Reliability of Electromyographic Assessment of Biceps Brachii and Triceps Brachii in Cricketers

Effects of isometric training and R.I.C.E. treatment on the arm muscle performance of swimmers with elbow pain

The effects of IT and R.I.C.E. treatment on arm muscle performance in overhead athletes with elbow pain (EP) have been partially validated. However, there is a lack of research evidence regarding the efficacy of these two methods on arm muscle performance among swimmers with EP. The aim of this study was to investigate the trends and differences in the effects of IT and R.I.C.E. treatment on arm muscle performance among swimmers with EP. The main outcomes were the time effects and group effects of interventions on muscle voluntary contraction (MVC). Sixty elite freestyle swimmers from Tianjin, China, voluntarily participated in the study and completed a 10-week intervention program. Swimmers with EP in the IT group showed a positive trend in MVC, with an approximately 2% increase, whereas the MVC of subjects in the R.I.C.E. treatment group and control group decreased by approximately 4% and 5%, respectively. In comparison, the effects of the IT intervention on the MVC of the triceps and brachioradialis muscles in swimmers with EP were significant (p = 0.042 < 0.05, p = 0.027 < 0.05). The mean MVC value of the IT group (0.60) was greater than that of the other two groups (0.51, 0.50). IT has a beneficial impact on the MVC performance of the triceps and brachioradialis muscles in swimmers with EP. It is recommended that professionals consider incorporating IT into regular training routines to mitigate the risk of EP issues. Future research should examine the effectiveness of both interventions on hand-grip strength and completion time in 50-m freestyle swim drills in order for swimmers with EP to return to this sport.

Trans-spinal magnetic stimulation induces co-activation of the diaphragm and biceps in healthy subjects

The present study was designed to examine the effect of trans-spinal magnetic stimulation on bilateral respiratory and forelimb muscles in healthy subjects. Two wings of a figure-of-eight magnetic coil were placed on the dorsal vertebrae, from the fifth cervical to the second thoracic dorsal vertebra with a center at the seventh cervical vertebra. The surface electromyograms of bilateral diaphragm and biceps were recorded in response to trans-spinal magnetic stimulation with 20%-100% maximum output of the stimulatory device in male (n = 12) and female participants (n = 8). Trans-spinal magnetic stimulation can induce a co-activation of bilateral diaphragm and biceps when the stimulation intensity is above 60%. The onset latency was comparable between the left and right sides of the muscles, suggesting bilateral muscles could be simultaneously activated by trans-spinal magnetic stimulation. In addition, the intensity-response curve of the biceps was shifted upward compared with that of the diaphragm in males, indicating that the responsiveness of the biceps was greater than that of the diaphragm. This study demonstrated the feasibility of utilizing trans-spinal magnetic stimulation to co-activate the bilateral diaphragm and biceps. We proposed that this stimulatory configuration can be an efficient approach to activate both respiratory and forelimb muscles.

Time of Day and Muscle Strength: A Circadian Output?

For more than 20 years, physiologists have observed a morning-to-evening increase in human muscle strength. Recent data suggest that time-of-day differences are the result of intrinsic, nonneural, muscle factors. We evaluate circadian clock data sets from human and mouse circadian studies and highlight possible mechanisms through which the muscle circadian clock may contribute to time-of-day muscle strength outcomes.

Mind-Muscle Connection: Verbal Instructions Alter Electromyographic Activity for Elbow Flexors and Extensors During Co-Contraction Training

