scholarly journals Body roll amplitude and timing in backstroke swimming and their differences from front crawl at the same swimming intensities

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomohiro Gonjo ◽  
Ricardo J. Fernandes ◽  
João Paulo Vilas-Boas ◽  
Ross Sanders
Keyword(s):  
Upper Limb ◽  
Repeated Measures ◽  
Whole Body ◽  
Anatomical Landmarks ◽  
Front Crawl ◽  
Repeated Measures Anova ◽  
Body Roll ◽  
Main Effects

AbstractThe current study investigated body roll amplitude and timing of its peak in backstroke and compared them with front crawl swimming. Nineteen anatomical landmarks were digitised using 80 swimming trial videos (ten swimmers × two techniques × four intensities) recorded by two above- and four below-water cameras. One upper-limb cycle was analysed for each trial, and shoulder and hip roll, whole-body roll (WBR), and WBR due to the buoyant torque (WBRBT) were obtained. Main effects of intensity and technique on the amplitude and timing to reach the peak in those variables were assessed by two-way repeated-measures ANOVA. Swimmers decreased their WBRBT amplitude with an increase in the intensity in both techniques (p ≤ 0.005). The same result was observed for the amplitude of WBR, shoulder roll, and hip roll only in front crawl (p ≤ 0.017). Swimmers maintained the timing of peak WBRBT in both techniques, while they shifted the timing of WBR and hip roll peak toward the beginning of the cycle when increasing the intensity in front crawl (p ≤ 0.017). In conclusion, swimmers maintain the amplitude of WBR, shoulder roll, and hip roll in backstroke when the intensity increases, whereas they reduce the amplitude of all rolls in front crawl.

Acute Effect of Front Crawl Sprint Resisted Swimming on the Propulsive Forces of the Hand

2013 ◽  
Vol 29 (1) ◽  
pp. 98-104 ◽  
Author(s):  
Vassilios Gourgoulis ◽  
Nikolaos Aggeloussis ◽  
Georgios Mavridis ◽  
Alexia Boli ◽  
Panagiotis Kasimatis ◽  
...  
Keyword(s):  
Performance Analysis ◽  
Repeated Measures ◽  
Acute Effect ◽  
Resultant Force ◽  
Added Resistance ◽  
Front Crawl ◽  
Repeated Measures Anova ◽  
Relative Contribution ◽  
Drag And Lift ◽  
Analysis System

The purpose of the current study was to investigate the acute effect of sprint resisted front crawl swimming on the propulsive forces of the hand. Eight female swimmers swam 25 m with maximal intensity, with and without added resistance. A bowl with a capacity of 2.2, 4 and 6 L was used as low, moderate and high added resistance, respectively. The underwater motion of the swimmer’s right hand was recorded using 4 cameras (60 Hz) and the digitization was undertaken using the Ariel Performance Analysis System. Repeated-measures ANOVA revealed that the velocity of the hand, the pitch and the sweepback angles of the hand, as well as the magnitude and the relative contribution of the drag and lift forces were not significantly modified and thus the magnitude of the resultant force did not change. Moreover, the magnitude of the effective force, as well as the angle formed between the resultant force and the axis of the swimming propulsion were not significantly affected. Thus, it could be concluded that resistance added as in this study did not alter the pattern of the propulsive hand forces associated with front crawl sprinting.

scholarly journals Ground Reaction Force Comparison Between Barefoot and Shod Single Leg Landing at Varied Heights

2021 ◽  
Vol 9 (4) ◽  
pp. 29
Author(s):  
Jocelyn E. Arnett ◽  
Cameron D. Addie ◽  
Ludmila M. Cosio-Lima ◽  
Lee E. Brown
Keyword(s):  
Ground Reaction Force ◽  
Repeated Measures ◽  
Reaction Force ◽  
Force Plate ◽  
Collegiate Athletes ◽  
Ground Reaction Forces ◽  
Repeated Measures Anova ◽  
Main Effect ◽  
Reaction Forces ◽  
Main Effects

Background: Landing is a common movement that occurs in many sports. Barefoot research has gained popularity in examining how shoes alter natural movements. However, it is unknown how a single leg landing under barefoot conditions, as well as landing height, affects ground reaction forces (GRF). Objective: The purpose of this research was to examine the differences in GRF during a single leg landing under barefoot and shod conditions from various heights. Methods: Sixteen female Division II collegiate athletes, 8 basketball (age: 19.88 ± 0.64 yrs; height: 1.77 ± 0.09 m; mass: 75.76 ± 12.97 kg) and 8 volleyball (age: 20.00 ± 1.07 yrs; height: 1.74 ± 0.08 m; mass: 72.41 ± 5.41 kg), performed single leg landings from 12, 18, 24, and 30 inches barefoot and shod. An AMTI AccuGait force plate was used to record GRF. A 2 (condition) x 4 (box height) x 2 (sport) repeated measures ANOVA was performed to determine any GRF differences. Results: There were no significant three way or two-way interactions (p > 0.05). There was also no main effect for sport (p > 0.05). There were main effects for footwear and box height (p = 0.000) where shod (2295.121 ± 66.025 N) had greater impact than barefoot (2090.233 ± 62.684 N). Conclusions: Single leg barefoot landings resulted in less vertical GRF than shod landings. This could be due to increased flexion at the joints which aids in force absorption.

