scholarly journals Electromyography features during physical and imagined standing up in healthy young adults, Phitsanulok, Thailand

2020 ◽  
Vol 35 (1) ◽  
pp. 89-101
Author(s):  
Kanokwan Srisupornkornkool ◽  
Kanphajee Sornkaew ◽  
Kittithat Chatkanjanakool ◽  
Chayanit Ampairattana ◽  
Pariyanoot Pongtasom ◽  
...  

PurposeTo compare the electromyography (EMG) features during physical and imagined standing up in healthy young adults.Design/methodology/approachTwenty-two participants (ages ranged from 20–29 years old) were recruited to participate in this study. Electrodes were attached to the rectus femoris, biceps femoris, tibialis anterior and the medial gastrocnemius muscles of both sides to monitor the EMG features during physical and imagined standing up. The %maximal voluntary contraction (%MVC), onset and duration were calculated.FindingsThe onset and duration of each muscle of both sides had no statistically significant differences between physical and imagined standing up (p > 0.05). The %MVC of all four muscles during physical standing up was statistically significantly higher than during imagined standing up (p < 0.05) on both sides. Moreover, the tibialis anterior muscle of both sides showed a statistically significant contraction before the other muscles (p < 0.05) during physical and imagined standing up.Originality/valueMuscles can be activated during imagined movement, and the patterns of muscle activity during physical and imagined standing up were similar. Imagined movement may be used in rehabilitation as an alternative or additional technique combined with other techniques to enhance the STS skill.

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 524
Author(s):  
Youngjin Lee ◽  
Minkyoung Kim ◽  
Haneul Lee

The present study was performed to assess the relationship between hand-held myotonometer MyotonPRO and shear wave elastography (SWE) measurements of lower limb muscle stiffness during resting and active voluntary contraction. Forty healthy young adults, (20 males and 20 females) participated in the study. The stiffness of each subject’s rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (MG) was measured repeatedly by MyotonPRO and SWE. Moderate to strong correlations between the two methods’ measurements were found for both resting and active voluntary contraction. (r = 0.416–0.669, p < 0.05; r = 0.398–0.594, p < 0.05, respectively). Muscle stiffness at rest was significantly lower compared contraction in all four muscles measured by both methods (p < 0.05). Intra-rater reliabilities were generally lower when measurements were taken during contraction. Additionally, when compared by gender, muscle stiffness measured by MyotonPRO was significantly higher at rest in men compared to women, except for the TA. However, a significant difference was found in TA muscle stiffness by gender when measured with SWE. When muscles were contracted, all muscles showed significantly higher stiffness in men compared to women. There were moderate to good correlations in muscle stiffness between measurements of SWE and MyotonPRO at rest and during active voluntary contraction. Additionally, both instruments showed good intra-rater reliability.


Diagnostics ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 362
Author(s):  
Haneul Lee ◽  
Kyuseok Kim ◽  
Youngjin Lee

Shear wave elastography with ultrasound is a noninvasive method used for measuring stiffness in the human body. Shear wave elastography can be used for accurately and quantitatively measuring stiffness. However, its disadvantage is that the stiffness value can vary significantly because the region of interest (ROI) setting depends on the diagnostic operator. In this study, a stiffness measurement program using color mapping in shear wave elastography was developed to address the above-mentioned disadvantage. Color map and color ratios were obtained and evaluated for major lower limb muscles (i.e., biceps femoris, medial gastrocnemius, rectus femoris, and tibialis anterior) at active voluntary contraction. According to the result, when the developed program was used, a small standard deviation compared to the conventional stiffness measurement method, such as kilopascal or meter per second unit using ROIs, was measured in all cases. In conclusion, our results demonstrate that the stiffness measurement method using our program is expected to improve reliability in shear wave elastography ultrasound imaging.


2021 ◽  
Vol 38 (5) ◽  
pp. 332-336
Author(s):  
Daniel Araya ◽  
Juan López ◽  
Germán Villalobos ◽  
Rodrigo Guzmán-Venegas ◽  
Oscar Valencia

