  
Gallus Gallus Domesticus ◽  
Myostatin Gene ◽  
Positive Correlation

Abstract. Tanjung A, Saragih HTSSG, Trijoko, Soenarwan HP, Widianto S, Mahardhika IWS, Daryono BS. 2019. Polymorphism of myostatin gene and its association with body weight traits in a hybrid of GAMA chicken (Gallus gallus domesticus Linn. 1758). Biodiversitas 20: 3207-3212. An experiment was conducted to detect SNP of the myostatin gene and its association with the body weight of hybrid chicken crossbreed from F1 Kamper and BC1 Broiler. Four F1 Kamper hens were crossbred with BC1 Broiler rooster. Day old chick (DOC) hatched were maintained for 49 days with body weight measurement every seven days. The blood samples from 49 days old chicken were taken for DNA isolation by Chelex 5% method and then amplification of the myostatin gene. PCR products were sequenced, and sequence alignment was performed using Clustal Omega to obtain SNP. The SNP obtained was analyzed by the Pearson correlation test with the body weight of forty nine-days-old chickens. The body weight of the hybrid chicken is higher than of Pelung chicken but lower than the Broiler. There are 7 SNPs in myostatin gene exons included 2 Adenine insertions, 1 Guanine deletion, and four substitutions (C2244G, G2283A, T4842G, G7378T) that yield nine haplotypes. Six haplotypes had different protein sequences with Myostatin protein, while three haplotypes were identical to Myostatin protein. The correlation analysis showed that there was a strong positive correlation (r = 0.736) between normal Myostatin protein and mutant to chicken body weight at 49-days-old. Adenine insertion to nucleotide 2099-2100 of myostatin gene had a very strong positive correlation (r = 0.800) to 49-days-old chicken body weight, although T4842G substitution had a strong negative relationship (r = -0.773) to 49-days-old chicken body weight. Adenine insertion to nucleotide 2099-2100 of myostatin gene could be a genetic marker of heavier body weight of the hybrid chicken.

scholarly journals Concurrent Validity of a Portable Force Plate Using Vertical Jump Force–Time Characteristics

2018 ◽  
Vol 34 (5) ◽  
pp. 410-413 ◽  
Author(s):  
Jason Lake ◽  
Peter Mundy ◽  
Paul Comfort ◽  
John J. McMahon ◽  
Timothy J. Suchomel ◽  
...  
Keyword(s):  
Concurrent Validity ◽  
Vertical Jump ◽  
Reaction Force ◽  
Force Plate ◽  
Vertical Force ◽  
Jump Height ◽  
Strength Index ◽  
Limits Of Agreement ◽  
Force Time ◽  
Plate System

This study examined concurrent validity of countermovement vertical jump reactive strength index modified and force–time characteristics recorded using a 1-dimensional portable and laboratory force plate system. Twenty-eight men performed bilateral countermovement vertical jumps on 2 portable force plates placed on top of 2 in-ground force plates, both recording vertical ground reaction force at 1000 Hz. Time to takeoff; jump height; reactive strength index modified; and braking and propulsion impulse, mean net force, and duration were calculated from the vertical force from both force plate systems. Results from both systems were highly correlated (r ≥ .99). There were small (d < 0.12) but significant differences between their respective braking impulse, braking mean net force, propulsion impulse, and propulsion mean net force (P < .001). However, limits of agreement yielded a mean value of 1.7% relative to the laboratory force plate system (95% confidence limits, 0.9%–2.5%), indicating very good agreement across all of the dependent variables. The largest limits of agreement were for jump height (2.1%), time to takeoff (3.4%), and reactive strength index modified (3.8%). The portable force plate system provides a valid method of obtaining reactive strength measures, and several underpinning force–time variables, from unloaded countermovement vertical jump. Thus, practitioners can use both force plates interchangeably.

Sign in / Sign up

Export Citation Format

Share Document