Activity Patterns and Timing of Muscle Activity in the Forward Walking and Backward Walking Stick Insect Carausius morosus

2010 ◽  
Vol 104 (3) ◽  
pp. 1681-1695 ◽  
Author(s):  
Philipp Rosenbaum ◽  
Anne Wosnitza ◽  
Ansgar Büschges ◽  
Matthias Gruhn
Keyword(s):  
Muscle Activity ◽  
Activity Patterns ◽  
Body Height ◽  
Stick Insect ◽  
Emg Activity ◽  
Electrical Measurements ◽  
Backward Walking ◽  
Tightly Coupled ◽  
Leg Kinematics ◽  
Leg Movements

Understanding how animals control locomotion in different behaviors requires understanding both the kinematics of leg movements and the neural activity underlying these movements. Stick insect leg kinematics differ in forward and backward walking. Describing leg muscle activity in these behaviors is a first step toward understanding the neuronal basis for these differences. We report here the phasing of EMG activities and latencies of first spikes relative to precise electrical measurements of middle leg tarsus touchdown and liftoff of three pairs ( protractor/retractor coxae, levator/depressor trochanteris, extensor/flexor tibiae) of stick insect middle leg antagonistic muscles that play central roles in generating leg movements during forward and backward straight walking. Forward walking stance phase muscle (depressor, flexor, and retractor) activities were tightly coupled to touchdown, beginning on average 93 ms prior to and 9 and 35 ms after touchdown, respectively. Forward walking swing phase muscle (levator, extensor, and protractor) activities were less tightly coupled to liftoff, beginning on average 100, 67, and 37 ms before liftoff, respectively. In backward walking the protractor/retractor muscles reversed their phasing compared with forward walking, with the retractor being active during swing and the protractor during stance. Comparison of intact animal and reduced two- and one-middle-leg preparations during forward straight walking showed only small alterations in overall EMG activity but changes in first spike latencies in most muscles. Changing body height, most likely due to changes in leg joint loading, altered the intensity, but not the timing, of depressor muscle activity.

Use of a Shoulder Rest for Playing the Violin Revisited: An Analysis of the Effect of Shoulder Rest Height on Muscle Activity, Violin Fixation Force, and Player Comfort

2019 ◽  
Vol 34 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Laura M Kok ◽  
Jim Schrijvers ◽  
Marta Fiocco ◽  
Barend van Royen ◽  
Jaap Harlaar
Keyword(s):  
Muscle Activity ◽  
Anterior Part ◽  
Activity Patterns ◽  
Deltoid Muscle ◽  
Surface Emg ◽  
Emg Activity ◽  
Linear Regression Models ◽  
Upper Trapezius ◽  
Shoulder Muscles ◽  
Rest Condition

AIMS: For violinists, the shoulder rest is an ergonomic adaptation to reduce musculoskeletal load. In this study, we aimed to evaluate how the height of the shoulder rest affects the violin fixation force and electromyographic (EMG) activity of the superficial neck and shoulder muscles. METHODS: In professional violinists, four different shoulder rest heights during five playing conditions were evaluated. Outcome variables included the jaw-shoulder violin fixation force and bilateral surface EMG of the upper trapezius (mTP), sternocleidomastoid (mSCM), and left anterior part of the left deltoid muscle (mDTA). Playing comfort was subjectively rated on a visual analogue scale (VAS). Linear regression models were estimated to investigate the influence of the shoulder rest height on muscle activity and violin fixation force as well as the muscle activity of the five evaluated muscles on violin fixation force. RESULTS: 20 professional violinists (4 males, 16 females, mean age 29.4 yrs) participated in this study. The shoulder rest condition had a significant effect on playing comfort (p<0.001), with higher shoulder rest conditions associated with decreased subjective playing comfort. The mean violin fixation force for each shoulder rest condition ranged between 2.92 and 3.39 N; higher shoulder rests were related to a higher violin fixation force (p<0.001). CONCLUSION: In this study, violin fixation force and muscle activity of the left mDTA increased while playing with an increasing height of the shoulder rest. As the shoulder rest influences muscle activity patterns and violin fixation force, adjustment of the shoulder rest and positioning of the violin need to be carefully optimized.