Introduction: Surface electromyography has been a technique used to describe muscle activity during running. However, there is little literature that analyses the behaviour of muscle coactivation in runners, describing the effect between two techniques associated with the initial contact, such as the use of rearfoot (RF) and forefoot (FF). Material and method: The purpose of this study was to compare muscle coactivation levels developed in the lower limb during two running techniques, FF vs RF. Fourteen amateur runners were evaluated (eight men, six women; age= 23.21 ± 3.58 years, mass= 63.89 ± 8.13 kg, height= 1.68 ± 0.08m). Surface electromyography was used to measure muscle activity during both running techniques evaluated on a treadmill, considering the muscle pairs: Rectus femoris- Biceps femoris (RFe-BF), Lateral Gastrocnemius–Tibialis Anterior (LG-TA), and Medial Gastrocnemius - Tibialis Anterior (MG-TA). These were calculated in three windows considering ten running cycles (0-5%, 80-100%, and 0-100%). To compare FF vs RF t-student test for paired data was used. Results: It was observed significant differences in the MG-TA pair (FF= 18.42 ± 11.84% vs RF = 39.05 ± 13.28%, p = 0.0018 during 0-5%, and RFe-BF pair (FF = 42.38 ± 18.11% vs RF = 28.37 ± 17.2%, p = 0.0331) during 80-100% of the race. Conclusion: Our findings show that the behaviour of muscle coactivation is different between FF vs RF techniques if we analyze little windows in the running cycle. This could be associated with an increase in the joint stability between these short intervals, represented in the initial and final regions of the running cycle.


2014 ◽  
Vol 23 (2) ◽  
pp. 107-122 ◽  
Author(s):  
W. Matthew Silvers ◽  
Eadric Bressel ◽  
D. Clark Dickin ◽  
Garry Killgore ◽  
Dennis G. Dolny

Context:Muscle activation during aquatic treadmill (ATM) running has not been examined, despite similar investigations for other modes of aquatic locomotion and increased interest in ATM running.Objectives:The objectives of this study were to compare normalized (percentage of maximal voluntary contraction; %MVC), absolute duration (aDUR), and total (tACT) lower-extremity muscle activity during land treadmill (TM) and ATM running at the same speeds.Design:Exploratory, quasi-experimental, crossover design.Setting:Athletic training facility.Participants:12 healthy recreational runners (age = 25.8 ± 5 y, height = 178.4 ± 8.2 cm, mass = 71.5 ± 11.5 kg, running experience = 8.2 ± 5.3 y) volunteered for participation.Intervention:All participants performed TM and ATM running at 174.4, 201.2, and 228.0 m/min while surface electromyographic data were collected from the vastus medialis, rectus femoris, gastrocnemius, tibialis anterior, and biceps femoris.Main Outcome Measures:For each muscle, a 2 × 3 repeated-measures ANOVA was used to analyze the main effects and environment–speed interaction (P ≤ .05) of each dependent variable: %MVC, aDUR, and tACT.Results:Compared with TM, ATM elicited significantly reduced %MVC (−44.0%) but increased aDUR (+213.1%) and tACT (+41.9%) in the vastus medialis, increased %MVC (+48.7%) and aDUR (+128.1%) in the rectus femoris during swing phase, reduced %MVC (−26.9%) and tACT (−40.1%) in the gastrocnemius, increased aDUR (+33.1%) and tACT (+35.7%) in the tibialis anterior, and increased aDUR (+41.3%) and tACT (+29.2%) in the biceps femoris. At faster running speeds, there were significant increases in tibialis anterior %MVC (+8.6−15.2%) and tACT (+12.7−17.0%) and rectus femoris %MVC (12.1−26.6%; swing phase).Conclusion:No significant environment–speed interaction effects suggested that observed muscle-activity differences between ATM and TM were due to environmental variation, ie, buoyancy (presumed to decrease %MVC) and drag forces (presumed to increase aDUR and tACT) in the water.


Author(s):  
Courtney Middelcoop ◽  
Colten Fales ◽  
Richard T. Stone ◽  
Joseph Kim ◽  
Kristina Schaffhausen ◽  
...  

In studying the effects of expertise on different performance aspects of the gymnastic vault event, various springboard types with similar compression forces were evaluated between expert and novice-level gymnasts. Surface EMGs (sEMG) were placed on four major muscles (biceps femoris, rectus femoris, gastrocnemius medialis, and tibialis anterior) to find each gymnasts’ maximum voluntary contraction. Similarly, board compression and knee flexion angles were also captured at various phases of the performed vaults. Given that gymnasts with more expertise were more consistent in their landing spot on the various vault boards, they had more consistent performance outputs as a result. Expert gymnasts did this by more accurately hitting the sweet spot, more consistently activating their hamstring and gastrocnemius, and decreasing variability during the initial contact phase. By doing this, board compression and performance were both optimized. Coaches can use this information to accelerate the development of novice gymnasts by targeting these aspects.


2018 ◽  
Vol 33 (4) ◽  
pp. 231-237
Author(s):  
Encarnación Liébana ◽  
Cristina Monleón ◽  
Raquel Morales ◽  
Carlos Pablos ◽  
Consuelo Moratal ◽  
...  

