Neuromuscular Activation During Short-Track Speed Skating in Young Athletes

2016 ◽  
Vol 11 (7) ◽  
pp. 848-854 ◽  
Author(s):  
Sabine Felser ◽  
Martin Behrens ◽  
Susanne Fischer ◽  
Mario Baeumler ◽  
Ralf Salomon ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Tibialis Anterior ◽  
Muscle Activation ◽  
Time Trial ◽  
Rectus Femoris ◽  
Young Athletes ◽  
Neuromuscular Activation ◽  
Leg Muscles ◽  
Maximum Effort ◽  
The Right

Purpose:To investigate differences in muscle activation of both legs between the straight and the curve and changes in muscle activity during a 1000-m time trial (TT) and their relationship to the change in skating velocity in 9 young short-track speed skaters. The authors recorded skating times and EMG data from different leg muscles during maximum-effort skating trials on the straight and in the curve, as well as during a 1000-m TT.Results:Muscle activation differs between the straight and the curves and between legs; ie, average activities of selected muscles of the right leg were significantly higher during skating through the curves than in the straights. This could not be observed for the left leg. The reduction in speed during the 1000-m TT highly correlates with the decrease in the muscle activity of both the tibialis anterior and the rectus femoris of the right leg. Muscle recruitment is different in relation to lap section (straight vs curve) and leg (right vs left leg). The decreased muscle activity of the tibialis anterior and rectus femoris of the right leg showed the highest relationships with the reduction in skating speed during the 1000-m TT.

Muscle Activation in the Main Muscle Groups of the Lower Limbs in High-Level Dancesport Athletes

2018 ◽  
Vol 33 (4) ◽  
pp. 231-237
Author(s):  
Encarnación Liébana ◽  
Cristina Monleón ◽  
Raquel Morales ◽  
Carlos Pablos ◽  
Consuelo Moratal ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Gastrocnemius Medialis ◽  
Leg Muscles ◽  
Relative Activation ◽  
Muscle Groups ◽  
High Level

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.

A Neuromuscular and Metabolic Comparison between Forward and Reverse Pedaling

1998 ◽  
Vol 14 (4) ◽  
pp. 401-411 ◽  
Author(s):  
Eadric Bressel ◽  
Gary D. Heise ◽  
Greg Bachman
Keyword(s):  
Oxygen Consumption ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Muscle Activation ◽  
Knee Extensor ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Half Cycle ◽  
Physically Active ◽  
Crank Angle

The purpose of this study was to determine how muscle activity and oxygen consumption are influenced by reverse pedaling (RP) compared to forward pedaling (FP). Seventeen physically active males performed FP and RP at an external workrate of 157 W (80 rpm) while EMG data were collected from five muscles: rectus femoris (RF), biceps femoris (BF), gastrocnemius (GN), tibialis anterior (TA), and vastus medialis (VM). Oxygen consumption (V̇O2 L·min-1) data were collected. On-time durations and EMG amplitudes were quantified for each half-cycle (first 180° and second 180° of crank angle). V̇O2 was similar between pedaling conditions while muscles RF and BF exhibited phasic shifts in response to RP with no amplitude change. VM showed an increase and GN displayed a decrease in EMG amplitude from FP to RP. The phasic shifts in muscle activation seen in RP, particularly in RF and BF, may alter the sequence of the knee extensor–hip extensor joint moments during the first half-cycle of pedaling.

Changes in muscle activities and kinematics due to simulated leg length inequalities

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hannah Lena Siebers ◽  
Jörg Eschweiler ◽  
Filippo Migliorini ◽  
Valentin Michael Quack ◽  
Markus Tingart ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Pelvic Obliquity ◽  
Lateral Flexion ◽  
Leg Length ◽  
Joint Angles ◽  
Leg Muscles ◽  
Compensation Mechanisms ◽  
Musculoskeletal Problems

