scholarly journals The Effect of Shoe Type and Load Carrying on Electromyographic Activity of Lower Extremity Muscles during Stair Ascent and Descent

2019 ◽  
Vol 5 (2) ◽  
pp. 92-101
Author(s):  
Nader Farahpour ◽  
◽  
Mahdi Majlesi ◽  
Mohammad Reza Hoseinpouri ◽  
◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Lower Extremity ◽  
Muscle Activity ◽  
The Body ◽  
Emg Activity ◽  
Load Factor ◽  
Electromyographic Activity ◽  
Stair Ascent ◽  
Load Carrying ◽  
Cartilage Wear

Objective Stair ascent and descent is an essential movement task in daily life in which individuals are subjected to repetitive impact forces. The purpose of this study was to evaluate the intensity of Electromyographic (EMG) activity in lower extremity muscles of healthy young men during stair ascent and descent task wearing different type of shoes and carrying loads. Methods Nine men with a mean age of 25.94±3.26 years, mean height of 174±7.4 cm, and mean weight of 70.95±8.25 kg were selected. Four stairs were fabricated and the electromyographic activity of their lower extremity muscles (two muscles in the posterior leg and three quadriceps muscles) in the right side of the body was measured using the 16-channel EMG system MA300 during the task. These tests were conducted in two conditions of with and without load carrying. The load was a cube-shaped box weighing 15% of the body weight. Three cases of footwear were set: barefoot, athletic shoes, and formal shoes. Repeated measure ANOVA was used for data analysis at the significant level of P<0.05. Results The load factor had a significant effect on the intensity of muscle activity. The intensity of muscle activity during ascending stairs was higher than that during descending. In stair descent task, the EMG activity of the vastus medialis muscle was greater than that of the vastus lateralis and rectus femoris muscles, which causes the patella to be pulled inward more leading to patellofemoral articular cartilage wear in the long term. Conclusion Stair ascent puts more pressure on the ankle and knee joints. When carrying the load up stairs, the use of proper shoes can greatly reduce the intensity of muscle activity and delay fatigue. It is, therefore, recommended that people with patellofemoral articular cartilage wear should not use the stairs, if possible.

scholarly journals Spatiotemporal distribution of location and object effects in the electromyographic activity of upper extremity muscles during reach-to-grasp

2016 ◽  
Vol 115 (6) ◽  
pp. 3238-3248 ◽  
Author(s):  
Adam G. Rouse ◽  
Marc H. Schieber
Keyword(s):  
Upper Extremity ◽  
Muscle Activity ◽  
Neural Control ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Proximal Muscle ◽  
Reach To Grasp ◽  
Distal Muscle ◽  
The Subject ◽  
Later Phase

In reaching to grasp an object, proximal muscles that act on the shoulder and elbow classically have been viewed as transporting the hand to the intended location, while distal muscles that act on the fingers simultaneously shape the hand to grasp the object. Prior studies of electromyographic (EMG) activity in upper extremity muscles therefore have focused, by and large, either on proximal muscle activity during reaching to different locations or on distal muscle activity as the subject grasps various objects. Here, we examined the EMG activity of muscles from the shoulder to the hand, as monkeys reached and grasped in a task that dissociated location and object. We quantified the extent to which variation in the EMG activity of each muscle depended on location, on object, and on their interaction—all as a function of time. Although EMG variation depended on both location and object beginning early in the movement, an early phase of substantial location effects in muscles from proximal to distal was followed by a later phase in which object effects predominated throughout the extremity. Interaction effects remained relatively small. Our findings indicate that neural control of reach-to-grasp may occur largely in two sequential phases: the first, serving to project the entire upper extremity toward the intended location, and the second, acting predominantly to shape the entire extremity for grasping the object.