Muscle Activity as a Releasing Factor for Pain in the Shoulder and Neck

Cephalalgia ◽  
1999 ◽  
Vol 19 (25_suppl) ◽  
pp. 1-8 ◽  
Author(s):  
RH Westgaard
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Experimental Situation ◽  
Activity Patterns ◽  
Trapezius Muscle ◽  
Emg Activity ◽  
Occupational Setting ◽  
Autonomic Activation ◽  
Pain Symptoms ◽  
Vocational Studies

In this review, the evidence for trapezius muscle activity as a releasing factor for shoulder and neck pain is considered, mainly on the basis of studies in our laboratory. Two lines of evidence are produced, (i) vocational studies in an occupational setting, where muscle activity pattern is recorded by surface EMG and a clinical examination of the shoulder region of the subjects performed; and (ii) laboratory studies where muscle activity patterns and pain development are recorded in an experimental situation with mental stress and minimal physical activity. The vocational studies demonstrate pain development in the shoulder and neck despite very low muscle activity recorded, making it very difficult to assume muscular involvement for all cases with such complaints. However, the hypothesis of pain development through overexertion of a subpopulation of low-threshold motor units also makes it difficult to draw a firm negative conclusion. The laboratory experiments, on the other hand, show that trapezius activity patterns in response to stress have many features that would be expected if muscle activation induces pain symptoms. It is further noted that the trapezius is the only muscle with activity patterns that show these features. Possibly, we observe the effects of parallel physiological phenomena, e.g., a systemic autonomic activation that induces pain symptoms and also facilitates the motor response of some muscles. Evidence of autonomic activation of trapezius is presented by the observation of low-level, rhythmic EMG activity during sleep. However, this is not firm evidence for the above hypothesis, which at present best serves as a basis for further experimentation.

scholarly journals Metabolic Costs and Muscle Activity Patterns During Robotic- and Therapist-Assisted Treadmill Walking in Individuals With Incomplete Spinal Cord Injury

2006 ◽  
Vol 86 (11) ◽  
pp. 1466-1478 ◽  
Author(s):  
Jeffrey F Israel ◽  
Donielle D Campbell ◽  
Jennifer H Kahn ◽  
T George Hornby
Keyword(s):  
Spinal Cord ◽  
Muscle Activity ◽  
Activity Patterns ◽  
Swing Phase ◽  
Emg Activity ◽  
Robotic Device ◽  
Incomplete Spinal Cord Injury ◽  
Robotic Assisted ◽  
Cord Injury ◽  
Metabolic Costs

AbstractBackground and Purpose. Robotic devices that provide passive guidance and stabilization of the legs and trunk during treadmill stepping may increase the delivery of locomotor training to subjects with neurological injury. Lower-extremity guidance also may reduce voluntary muscle activity as compared with compliant assistance provided by therapists. The purpose of this study was to investigate differences in metabolic costs and lower-limb muscle activity patterns during robotic- and therapist-assisted treadmill walking. Subjects. Twelve ambulatory subjects with motor incomplete spinal cord injury participated. Methods. In 2 separate protocols, metabolic and electromyographic (EMG) data were collected during standing and stepping on a treadmill with therapist and robotic assistance. During robotic-assisted walking, subjects were asked to match the kinematic trajectories of the device and maximize their effort. During therapist-assisted walking, subjects walked on the treadmill with manual assistance provided as necessary. Results. Metabolic costs and swing-phase hip flexor EMG activity were significantly lower when subjects were asked to match the robotic device trajectories than with therapist-assisted walking. These differences were reduced when subjects were asked to maximize their effort during robotic-assisted stepping, although swing-phase plantar-flexor EMG activity was increased. In addition, during standing prior to therapist- or robotic-assisted stepping, metabolic costs were higher without stabilization from the robotic device. Discussion and Conclusion. Differences in metabolic costs and muscle activity patterns between therapist- and robotic-assisted standing and stepping illustrate the importance of minimizing passive guidance and stabilization provided during step training protocols.

scholarly journals Vision fine-tunes preparation for landing in the cane toad, Rhinella marina

2018 ◽  
Vol 14 (9) ◽  
pp. 20180397 ◽  
Author(s):  
Laura J. Ekstrom ◽  
Chris Panzini ◽  
Gary B. Gillis
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Activity Patterns ◽  
Fine Tuning ◽  
Emg Activity ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Impact Forces ◽  
Before And After ◽  
The Impact

In toad hopping, the hindlimbs generate the propulsive force for take-off while the forelimbs resist the impact forces associated with landing. Preparing to perform a safe landing, in which impact forces are managed appropriately, likely involves the integration of multiple types of sensory feedback. In toads, vestibular and/or proprioceptive feedback is critical for coordinated landing; however, the role of vision remains unclear. To clarify this, we compare pre-landing forelimb muscle activation patterns before and after removing vision. Specifically, we recorded EMG activity from two antagonistic forelimb muscles, the anconeus and coracoradialis, which demonstrate distance-dependent onset timing and recruitment intensity, respectively. Toads were first recorded hopping normally and then again after their optic nerves were severed to remove visual feedback. When blind, toads exhibited hop kinematics and pre-landing muscle activity similar to when sighted. However, distance-dependent relationships for muscle activity patterns were more variable, if present at all. This study demonstrates that blind toads are still able to perform coordinated landings, reinforcing the importance of proprioceptive and/or vestibular feedback during hopping. But the increased variability in distance-dependent activity patterns indicates that vision is more responsible for fine-tuning the motor control strategy for landing.

