Specific Eccentric-Isokinetic Cluster Training Improves Static Strength Elements on Rings for Elite Gymnasts

Effect of Eccentric Training with Different Durations, Intensities, and Contraction Velocities on Upper Limb Muscle Strength: A Meta-Analysis

Eccentric training may be more effective for muscle strength, but the optimal duration, intensity, and contraction velocity for improving upper limb strength remain unclear. We conducted a search across four databases (PubMed, Embase, Web of Science, and Cochrane) to evaluate the impact of eccentric training on upper limb skeletal muscle strength. A meta-analysis using standardized mean differences (SMDs) and 95% confidence intervals (CIs) was performed. The results from 11 studies involving 368 participants indicated that eccentric training significantly enhanced upper limb strength (SMD = 0.55, CI: 0.32-0.79). Subgroup analysis showed a slight increase in strength in the 1-4 week period (SMD = 0.38, CI: 0.02-0.73), a significant increase in the 4-8 week period (SMD = 0.69, CI: 0.27-1.10), and a substantial increase at 20 weeks (SMD = 0.71, CI: 0.22-1.21). Moderate intensity showed moderate improvements (SMD = 0.47, CI: 0.18-0.77), while high intensity led to significant adaptations (SMD = 0.70, CI: 0.30-1.10). Rapid eccentric contractions (SMD = 0.70, CI: 0.39-1.02) outperformed slow contractions (SMD = 0.35, CI: -0.01-0.71). Eccentric training is effective, with significant results generally requiring 4-8 weeks of high-intensity rapid eccentric training.

An Analysis of the Kinetic Energy in the Basket to Handstand on Parallel Bars: A Case Study of an Elite Gymnast

(1) Background: This study aimed to examine the differences in the kinetic energy of the body's center of mass between successful and unsuccessful attempts at transitioning from a basket to a handstand on the parallel bars. Special attention was given to the analysis of kinetic energy as a key factor in the efficient execution of this complex element. (2) Methods: The sample consisted of 10 successful and 10 unsuccessful attempts performed by an elite gymnast (a multiple-medalist in World and European Championships). All attempts and kinematic data were recorded and analyzed using high-frequency cameras (300 Hz) and the Ariel Performance 3D video system, respectively. Successful and unsuccessful performances were compared using a paired-sample t-test. (3) Results: Significant differences in kinetic energy were observed in the first part of the anti-gravitational phase of movement between successful and unsuccessful attempts. Successful attempts demonstrated a more favorable position at the beginning of this phase, allowing better utilization of accumulated kinetic energy-a higher position of the feet and hips, and a smaller shoulder joint angle at the moment the shoulder passed through the lower vertical. (4) Conclusions: Successful attempts in gymnastics are characterized by better biomechanical optimization and efficient kinetic energy use, achieved through an earlier entry into the second phase of movement with optimal body positioning, leading to greater peripheral and angular velocities crucial for performance.

Anconeus Exertional Compartment Syndrome and Posterolateral Rotatory Elbow Instability: A Clinical Association and Rare Cause of Elbow Pain

Background

Anconeus compartment syndrome is a rarely reported compartment syndrome in the anconeus muscle compartment of the forearm. It has anatomic and pathophysiological associations with posterolateral rotatory instability (PLRI) of the elbow.

Purpose

To present the history, management, and outcomes of 4 patients with anconeus compartment syndrome. Secondary aims were to (1) establish normative anconeus pressures and (2) measure the volume of this compartment with and without PLRI in cadavers.

Study Design

Case series; Level of evidence, 4.

Methods

Four patients with clinical signs of anconeus compartment syndrome (2 gymnasts, 1 swimmer, and 1 footballer/weightlifter) were identified over a 3-year period (2015-2017 inclusive). Patient history, sporting activity, physical examination, anconeus compartment pressures, and treatment outcomes were recorded. Manometry of the anconeus compartment in 2 healthy male controls was performed to establish normative compartment pressures. Anconeus volumetric anatomy and the effect of creating PLRI on compartment volume was investigated in 4 cadaveric elbows.

