IMPORTANT PERFORMANCE FACTORS IN GYMNASTICS FROM A BIOMECHANICAL PERSPECTIVE

Perhaps more than in any other sport, success in gymnastics depends on the ability of the athlete to blend a variety of physical, physiological, and psychological attributes in a routine that taxes the body and mind. Without denying the importance of physiological, psychological, and other variables, this paper (based on Prassas et al., 2006) will discuss performance variables important in putting together a winning gymnastics routine from a biomechanical perspectiv

COMPARATIVE STUDY OF GIANT SWINGS ON THE PARALLEL BARS

The purpose of this study was to provide descriptive and comparative data on kinematic data of giant swings on the parallel bars. Fourteen giants were studied. Results showed that, giants on the parallel bars exhibited larger range of motion in all joints as compared to giants in other apparatuses. No significant differences were found between (parallel bars) giants receiving larger or smaller deductions from qualified judges and this may be attributed to the (similar) skill level of the subjects

TECHNIQUE ANALYSIS OF THE BACK TOSS ON THE PARALLEL BARS PERFORMED BY ELITE GYMNASTS

The back toss (BT), a skill frequently performed by gymnasts on the parallel bars (PB), involves a release-regrasp swing type of motion from a handstand to a handstand position. Mastering the skill is beneficial not only for points awarded to gymnasts by the judges for the skill itself but also for its contribution towards the perfect execution of other PB skills including the most current1 PB dismounts. The purpose of this study was to: I) identify the skill variables best correlating with the scores given to the BTs by qualifying judges, and 2) to identify the differences in technique between the most and least skillful BTs. Seventeen BTs, recorded during the 1990 United States Gymnastics Federation Championships with a NAC 400 HSV camera operating at 200 Hz, were analyzed utilizing the Arid Performance Analysis System (APAS). Two dimensional position data of 4 (for BTs without knee or elbow joint flexion) to 6 (BTs with elbow and/or knee joint flexion) body points were digitally smoothed before being submitted to further analysis. Product moment correlations between mechanical variables and the scores given to the BTs by qualifying judges, indicate that the best predictors of a good score are the shoulder joint angle at regrasp (p = .001), the time the gymnasts were airborne (p = .021), the horizontal velocity of the center of gravity (COG) at release (p = .022), the hip joint angle at release (p = .025), the hip joint angle at release and the minimum hip joint angle (p = .025 and .048, respectively), the normalized maximum height of the COG above the bar (p =.028), the greatest total angular momentum (p = .035), and the shoulder joint angle at release (p = .054). Paired t tests between variables of the most (N=8) and least (N=9) skillful BTs indicate that the discriminating factors are the hip joint angle at release (p = .03), the shoulder joint angle at regrasp (p = .032), time from the smallest hip joint angle to zero degrees of anterior shoulder joint angle (p = .049), and the horizontal velocity of the COG at release (p = .058). Additional factors differentiating the best and worst BTs studied are the time from zero degrees of anterior shoulder joint angle to release (p = .06), and the shoulder joint angle at release (p = .066

DYNAMICS OF FORWARD SWINGING SKILLS ON THE PARALLEL BARS

INTRODUCTION AND PURPOSE: There is a need for and value in studying individual skills on any gymnastic apparatus. Identifying skills that share common elements and could be grouped together may be of greater value, however. On the parallel bars, the back toss (BT) and the backward somersault dismount (BD) appear to share common elements, at least qualitatively. Although both skills have been studied independently and their kinematics have also been presented as a group, their dynamics have not been investigated. The purpose of this investigation was to study the dynamics of the upswing phase of forward swinging skills (FS) on the parallel bars which appear to share common elements. METHODS: Thirty-four FS recorded with a NAC 400 HSV camera were analyzed utilizing an Ariel Performance Analysis System. The analyzed FS were rated by two internationally-qualified judges. Two dimensional position data of four to six body points were digitally smoothed before further analysis. Variables examined were: 1) average vertical and horizontal forces during the upswing phase of FS, 2) reduction of vertical force prior to takeoff, and 3) angular momentum at takeoff. Forces were calculated utilizing the impulse-momentum relationship and normalized by body weight. Angular momentum was normalized for height and mass. RESULTS: Independent t-tests between the BT (n=16) and BD (n=18) revealed a significant (

