THE EFFECT OF VERBAL FEEDBACK ON BIOMECHANICAL PERFORMANCE DURING SWIMMING ERGOMETRY
Krystyna Zatoń, Izabela Cześniewicz, Stefan Szczepan
Purpose. The aim was to investigate the effects of verbal feedback on biomechanical performance variables during swimming ergometry.
Methods. The total of 100 healthy and physically active males (19.56 ± 1.32 years of age, 181.23 ± 4.35 cm in height, and 70.54 ± 8.6 kg in weight) participated in the study. The subjects were randomized into 2 groups (experimental and control); 2 sessions were administered. In the first session (pre-test), both groups completed the butterfly stroke on a swimming ergometer in identical conditions. In the second session (post-test), the experimental group received verbal instructions that conveyed kinaesthetic information. To rationalize verbal information, the criteria of efficient didactic communication were applied (syntax, semantics, and pragmatics). Biomechanical performance was monitored continuously by measuring work output (J), total force (N), power output (W), and total distance of hand travel (cm).
Results. Differences in the average values of the analysed variables between groups and samples were determined with a multivariate analysis of variance (MANOVA) (p < 0.05). The analysis of the results showed that the inclusion of verbal feedback resulted in statistically significant increases between pre- and post-test in all biomechanical variables in the experimental group, as well as in significant between-group differences post-test.
Conclusions. Appropriately prepared verbal cues following the criteria of efficient didactic communication may improve biomechanical performance during movement execution on a swimming ergometer.
Key words: swimming, verbal information, kinaesthetic information, work output, total force, power output
CONSIDERING VALUES IN THE SPORT EXPERIENCES OF WHEELCHAIR BASKETBALL PLAYERS
Purpose. The paper aims to discuss a diversity of sport experiences in individuals with physical disabilities who are members of a wheelchair basketball club. The sample of the study consisted of 10 males with physical disabilities (aged 18–40 years).
Methods. The study used in-depth interviews, and a systems method was applied to analyse the interview data. The method allows for examining sport as a value which is neither fully autonomous nor predetermined.
Results. Despite the differences in the sample, it can be assumed that players with physical disabilities experience sport in similar ways. However, their experiences may differ in terms of kinds, forms, contents, positions, and functions of sport. This diversity represents the dynamics of relations, interactions, and interdependences among values in the participants’ respective axiological systems. Besides, it also reflects the ways in which the participants perceive themselves in the context of multiple practices of daily life.
Conclusions. An essential difference between the experience of players from various countries may therefore lie chiefly in the context (e.g. social, economic, political) in which players function and in which they realize particular values. Further research should take this context into account and investigate in particular its dependencies and relations with other values, such as health, physical ability, work, education, etc. Also, research concerning how sport is experienced from the perspective of different types and levels of disability or from the perspective of gender could prove interesting.
Key words: sport, values, individuals with physical disabilities
THE CONTEXTUAL INTERFERENCE EFFECT ON THE PERFORMANCE OF FUNDAMENTAL MOTOR SKILLS IN ADULTS
JUDITH JIMENEZ-DIAZ, MARIA MORERA-CASTRO, WALTER SALAZAR
Purpose. The aim of the study was to analyse the effect of contextual interference on acquisition and retention for jump and throw in adults.
Methods. The participants (n = 50) were randomly assigned to 3 groups: blocked practice (BP), random practice (RP), and control group (CG). During each practice session, the BP group performed 20 trials of one skill, followed by 20 trials of the second skill, while the RP group performed 20 trials for each skill in a random order. The CG participated in physical activities that did not include any of these two skills. The intervention consisted of 7 sessions. Skill performance was assessed with the Test of Fundamental Motor Skills for Adults – for pretest, acquisition, and retention. The test has content validity established by logical validity, as well as documented intra-class reliability (calculated via test-retest) and inter-rater reliability.
Results. A two-way ANOVA [group (3) × measurement (3)] with repeated measures in the last factor revealed a significant interaction in throw (F = 5.81; p = 0.001) and jump (F = 10.92; p = 0.001). Post-hoc analyses indicated that the BP and RP groups improved from pretest to acquisition. The CG was statistically significantly different from the experimental groups in the acquisition and retention phase. The RP and BP groups were not statistically different in any phase, both of the skills being assessed.