Analysis of Physiological Signals of Individuals with Eyes Closed Subjected to Unexpected Direction-Specific Stimuli Causing Instability

2020 ◽  
Vol 10 (11) ◽  
pp. 2754-2763
Author(s):  
Sunhye Shin ◽  
Chul Un Hong ◽  
Kyong Kim ◽  
Tae Kyu Kwon
Keyword(s):  
Lower Extremity ◽  
Muscle Activity ◽  
Postural Balance ◽  
Balance Control ◽  
Center Of Gravity ◽  
Training System ◽  
The Body ◽  
Physiological Signals ◽  
Eyes Closed ◽  
Lower Extremity Muscle

Research regarding the cerebral cortex and muscle activity patterns of the body used for postural balance control when sudden instability stimuli occur is lacking. This study analyzed individuals' physiological signals when direction-specific instability stimuli were applied while their eyes were closed. Healthy adults in their 20s maintained their postural balance while looking at the center of gravity provided by a monitor with a three-dimensional dynamic postural balance training system. We performed electroencephalography (EEG) and measured trunk and lower extremity muscle activity of participants with their eyes closed when subjected to four direction-specific instability stimuli (anterior, posterior, left, and right). EEG results showed that gamma waves increased significantly with an unbalanced stimulus when the participant's eyes were open and closed. The increased gamma wave rate with eyes closed was low in the exercise planning area, where information is relatively integrated and exercise is planned without visual information. EMG results showed fewer gamma waves on EEG due to the low focus on postural control because participants could not observe the center of gravity, which is the basis for balance. The trunk and lower extremity muscles tended to be used more due to the larger body perturbation angle. These outcomes can be used as basic data regarding how the human brain and muscles maintain postural balance when an unexpected external instability stimulus occurs. Quantitative postural balance rehabilitation training protocols for the elderly and those with disabilities can be created based on these outcomes.

scholarly journals Quantification of the Differences in Electromyographic Activity Magnitude Between the Upper and Lower Portions of the Rectus Abdominis Muscle During Selected Trunk Exercises

2001 ◽  
Vol 81 (5) ◽  
pp. 1096-1101 ◽  
Author(s):  
Gregory J Lehman ◽  
Stuart M McGill
Keyword(s):  
Muscle Activity ◽  
Abdominal Muscle ◽  
Rectus Abdominis ◽  
Oblique Muscle ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Rectus Abdominis Muscle ◽  
Emg Signal ◽  
External Oblique Muscle ◽  
External Oblique

Abstract Background and Purpose. Controversy exists around exercises and clinical tests that attempt to differentially activate the upper or lower portions of the rectus abdominis muscle. The purpose of this study was to assess the activation of the upper and lower portions of the rectus abdominis muscle during a variety of abdominal muscle contractions. Subjects. Subjects (N=11) were selected from a university population for athletic ability and low subcutaneous fat to optimize electromyographic (EMG) signal collection. Methods. Controlling for spine curvature, range of motion, and posture (and, therefore, muscle length), EMG activity of the external oblique muscle and upper and lower portions of rectus abdominis muscle was measured during the isometric portion of curl-ups, abdominal muscle lifts, leg raises, and restricted or attempted leg raises and curl-ups. A one-way repeated-measures analysis of variance was used to test for differences in activity between exercises in the external oblique and rectus abdominis muscles as well as between the portions of the rectus abdominis muscle. Results. No differences in muscle activity were found between the upper and lower portions of the rectus abdominis muscle within and between exercises. External oblique muscle activity, however, showed differences between exercises. Discussion and Conclusion. Normalizing the EMG signal led the authors to believe that the differences between the portions of the rectus abdominis muscle are small and may lack clinical or therapeutic relevance.

Effect of sleep-induced increases in upper airway resistance on respiratory muscle activity

1991 ◽  
Vol 70 (1) ◽  
pp. 158-168 ◽  
Author(s):  
K. G. Henke ◽  
J. A. Dempsey ◽  
M. S. Badr ◽  
J. M. Kowitz ◽  
J. B. Skatrud
Keyword(s):  
Muscle Activity ◽  
Respiratory Muscle ◽  
Peak Flow ◽  
Nrem Sleep ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Stage 2 Sleep ◽  
Expiratory Muscles ◽  
Resistive Loads ◽  
Respiratory Muscle Activity