Dancers are subjected to high-intensity workouts when they practice dancesport, and according to the literature, they are prone to injury, primarily of the lower limbs. The purpose of this study was to determine whether differences exist in relative activation amplitudes for dancers involved in dancesport due to muscle, gender, and type of dance. Measurements were carried out using surface electromyography equipment during the choreography of a performance in the following leg muscles: rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius medialis. Eight couples of active dancesport athletes (aged 20.50±2.75 yrs) were analyzed. Significant gender differences were found in rumba in the tibialis anterior (p≤0.05) and gastrocnemius medialis (p≤0.05). Based on the different activations, it is possible to establish possible mechanisms of injury, as well as tools for preventing injuries and improving sports performance.


2005 ◽  
Vol 94 (2) ◽  
pp. 1158-1168 ◽  
Author(s):  
A. M. Schillings ◽  
Th. Mulder ◽  
J. Duysens

Falls are a major problem in older adults. Many falls occur because of stumbling. The aim of the present study is to investigate stumbling reactions of older adults and to compare them with young adults. While subjects walked on a treadmill, a rigid obstacle unexpectedly obstructed the forward sway of the foot. In general, older adults used the same movement strategies as young adults (“elevating” and “lowering”). The electromyographic responses were categorized according to latencies: short-latency (about 45 ms, RP1), medium-latency (about 80 ms, RP2), and long-latency responses (about 110 ms, RP3; about 160 ms, RP4). Latencies of RP1 responses increased by about 6 ms and of RP2 by 10–19 ms in older adults compared with the young. Amplitudes of RP1 were similar for both age groups, whereas amplitudes of RP2–RP4 could differ. In the early-swing elevating strategy (perturbed foot directly lifted over the obstacle) older adults showed smaller responses in ipsilateral upper-leg muscles (biceps femoris and rectus femoris). This was related to shorter swing durations, more shortened step distances, and more failures in clearing the obstacle. In parallel, RP4 activity in the contralateral biceps femoris was enhanced, possibly pointing to a higher demand for trunk stabilization. In the late-swing lowering strategy (foot placed on the treadmill before clearing the obstacle) older adults showed lower RP2–RP3 responses in most muscles measured. However, kinematic responses were similar to those of the young. It is concluded that the changes in muscular responses in older adults induce a greater risk of falling after tripping, especially in early swing.


1997 ◽  
Vol 01 (02) ◽  
pp. 95-109 ◽  
Author(s):  
W. Herzog ◽  
T. R. Leonard

The dynamic properties of the cat soleus muscle were studied in freely walking animal preparations. The force and EMG responses of the soleus following supramaximal, ins tants of the step cycle. The sensorimotor interactions of soleus with the medial head of the gastrocnemius (a functional agonist of the soleus at the ankle) and the tibialis anterior (a functional antagonist of soleus at the ankle) were studied by measuring their force and EMG responses following the artifical stimulation of the soleus nerve. Supramaximal nerve stimulation showed distinct increases in the soleus forces during the entire swing phase and the second part (after peak forces had been reached) of the stance phase. Soleus forces could only be increased slightly in the first part of stance (from paw contact to peak force). These results suggest that force production of the soleus is virtually maximal during the early phases of stance but is submaximal for the remainder of the step cycle. Forces and EMGs of the medial gastrocnemius muscle were affected by the soleus nerve stimulation only in the latter part of the swing phase. In these cases, the force and EMG of the medial gastrocnemius were reduced significantly for the step cycle following the perturbation. The active force production of soleus during late swing causes an inhibition of medial gastrocnemius activity and force. Forces and EMGs of the tibialis anterior muscle were always affected by the soleus nerve stimulation during the swing phase of the step cycle. In these case, the force EMG of the medial gastrocnemius were reduced significantly for the step cycle following the perturbation. The active force production of soleus during late swing causes an inhibition of medial gastrocnemius activity and force. Forces and EMGs of the tibialis anterior muscle were always affected by the soleus nerve stimulation during the swing phase of the step cycle. In these instances, forces and EMGs of the tibialis anterior were significantly increased compared to step cycles preceding or following the perturbation. Part of the force enhancement is caused by the stretch of the activated tibialis anterior by the soleus, and part of the enhancement is caused by reflex activation. No effects on forces or EMGs of the tibialis anterior were observed when the soleus nerve stimulation showed its effects during the stance phase of the step cycle. The results of theis study suggest that the magnitude and the quality of ensorimotor interactions of soleus with medial gastrocnemius and tibialis anterior depend on the phase of the step cycle. The strongest interactions appear to exist during the swing phase; no observable interactions were found during stance.


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