Trunk Muscle Activity Increases With Unstable Squat Movements

2005 ◽  
Vol 30 (1) ◽  
pp. 33-45 ◽  
Author(s):  
Kenneth Anderson ◽  
David G. Behm
Keyword(s):  
Vastus Lateralis ◽  
Spinal Column ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Key Words Electromyography ◽  
Concentric Contractions ◽  
Resistance Stability ◽  
Male Subjects

The objective of this study was to determine differences in electromyographic (EMG) activity of the soleus (SOL), vastus lateralis (VL), biceps femoris (BF), abdominal stabilizers (AS), upper lumbar erector spinae (ULES), and lumbo-sacral erector spinae (LSES) muscles while performing squats of varied stability and resistance. Stability was altered by doing the squat movement on a Smith machine, a free squat, and while standing on two balance discs. Fourteen male subjects performed the movements. Activities of the SOL, AS, ULES, and LSES were highest during the unstable squat and lowest with the Smith machine protocol (p <  0.05). Increased EMG activity of these muscles may be attributed to their postural and stabilization role. Furthermore, EMG activity was higher during concentric contractions compared to eccentric contractions. Performing squats on unstable surfaces may permit a training adaptation of the trunk muscles responsible for supporting the spinal column (i.e., erector spinae) as well as the muscles most responsible for maintaining posture (i.e., SOL). Key words: electromyography, concentric, eccentric, resistance training, stabilizers

Relationship Between Speed of Performing Leg Extension With 30 RM Load and the Selected EMG Variables of Selected Quadricep Muscles

2021 ◽  
Vol 10 (1) ◽  
pp. 61-76
Author(s):  
Dhananjoy Shaw ◽  
Deepak Singh ◽  
Umesh Kumar Ahlawat ◽  
Manvinder Kaur ◽  
Dinesh Bhatia
Keyword(s):  
Significant Relationship ◽  
Rank Order ◽  
Vastus Lateralis ◽  
Emg Activity ◽  
Median Frequency ◽  
Healthy Male ◽  
Leg Extension ◽  
Integrated Emg ◽  
Male Subjects ◽  
New Criteria

The aim of the study was to assess the effects of speed of leg extension exercise with 30 RM load on the EMG activity of Vastus Medialis (VM) and Vastus Lateralis (VL). Seventeen healthy male subjects performed 30 repetition of leg extension exercise with 30 RM load in minimum time possible and EMG activity from VM and VL of right lower extremity was recorded simultaneously. Two new criteria, namely gross load speed of movement (GLSM) and relative load speed of movement (RLSM) were developed as the variables of speed of exercise. Selected variables of EMG activity were median frequency (MDF), mean frequency (MNF), root mean square (RMS), and integrated EMG (IEMG). Product moment and rank order correlation were calculated between the selected variables of EMG activity and selected variables of speed of exercise. The selected EMG variables, namely MDF and MNF, reported a negative significant relationship (p<0.05) with selected variables of speed of exercise whereas a selected EMG variables, namely RMS reported a positive significant relationship (p<0.05) with selected with the selected variables of speed of exercise.

scholarly journals Kinematic and EMG Comparison Between Variations of Unilateral Squats Under Different Stabilities

2020 ◽  
Vol 4 (02) ◽  
pp. E59-E66
Author(s):  
Roland van den Tillaar ◽  
Stian Larsen
Keyword(s):  
Muscle Activity ◽  
Rectus Femoris ◽  
Gluteus Medius ◽  
Biceps Femoris ◽  
Peak Force ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Training Experience ◽  
Free Weight ◽  
Weight Condition

AbstractThe purpose of the study was to compare kinematics and muscle activity between two variations of unilateral squats under different stability conditions. Twelve male volunteers (age: 23±5 years, mass: 80±17 kg, height: 1.81±0.11 m, strength-training experience: 4.3±1.9 years) performed four repetitions with the same external load (≈4RM). Two variations (with the non-stance leg forwards vs. backwards) were performed in a Smith-machine and free-weight condition. The variables were barbell velocity, lifting time and surface electromyography activity of the lower extremity and trunk muscles during the descending and ascending phase. The main findings were 1) peak force was higher when performing the unilateral squats in the Smith machine; 2) peak ascending barbell velocity increased from repetition 3–4 with free weight; and 3) muscle activity from the rectus femoris, vastus lateral, biceps femoris, gluteus medius, and erector spinae increased with repetitions, whereas gluteus, and medial vastus and shank muscles were affected by the conditions. It was concluded that more peak force could be produced because of increased stability. However, peak barbell velocity increased from repetition to repetition in free-weight unilateral squats, which was probably because the participants grew more comfortable. Furthermore, increased instability causes more gluteus and vastus medial activation and foot variations mainly affected the calf muscles.