Conclusions. No contextual interference effect on fundamental motor skills in adults was found. Nonetheless, the results suggest that RP and BP improved performance for both skills.
Key words: motor learning, distance jump, overarm throw, blocked practice, random practice
SOMATIC AND FUNCTIONAL COMPENSATIONS IN JUNIOR BADMINTON PLAYERS
JANUSZ JAWORSKI, MICHAŁ ŻAK, GRZEGORZ LECH, PRZEMYSŁAW BUJAS, STANISŁAW ŻAK, DARIUSZ TCHÓRZEWSKI
Purpose. The aim of the study was to examine mutual compensations of somatic and functional variables in a group of junior badminton players.
Methods. The material of the study represented the results of 24 elite Polish badminton players with average competitive experience of 8.2 year. Basic somatic characteristics, coordination motor abilities, and motor fitness in terms of speed abilities, maximum anaerobic power, muscle strength, and cardiorespiratory strength were examined.
Results. The morphofunctional profiles in 7 players with top skill level are not identical. The variables that form these profiles interact with and compensate for each other. Some elite players show dominance of physical abilities, while somatic or coordination motor abilities are more pronounced in others. Several athletes were also characterized by a balanced morphofunctional profile.
Conclusions. The phenomenon observed requires further examinations, especially those based on the data derived from the category of senior champions.
Key words: badminton, junior players, training, somatic features
A NOVEL INTERVENTION PROGRAM (CRICFIT) FOR THE STRENGTH AND CONDITIONING OF ADOLESCENT CRICKET PLAYERS
LEE POTE, CANDICE CHRISTIE
Purpose. The purpose of the current investigation was to examine the effects of a 4-week field-based intervention program (CricFit) on general fitness, with the program designed to reflect the demands of the game in an adolescent population.
Methods. The total of 28 schoolboy cricketers (aged 15–19 years) were assigned to either a control (n = 14) or experimental (n = 14) group. Both groups performed traditional net and field-based training over a 4-week period (one net- and one field-based session), with the experimental group executing 2 additional 35–45-minute conditioning sessions per week. Prior to and post the 4-week period, measures were recorded with a test battery that was specific to the movement demands associated with intermittent sports.
Results. Both groups showed significant (p < 0.05) improvements in most responses, but the changes for the experimental group were greater than those shown in the control group, likely owing to the additional conditioning sessions. Furthermore, significant (p < 0.05) changes were observed between the two groups for the percentage body fat, flexibility, plank time, 20-m sprint time, push ups, and 25-m shuttle distance.
Conclusions. It was concluded that the CricFit intervention program can be used by coaches and conditioning specialists to improve cricket-specific fitness throughout the pre-season period.
Key words: fitness, high school students, physical training
RELATIONSHIP BETWEEN MUSCLE ARCHITECTURE AND BADMINTON-SPECIFIC PHYSICAL ABILITIES
ALI MD NADZALAN, NUR IKHWAN MOHAMAD, JEFFREY LOW FOOK LEE, CHAMNAN CHINNASEE
Purpose. The study aimed at determining the relationships between muscle architecture and badminton-specific physical abilities.
Methods. The total of 30 university level badminton players (mean age: 22.1 ± 1.4 years) were recruited as participants and underwent assessment of muscle architecture and badminton-specific physical abilities. Pennation angle, fascicle length, and muscle thickness of vastus medialis, vastus lateralis, rectus femoris, and biceps femoris were determined with ultrasonography for muscle architecture variables. Lunge one repetition maximum (1RM), lunge relative 1RM, standing long jump, vertical jump, and agility t-test were performed for physical abilities. The relationship between all muscle architectures and physical abilities was determined with the use of Pearson correlation.
Results. The results showed that the pennation angle and muscle thickness were positively correlated while fascicle length was negatively correlated with the physical abilities except for the agility test.
Conclusions. The study demonstrates that the possibilities of training performed by athletes affect their muscle architecture; further studies are required to examine how different kinds of training affect muscle architecture, which can then influence performance in sports.
Purpose. This study investigated the association between physical activity (PA), motor competence (MC), and perceived physical competence (PPC) in 56 boys and 65 girls aged 6–9 years.