To investigate the response of inspiratory and expiratory muscles to naturally occurring inspiratory resistive loads in the absence of conscious control, five male "snorers" were studied during non-rapid-eye-movement (NREM) sleep with and without continuous positive airway pressure (CPAP). Diaphragm (EMGdi) and scalene (EMGsc) electromyographic activity were monitored with surface electrodes and abdominal EMG activity (EMGab) with wire electrodes. Subjects were studied in the following conditions: 1) awake, 2) stage 2 sleep, 3) stage 3/4 sleep, 4) CPAP during stage 3/4 sleep, 5) CPAP plus end-tidal CO2 pressure (PETCO2) isocapnic to stage 2 sleep, and 6) CPAP plus PETCO2 isocapnic to stage 3/4 sleep. Inspired pulmonary resistance (RL) at peak flow rate and PETCO2 increased in all stages of sleep. Activity of EMGdi, EMGsc, and EMGab increased significantly in stage 3/4 sleep. CPAP reduced RL at peak flow, increased tidal volume and expired ventilation, and reduced PETCO2. EMGdi and EMGsc were reduced, and EMGab was silenced. During CPAP, with CO2 added to make PETCO2 isocapnic to stage 3/4 sleep, EMGsc and EMGab increased, but EMGdi was augmented in only one-half of the trials. EMG activity in this condition, however, was only 75% (EMGsc) and 43% (EMGab) of the activity observed during eupneic breathing in stage 3/4 sleep when PETCO2 was equal but RL was much higher. We conclude that during NREM sleep 1) inspiratory and expiratory muscles respond to internal inspiratory resistive loads and the associated dynamic airway narrowing and turbulent flow developed throughout inspiration, 2) some of the augmentation of respiratory muscle activity is also due to the hypercapnia that accompanies loading, and 3) the abdominal muscles are the most sensitive to load and CO2 and the diaphragm is the least sensitive.

Electromyographic Activity of Trunk Muscles During Flexion-Distraction Treatment of Low Back Patients

1999 ◽  
Author(s):  
Maruti R. Gudavalli ◽  
Jerrilyn A. Backman ◽  
Steven J. Kirstukas ◽  
Anant V. Kadiyala ◽  
Avinash G. Patwardhan ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Low Back ◽  
Mean Values ◽  
Flexion Extension ◽  
Left And Right ◽  
The Mean

Abstract The objective of this study was to determine the electromyographic (EMG) activity of the superficial muscles during the treatment of low back patients during a conservative procedure known as the Cox flexion-distraction procedure. A total of 33 low back pain patients were recruited for this study from chiropractic and allopathic orthopedic clinics. EMG signals were collected while the patient was in a prone relaxed position, during the treatment using the flexion-distraction procedure, and during maximum voluntary exertions in the three planes (flexion, extension, left and right lateral bending, and left and right twisting). The mean values of the Root Mean Square (RMS) values of EMG ratios during treatment versus resting indicate that the muscles are active during the treatment. This activity is more than the activity at rest. However the mean values of the RMS EMG ratios (during treatment versus maximum voluntary contraction) are small indicating that the muscle activity during treatment may not influence the treatment loads. The left and right muscles in all muscle groups were similarly active. During the treatment, erector spinae muscles were the most active, followed by the external oblique, and the rectus abdominus muscles. The results from this study provide quantitative data for the muscle activity during the flexion-distraction treatment. This information can be incorporated into computer models to estimate the loads generated during the flexion-distraction treatment due to the muscle activity compared to the loads generated by the chiropractic physician.

Effect of Humeral-Elevation Angle on Electromyographic Activity in the Serratus Anterior During the Push-Up-Plus Exercise

2017 ◽  
Vol 26 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Ui-jae Hwang ◽  
Oh-yun Kwon ◽  
In-cheol Jeon ◽  
Si-hyun Kim ◽  
Jong-hyuck Weon
Keyword(s):  
Outcome Measures ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Elevation Angle ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Serratus Anterior ◽  
Repeated Measures Design ◽  
Activity Ratios ◽  
Push Up

