Elbow Joint Position and Force Senses in Young and Adult Untrained People and Gymnasts.

Joint position (JPS) and force senses (FS) are the proprioception modalities. While the development of JPS was investigated both in children/adult and athlete/untrained conditions, there is a lack of insight into the development of FS. Overall, 28 gymnasts and 25 untrained controls underwent proprioception testing. They were divided into two groups: 9 to 11-year-old boys (13 gymnasts and 10 non-athletes) and 18 to 25-year-old adults (15 gymnasts and 15 non-athletes). The testing was performed at an isokinetic dynamometer and included elbow JPS and FS (20% and 50% maximal voluntary contraction) tasks. Children had two times higher error in JPS (p < 0.01) and 50% higher errors in FS of both flexor (p < 0.001) and extensor muscles (p < 0.05) in comparison with adults. Only in the 50% maximal voluntary contraction task, gymnasts showed 33% lower error than the controls (p < 0.01). Untrained boys presented 54%, 132%, and 169% higher error for elbow flexor performance than young gymnasts, untrained adults, and adult gymnasts, respectively (p < 0.01). The 9 to 11-year-old participants were characterized by a lower precision of JPS and FS performance in comparison with adults. Gymnastic training can possibly accelerate the development of FS when higher loads are considered.

The Neuromuscular Characteristics of Gymnasts' Jumps and Landings at Particular Stages of Sports Training.

Safe and proper landings are crucial elements of gymnastics events. Long-term training leads to specific neuromuscular adaptations which are yet to be explored in terms of gymnastic landings. The aim of the study was to assess differences in landings' neuromuscular characteristics between gymnasts at three subsequent gymnastic training stages and age-matched non-athletes. Forty-six gymnasts (G) and 58 controls (C) performed countermovement jumps on a force plate with simultaneous surface electromyography (SEMG) of lower body muscles, measured during the pre-(100 ms) and post-landing phase (0-100 and 0-200 ms). Three age groups participated in the study: 8-10 (G1, C1), 12-14 (G2, C2), 18-25 (G3, C3) years. Analysis included the normalized root mean square (NRMS) SEMG signal and ground reaction forces (GRFs). Gymnasts achieved 13% higher values (p = 0.04) of relative peak GRFs in comparison with controls. It was especially seen in 8-10-year-olds: G1 presented 33% higher (p = 0.03) results than C1 and G2. In SEMG analysis, gymnasts showed overall lower NRMS values in comparison with the controls. In the pre-landing phase, the NRMS in the rectus femoris was from 1.6 up to 3.4 times higher for C1 (p = 0.02) than for C2, G2, C3, and G3. Gymnasts across subsequent training stages exhibit different patterns of neuromuscular coordination during landings. The highest GRF observed in the youngest gymnasts may be a potential risk factor of injuries. Therefore, further injury-focused investigation is recommended to monitor landing strategies among gymnasts of different stages with particular emphasis on the beginners.

Neuromuscular and Torque Kinetic Changes After 10 Months of Explosive Sport Training in Prepubertal Gymnasts.

PURPOSE: To determine neuromuscular and torque kinetic changes after 10 months of explosive sport training in the elbow of prepubertal gymnasts compared with untrained age-matched controls. METHODS: In 15 young gymnasts (9.02 [0.41] y) and 15 age-matched untrained males (8.76 [0.51] y), the rate of torque development (RTD) using the Biodex System 4 and the coactivation index were evaluated using electromyography. Explosive strength variables were normalized to the peak torque. Measures were determined twice: before and after a 10-month period of gymnastic training. Covariation analysis was used to account for differences in baseline values between gymnasts and controls. RESULTS: After 10 months of training, gymnasts demonstrated a significantly (P < .05) greater increase in normalized peak RTD values in elbow flexion compared with controls (7.76% vs 0.65%). Covariation analysis also revealed a significantly (P < .05) greater reduction in the coactivation index of elbow extension in the gymnasts (-7.81% [5.44%] points) compared with controls (-1.23% [6.32%] points). CONCLUSIONS: Compared with physical development alone, 10 months of explosive-strength training of young gymnasts is sufficient to increase torque-normalized RTD in the elbow joint of prepubertal boys. The RTD changes the authors observed in antagonistic elbow functions vary among gymnasts due to the specific demands of gymnastic training.