Abstract Muscle imbalances are a leading cause of musculoskeletal problems. One example are leg length inequalities (LLIs). This study aimed to analyze the effect of different (simulated) LLIs on back and leg muscles in combination with kinematic compensation mechanics. Therefore, 20 healthy volunteers were analyzed during walking with artificial LLIs (0–4 cm). The effect of different amounts of LLIs and significant differences to the reference condition without LLI were calculated of maximal joint angles, mean muscle activity, and its symmetry index. While walking, LLIs led to higher muscle activity and asymmetry of back muscles, by increased lumbar lateral flexion and pelvic obliquity. The rectus femoris showed higher values, independent of the amount of LLI, whereas the activity of the gastrocnemius on the shorter leg increased. The hip and knee flexion of the long leg increased significantly with increasing LLIs, like the knee extension and the ankle plantarflexion of the shorter leg. The described compensation mechanisms are explained by a dynamic lengthening of the short and shortening of the longer leg, which is associated with increased and asymmetrical muscle activity. Presenting this overview is important for a better understanding of the effects of LLIs to improve diagnostic and therapy in the future.

Lower-Extremity Muscle Activity During Aquatic and Land Treadmill Running at the Same Speeds

2014 ◽  
Vol 23 (2) ◽  
pp. 107-122 ◽  
Author(s):  
W. Matthew Silvers ◽  
Eadric Bressel ◽  
D. Clark Dickin ◽  
Garry Killgore ◽  
Dennis G. Dolny
Keyword(s):  
Lower Extremity ◽  
Outcome Measures ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Swing Phase ◽  
Treadmill Running ◽  
Vastus Medialis ◽  
Lower Extremity Muscle

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.

scholarly journals Effects of a Dynamic Chair on Chair Seat Motion and Trunk Muscle Activity during Office Tasks and Task Transitions

2018 ◽  
Vol 15 (12) ◽  
pp. 2723 ◽  
Author(s):  
Corina Nüesch ◽  
Jan-Niklas Kreppke ◽  
Annegret Mündermann ◽  
Lars Donath
Keyword(s):  
Young Adults ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Dynamic Condition ◽  
Trunk Muscle ◽  
Erector Spinae ◽  
Task Transition ◽  
The Right ◽  
Hand Writing ◽  
And Task

Employing dynamic office chairs might increase the physical (micro-) activity during prolonged office sitting. We investigated whether a dynamic BioSwing® chair increases chair sway and alters trunk muscle activation. Twenty-six healthy young adults performed four office tasks (reading, calling, typing, hand writing) and transitions between these tasks while sitting on a dynamic and on a static office chair. For all task-transitions, chair sway was higher in the dynamic condition (p < 0.05). Muscle activation changes were small with lower mean activity of the left obliquus internus during hand writing (p = 0.07), lower mean activity of the right erector spinae during the task-transition calling to hand writing (p = 0.036), and higher mean activity of the left erector spinae during the task-transition reading to calling (p = 0.07) on the dynamic chair. These results indicate that an increased BioSwing® chair sway only selectively alters trunk muscle activation. Adjustments of chair properties (i.e., swinging elements, foot positioning) are recommended.

scholarly journals Electromyographic responses to Nordic curl and prone leg curl exercises in football players

2021 ◽  
Vol 25 (5) ◽  
pp. 288-298
Author(s):  
Murat Çilli ◽  
Merve N. Yasar ◽  
Onur Çakir
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Total Duration ◽  
Rectus Femoris ◽  
Random Order ◽  
Biceps Femoris ◽  
Activation Rate ◽  
Significant Difference ◽  
Activation Rates ◽  
Short Time

Background and Study Aim. The aim of this study is to examine the electromyographic responses to Nordic curl and prone leg curl exercises, having two different mechanics. Material and Methods. The athletes performed the prone leg curl and Nordic curl exercises in random order, 6 repetitions each. Electromyographic data of semimemranosus, semitendinosus, biceps femoris and rectus femoris muscles were recorded by 8-channel electromyography in order to examine the muscle responses to exercises. Total duration of exercise, cumulative integrated electromyographic values and muscle activation rates in 5 different intensity zones determined according to MVC% values have been compared. Results. Prone leg curl exercise occurred in less time than Nordic curl exercise. According to the cumulative integrated electromyography data results, all muscles showed similar muscle activation in both exercises. Comparing the muscle activation rates in the five intensity zones, more muscle activity was observed for Nordic curl exercise in the first intensity zone, while prone leg curl exercise was more active in the third and fourth zones. During the prone leg curl exercise, the muscle activation rate of the dominant leg is higher in the first intensity zone, whereas the non-dominant leg in the fourth intensity zone has a higher muscle activation. During the Nordic curl exercise, the muscle activation rates of the dominant leg in the first and fifth intensity zones are higher, whereas the nondominant leg in the fourth intensity zone is higher. Conclusions. Prone leg curl exercises can be preferred in order to stimulate high muscle activation in a short time. Comparing the two exercises there was no significant difference in muscle activity in dominant and nondominant legs.