scholarly journals Performance of upper limb velocity at different maturation stages in young sports practitioners

2020 ◽  
Vol 19 (5) ◽  
pp. 352
Author(s):  
Leandro Medeiros Silva ◽  
Matheus Peixoto Dantas ◽  
Roberto Fernandes Da Costa ◽  
Rômulo Vasconcelos Teixeira ◽  
Paulo Moreira Silva Dantas ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Upper Limb ◽  
Interaction Effect ◽  
Repeated Measures ◽  
Bone Age ◽  
Maturation Stage ◽  
Repeated Measures Anova ◽  
Maturation Stages ◽  
Delayed Group ◽  
Motor Condition

Introduction: Test batteries have become indispensable for the assessment of performance, maintenance of health, and motor condition, as this also represents a requirement for learning specific skills. Objective: Comparing the performance in different stages of the upper limb velocity test at different maturation stages in children and adolescents. Methods: 91 children and adolescents of both sexes, aged 8 to 14 years, participated in the study. Bone age, anthropometric, and upper limb velocity assessments were executed. A Mixed Repeated Measures ANOVA was used to verify the interaction effect [3 (conditions) x 3 (times)] on the upper limb velocity test phases at different maturation stages. Results: The accelerated stage showed the best performance in all stages of the upper limb velocity test, while for the total performance the delayed group had the lowest achievement. Conclusion: The data indicate that individuals who are in an accelerated maturation stage perform better in the upper limb velocity test than their peers in regular and delayed stages, although the test development curve is similar for all stages.Keywords: anthropometry, child, adolescent, exercise.

scholarly journals The Effects of Whole-Body Vibration on Fatigue in Vertical Jump Performance and Isometric Mid-Thigh Pull Measures

Vibration ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 759-767
Author(s):  
Nicole C. Dabbs ◽  
Sergio Espericueta ◽  
Sean Bonilla ◽  
Margaret T. Jones
Keyword(s):  
Repeated Measures ◽  
Vertical Jump ◽  
Reaction Force ◽  
Whole Body ◽  
Lower Body ◽  
Jump Performance ◽  
Main Effect ◽  
Low Amplitude ◽  
Main Effects ◽  
Active Adults

The purpose of this study is to determine the effects of coupling WBV and acute muscular fatigue to determine its effects on countermovement vertical jump (CMVJ) performance and isometric mid-thigh pull (IMTP). Twenty-eight healthy active adults volunteered for five-day study. Testing sessions 2–5 included one of four conditions: No WBV and no fatigue (CON), WBV and fatigue (WBV + FAT), WBV and no fatigue (WBV), and no WBV and fatigue (FAT). WBV was performed using a frequency of 50 Hz and a low amplitude while performing quarter squats for a total of 4 min with a 30 s rest or work ratio. Lower-body fatigue induced using Bosco fatigue protocol. CMVJ and IMTP were performed on force plates. SPSS was used to perform a 2 × 2 Repeated Measures ANOVA. Significant main effects were found for fatigue in CMVJ-height and CMVJ-peak ground reaction force, no significant main effect for WBV, and no significant interactions. Lower-body fatigue decreases vertical jump performance, and WBV did not attenuate the detrimental effects of lower-body fatigue.

Verbal and Operant Responses of Young Children to Vocal versus Instrumental Song Performances

1997 ◽  
Vol 45 (2) ◽  
pp. 234-244 ◽  
Author(s):  
Wendy L. Sims ◽  
Jane W. Cassidy
Keyword(s):  
Young Children ◽  
Repeated Measures ◽  
Rating Scale ◽  
Dependent Measure ◽  
Kindergarten Children ◽  
Music Preference ◽  
Repeated Measures Anova ◽  
Use Of Time ◽  
Musical Characteristics ◽  
Main Effects

The purpose of this research was to investigate the effects of the presence or absence of lyrics in children s musical selections on two types of young children's responses to music. Of additional interest were differences in responses due to subjects' ages and genders. Two studies were designed to compare responses to recorded lullabies with the melodies performed either by a woman singing the lyrics or by a solo instrument. In Study 1, a pictographic rating scale was used to obtain like-dislike responses to 10 music excerpts from 40 children, ages 4 and 5 years. Results of a three-way repeated-measures ANOVA indicated no significant differences due to the main effects of performance medium, age, or gender, with no significant interactions. Subjects for Study 2 were 51 preschool and kindergarten children. Each child individually listened to two pieces with lyrics and two without lyrics for as long as he or she chose, up to the compute duration of each piece. Time spent listening was recorded to the nearest second. Results of a three-way repeated-measures ANOVA indicated no significant differences due to the main effects of performance medium or song although girls did listen significantly longer than boys did. The results of both studies are consistent with the results of previous research indicating that young children s music attitudes and preferences do not seem to be based on specific musical characteristics and that children may have very idiosyncratic responses and listening styles. The use of time spent listening as a dependent measure for music preference is called into question.