Methods. PA was recorded by Omron HJ-720IT pedometers, MC was assessed with the Bruininks-Oseretsky Test of Motor Proficiency, second edition, and PPC was determined with the physical competence subscale of the Pictorial Scale of Perceived Competence and Social Acceptance for Young Children, Greek version.
Results. ANCOVA (with age as a covariate) revealed that boys were significantly more active than girls. Correlations among PA, MC, and PPC were not significant in either gender.
Conclusions. It seems that between 6 and 9 years of age, the relation among PA, MC, and PPC has not been formed yet. This age range is offered for interventions targeting these factors in order for their relationship to be enhanced later in life. However, further research for the investigation of other variables that may associate with PA at this age is needed.
Key words: pedometers, motor skills, self perception, childhood
DUAL-TASK EXERCISE AS A THERAPY FOR EXECUTIVE MOTOR FUNCTION IN PARKINSON’S DISEASE
GILMARA GOMES DE ASSIS, TATIANE ALVES DA SILVA, PAULO MOREIRA SILVA DANTAS
Purpose. To evaluate the effects of aerobic exercise with dual-task on the motor function in patients with Parkinson’s disease.
Methods. Clinically evaluated by the Unified Parkinson’s Disease Rating Scale – III and the Senior Fitness Test battery, 20 patients with Parkinson’s disease were randomly divided into a control and an experimental group, with the latter performing a 4-week program of water-walking in a deep pool while executing dual-tasks. Evaluations were made before and after 4 weeks in both groups.
Results. Patients with Parkinson’s disease revealed significant improvements in pre-/post-exercise motor function, with a moderate effect (p < 0.001; d = 0.44). Bradykinesia (p < 0.001) and agility (p < 0.001) exhibited significant changes individually.
Conclusions. Regular exercise combined with executive challenge such as dual-task may counteract the advanced motor symptoms of Parkinson’s disease neurodegeneration.
GLUTEAL ACTIVATION AND INCREASED FRONTAL PLANE PROJECTION ANGLE DURING A STEP-DOWN TEST IN YOUNG WOMEN
ALEXANDRE CARVALHO BARBOSA, EDGAR RAMOS VIEIRA, MICHELLE ALMEIDA BARBOSA, ILHA FERNANDES, MARCELA DAMÁZIO, BÁRBARA BADARÓ
Purpose. To investigate how the activation of gluteus maximus and gluteus medius interacts with different frontal plane projection angles (FPPA) in healthy young women presenting dynamic knee valgus in one limb while performing the step-down test.
Methods. The total of 18 young women presenting FPPA > 15° during the step-down test in one limb (dynamic knee valgus) were assessed. The other limb should present less than 15° for comparisons. The amplitude of muscle activation was assessed through surface electromyography of gluteus medius and gluteus maximus during 8 subsequent weight bearing step-down tests.
Results. FPPA was positively correlated with gluteus maximus activation and with the assessed side showing FPPA > 15°, which also revealed increased activation of gluteus maximus. No differences were noted for gluteus medius. The principal component analysis explained 73% of the variance in 2 components, with gluteus maximus explaining 48% of the variance on the 1st component. Gluteus medius explained 25% on the 2nd component.
Conclusions. Gluteus maximus seems to be a major component to explain dynamic knee valgus in women without symptoms of patellofemoral pain, probably owing to weakness and lack of stabilization of other proximal muscles of the hip-knee complex during the task.
BASKETBALL JUMP SHOT PERFORMED BY ADULTS AND CHILDREN
VICTOR HUGO ALVES OKAZAKI, ANDRÉ LUIZ FÉLIX RODACKI
Purpose. The study compared the performance of basketball jump shots between children and adults.
Methods. A kinematic analysis was used to evaluate shots performance (2D; sagittal plane; 100 Hz). A biomechanical model (6 points and 4 body segments) provided the shoulder, elbow, and wrist angular displacements and velocities.
Results. Children performed simultaneous movements of the shoulder-elbow-wrist joints to release the ball. Adults executed a countermovement around the elbow and wrist, but with greater constraint around the shoulder joint. This strategy may have allowed adults to achieve higher release, smaller variability, and better accuracy.
Conclusions. Differences in performance between adults and children were explained by the participants’ physical characteristics and time of practice (experience).
Key words: free-throw, basketball, kinematics, motor control, biomechanics