Muscle coordination in cycling: effect of surface incline and posture

1998 ◽  
Vol 85 (3) ◽  
pp. 927-934 ◽  
Author(s):  
Li Li ◽  
Graham E. Caldwell
Keyword(s):  
Lower Extremity ◽  
High Speed ◽  
Vastus Lateralis ◽  
Activity Patterns ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Knee Extensors ◽  
Emg Activity ◽  
Muscle Coordination

The purpose of the present study was to examine the neuromuscular modifications of cyclists to changes in grade and posture. Eight subjects were tested on a computerized ergometer under three conditions with the same work rate (250 W): pedaling on the level while seated, 8% uphill while seated, and 8% uphill while standing (ST). High-speed video was taken in conjunction with surface electromyography (EMG) of six lower extremity muscles. Results showed that rectus femoris, gluteus maximus (GM), and tibialis anterior had greater EMG magnitude in the ST condition. GM, rectus femoris, and the vastus lateralis demonstrated activity over a greater portion of the crank cycle in the ST condition. The muscle activities of gastrocnemius and biceps femoris did not exhibit profound differences among conditions. Overall, the change of cycling grade alone from 0 to 8% did not induce a significant change in neuromuscular coordination. However, the postural change from seated to ST pedaling at 8% uphill grade was accompanied by increased and/or prolonged muscle activity of hip and knee extensors. The observed EMG activity patterns were discussed with respect to lower extremity joint moments. Monoarticular extensor muscles (GM, vastus lateralis) demonstrated greater modifications in activity patterns with the change in posture compared with their biarticular counterparts. Furthermore, muscle coordination among antagonist pairs of mono- and biarticular muscles was altered in the ST condition; this finding provides support for the notion that muscles within these antagonist pairs have different functions.

scholarly journals Activity of upper limb and trunk muscles during power walking

2015 ◽  
Vol 9 (2) ◽  
Author(s):  
Johann Peter Kuhtz-Buschbeck ◽  
Antonia Frendel
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Normal Walking ◽  
Arm Swing ◽  
Temporal Muscle ◽  
Limb Muscles ◽  
Emg Patterns

<p>Background: Arm swing is deliberately emphasized during power walking, a popular aerobic fitness exercise. Electromyographic (EMG) activation curves of arm and shoulder muscles during power walking have not yet been examined. Aim: To describe the amount and pattern of EMG activity of upper limb muscles during power walking. Data are compared to normal walking and jogging. Method:  Twenty volunteers were examined on a treadmill at 6 km/h during (a) normal walking, (b) power walking, (c) jogging. EMG data were collected for the trapezius (TRAP), anterior (AD) and posterior deltoid (PD), biceps (BIC), triceps (TRI), latissimus dorsi (LD) and erector spinae (ES) muscles. Results:  Activity of four muscles (AD, BIC, PD, TRAP) was three- to fivefold stronger during power walking than normal walking. Smaller significant increases involved the TRI, LD and ES. Two muscles (AD, TRAP) were more active during power walking than running. Normal walking and power walking involved similar EMG patterns of PD, LD, ES, while EMG patterns of running and walking differed. Interpretation: Emphasizing arm swing during power walking triples the EMG activity of upper limb muscles, compared to normal walking. Similar basic temporal muscle activation patterns in both modes of walking indicate a common underlying motor program. </p>

scholarly journals Activity of upper limb and trunk muscles during power walking

2015 ◽  
Vol 9 (2) ◽  
Author(s):  
Johann Peter Kuhtz-Buschbeck ◽  
Antonia Frendel
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Normal Walking ◽  
Arm Swing ◽  
Temporal Muscle ◽  
Limb Muscles ◽  
Emg Patterns