Context:The push-up-plus (PP) exercise has been recommended for strengthening of the serratus anterior (SA). Previous studies have investigated the effect of different stability properties of the base of support to adjust the difficulty level of SA muscle-strengthening exercises in the PP position. However, the optimal humeral-elevation angle (HEA) for selective activation and maximum contraction of the SA during PP has not been investigated.Objectives:To assess the effects of HEA during PP on electromyographic (EMG) activity in the SA, upper trapezius (UT), and pectoralis major (PM) and on the UT:SA and PM:SA activity ratios.Design:Comparative, repeated-measures design.Setting:University research laboratory.Participants:29 healthy men.Main Outcome Measures:The subjects performed PP at 3 different HEAs (60°, 90°, and 120°); EMG activity in the SA, UT, and PM was measured, and the UT:SA and PM:SA activity ratios were calculated. Differences in muscle activity and ratios between the 60°, 90°, and 120° HEAs were assessed using 1-way repeated-measures analysis of variance; the Bonferroni correction was applied.Results:SA muscle activity was significantly increased, in order of magnitude, at the 120°, 90°, and 60° HEAs. UT:SA and PM:SA activity ratios were significantly greater during performance of the PP at an HEA of 60° than at HEAs of 120° and 90°.Conclusion:The results suggest that an HEA of 120° should be used during performance of the PP because it produces greater SA activation than HEAs of 60° and 90°.

scholarly journals Walking With a Robotic Exoskeleton Does Not Mimic Natural Gait: A Within-Subjects Study (Preprint)

2018 ◽  
Author(s):  
Chad Swank ◽  
Sharon Wang-Price ◽  
Fan Gao ◽  
Sattam Almutairi
Keyword(s):  
Lower Extremity ◽  
Muscle Activity ◽  
Stance Phase ◽  
Swing Phase ◽  
Healthy Adults ◽  
Emg Activity ◽  
Robotic Exoskeleton ◽  
Gait Parameters ◽  
Muscle Groups ◽  
The Impact

BACKGROUND Robotic exoskeleton devices enable individuals with lower extremity weakness to stand up and walk over ground with full weight-bearing and reciprocal gait. Limited information is available on how a robotic exoskeleton affects gait characteristics. OBJECTIVE The purpose of this study was to examine whether wearing a robotic exoskeleton affects temporospatial parameters, kinematics, and muscle activity during gait. METHODS The study was completed by 15 healthy adults (mean age 26.2 [SD 8.3] years; 6 males, 9 females). Each participant performed walking under 2 conditions: with and without wearing a robotic exoskeleton (EKSO). A 10-camera motion analysis system synchronized with 6 force plates and a surface electromyography (EMG) system captured temporospatial and kinematic gait parameters and lower extremity muscle activity. For each condition, data for 5 walking trials were collected and included for analysis. RESULTS Differences were observed between the 2 conditions in temporospatial gait parameters of speed, stride length, and double-limb support time. When wearing EKSO, hip and ankle range of motion (ROM) were reduced and knee ROM increased during the stance phase. However, during the swing phase, knee and ankle ROM were reduced when wearing the exoskeleton bionic suit. When wearing EKSO, EMG activity decreased bilaterally in the stance phase for all muscle groups of the lower extremities and in the swing phase for the distal muscle groups (tibialis anterior and soleus) as well as the left medial hamstrings. CONCLUSIONS Wearing EKSO altered temporospatial gait parameters, lower extremity kinematics, and muscle activity during gait in healthy adults. EKSO appears to promote a type of gait that is disparate from normal gait in first-time users. More research is needed to determine the impact on gait training with EKSO in people with gait impairments.

scholarly journals ELECTROMYOGRAPHIC ACTIVITY OF VARIOUS MUSCLES DURING SIT-TO-STAND IN PATIENTS WITH STROKE: A META-ANALYSIS

2018 ◽  
Vol 4 (3) ◽  
pp. 14-20 ◽  
Author(s):  
Dimple, Antiya ◽  
Suvarna Ganvir
Keyword(s):  
Lower Extremity ◽  
Tibialis Anterior ◽  
Muscle Activation ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Control Group ◽  
Electromyographic Activity ◽  
Exclusion Criteria ◽  
Sit To Stand ◽  
Depth Analysis

