Effects of 8-Week Electromyostimulation Training on Upper-Limb Muscle Activity and Respiratory Gas Analysis in Athletes with Disabilities.

This study was aimed at verifying the efficacy of EMS training by investigating the changes in upper-limb muscle functions and energy expenditure in athletes with disabilities after an 8-week intervention of EMS training. We compared variations in muscle activity, respiratory gas, and symmetry index (SI) after an 8-week intervention in eight professional male athletes with disabilities wearing an electromyostimulation (EMS) suit (age: 42.00 ± 8.67 years, height: 1.65 ± 0.16 m, weight: 64.00 ± 8.72 kg, career length: 11.75 ± 3.83 years). For EMS training, each participant wore an EMS suit. EMS was applied to the upper-limb muscles pectoralis major and triceps at 40 °C water temperature, with a 25 Hz frequency (duty cycle 10%) for 15 min, followed by a 5 Hz frequency (duty cycle 5%) for 5 min. The pre- and post-intervention measurements were taken in the same way at a pre-set time (for 1 h, twice a week) for 8 weeks. Training involved a seated chest press, and the muscle activity (pectoralis major, triceps, and antebrachial muscles), upper-limb SI, and respiratory gas variables (maximal oxygen consumption (VO2), carbon dioxide output (VCO2), respiratory quotient (RQ), metabolic equivalents (METs), and energy expenditure per min (Energy expended per minute; EEm)) were analyzed. Variations pre- and post-intervention across the measured variables were analyzed. Regarding the change in muscle activity, significant variations were found in the pectoralis major right (p < 0.004), pectoralis major left (p < 0.001), triceps right (p < 0.002), and antebrachial right (p < 0.001). Regarding left-to-right SI, a positive change was detected in the pectoralis major and triceps muscles. Additionally, respiratory gas analysis indicated significant variations in VO2 (p < 0.001), VCO2 (p < 0.001), METs (p < 0.001), and EEm (p < 0.001). EMS training improved muscle strength and respiratory gas variables and is predicted to contribute to enhanced muscle function and rehabilitation training for athletes with disabilities.

The effect of visual field condition on kinetic in upper extremities and e.m.g in lower extremities while performing reaching in normal adults.

[Purpose] The aims of this study was to investigate mean velocity and angle of shoulder joint, activation of tibialis anterior and gastrocnemius according to both eyes, dominant eye and non-dominant eye condition during reaching task in normal adults. [Subjects and Methods] Our research recruited 24 participants (male 11, female 13) in Silla University. Participants were performed reaching out movement by conditions of both eye, dominants eye, non-dominants eye. The target was placed at 45 degree diagonal direction and distance far away 130% of their arm length. Kinetic analysis of the upper extremities was investigated by QUALISYS 3-dimensional motion analysis system. Muscle activation were measured by EMG during reaching tasks. The collected data were statistically processed using the SPSS for win version 20.0. [Results] There was a significant difference of shoulder joint velocity of flexion, abduction and internal rotation according to visual field condition during reaching tasks. There was no significant difference of shoulder joint angle and muscle activation according to visual field conditions during reaching tasks. [Conclusion] In conclusion, visual field has an influence on shoulder joint velocity. Therefore, the visual field may be to play an important role in reach performance.

Analysis of the influential factors of maximal-effort expiratory capacity of elderly women.

[Purpose] The purpose of this study was to find the influential factors of maximal-effort expiratory capacity of elderly women. [Subjects and Methods] The subjects of this study were 83 healthy elderly women. The study's methods and purpose were explained and these women agreed to participate. The maximal-effort expiratory capacity was measured using spirometry (Pony FX, COSMED Inc., Italy). We measured forced vital capacity, forced expiratory volume in 1 second, forced expiratory volume in 1 second/forced vital capacity, maximal expiratory flow 75%, maximal expiratory flow 50%, and maximal expiratory flow 25%. [Results] Regarding forced vital capacity and forced expiratory volume in 1 second, it was found that height and age were influential factors. Regarding forced expiratory volume in 1 second/forced vital capacity %, maximal expiratory flow 75%, maximal expiratory flow 50%, and maximal expiratory flow 25%, it was found that only age was an influential factor. [Conclusion] This study demonstrated that the most influential factors of maximal-effort expiratory capacity of elderly women were age, and the second influential factor was height. We noticed that weight was the least influential factor among them.

The effects of stretching exercise for upper trapezius on the asymmetric rate of bite force.