scholarly journals The Effect of Waves on the Performance of Five Different Swimming Strokes

2018 ◽  
Vol 11 (1) ◽  
pp. 41-49
Author(s):  
Per-Ludvik Kjendlie ◽  
Tommy Pedersen ◽  
Robert Stallman
Keyword(s):  
Wave Height ◽  
Repeated Measures ◽  
Average Velocity ◽  
Rank Order ◽  
Front Crawl ◽  
Repeated Measures Anova ◽  
Life Saving ◽  
Wave Heights ◽  
Different Levels ◽  
Unsteady Conditions

Objective:Little is known about the transfer of swimming skills from flat, calm conditions to outdoor, unsteady conditions. The aim of the present study was to investigate the velocity decrement of several life-saving, self-rescue and rescue related strokes when introducing waves of different heights.Methods:Thirty-three subjects swam twelve 25m sprints each, in a randomized order, in a 3x4 (wave height x stroke) design. The wave heights were flat, medium (ca 20 cm) or large (ca 40 cm), in a specially designed wave-simulating pool. The strokes studied were front crawl, head-up crawl, back crawl and breaststroke. A subgroup swam front crawl, head-up crawl and head-up crawl with fins. A repeated measures ANOVA showed a significant effect of stroke, F(3,23)=108 (p<0.001), showing that these four strokes have different levels of performance; and wave height F(2,24)=87 (p<0.001), showing that introducing waves reduced velocity, but there was no interaction effect. The fastest stroke in flat water was not surprisingly, front crawl, followed by head-up crawl, back crawl and breaststroke. When introducing medium or large waves, the order of strokes from fastest to slowest was identical to flat-water conditions. The average velocity decrement when introducing medium and large waves was 3% and 7% respectively. For the subgroup swimming with fins, this was the fastest stroke, followed by front crawl, and head-up crawl. This order did not change when introducing waves, and the velocity decrement was 4 and 2% for medium and large waves respectively (not significantly different from other strokes).Result:The conclusion is that the rank order of strokes does not change when introducing waves and that no stroke seems to perform relatively better in unsteady water compared to flat water. Other aspects than performance and velocity should be considered when choosing strokes for swimming in waves, these are discussed in the paper.

One Size Fits All?

Methodology ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Manuel C. Voelkle ◽  
Patrick E. McKnight
Keyword(s):  
Repeated Measures ◽  
Structural Equation ◽  
Type I Error ◽  
Equation Modeling ◽  
Type I ◽  
Finite Sample ◽  
Traditional Methods ◽  
Repeated Measures Anova ◽  
Special Cases ◽  
Latent Curve

The use of latent curve models (LCMs) has increased almost exponentially during the last decade. Oftentimes, researchers regard LCM as a “new” method to analyze change with little attention paid to the fact that the technique was originally introduced as an “alternative to standard repeated measures ANOVA and first-order auto-regressive methods” (Meredith & Tisak, 1990, p. 107). In the first part of the paper, this close relationship is reviewed, and it is demonstrated how “traditional” methods, such as the repeated measures ANOVA, and MANOVA, can be formulated as LCMs. Given that latent curve modeling is essentially a large-sample technique, compared to “traditional” finite-sample approaches, the second part of the paper addresses the question to what degree the more flexible LCMs can actually replace some of the older tests by means of a Monte-Carlo simulation. In addition, a structural equation modeling alternative to Mauchly’s (1940) test of sphericity is explored. Although “traditional” methods may be expressed as special cases of more general LCMs, we found the equivalence holds only asymptotically. For practical purposes, however, no approach always outperformed the other alternatives in terms of power and type I error, so the best method to be used depends on the situation. We provide detailed recommendations of when to use which method.

Comparison of static ocular counter-roll induced by active and passive head tilt and whole body roll

2005 ◽  
Vol 32 (S 4) ◽  
Author(s):  
V.C Zingler ◽  
D Krivoshey ◽  
E Schneider ◽  
S Glasauer ◽  
T Brandt ◽  
...  
Keyword(s):  
Head Tilt ◽  
Whole Body ◽  
Body Roll

Time of imagery’s effect on performance and self-efficacy in college baseball players

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Colton Haight ◽  
Sandra Moritz ◽  
Tanis Walch
Keyword(s):  
Self Efficacy ◽  
Repeated Measures ◽  
Group Interaction ◽  
Physical Effect ◽  
Baseball Players ◽  
Repeated Measures Anova ◽  
Significant Time ◽  
Imagery Group ◽  
College Baseball ◽  
Group 2

AbstractThe relationships among the time of imagery use on performance and self-efficacy in college baseball players during a hitting task was examined. Participants (n=24) were randomly assigned to one of three imagery conditions: (a) before practice, (b) during practice, (c) after practice. A one-shot MG-M imagery intervention was used. Results from a 3 (imagery group) ×2 (pretest and posttest) repeated measures ANOVA showed only a significant time by imagery group interaction for self-efficacy (F (2, 21)=4.67, p<0.05). These findings suggest that imagery had a stronger psychological effect than physical effect.

Sign in / Sign up

Export Citation Format

Share Document