Forelimb brachial muscle activation patterns using surface electromyography and their relationship to kinematics in normal dogs walking and trotting

2014 ◽  
Vol 10 (1) ◽  
pp. 13-22 ◽  
Author(s):  
T.C. Garcia ◽  
B.K. Sturges ◽  
S.M. Stover ◽  
K. Aoki ◽  
J.M. Liang ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Surface Electromyography ◽  
Muscle Activation ◽  
Biceps Brachii ◽  
Elbow Flexor ◽  
Median Frequency ◽  
Joint Angles ◽  
Muscle Activation Patterns ◽  
The Right ◽  
Elbow Extensor

The objective of this study was to determine activity of the elbow flexor and elbow extensor groups of muscles relative to shoulder and elbow joint kinematics in normal walking and trotting dogs using surface electromyography (EMG), and to determine if muscle activity varies with gait or limb. Ten healthy mixed-breed dogs were walked and trotted across embedded force plates in a 6 m walkway while simultaneously recording muscle activation using surface EMG positioned over the biceps brachii (elbow flexor group) and triceps brachii (elbow extensor group); peak shoulder, elbow, and carpal joint angles from motion capture, and ground reaction forces. EMG magnitude, timing, and power spectral density (PSD) were used to analyse muscle activity. The effects of gait type and limb side on EMG measures and joint angles were assessed using an analysis of variance. Results showed that the elbow flexor group was maximally active at end of stance. The elbow extensor group was maximally active at the beginning of stance. Muscle activity occurred earlier in the gait phase (stance or swing) in the trot compared to the walk. The amplitude, frequency at maximum PSD (elbow flexor group only) and the median frequency were larger on the right side than on the left side. The maximum PSD and integrated PSD were larger on the left side than the right side. These data provide a reference for identifying abnormalities associated with orthopaedic, neurological, or rehabilitative changes. Limb asymmetry observed in muscle activation in clinically normal dogs should be further evaluated.

scholarly journals Bilateral Limb Phase Relationship and Its Potential to Alter Muscle Activity Phasing During Locomotion

2009 ◽  
Vol 102 (5) ◽  
pp. 2856-2865 ◽  
Author(s):  
Laila Alibiglou ◽  
Citlali López-Ortiz ◽  
Charles B. Walter ◽  
David A. Brown
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Angular Position ◽  
Phase Relationship ◽  
Rectus Femoris ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Relative Contribution ◽  
Coordination Patterns ◽  
Muscle Phasing

It is well established that the sensorimotor state of one limb can influence another limb and therefore bilateral somatosensory inputs make an important contribution to interlimb coordination patterns. However, the relative contribution of interlimb pathways for modifying muscle activation patterns in terms of phasing is less clear. Here we studied adaptation of muscle activity phasing to the relative angular positions of limbs using a split-crank ergometer, where the cranks could be decoupled to allow different spatial angular position relationships. Twenty neurologically healthy individuals performed the specified pedaling tasks at different relative angular positions while surface electromyographic (EMG) signals were recorded bilaterally from eight lower extremity muscles. During each experiment, the relative angular crank positions were altered by increasing or decreasing their difference by randomly ordered increments of 30° over the complete cycle [0° (in phase pedaling); 30, 60, 90, 120, 150, and 180° (standard pedaling); and 210, 240, 270, 300, and 330° out of phase pedaling]. We found that manipulating the relative angular positions of limbs in a pedaling task caused muscle activity phasing changes that were either delayed or advanced, dependent on the relative spatial position of the two cranks and this relationship is well-explained by a sine curve. Further, we observed that the magnitude of phasing changes in biarticular muscles (like rectus femoris) was significantly greater than those of uniarticular muscles (like vastus medialis). These results are important because they provide new evidence that muscle phasing can be systematically influenced by interlimb pathways.