Results

All 4 patients had microtraumatic PLRI, and 2 patients had anconeus hypertrophy. Anconeus compartment pressures at rest and at 2-minutes postexercise were median 28.0 and 67.5 mm Hg, respectively, in the patients and mean 16.5 and 18 mm Hg, respectively, in the controls. Simultaneous fasciotomy and PLRI reconstructive procedures were performed in 2 patients, with outcomes showing full return to competition. Fasciotomy alone was performed in 2 patients to allow return to competition, with both requiring later reconstruction to address PLRI. Cadaver dissection revealed that the anconeus compartment was extremely small and that creation of PLRI reduced the direct volume of the compartment and increased the distance between the anconeus origin and insertion.

Conclusion

Our case series demonstrated that anconeus compartment syndrome can occur in upper limb-dominant athletes in the presence of PLRI and anconeus hypertrophy. Pain is relieved by fasciotomy, but definitive treatment of the underlying instability prevents further symptomatology.

What We Do Not Know About Stretching in Healthy Athletes: A Scoping Review with Evidence Gap Map from 300 Trials

BACKGROUND

Stretching has garnered significant attention in sports sciences, resulting in numerous studies. However, there is no comprehensive overview on investigation of stretching in healthy athletes.

OBJECTIVES

To perform a systematic scoping review with an evidence gap map of stretching studies in healthy athletes, identify current gaps in the literature, and provide stakeholders with priorities for future research.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and PRISMA-ScR guidelines were followed. We included studies comprising healthy athletes exposed to acute and/or chronic stretching interventions. Six databases were searched (CINAHL, EMBASE, PubMed, Scopus, SPORTDiscus, and Web of Science) until 1 January 2023. The relevant data were narratively synthesized; quantitative data summaries were provided for key data items. An evidence gap map was developed to offer an overview of the existing research and relevant gaps.

RESULTS

Of ~ 220,000 screened records, we included 300 trials involving 7080 athletes [mostly males (~ 65% versus ~ 20% female, and ~ 15% unreported) under 36 years of age; tiers 2 and 3 of the Participant Classification Framework] across 43 sports. Sports requiring extreme range of motion (e.g., gymnastics) were underrepresented. Most trials assessed the acute effects of stretching, with chronic effects being scrutinized in less than 20% of trials. Chronic interventions averaged 7.4 ± 5.1 weeks and never exceeded 6 months. Most trials (~ 85%) implemented stretching within the warm-up, with other application timings (e.g., post-exercise) being under-researched. Most trials examined static active stretching (62.3%), followed by dynamic stretching (38.3%) and proprioceptive neuromuscular facilitation (PNF) stretching (12.0%), with scarce research on alternative methods (e.g., ballistic stretching). Comparators were mostly limited to passive controls, with ~ 25% of trials including active controls (e.g., strength training). The lower limbs were primarily targeted by interventions (~ 75%). Reporting of dose was heterogeneous in style (e.g., 10 repetitions versus 10 s for dynamic stretching) and completeness of information (i.e., with disparities in the comprehensiveness of the provided information). Most trials (~ 90%) reported performance-related outcomes (mainly strength/power and range of motion); sport-specific outcomes were collected in less than 15% of trials. Biomechanical, physiological, and neural/psychological outcomes were assessed sparsely and heterogeneously; only five trials investigated injury-related outcomes.

CONCLUSIONS

There is room for improvement, with many areas of research on stretching being underexplored and others currently too heterogeneous for reliable comparisons between studies. There is limited representation of elite-level athletes (~ 5% tier 4 and no tier 5) and underpowered sample sizes (≤ 20 participants). Research was biased toward adult male athletes of sports not requiring extreme ranges of motion, and mostly assessed the acute effects of static active stretching and dynamic stretching during the warm-up. Dose-response relationships remain largely underexplored. Outcomes were mostly limited to general performance testing. Injury prevention and other effects of stretching remain poorly investigated. These relevant research gaps should be prioritized by funding policies.

REGISTRATION

OSF project ( https://osf.io/6auyj/ ) and registration ( https://osf.io/gu8ya ).