Crushing motor patterns in drum (Teleostei: Sciaenidae): functional novelties associated with molluscivory

2000 ◽  
Vol 203 (20) ◽  
pp. 3161-3176 ◽  
Author(s):  
J.R. Grubich
Keyword(s):  
Muscle Activity ◽  
Activity Patterns ◽  
Motor Pattern ◽  
Prey Type ◽  
Red Drum ◽  
Canonical Variate ◽  
Emg Activity ◽  
Motor Patterns ◽  
Activity Intensity ◽  
Pharyngeal Muscles

This study explores the evolution of molluscivory in the marine teleost family Sciaenidae by comparing the motor activity patterns of the pharyngeal muscles of two closely related taxa, the molluscivorous black drum (Pogonias cromis) and the generalist red drum (Sciaenops ocellatus). Muscle activity patterns were recorded simultaneously from eight pharyngeal muscles. Electromyographic (EMG) activity was recorded during feeding on three prey types that varied in shell hardness. Canonical variate and discriminant function analyses were used to describe the distinctness of drum pharyngeal processing behaviors. Discriminant functions built of EMG timing variables were more accurate than muscle activity intensity at identifying cycles by prey type and species. Both drum species demonstrated the ability to modulate pharyngeal motor patterns in response to prey hardness. The mean motor patterns and the canonical variate space of crushing behavior indicated that black drum employed a novel motor pattern during molluscivory. The mollusc-crushing motor pattern of black drum is different from other neoteleost pharyngeal behaviors in lacking upper jaw retraction by the retractor dorsalis muscle. This functional modification suggests that crushing hard-shelled marine bivalves requires a ‘vice-like’ compression bite in contrast to the shearing forces that are applied to weaker-shelled fiddler crabs by red drum and to freshwater snails by redear sunfish.

scholarly journals Static vs. Dynamic Acute Stretching Effect on Quadriceps Muscle Activity during Soccer Instep Kicking

2013 ◽  
Vol 39 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Mohammadtaghi Amiri-Khorasani ◽  
Eleftherios Kellis
Keyword(s):  
Angular Velocity ◽  
Muscle Activity ◽  
High Speed ◽  
Muscle Activation ◽  
Body Height ◽  
Rectus Femoris ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Emg Activity ◽  
Dynamic Stretching

Abstract The purpose of this study was to compare the effects of static and dynamic stretching on quadriceps muscle activation during maximal soccer instep kicking. The kicking motion of twelve male college soccer players (body height: 174.66 ± 5.01 cm; body mass: 72.83 ± 4.83 kg; age: 18.83 ± 0.75 years) was captured using six synchronized high-speed infra-red cameras whilst electromyography (EMG) signals from vastus medialis (VM), lateralis (VL) and rectus femoris (RF) were recorded before and after static or dynamic stretching. Analysis of variance designs showed a higher increase in knee extension angular velocity (9.65% vs. -1.45%, p < 0.001), RF (37.5% vs. -8.33%, p < 0.001), VM (12% vs. - 12%, p < 0.018), and VL EMG activity (20% vs. -6.67%, p < 0.001) after dynamic stretching exercises. Based on these results, it could be suggested that dynamic stretching is probably more effective in increasing quadriceps muscle activity and knee extension angular velocity during the final swing phase of a maximal soccer instep kick than static stretching.

scholarly journals Muscle Activity Asymmetry of the Lower Limbs During Sprinting in Elite Soccer Players

2020 ◽  
Vol 75 (1) ◽  
pp. 239-245
Author(s):  
Przemysław Pietraszewski ◽  
Artur Gołaś ◽  
Aleksander Matusiński ◽  
Sylwia Mrzygłód ◽  
Aleksandra Mostowik ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Body Height ◽  
Lower Limbs ◽  
Soccer Players ◽  
Emg Activity ◽  
Professional Soccer ◽  
Left And Right ◽  
Muscle Groups ◽  
The Right ◽  
Lh Rh

Abstract The analysis of movement patterns through EMG activity provides the opportunity to identify the muscle groups most involved in a particular exercise, and to determine the scope of inter-limb deficiencies. The aim of the present study was to investigate the effects of a side-to-side muscle activity asymmetry between the left and the right lower limb during sprinting in soccer players. Sixteen professional soccer players took part in the study. Their age, body mass and body height equaled 23.7 ± 7.6 years, 81.2 ± 10.8 kg and 179.3 ± 12.2 cm, respectively. The sprint test consisted of two maximal sprints over 30 m with a 5-min rest interval between each sprint. EMG was recorded bilaterally from the quadriceps, hamstrings and gluteal muscles. Regression analysis revealed a significant effect of a side-to-side average muscle activity asymmetry between the left and right hamstring (LH/RH) muscles during the speed tests at 5 m (p = 0.044), and 30 m (p = 0.045), as well as the left and right glutes (LG/RG) at 5 m (p = 0.044) and 30 m (p = 0.043). Our results indicate that hamstring and glute muscles should be selectively and additionally activated during resistance training in soccer players to prevent injuries and improve sprint performance.