Aims:-To provide a comprehensive information about analysis of activation of various muscles during Sit-to-Stand in patients with stroke. To determine if there exists any common pattern of muscle activation. To give direction to future studies regarding the muscles to be investigated during Sit-to-Stand. Methods-  A  literature  search  was  performed  with  help  of  the  most commonly used database i.e. PubMed to select the studies related to electromyographic activities of various lower extremity, trunk and upper extremity muscles during Sit-to-Stand activity, published till 2016. The Inclusion criteria for the study were Prospective or retrospective cohort studies, studies that included only participants with stroke leading to hemiparesis and/or along with healthy participants as control group and studies that measured the EMG activity in either trunk muscles and/or limb muscles during sit to stand. The exclusion criteria were if their population of interest also included patients with other neurological conditions and studies in any language other than English. Two independent investigators assessed the studies based on inclusion and exclusion criteria.  Keywords used during the search were Electromyography, Stroke, Sit-to-Stand. The studies were thoroughly evaluated with respect to the Sit-to-Stand procedure and variety of muscles that were investigated through EMG analysis. Results: With the help of given keywords, abstracts/articles of 21 studies were retrieved from the database. After initial screening of the abstracts 12 studies were selected for in depth analysis. Various lower extremity muscles including Tibialis Anterior, Soleus, Quadriceps, Vastusmedialis, Gluteus Maximus were investigated in the studies. In 2 studies, Trunk muscles were investigated whereas in one study Triceps muscle activity was analyzed during Sit-to Stand activity in patients with stroke. Conclusion: From this study it can be concluded that the activity of Tibialis Anterior muscle was investigated more frequently by various researchers followed by the activity of Soleus and Quadriceps muscle.

Tibial Rotation Influences Muscle Activity and Motion of Lower Extremity during The Stair Ascent

2011 ◽  
Vol 21 (4) ◽  
pp. 467-477
Author(s):  
Jeong-Il Kang ◽  
Yu-Kyung Lee ◽  
Seung-Kyu Park ◽  
Joon-Hee Lee ◽  
Dae-Jung Yang ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Muscle Activity ◽  
Tibial Rotation ◽  
Stair Ascent

Contralateral Movement and Extensor Force Generation Alter Flexion Phase Muscle Coordination in Pedaling

2000 ◽  
Vol 83 (6) ◽  
pp. 3351-3365 ◽  
Author(s):  
Lena H. Ting ◽  
Steven A. Kautz ◽  
David A. Brown ◽  
Felix E. Zajac
Keyword(s):  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
The Body ◽  
Force Generation ◽  
Mechanical Transmission ◽  
Electromyographic Activity ◽  
Neural Pathways ◽  
Control Mechanisms ◽  
Muscle Coordination

The importance of bilateral sensorimotor signals in coordination of locomotion has been demonstrated in animals but is difficult to ascertain in humans due to confounding effects of mechanical transmission of forces between the legs (i.e., mechanical interleg coupling). In a previous pedaling study, by eliminating mechanical interleg coupling, we showed that muscle coordination of a unipedal task can be shaped by interlimb sensorimotor pathways. Interlimb neural pathways were shown to alter pedaling coordination as subjects pedaling unilaterally exhibited increased flexion-phase muscle activity compared with bilateral pedaling even though the task mechanics performed by the pedaling leg(s) in the unilateral and bilateral pedaling tasks were identical. To further examine the relationship between contralateral sensorimotor state and ipsilateral flexion-phase muscle coordination during pedaling, subjects in this study pedaled with one leg while the contralateral leg either generated an extensor force or relaxed as a servomotor either held that leg stationary or moved it in antiphase with the pedaling leg. In the presence of contralateral extensor force generation, muscle activity in the pedaling leg during limb flexion was reduced. Integrated electromyographic activity of the pedaling-leg hamstring muscles (biceps femoris and semimembranosus) during flexion decreased by 25–30%, regardless of either the amplitude of force generated by the nonpedaling leg or whether the leg was stationary or moving. In contrast, rectus femoris and tibialis anterior activity during flexion decreased only when the contralateral leg generated high rhythmic force concomitant with leg movement. The results are consistent with a contralateral feedforward mechanism triggering flexion-phase hamstrings activity and a contralateral feedback mechanism modulating rectus femoris and tibialis anterior activity during flexion. Because only muscles that contribute to flexion as a secondary function were observed, it is impossible to know whether the modulatory effect also acts on primary, unifunctional, limb flexors or is specific to multifunctional muscles contributing to flexion. The influence of contralateral extensor-phase sensorimotor signals on ipsilateral flexion may reflect bilateral coupling of gain control mechanisms. More generally, these interlimb neural mechanisms may coordinate activity between muscles that perform antagonistic functions on opposite sides of the body. Because pedaling and walking share biomechanical and neuronal control features, these mechanisms may be operational in walking as well as pedaling.

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