Background: Arm swing is deliberately emphasized during power walking, a popular aerobic fitness exercise. Electromyographic (EMG) activation curves of arm and shoulder muscles during power walking have not yet been examined. Aim: To describe the amount and pattern of EMG activity of upper limb muscles during power walking. Data are compared to normal walking and jogging. Method: Twenty volunteers were examined on a treadmill at 6 km/h during (a) normal walking, (b) power walking, (c) jogging. EMG data were collected for the trapezius (TRAP), anterior (AD) and posterior deltoid (PD), biceps (BIC), triceps (TRI), latissimus dorsi (LD) and erector spinae (ES) muscles. Results: Activity of four muscles (AD, BIC, PD, TRAP) was three- to fivefold stronger during power walking than normal walking. Smaller significant increases involved the TRI, LD and ES. Two muscles (AD, TRAP) were more active during power walking than running. Normal walking and power walking involved similar EMG patterns of PD, LD, ES, while EMG patterns of running and walking differed. Interpretation: Emphasizing arm swing during power walking triples the EMG activity of upper limb muscles, compared to normal walking. Similar basic temporal muscle activation patterns in both modes of walking indicate a common underlying motor program.

scholarly journals THE EFFECT OF LOCAL VIBROSTIMULATION ON ELECTROMYOGRAPHY PARAMETERS IN ROWERS

2017 ◽  
Vol 3 ◽  
pp. 325
Author(s):  
Kalvis Ciekurs ◽  
Viesturs Krauksts ◽  
Daina Krauksta ◽  
Baiba Smila ◽  
Aivars Kaupuzs
Keyword(s):  
Biceps Brachii ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Mathematical Statistics ◽  
Triceps Brachii ◽  
The Mean ◽  
Moving Speed

Local vibrostimulation (further in text - LV) is innovation as a part of training method that helps athletes to regain the power and get ready for next training faster. There are many discussions about how to increase moving speed in rowers. Many scientists research the possibilities of increasing moving speed in this sport. The following methods were used in the study: tests – Concept-2, LV manipulations, electromyography and mathematical statistics. The electromyography was made with Biometric LTD. LV manipulations were done to the muscles erector spinae, latisimus dorsi, teres major, teres minor, trapezius, infraspinatus, deltoideus, slenius capitis, triceps brachii, gluteus maximus, semitendinosus, biceps femoris, semimembranosus, castrocnemius, tendo calcaneus, rectus femoris, vastus lateralis, tensor fascia latae, vastus medialis, sarterius, ligamentum patellae, tibialis anterior, rectus abdominis, pectoralis major and biceps brachii. We using 100 Hz frequency, 2 – 4 mm amplitude and different pressure on the muscles. The total LV application time was 5 to 20  min. The obtained data were processed using mathematical statistics. The results: having stated the result difference before LV and after it. The results testify significant improvement of Concept-2 tests results and electromyography results, what is showed by the difference of the mean results. Comparing the results of the rowers of EG and CG they have differences in the left side muscle latissimus dorsi after the t-test where p>0.05, but stating the percentage of the mean result difference of this muscle it was found out that p>0.05 what also shows significant changes in the muscle biopotential (mV).

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.

Behavior of coactive muscles during fatigue

1993 ◽  
Vol 74 (1) ◽  
pp. 170-175 ◽  
Author(s):  
J. A. Psek ◽  
E. Cafarelli
Keyword(s):  
Time Course ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Close Correlation ◽  
Voluntary Contraction ◽  
Knee Extensors ◽  
Emg Activity ◽  
Short Period ◽  
Force Time ◽  
Knee Flexors

Coactivation is antagonist muscle activity that occurs during voluntary contraction. Recently, we showed that the extent of coactivity in the knee flexors decreases after a short period of resistance training of the knee extensors (8). The purpose of the present experiment was to study the time course of coactivation in the knee flexors during fatigue of the knee extensors. Ten male subjects performed repeated submaximal static leg extensions in a low-intensity long-duration and a high-intensity short-duration fatigue protocol until they could no longer produce the required force [time limit of endurance (Tlim)]. Maximal voluntary contraction (MVC), submaximal force, and surface electromyographic (EMG) activity were measured periodically. Vastus lateralis EMG increased progressively during fatigue of the extensor muscles (P < 0.05), resulting in a 38% change from control at Tlim. Biceps femoris EMG, which was our measure of coactivation, also increased by approximately 60% at Tlim in each protocol (P < 0.05). These observations lead us to conclude that a small but significant force loss during repeated static contractions to Tlim is due to an increase in antagonist activity. Moreover, the close correlation between the antagonist and agonist EMG supports the notion of a "common drive" to both motoneuron pools (10).