The Effects of Resistance Training on Sport-Specific Performance of Elite Athletes: A Systematic Review with Meta-Analysis

This systematic review examines the influence of resistance training (RT) on the performance outcomes of elite athletes. Adhering to PRISMA guidelines, a comprehensive search across PubMed, Scopus, SPORTDiscus, and Web of Science databases was conducted, considering studies up to November 19, 2023. The inclusion criteria were elite athletes involved in high-level competitions. Studies were categorized by the competitive level among elite athletes, athlete's sex, performance outcomes, and a training modality with subgroup analyses based on these factors. Thirty-five studies involving 777 elite athletes were included. The results of the meta-analysis revealed a large and significant overall effect of RT on sport-specific performance (standardized mean difference, SMD = 1.16, 95% CI: 0.65, 1.66), with substantial heterogeneity (I2 = 84%). Subgroup analyses revealed differential effects based on the competitive level, the type of sport-specific outcomes, and sex. National elite athletes showed more pronounced (large SMD) benefits from RT compared to international elite athletes (small SMD). Global outcomes revealed a medium but non-significant (p > 0.05) SMD, while local outcomes showed a large SMD. Notably, female athletes exhibited a large SMD, though not reaching statistical significance (p > 0.05), probably due to limited study participants. No significant (p > 0.05) differences were found between heavy and light load RT. Resistance training is effective in improving sport-specific performance in elite athletes, with its effectiveness modulated by the competitive level, the type of the performance outcome, and athlete's sex. The findings underscore the need for personalized RT regimens and further research, particularly in female elite athletes, as well as advanced RT methods for international elite athletes.

A Systematic Review of Dynamic, Kinematic, and Muscle Activity during Gymnastic Still Rings Elements

Still rings are a unique gymnastics apparatus allowing for a combination of dynamic and static elements in a specific technique. This review aimed to compile the dynamic, kinematic, and EMG characteristics of swing, dismount, handstand, strength, and hold elements on still rings. This systematic review was conducted in concordance with PRISMA in PubMed, EBSCOhost, Scopus, and Web of Science databases. In total, 37 studies were included, describing the strength and hold elements, the kip and swing elements, swing through or to handstand, and dismounts. The current evidence suggests that the execution of gymnastics elements on still rings and training drills requires a high training load. Specific preconditioning exercises could be used to train for the Swallow, iron cross, and support scale. Negative impacts of load during hold elements can be reduced by special support devices such as the Herdos or support belts. Another aspect is improving strength prerequisites by exercises such as bench presses, barbell exercises, and support belts, where the main focus should be on muscular coordination similar to the other considerable elements. Electromyography is an appropriate tool for the investigation of muscular coordination and force platforms for assessing a sufficient strength level to successfully perform elements on still rings.

Real-time video and force analysis feedback system for learning strength skills on rings in men's artistic gymnastics

The importance of objective evaluations has gathered more attention than before for a fairer and better performance judgment in gymnastics. The purpose of this report was to disseminate information about our system and provide an example of data utilisation in high-level competitive training from a practical standpoint. The system combined video and force data, measured with two force transducers at the top of the ring cables, wirelessly transmitted to a computer. The force data synchronised with the video were available in real time or immediately after trials, making it possible to objectively quantify the amount of spotting that a gymnast received as external physical assistances. The simplicity of the setup and several special functions of the system led athletes and coaches spontaneously to use it in their regular training to quantify their skill level. Based on the regular utilisation of the system, the general correspondence between objectively measured values and the subjective perception of spotters was determined. In addition, the data suggested the possibility of technical evaluation of a certain type of strength skill based on force data. The data that are shared in this report should be beneficial in facilitating activities to integrate science into practice in gymnastics.

Combined Eccentric-Isokinetic and Isoinertial Training Leads to Large Ring-Specific Strength Gains in Elite Gymnasts

In male elite gymnastics, lately, eccentric training is often used to improve the maximum specific strength of static elements on rings. Therefore, in this study, we aimed to investigate the effects of a three-week, gymnastic-specific, eccentric-isokinetic (0.1 m/s) cluster training with a change of stimulus after three of six training sessions (eccentric-isokinetic with additional load) on a computer-controlled training device on the improvement of the elements swallow and support scale on rings. Maximum strength and strength endurance in maintaining the static positions of ten international elite male gymnasts were determined on a weekly basis. After three weeks of training, specific maximum strength and strength endurance increased significantly (strength: swallow: +8.72%, p < 0.001; support scale: 8.32%, p < 0.0001; strength endurance: swallow: +122.36%; p = 0.02; Support Scale: +93.30%; p = 0.03). Consequently, top gymnasts can considerably improve ring-specific strength and strength endurance in only three weeks. The separate analysis of the effects of both eccentric-isokinetic training modalities showed that efficiency might even be increased in future training interventions. We suggest using this type of training in phases in which the technical training load is low and monitoring the adaptations in order to compile an individually optimized training after an intervention.

