An investigation into the possible physiological mechanisms associated with changes in performance related to acute responses to different preactivity stretch modalities

2010 ◽  
Vol 35 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Iain M. Fletcher ◽  
Mathew M. Monte-Colombo
Keyword(s):  
Heart Rate ◽  
Core Temperature ◽  
Muscle Activity ◽  
Rectus Femoris ◽  
Peak Torque ◽  
Drop Jump ◽  
Warm Up ◽  
Acute Responses ◽  
Rectus Femoris Muscle ◽  
Condition Heart Rate

The aim of this study was to explore the potential mechanisms underlying performance changes linked to different warm-up stretch modalities. Twenty-one male collegiate–semiprofessional soccer players (age, 20.8 ±2.3 years) performed under 3 different warm-up conditions: a no-stretch warm-up (WU), a warm-up including static passive stretches (SPS), and a warm-up incorporating static dynamic stretches (SDS). Countermovement jump, drop jump, peak torque, heart rate, core temperature, movement kinematics, and electromyography (EMG) were recorded for each intervention. Significant increases (p < 0.001) in performance were recorded for the countermovement, drop jump, and peak torque measures when the SDS was compared with the WU and SPS trials. When mechanism data were analysed, heart rate was significantly higher (p < 0.001) in the SDS condition compared with the SPS and WU conditions (a pattern also shown with core temperature), whereas the WU condition heart rate was also significantly higher than the SPS condition heart rate. When EMG data were examined for the rectus femoris muscle, significantly greater (p < 0.01) muscle activity was observed in the SDS condition compared with the SPS condition. It seems the most likely mechanisms to explain the increase in performance in the SDS condition compared with the SPS condition are increased heart rate, greater muscle activity, and increased peak torque.

scholarly journals Electromyographic Analysis of Traditional and Nontraditional Abdominal Exercises: Implications for Rehabilitation and Training

2006 ◽  
Vol 86 (5) ◽  
pp. 656-671 ◽  
Author(s):  
Rafael F Escamilla ◽  
Eric Babb ◽  
Ryan DeWitt ◽  
Patrick Jew ◽  
Peter Kelleher ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Latissimus Dorsi ◽  
Rectus Femoris ◽  
Rectus Abdominis ◽  
Oblique Muscle ◽  
Emg Activity ◽  
Internal Oblique ◽  
Rectus Femoris Muscle ◽  
Femoris Muscle ◽  
Roll Out

Abstract Background and Purpose. Performing nontraditional abdominal exercises with devices such as abdominal straps, the Power Wheel, and the Ab Revolutionizer has been suggested as a way to activate abdominal and extraneous (nonabdominal) musculature as effectively as more traditional abdominal exercises, such as the crunch and bent-knee sit-up. The purpose of this study was to test the effectiveness of traditional and nontraditional abdominal exercises in activating abdominal and extraneous musculature. Subjects. Twenty-one men and women who were healthy and between 23 and 43 years of age were recruited for this study. Methods. Surface electromyography (EMG) was used to assess muscle activity from the upper and lower rectus abdominis, external and internal oblique, rectus femoris, latissimus dorsi, and lumbar paraspinal muscles while each exercise was performed. The EMG data were normalized to maximum voluntary muscle contractions. Differences in muscle activity were assessed by a 1-way, repeated-measures analysis of variance. Results. Upper and lower rectus abdominis, internal oblique, and latissimus dorsi muscle EMG activity were highest for the Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees. External oblique muscle EMG activity was highest for the Power Wheel (pike, knee-up, and roll-out) and hanging knee-up with straps. Rectus femoris muscle EMG activity was highest for the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up. Lumbar paraspinal muscle EMG activity was low and similar among exercises. Discussion and Conclusion. The Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees not only were the most effective exercises in activating abdominal musculature but also were the most effective in activating extraneous musculature. The relatively high rectus femoris muscle activity obtained with the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up may be problematic for some people with low back problems.

scholarly journals Lower Extremity Muscle Activity During a Women's Overhand Lacrosse Shot

2014 ◽  
Vol 41 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Brianna M. Millard ◽  
John A. Mercer
Keyword(s):  
Lower Extremity ◽  
Muscle Activity ◽  
Body Height ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Medial Gastrocnemius ◽  
Discrete Events ◽  
Warm Up ◽  
Lower Extremity Muscle ◽  
One Year