Biomechanics of Trunk During Walking Carrying Load on One Hand Using Nonlinear Methods

2014 ◽  
Author(s):  
Vikas Yadav ◽  
Maruti Ram Gudavalli ◽  
P. K. Raju ◽  
Dan Marghitu
Keyword(s):  
Correlation Dimension ◽  
Reaction Force ◽  
Force Plate ◽  
Approximate Entropy ◽  
Peak Force ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Median Frequency ◽  
Trunk Motion

Activities of daily living include carrying objects using one hand. Carrying a load using one hand can alter the loading on the musculoskeletal system as well as the walking pattern. The objective of this pilot study was to quantify the ground reaction forces, electromyographic (EMG) activity of trunk muscles, and trunk motion during walking. Nine human volunteers with no symptoms of pain were recruited from the student and employee population of an academic institution. Data were recorded from 8 volunteer subjects. Participants were asked to walk at self-selected speed back and forth at their comfortable speed carrying loads varying from 0 to 25 pounds on right hand on a wooden walking platform for 30 steps/cycles. Motion data were recorded from T1, L1, L3, and S1 vertebrae at a sampling frequency of 120 Hz. Range of Motion (ROM), Correlation Dimension (CoD), and Approximate Entropy (ApEn) was computed using custom written MatLab programs. EMG data were recorded from six muscle groups bilaterally (right and left): Erector Spinae, Multifidus, Latissimus Dorsi, Internal Obliques, External Obliques and Rectus Abdominis at a frequency of 1200 Hz. Root mean square EMG values, Mean and Median Frequency of the EMG data were calculated to observe the effect of increasing load on muscle fatigue using custom developed MatLab program. Ground reaction force (GRF) data were collected using a force plate and the associated 1st peak force (Fz1), 2nd Peak force (Fz3) and minimum force (Fz2) between the two peak forces were calculated during gait cycle. The ROM values had a range from 2.6–3.2 deg. for Lumbar lateral bending (LB), 6.7–8.7 deg. for Thoracic LB. Approximate Entropy (ApEn) values ranged from 0.20–0.40 for Lumbar LB motion and 0.30–0.50 for Thoracic LB motion. Correlation Dimension (CoD) values ranged from 1.20–1.40 for lumbar LB and 1.20–1.30 for Thoracic LB. Normalized GRF increased during walking with increased load. Significance difference (P<0.05) were found for vGRF with increase in load. Motion and EMG data did not reveal any significant differences.

Effect of Absolute and Relative Loading on Muscle Activity During Stable and Unstable Squatting

2010 ◽  
Vol 5 (2) ◽  
pp. 177-183 ◽  
Author(s):  
Jeffrey M. McBride ◽  
Tony R. Larkin ◽  
Andrea M. Dayne ◽  
Tracie L. Haines ◽  
Tyler J. Kirby
Keyword(s):  
Body Mass ◽  
Muscle Activity ◽  
Vastus Lateralis ◽  
Force Plate ◽  
Rest Period ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Repetition Maximum ◽  
Maximum Test ◽  
Significant Difference

Purpose:The purpose of this investigation was to determine the effect of stable and unstable conditions on one repetition maximum strength and muscle activity during dynamic squatting using absolute and relative loading.Methods:Ten recreationally weight-trained males participated in this study (age = 24.1 ± 2.0 y, height = 178.0 ± 5.6 cm, body mass = 83.7 ± 13.4 kg, 1RM/body mass = 1.53 ± 0.31), which involved two laboratory sessions separated by 1 wk. Linear position transducers were used to track bar displacement while subjects stood on a force plate for all trials. Vastus lateralis (VL), biceps femoris (BF) and erector spinae (L1) muscle activity (average integrated EMG [IEMG]) was also recorded during all trials. During the frst session subjects complete a one repetition maximum test in a stable dynamic squat (S1RM = 128.0 ± 31.4 kg) and an unstable dynamic squat (U1RM = 83.8 ± 17.3 kg) in a randomized order with a 30-min rest period between conditions. The second session consisted of the performance of three trials each for 12 different conditions (unstable and stable squats using three different absolute loads [six conditions] and unstable and stable squats using three different relative loads [six conditions]).Results:Results revealed a statistically significant difference between S1RM and U1RM values (P < .05). The stable trials resulted in the same or a significantly higher value for VL, BF and L1 muscle activity in comparison with the unstable trials for all twelve conditions.Conclusions:Unstable squatting is of equal or less (depending on the loading condition) benefit to improving or maximizing muscle activity during resistance exercise.

Sign in / Sign up

Export Citation Format

Share Document