Changes in the Muscle Activity of Gymnasts During a Handstand on Various Apparatus.

Kochanowicz, A, Niespodzinski, B, Mieszkowski, J, Marina, M, Kochanowicz, K, and Zasada, M. Changes in the muscle activity of gymnasts during a handstand on various apparatus. J Strength Cond Res 33(6): 1609-1618, 2019-Gymnasts perform handstands on various apparatus, both in stable and unstable conditions. Such performances require specific muscle activation, which should differ depending on the condition and expertise of the gymnast. Therefore, the aim of the study was to evaluate (a) the difference in electromyography (EMG) between handstands performed on 3 apparatus (floor, rings, and parallel bars); and (b) the difference between young and well-trained adult gymnasts. Ten adult (25 ± 3.94 years) and 15 young (13.9 ± 0.7 years) gymnasts participated in the study. We investigated EMG amplitude in 13 muscles normalized by arbitrary angle maximal isometric voluntary contraction (normalized root mean square [NRMS]). In comparison with the handstand on the floor (61 ± 28%), the wrist flexor muscles of gymnasts exhibited a decreased NRMS on the parallel bars (44 ± 25%; p = 0.017), and rings (46 ± 32%; p = 0.029), whereas no changes were observed in the triceps brachii. The rest of the investigated muscles showed a higher NRMS in rings. Differences between young and adult gymnasts were seen in the triceps brachii and anterior deltoid muscles, where more experienced gymnasts showed 19.1% (p = 0.014) and 17.6% (p = 0.048) lower NRMS, respectively. The different gymnastic apparatus led to specific muscle activation. This activation predominantly depended on hand support conditions, which alternated the primary wrist strategy of the handstand balance control, and in consequence, the activation of other muscles controlling balance. Training focused on the development of motor control and strength of the anterior deltoid, pectoralis major, latissimus dorsi, biceps brachii, and trapezius descendens muscles to improve handstand performance.

Relationship between postural control and muscle activity during a handstand in young and adult gymnasts.

The aim of this study was to evaluate the relationship between muscle activity and inter-muscle contributions patterns and postural control during a handstand. Additionally, outcomes were compared between young and adult gymnasts (mean ±â€¯SD: 13.9 ±â€¯0.7 and 23 ±â€¯3 years respectively). Participants performed three trials of a 10 s handstand on a force platform with simultaneous EMG signal recording at the upper and lower limbs. Adult gymnasts demonstrated significantly better postural control in each studied variable. The wrist flexors demonstrated the highest relative mean (60%) and peak (200%) EMG activity of all muscle groups studied. Wrist flexor activity was also highly correlated with postural control variables in both groups. The trapezius descendens and wrist flexor muscles demonstrated the highest contribution (20-26% and 25.5-28% respectively), followed by anterior deltoid (15-18%) and triceps brachii (13-16%) in both groups. The young gymnast group demonstrated significantly greater mean relative muscle activity at the triceps brachii, biceps brachii and rectus femoris compared with the adult group (88% (p = 0.023), 150% (p = 0.003) and 75% (p = 0.039) respectively). To conclude, despite comparable inter-muscle contributions during a handstand, young and adult gymnasts demonstrated a different relationship between muscle activity and postural control variables.

The effect of gymnastic training on muscle strength and co-activation during isometric elbow and glenohumeral flexion/extension.

BACKGROUND: The purpose of the study was to demonstrate the differences between non-athletes and gymnasts at the pre- and post-pubertal age in the development of peak torque and ensuing flexion/extension ratios at the elbow and the glenohumeral joints, as well as to assess the relevance of the above activities for the co-activation of selected muscles. METHODS: The study involved 20 gymnasts and 20 non-athletes aged 8-9 years, in addition to 12 gymnasts and 16 non-athletes aged 18-25 years. Measurements of the isometric peak torque (PKTQ) were taken for flexion and extension at the elbow and the glenohumeral joints. The method of surface electromyography (EMG) was applied in order to determine the neurophysiological characteristics of the strength and capabilities of these joints. RESULTS: In the group of older gymnasts the PKTQ ratio of the glenohumeral flexors to extensors was the lowest (0.72) and was significantly different from the other groups. This result was consisted with the 30% higher PKTQ values (P<0.01) of the glenohumeral extensors and a 41% reduction in their EMG in flexion in comparison to non-athletes. CONCLUSIONS: Apart from demonstrating the effects of long-term gymnastic training, the results give information about the imbalance between the agonists and the antagonists of the arm, which can predispose to more frequent injuries. A disproportionately greater development of strength capabilities of extensor muscles in relation to arm flexors among experienced gymnasts can provide valuable information for physiotherapists and coaches on individuation of athletes' special preparation - essential in teaching many complex gymnastic exercises.