AbstractThe purpose of this study was to describe lower extremity muscle activity during the lacrosse shot. Participants (n=5 females, age 22±2 years, body height 162.6±15.2 cm, body mass 63.7±23.6 kg) were free from injury and had at least one year of lacrosse experience. The lead leg was instrumented with electromyography (EMG) leads to measure muscle activity of the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (GA). Participants completed five trials of a warm-up speed shot (Slow) and a game speed shot (Fast). Video analysis was used to identify the discrete events defining specific movement phases. Full-wave rectified data were averaged per muscle per phase (Crank Back Minor, Crank Back Major, Stick Acceleration, Stick Deceleration). Average EMG per muscle was analyzed using a 4 (Phase) x 2 (Speed) ANOVA. BF was greater during Fast vs. Slow for all phases (p<0.05), while TA was not influenced by either Phase or Speed (p>0.05). RF and GA were each influenced by the interaction of Phase and Speed (p<0.05) with GA being greater during Fast vs. Slow shots during all phases and RF greater during Crank Back Minor and Major as well as Stick Deceleration (p<0.05) but only tended to be greater during Stick Acceleration (p=0.076) for Fast vs. Slow. The greater muscle activity (BF, RF, GA) during Fast vs. Slow shots may have been related to a faster approach speed and/or need to create a stiff lower extremity to allow for faster upper extremity movements.

scholarly journals Acute Responses of Core Muscle Activity during Bridge Exercises on the Floor vs. the Suspension System

2021 ◽  
Vol 18 (11) ◽  
pp. 5908
Author(s):  
Jim T. C. Luk ◽  
Freeman K. C. Kwok ◽  
Indy M. K. Ho ◽  
Del P. Wong
Keyword(s):  
Muscle Activity ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Suspension System ◽  
Erector Spinae ◽  
Healthy Male ◽  
Neuromuscular Activation ◽  
Lumbar Multifidus ◽  
Acute Responses

This study aimed to compare the neuromuscular activation of selected core musculature in supine and prone bridge exercises under stable versus suspended conditions. Forty-three healthy male participants were recruited to measure the electromyographic activities of the rectus abdominis (RA), lumbar multifidus (LM), thoracic erector spinae (TES), rectus femoris (RF), gluteus maximus (GM), and biceps femoris (BF) during supine and prone bridge exercises under six conditions: control, both arms and feet on the floor (Pronecon and Supinecon); arms on the floor and feet on the suspension system (Prone-Feetsuspension and Supine-Feetsuspension); and arms on the suspension system and feet on the floor (Prone-Armsuspension and Supine-Armsuspension). Prone-Armsuspension yielded significantly higher activities in the RA, RF, TES, and LM than Prone-Feetsuspension (p < 0.01) and Pronecon (p < 0.001). Moreover, Supine-Feetsuspension elicited significantly higher activities in the RA, RF, TES, LM, and BF than Supine-Armsuspension (p < 0.01) and Supinecon (p < 0.001). Furthermore, Supine-Feetsuspension elicited significantly higher activities in the RF, TES, and BF than Supinecon (p < 0.01). Therefore, if the RA and/or RF were the target training muscles, then Prone-Armsuspension was recommended. However, if the TES, LM, and/or BF were the target training muscles, then Supine-Feetsuspension was recommended.

scholarly journals HEART RATE AND LOWER LIMB MUSCLE ACTIVITY ON CYCLE ERGOMETER

2020 ◽  
Vol 26 (6) ◽  
pp. 487-492
Author(s):  
Paulo Rui de Oliveira ◽  
Robson Dias Scoz ◽  
Bruno Mazziotti Oliveira Alves ◽  
Thiago Rosa de Mesquita ◽  
Rubens Alexandre da Silva Junior ◽  
...  
Keyword(s):  
Heart Rate ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Cycle Ergometer ◽  
Lower Limbs ◽  
Vastus Medialis ◽  
Emg Signal ◽  
Significant Difference ◽  
Rate Behavior

ABSTRACT Introduction: Muscle activity in the pedal stroke movement on a cycle ergometer can be measured by surface electromyography, as an effective and improved method for studying muscle action and objectively determining the different action potentials of the muscles involved in specific movements. Heart rate behavior is an important factor during exercise with load. Objective: To identify heart rate behavior and pattern of muscle activity of the rectus femoris and vastus medialis in healthy subjects in the pedaling dynamic at different loads, submaximal test, on an instrumented cycle ergometer. Methods: 20 healthy adults were evaluated. Heart rate measurement was performed, together with electromyographic analysis, in the time domain, of the rectus femoris and vastus medialis muscles during incremental exercise of the lower limbs on the cycle ergometer. Results: Heart rate behavior presented significant difference for p≥0.05 in relation to increased loads. The EMG signal intensity from the vastus medialis muscle (normalized RMS value) in each quadrant of the pedaling cycle showed significant difference for p≥0.05 in relation to quadrants I, II and IV and significant difference for p≥0.05 in relation to quadrants III and IV. In the rectus femoris (RF) muscle, there was significant difference for p≥0.05 in relation to quadrants I, II and IV and significant difference for p≥0.05 in relation to quadrants I, II and III. Conclusion: An increase in heart rate proportional to the increase in load was observed, as well as an increase in the amplitude of the electromyographic signal proportional to the increase in load. It was possible to identify the pattern of muscle activation in the studied quadrants during pedal stroke movements, independent of load. Level of evidence III; Study of non-consecutive patients; without uniform application of the “gold” standard reference.

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