ASSESSMENT OF CHARACTERISTICS OF PHYSICAL CONDITIONING RELATING TO STRENGTH AND SPEED IN VOLLEYBALL

INTRODUCTION AND PURPOSE: Selection of the most talented young athletes frequently necessitates the screening of a large number of youngsters. In most sports, including volleyball, screening is for practical reasons limited to a small number of simple physical activities (SPA). It is questionable how well the particular SPA measure the characteristics of physical conditioning which are important for success in the sport. Therefore the purpose of this study was to: 1) measure characteristics of physical conditioning relating to strength and/or speed (CPC) in youngsters who were just selected to begin practicing volleyball on the basis of their performance in SPA, and 2) examine the relationship between the results of the SPA and the measured CPC. METHODS: Seventeen youngsters (mean age=9.3 years) were selected by the Greek Volleyball Federation to begin practicing the sport on the basis of their performance in the following SPA: a) 30 meter sprint, b) shot putting 1 Kg, and 3) standing long jump. On the basis of previous research, the 17 youngsters’ CPC relating to speed and strength was measured by testing them on: 1) maximum isometric push-off force (Fmax), 2) vertical counter-movement jump (CMJ), 3) vertical jump from a flexed hip, knee, and ankle joint position (SJ), 4) drop vertical jumps from heights of 10-30cm (DJ) and 5) maximum pedaling rate (zero resistance). RESULTS: The results revealed a high correlation between performance in the 3 SPA (r=0.93-0.99, ). Comparison between performance in the 3 SPA and performance in the 5 CPC revealed: 1) high correlations between performance in the 3 SPA and maximum pedaling rate (r=0.93, ), 2) moderate correlations between performance in the 3 SPA and Fmax (r=-0.38), and 3) non significant correlations between performance in the 3 SPA and the remaining CPC. CONCLUSIONS: This study revealed that performance in the 3 SPA utilized by the Greek Volleyball Federation correlates highly to only one of the measured CPC, moderately to a second CPC, and does not significantly correlate to the remaining measured CPC. Based on these results, the appropriateness of the 3 SPA as tools for the identification of CPC is questioned. It will be difficult to further improve CPC, if the tools utilized to identify them are questionable

MECHANICAL ANALYSIS OF THE INVERTED GIANT SWING

Strength, balance, flexibility, speed, proper timing, and stamina have long been considered a necessity for the sport of gymnastics. However, the explosive worldwide development of the sport the last decade established another factor --the mastering of swinging --to be of paramount importance for gymnasts desiring to succeed in competition. Among the different kinds of swings, the giant swing refers to those gymnastic skills which require a full 360 degree rotation of the gymnast's suspended body about a relatively fixed point. Depending on the direction of the rotation, the gymnast's body configuration and the type of handgrasp, the degree of difficulty for the various types of the existing giant swings ranges from low to high. With reference to the horizontal bar, the forward and backward giant swings are considered, for example, fundamental but of low difficulty, whereas the so called "inverted" and "German" giant swinqs are given high marks for difficulty

MECHANICS OF THE STOOP-IN-PIKE THROUGH TO INVERTED GIANTS

Gymnastics is a versatile sport that encourages and rewards individuality and creativity. As a result, a great number of skills have been developed on each piece of apparatus over the years; more are expected in the future. Although most ofthese skills are unique to each apparatus, some broad classifications can be made. Generally, gymnastic skills are of the "swinging", "balance", "strength", or "tumbling" type. Or they can be classified as "primary" and "secondary". Primary skills are skills that constitute the "core" of each individual routine such as giant swings, somersaults, handstands, etc. Secondary are skills connecting the primary ones within a routine, such as the round-off, handsprings, various leaps and the "stoop-in pike through to inverted giants"

KINEMATIC COMPARISON OF THE OVERGRIP AND UNDERGRIP DISMOUNT GIANT SWINGS ON THE UNEVEN BARS

INTRODUCTION: Uneven bar dismounts are executed from either overgrip or undergrip giant swings. Gymnasts performing either of these two styles of dismounts attempt to optimize release conditions by incorporating a beat swing associated with hip joint motion. The purpose of this study was to quantify projectile determinants, and swing and beat characteristics of the overgrip and undergrip dismount giant swings on the uneven bars. METHODS: Thirteen (seven undergrip and six overgrip) giant swings, were recorded during the 1994 World Gymnastics Championships (Dortmund, Germany) with 2 video cameras operating at 50 Hz. They were analyzed utilizing the Ariel Performance Analysis System (APAS). Three dimensional position data of 12 body points (ankles, knees, hips, shoulders, elbows, and hands) and a point on the top bar were digitally smoothed before being submitted to further analysis. RESULTS: Results showed no significant differences between overgrip and undergrip dismount giant swings in terms of center of mass (CM) maximum and release angular velocities, CM position, and CM horizontal and vertical release velocities. Radius of gyration at release, reflecting body configuration, was significantly different (51.6 vs. 58.8 % of height for undergrip and overgrip dismount giants, respectively; ). There were significant differences in the mechanics of the beat swing in terms of both magnitude of hip joint range of motion (111 vs. 65 degrees for undergrip and overgrip dismount giants, respectively; ), and timing of the beat swing (starting in the first quadrant for the overgrip and second quadrant for the undergrip dismount giants; and finishing in the second quadrant for the overgrip and third quadrants for the undergrip dismount giants; ). CONCLUSION: Results indicate that overgrip and undergrip giant swings generated similar projectile determinants for uneven bars dismounts. There were, however, significant differences between the two swings in the timing and magnitude of the hip joint beat action which partially generates the projectile determinants

SCORE PREDICTION ON KIPS PERFORMED ON THE PARALLEL BARS

INTRODUCTION: Kips are performed by both male and female gymnasts in a variety of apparatus including the parallel bars. Althought kips are considered to be one of the fundamental skills in gymnastics, research is scarse (Prassas, 1993). The purpose of this study was to investigate the factors that influence the score awarded to kips performed on the parallel bars by qualified judges