Phase-dependent modulations of anticipatory postural activity during human locomotion

1991 ◽  
Vol 66 (1) ◽  
pp. 12-19 ◽  
Author(s):  
H. Hirschfeld ◽  
H. Forssberg
Keyword(s):  
Muscle Activity ◽  
Tibialis Anterior ◽  
Audio Signal ◽  
Human Locomotion ◽  
Step Cycle ◽  
Postural Activity ◽  
Leg Muscles ◽  
Hamstring Muscles ◽  
In The Beginning ◽  
Support Phase

1. The ability of the CNS to coordinate several motor tasks was studied in humans walking on a treadmill while pulling on a handle. Subjects were instructed to respond to an audio signal that was presented in different phases of the step cycle. Electromyograph (EMG) and movements were recorded from the left arm and leg. 2. The activity of the arm muscle was preceded by postural activity in the leg muscles. The pattern of the anticipatory postural activity differed in the various phases of the step cycle. Lateral gastrocnemius and hamstring muscles were activated during responses occurring in the early support phase whereas tibialis anterior and quadriceps muscles were activated when the pull was exerted during the late support phase and during the swing phase. In the middle of the support phase the combination of both muscle activity was present. 3. The temporal sequencing and the spatial distribution of the anticipatory muscle activity changed gradually. Early during the support phase the hamstring muscles were activated before the gastrocnemius muscle, whereas the order was reversed during midstance. The EMG amplitude of the hamstring and gastrocnemius muscles was largest in the beginning of the support phase and then gradually decreased, whereas the amplitude of the tibialis anterior and quadriceps muscles increased during the later parts of the support phase. 4. The anticipatory responses to pulls exerted during the first part of the support phase reduced the ankle flexion during the single support phase.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Lower extremity muscle activation during horizontal and uphill running

1997 ◽  
Vol 83 (6) ◽  
pp. 2073-2079 ◽  
Author(s):  
Mark A. Sloniger ◽  
Kirk J. Cureton ◽  
Barry M. Prior ◽  
Ellen M. Evans
Keyword(s):  
Lower Extremity ◽  
High Intensity ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Peak Oxygen Uptake ◽  
Lower Extremity Muscle ◽  
Or Groups ◽  
Exercise Induced ◽  
The Right

Sloniger, Mark A., Kirk J. Cureton, Barry M. Prior, and Ellen M. Evans. Lower extremity muscle activation during horizontal and uphill running. J. Appl. Physiol. 83(6): 2073–2079, 1997.—To provide more comprehensive information on the extent and pattern of muscle activation during running, we determined lower extremity muscle activation by using exercise-induced contrast shifts in magnetic resonance (MR) images during horizontal and uphill high-intensity (115% of peak oxygen uptake) running to exhaustion (2.0–3.9 min) in 12 young women. The mean percentage of muscle volume activated in the right lower extremity was significantly ( P <0.05) greater during uphill (73 ± 7%) than during horizontal (67 ± 8%) running. The percentage of 13 individual muscles or groups activated varied from 41 to 90% during horizontal running and from 44 to 83% during uphill running. During horizontal running, the muscles or groups most activated were the adductors (90 ± 5%), semitendinosus (86 ± 13%), gracilis (76 ± 20%), biceps femoris (76 ± 12%), and semimembranosus (75 ± 12%). During uphill running, the muscles most activated were the adductors (83 ± 8%), biceps femoris (79 ± 7%), gluteal group (79 ± 11%), gastrocnemius (76 ± 15%), and vastus group (75 ± 13%). Compared with horizontal running, uphill running required considerably greater activation of the vastus group (23%) and soleus (14%) and less activation of the rectus femoris (29%), gracilis (18%), and semitendinosus (17%). We conclude that during high-intensity horizontal and uphill running to exhaustion, lasting 2–3 min, muscles of the lower extremity are not maximally activated, suggesting there is a limit to the extent to which additional muscle mass recruitment can be utilized to meet the demand for force and energy. Greater total muscle activation during exhaustive uphill than during horizontal running is achieved through an altered pattern of muscle activation that involves increased use of some muscles and less use of others.

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