scholarly journals The Existence of a Sticking Region in Free Weight Squats

2014 ◽  
Vol 42 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Roland van den Tillaar ◽  
Vidar Andersen ◽  
Atle Hole Saeterbakken
Keyword(s):  
Resistance Training ◽  
Body Mass ◽  
Muscle Activity ◽  
Bench Press ◽  
Body Height ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Emg Activity ◽  
Training Experience ◽  
Free Weight

Abstract The aim of this study was to investigate the existence of the sticking region in two legged free weight squats. Fifteen resistance-training males (age 24 ± 4 years, body mass 82 ± 11 kg, body height 179 ± 6 cm) with 6 ± 3 years of resistance-training experience performed 6-RM in free weight squats. The last repetition was analyzed for the existence of a sticking region. Only in 10 out of 15 participants a sticking region was observed. The observed sticking region was much shorter than in the bench press. Furthermore, rectus femoris decreased the EMG activity in contrast to increased EMG activity in biceps femoris around the sticking and surrounding region. No significant change in EMG activity was found for the lateral and medial vastus muscles. It is suggested that a combination of these muscle activity changes could be one of the causes of the existence of the sticking region in free weight squats

scholarly journals Sleep Pattern and Night-Time Muscle Activity in Children With Cerebral Palsy Compared to Typically Developing Peers

2021 ◽  
Vol 18 (2) ◽  
pp. 106-116
Author(s):  
Anina Ritterband-Rosenbaum ◽  
Mark Schram Christensen ◽  
Mai Choe Lund ◽  
Mia Dyhr Thomsen ◽  
Maria Joy Normann Haverberg ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Muscle Activity ◽  
Sleep Stage ◽  
Activity Patterns ◽  
Emg Activity ◽  
Sleep Stages ◽  
Typically Developing ◽  
Night Time ◽  
Significant Difference ◽  
Children With Cerebral Palsy

Objectives: To compare night-time muscle activity in children with cerebral palsy (CP) with that in typical developing peers. Methods: Polysomnography with electroencephalography (EEG), electrocardiogram, electromyography (EMG), respiration, and electrooculography movements recorded during one night were used to characterize sleep stages in a group of children with CP (Gross Motor Function Classification Scale I–III) and a group of typically developing (TD) children (aged 3–13 years). Periods of EMG activity for the tibialis anterior and soleus (SOL) muscles were identified, and the coherence between EEG and EMG was measured to assess corticomuscular drive during sleep. Results: There were no significant differences between the groups in total sleep time, average time spent awake, or rapid eye movement, N1, and N3 sleep. Children with CP spent significantly less time in N2 than their healthy peers (43% vs. 51%, p=0.03). There was only a significant difference between TD and CP in SOL muscle activity during the wake stage. Otherwise, there were no differences between groups in coherence in EEG and EMG signals for any sleep stage. Conclusion: Mildly affected children with CP do not show altered night sleep or muscle activity patterns as compared to TD peers. Abnormal muscle activity is unlikely to contribute to sleep disturbance, development of contractures, joint deformation, pain, or general discomfort in this group of children with CP.

scholarly journals Happy Enough to Relax? How Positive and Negative Emotions Activate Different Muscular Regions in the Back - an Explorative Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Clara Scheer ◽  
Simone Kubowitsch ◽  
Sebastian Dendorfer ◽  
Petra Jansen
Keyword(s):  
Muscle Activity ◽  
Negative Emotions ◽  
Activity Patterns ◽  
Large Body ◽  
Reciprocal Relationship ◽  
Emg Activity ◽  
Sitting Posture ◽  
Elevated Activity ◽  
Resting Period ◽  
Positive And Negative Emotions

Embodiment theories have proposed a reciprocal relationship between emotional state and bodily reactions. Besides large body postures, recent studies have found emotions to affect rather subtle bodily expressions, such as slumped or upright sitting posture. This study investigated back muscle activity as an indication of an effect of positive and negative emotions on the sitting position. The electromyography (EMG) activity of six back muscles was recorded in 31 healthy subjects during exposure to positive and negative affective pictures. A resting period was used as a control condition. Increased muscle activity patterns in the back were found during the exposure to negative emotional stimuli, which was mainly measured in the lumbar and thorax regions. The positive emotion condition caused no elevated activity. The findings show that negative emotions lead to increased differential muscle activity in the back and thus corroborate those of previous research that emotion affects subtle bodily expressions.

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