Co-contraction training has demonstrated similar electromyographic (EMG) activity levels compared to conventional strength training. Since verbal instructions can increase EMG activity on target muscles during conventional exercises, the same should occur during co-contraction. In this study we analyzed whether different verbal instructions would alter the EMG activity of target muscles - biceps brachii (BB) and triceps brachii lateral head (TB) - during co-contraction training for the elbow joint. Seventeen males with experience in strength training performed a co-contraction set in two verbal instruction conditions to emphasize either elbow flexion or elbow extension. Surface electrodes were fixed over biceps brachii and triceps brachii lateral head muscles. We measured EMG mean amplitude and analyzed data with 2-way ANOVA. We found a significant interaction between muscle and verbal instruction (p = 0.002). Post hoc tests indicated that verbal instructions (p = 0.001) influenced the BB EMG activity (elbow flexion: M = 68.74, SD = 17.96%; elbow extension: M = 53.47, SD = 16.13%); and also showed difference (p = 0.006) in the EMG activity between BB and TB with verbal instruction emphasizing the elbow extension (BB: M = 53.47, SD = 16.13%; TB: M = 69.18, SD = 21.79%). There was a difference in the EMG ratio of BB/TB (p = 0.001) when focusing on elbow flexion (M = 1.09, SD = 0.30) versus elbow extension (M = 0.81, SD = 0.25). As verbal instruction modified the magnitude of muscle recruitment during co-contractions for elbow joint muscles, there is a clear mind-muscle connection of importance to this method of training. Also, of importance to trainers, verbal instructions seemed to affect individuals differentially.

Adaptations of the Upper Body to Plyometric Training in Cricket Players of Different Age Groups

CONTEXT

Neuromuscular adaptations following exercise training are believed to enhance sports performance. While abundant research is available on adaptations of the lower body to plyometric training, little is known about adaptations of the upper body to plyometric training.

OBJECTIVE

To examine the effect of plyometric training on neuromuscular adaptations in cricket players of different age groups.

DESIGN

Randomized parallel group active-controlled trial.

SETTING

Research laboratory, school cricket ground, and sports complex field.

PARTICIPANTS

Fifty-nine cricket players were randomly assigned to either the experimental group or the control group.

INTERVENTIONS

The experimental group was subjected to 8 weeks of medicine ball plyometric training held thrice per week. Neuromuscular adaptations were analyzed pretraining and posttraining in 3 age groups: <18, 18-25, and >25 years. Analysis of variance was used to ascertain the training effects between and within the 6 subgroups, that is, age group <18 years (control and experimental), age group 18-25 years (control and experimental), and age group >25 years (control and experimental).

MAIN OUTCOME MEASURES

Muscle activation, upper body balance, upper body power, and muscle strength.

RESULTS

Out of 59, 55 participants completed the study. Subjects aged <18 years (adolescents) showed significantly greater improvements than those from the groups 18-25 years and >25 years (adults) on upper body balance and upper body power. Significant improvements were observed in the experimental subjects of all age groups on their muscle activity of biceps brachii, upper body balance, and upper body power following medicine ball plyometric training.

CONCLUSIONS

Though adolescent subjects were found to be more adaptive than adult subjects, experimental subjects showed significantly greater neuromuscular adaptations to medicine ball plyometric training than controls. These findings emphasize the need for coaches and athletic trainers to inculcate medicine ball plyometric exercises in training regimes of cricket players so as to improve their upper body performance.

Variations in cricket players' upper body dynamic balance across different levels of competition

BACKGROUND

Balance ability has been associated with performance and injury prevention in athletes. Previous studies have investigated the differences in lower body dynamic balance abilities among male high school, collegiate and professional soccer players.

OBJECTIVE

To investigate the differences on the Upper Quarter Y-Balance Test (UQYBT) in school, collegiate and employed cricket players.

SUBJECTS

Dynamic balance data were collected for school (SCH; n = 22), collegiate (COL; n = 19) and employed (EMP; n = 15) cricket players of Jamia Millia Islamia, New Delhi, India using the UQYBT standardized protocol.

METHODS

For the UQYBT, the participant reached with one hand in the medial, superolateral and inferolateral directions while maintaining three points of contact (other hand and both feet). The test was performed for both non-dominant and dominant hands.

RESULTS

The SCH group had the least medial reach distance than the other two groups (p = 0.010). Also, SCH players tended to exhibit a lower composite reach score than the other groups, but this difference was not significant (p > 0.05). No bilateral differences were observed among the three groups in any of the reach directions.

CONCLUSIONS

Upper body dynamic balance performance varied with the competition level. This may indicate that athletes' movement strategies may be different depending on the competition level and that normative values may need to be established for each competition level.