[Purpose] The purpose of this study was to observe the effects of stretching the upper trapezius muscle on the asymmetric rate of bite force. [Subjects] Forty-seven female university students who had all their original teeth, had no disorders in the temporomandibular joints, and had never worn braces; participated in this study. [Methods] An occlusometer was used to measure biting forces. Subsequently, stretching exercises of the upper trapezius were performed. The subjects were divided into 3 groups at the start of the testing: the asymmetric rate of the first group was less than 10%; the asymmetric rate of the second group was between 10% and 20%; and the asymmetric rate of the third group was more than 20%. The stretching exercises were done on the dominant side of the upper trapezius. [Results] After the stretching exercises of the upper trapezius, the results showed that for the first group, whose asymmetric rate of biting force was less than 10%, there was a significant increase in asymmetric rate (from 5.1% to 10.3%). For the second group, whose asymmetric rate of biting force was measured to be between 10% and 20%, the asymmetric rate decreased from 14.7% to 14.3%, but the change was not statistically significant. For the third group, whose asymmetric rate of biting force was more than 20%, there was a significant decrease in asymmetric rate (from 27.8% to 12.6%). [Conclusion] We concluded that stretching exercises of the upper trapezius muscle had a direct effect on the asymmetric rate of biting force.

Effects of combined exercise on changes of lower extremity muscle activation during walking in older women.

[Purpose] The purpose of this study was to demonstrate the effects of combined exercise for a period of 12 weeks on the changes in lower extremity muscle activation during walking in older women. [Subjects] The subjects of this study were 22 elderly women who were 65 years of age or older and living in B-City. The subjects had no nervous system or muscular system diseases that might affect walking in the previous two years. [Methods] Muscle activation was measured by using surface EMG (QEMG-8, Laxtha, Daejeon, Republic of Korea). The subjects were asked to walk on an 8 m of footpath at a natural speed. In order to minimize the noise from the cable connecting the EMG measuring instrument to the electrodes, tape was used to affix the electrodes so that they would not fall off the subjects. The EMG data were analyzed by using the RMS. [Results] Muscle activation of the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius was increased significantly after combined exercise for 12 weeks. However, no increase was observed in the left biceps femoris. [Conclusion] It was demonstrated that our exercise program, which includes aerobic walking exercises, senior-robics, and muscle strengthening exercises using elastic bands, is very effective for reorganizing the normal gait pattern in the cerebral cortex and improving muscle strength.

The effects of elbow joint angle changes on elbow flexor and extensor muscle strength and activation.

[Purpose] This research investigated the relationship between elbow joint angle and elbow flexor and extensor strength and activation, taking into consideration the length-tension tension curve of the muscle. [Subjects] There were 30 research subjects in total, 15 male and 15 female college students from Busan S University who had no functional disabilities that might affect measurement of muscle strength and muscle activation, and none had they experienced any damage in their upper extremities or hands. [Methods] The elbow joint angles were positioned at angles of 56°, 70° and 84°, and then muscle strength and activation were compared. Repeated measures ANOVA was used for statistical analysis, and the paired t-test was used to identify the difference between each angle. We used the SPSS for windows (ver. 21.0) statistical software and a significance level of α=0.05. [Results] The results showed that muscle strength and activation of the biceps was highest when the joint was placed at 56°. On the other hand, for the triceps, the result was highest when the joint angle was placed at 84°. [Conclusion] The tests confirmed that muscle strength and activation were highest at the joint angle at which the muscle was stretched to 20% more than the resting position in concentric contraction.

The effects of active scapular protraction on the muscle activation and function of the upper extremity.

[Purpose] The purpose of this study was to determine the effects of adjusting the scapula into its ideal position through active scapular protraction on the muscle activation and function of the upper extremity. [Subjects] Twenty female college students aged 19-21 without any physical or functional disability were the subjects of this study. They had no history of injury to their upper extremities or hands. [Methods] After the initial measurements the experimental group was asked to perform active scapular protraction; then, their grip strength and muscle activation were measured again. Every action was maintained for 5 seconds and repeated 3 times. The mean values of the measurements were analyzed. A resting of 1 minute was given between each action. [Results] The results revealed a significant change in the experimental group's grip strength after active scapular protraction had been performed. The surrounding muscles of the scapula, such as the serratus anterior, upper trapezius, flexor carpi ulnaris, flexor carpi radialis and palmaris longus, showed significant changes in muscle activation after active scapular protraction. The muscles of the upper extremity also showed significant changes after active scapular protraction. [Conclusion] The adjustment of scapula into its ideal position through active scapular protraction increased the activations of the muscles surrounding the shoulder joint and improved the function of the upper extremity.