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The article presents the results of a study which analyzed data about the effects of acute static stretching on females, in terms of torque and electromyography. An overview of related previous research is provided, along with details of the experimental protocol. Normalized and non-normalized data from both athletes and non-athletes was studied.

The article reports on research conducted to determine the effects acute low- and high-volume static and proprioceptive neuromuscular facilitation (PNF) stretching had on athletes who performed a one-repetition maximum bench press. Researchers evaluated 15 college football players. They found that there were no significant differences in bench press performance in athletes who participated in either type of stretching.

The purpose of the study was to examine the potential for using the mechanomyographic (MMG) signal as a biofeedback method to enhance muscular relaxation and to improve performance during forearm flexion repetitions to fatigue. Twelve adult (mean ± SD; age: 22.0 ± 1.1 years) moderately trained subjects (weight: 82.3 ± 29.2 kg; height: 165.7 ± 49.0 cm) were instructed to relax the biceps brachii muscle using MMG biofeedback (BIO) provided by viewing a computer screen graphically displaying the MMG signal and then without using MMG biofeedback (NOBIO). Electromyographic (EMG) and MMG signals were detected midway over the biceps brachii during the relaxation protocol. In subsequent visits to the laboratory, subjects performed as many repetitions as possible at 85% of 1 repetition maximum with BIO and NOBIO using the seated preacher curl exercise. Two-way (biofeedback × gender) mixed factorial analyses of variance revealed significantly (p < 0.05) lower MMG (mean ± SEM; BIO = 0.6 ± 0.1 mV; NOBIO = 1.1 ± 0.2 mV) and EMG amplitudes (BIO = 6.6 ± 0.6 μV; NOBIO = 9.4 ± 1.4 μV) for BIO when subjects were instructed to relax the biceps brachii muscle. There was no significant difference in the number of forearm flexion repetitions performed for BIO (mean ± SD; 7.9 ± 0.4 reps) vs. NOBIO (8.1 ± 0.6 reps). The results of the present study revealed that using MMG as a biofeedback technique can enhance the development of muscle relaxation, but is not useful in delaying fatigue during forearm flexion repetitions. Our results may have been influenced by a relatively short training phase designed to teach subjects to use the MMG signal as a biofeedback method. Future studies are needed to determine whether MMG biofeedback can be used for other purposes. If MMG is found to be useful as a biofeedback method, it has some distinct practical advantages over EMG that the strength and conditioning athlete and professional may find appealing. [ABSTRACT FROM AUTHOR]

The purpose of this investigation was to determine the effect of hyperhydration on the electromyographic (EMG) and mechanomyographic (MMG) responses during isometric and isokinetic muscle actions of the biceps brachii. Eight (22.1 ± 1.8 years, 79.5 ± 22.8 kg) subjects were tested for maximal isometric, submaximal isometric, and maximal concentric isokinetic muscle strength in either a control (C) or hyperhydrated (H) state induced by glycerol ingestion while the EMG and MMG signals were recorded. Although fluid retention was significantly greater during the H protocol, the analyses indicated no change in torque, EMG amplitude, EMG mean power frequency (MPF), MMG amplitude, or MMG MPF with hyper-hydration. These results indicated that glycerol-induced fluid retention does not affect the torque-producing capabilities of a muscle, the impulses (EMG) going to a muscle, or muscular vibrations (MMG). It has been suggested that EMG and MMG can be used as direct electrical/mechanical monitoring, which could be presented to trainers and athletes; however, before determining the utility of these signals, the MMG and EMG responses should be examined under a variety of conditions such as in the present study. [ABSTRACT FROM AUTHOR]