Effect of Lower and Upper Body High Intensity Training on Genes Associated with Cellular Stress Response.

This study aimed to compare the effect of upper and lower body high intensity exercise (HIE) on select gene expression in athletes. Fourteen elite male artistic gymnasts (age 20.9 ± 2.6 years; weight 68.6 ± 7.2 kg; fat free mass 63.6 ± 6.7 kg; height 1.70 ± 0.04 m) performed lower and upper body 30 s Wingate Tests (WAnTs) before and after eight weeks of specific HIIT. Two milliliters of blood was collected before and after (5, 30 min, resp.) lower and upper body WAnTs, and select gene expression was determined by PCR. Eight weeks of HIIT caused a significant increase in maximal power (722 to 751 Wat), relative peak power in the lower body WAnTs (10.1 to 11 W/kg), mean power (444 to 464 W), and relative mean power (6.5 to 6.8 W/kg). No significant differences in lower versus upper body gene expression were detected after HIIT, and a significant decrease in the IL6/IL10 ratio was observed after lower (-2∧0.57 p = 0.0019) and upper (-2∧0.5 p = 0.03) WAnTs following eight weeks of HIIT. It is hypothesized that a similar adaptive response to exercise may be obtained by lower and upper body exercise.

Cellular Stress Response Gene Expression During Upper and Lower Body High Intensity Exercises.

OBJECTIVES: The aim was to compare the effect of upper and lower body high-intensity exercise on chosen genes expression in athletes and non-athletes. METHOD: Fourteen elite male artistic gymnasts (EAG) aged 20.6 ± 3.3 years and 14 physically active men (PAM) aged 19.9 ± 1.0 years performed lower and upper body 30 s Wingate Tests. Blood samples were collected before, 5 and 30 minutes after each effort to assess gene expression via PCR. RESULTS: Significantly higher mechanical parameters after lower body exercise was observed in both groups, for relative power (8.7 ± 1.2 W/kg in gymnasts, 7.2 ± 1.2 W/kg in controls, p = 0.01) and mean power (6.7 ± 0.7 W/kg in gymnasts, 5.4 ± 0.8 W/kg in controls, p = 0.01). No differences in lower versus upper body gene expression were detected for all tested genes as well as between gymnasts and physical active man. For IL-6 m-RNA time-dependent effect was observed. CONCLUSIONS: Because of no significant differences in expression of genes associated with cellular stress response the similar adaptive effect to exercise may be obtained so by lower and upper body exercise.

Maximal Power of the Lower Limbs of Youth Gymnasts and Biomechanical Indicators of the Forward Handspring Vault Versus the Sports Result.

The aim of the study was to define the relationship between maximal power of lower limbs, the biomechanics of the forward handspring vault and the score received during a gymnastics competition. The research involved 42 gymnasts aged 9-11 years competing in the Poland's Junior Championships. The study consisted of three stages: first -estimating the level of indicators of maximal power of lower limbs tested on a force plate during the countermovement jump; second - estimating the level of biomechanical indicators of the front handspring vault. For both mentioned groups of indicators and the score received by gymnasts during the vault, linear correlation analyses were made. The last stage consisted of conducting multiple regression analysis in order to predict the performance level of the front handspring vault. Results showed a positive correlation (0.401, p < 0.05) of lower limbs' maximal power (1400 ± 502 W) with the judges' score for the front handstand vault (13.38 ± 1.02 points). However, the highest significant (p < 0.001) correlation with the judges' score was revealed in the angle of the hip joint in the second phase of the flight (196.00 ± 16.64°) and the contact time of hands with the vault surface (0.264 ± 0.118 s), where correlation coefficients were: -0.671 and -0.634, respectively. In conclusion, the angles of the hip joint in the second phase of the flight and when the hands touched the vault surface proved to be the most important indicators for the received score.

Neurofeedback training for peak performance.

AIM: One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs). CASE STUDY: The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. CONCLUSION: Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.