Frequency Shifts in Muscle Activation during Static Strength Elements on the Rings before and after an Eccentric Training Intervention in Male Gymnasts

During ring performance in men's gymnastics, static strength elements require a high level of maximal muscular strength. The aim of the study was to analyze the effect of a four-week eccentric-isokinetic training intervention in the frequency spectra of the wavelet-transformed electromyogram (EMG) during the two static strength elements, the swallow and support scale, in different time intervals during the performance. The gymnasts performed an instrumented movement analysis on the rings, once before the intervention and twice after. For both elements, the results showed a lower congruence in the correlation of the frequency spectra between the first and the last 0.5 s interval than between the first and second 0.5 s intervals, which was indicated by a shift toward the predominant frequency around the wavelet with a center frequency of 62 Hz (Wavelet W10). Furthermore, in both elements, there was a significant increase in the congruence of the frequency spectra after the intervention between the first and second 0.5 s intervals, but not between the first and last ones. In conclusion, the EMG wavelet spectra presented changes corresponding to the performance gain with the eccentric training intervention, and showed the frequency shift toward a predominant frequency due to acute muscular fatigue.

Effect of 12 Weeks Core Training on Core Muscle Performance in Rhythmic Gymnastics

BACKGROUND

Rhythmic gymnastics performance is characterized by technical elements involving flexibility, aerobic capacity and strength. Increased core strength in rhythmic gymnastics could lead to improved sporting performance.

OBJECTIVE

The aim of this study was to analyze the effect of 12 weeks of core muscle training on core muscle performance in rhythmic gymnasts.

METHODS

A randomized controlled study involving 24 rhythmic gymnastics was conducted. Participants were randomly assigned to a control group (CG; n = 12; age 13.50 ± 3.17 years) or a training group (TG; n = 12; age 14.41 ± 2.35 years). Body composition, isometric strength of trunk, core endurance and core muscle electromyographic activity were measured (EMG) after 12 weeks of core training. Independent sample t-tests were carried out to compare baseline values between groups. A two-way repeated-measures analysis of variance (ANOVA) (time × group) was applied.

RESULTS

The TG improved body composition, trunk lean mass (mean differences MD = -0.31; p = 0.040), lean mass (MD = 0.43; p = 0.037) and bone mass (MD = -0.06; p < 0.001) after training. Core training increased isometric strength of trunk, flexion test (MD = -21.53; p = 0.019) and extension test (MD = 22.7; p = 0.049), as well as the prone bridge core endurance test (MD = -11.27; p = 0.040). The EMG values also increased in the TG in prone bridge for front trunk (MD = -58.58; p = 0.026).

CONCLUSIONS

Core strength training leads to improvements in body composition, as well as improvements in trunk strength and increases in muscle electromyographic activity. These improvements could therefore improve performance during competitive rhythmic gymnastics exercises.

Maximum Strength Benchmarks for Difficult Static Elements on Rings in Male Elite Gymnastics

On rings, in men’s artistic gymnastics, the general strength requirements for important static elements remain elusive. Therefore, the aim was to describe the relationship between a new conditioning strength test and a maximum strength test of static elements on rings in order to determine the minimal strength level (benchmarks) required to maintain these elements with one’s own body weight. Nineteen elite gymnasts performed a concentric (1RM isoinertial) and eccentric (isokinetic: 0.1 m/s) conditioning strength test for swallow/support scale (supine position) and inverted cross (seated position) on a computer-controlled device and a maximum strength test maintaining these elements for 5 s on rings with counterweight or additional weight. High correlation coefficients were found between the conditioning maximum strength for swallow/support scale (r: 0.65 to 0.92; p < 0.05) and inverted cross (r: 0.62 to 0.69; p > 0.05) and the maximum strength of the elements on rings. Strength benchmarks varied between 56.66% (inverted cross concentric) and 94.10% (swallow eccentric) of body weight. Differences in biomechanical characteristics and technical requirements of strength elements on rings may (inter alia) explain the differences between correlations. Benchmarks of conditioning strength may help coaches and athletes systematize the training of strength elements on rings.