TRAINING LOAD DEMANDS MEASURED BY SURFACE ELECTROMYOGRAPHY WEARABLE TECHNOLOGY WHEN PERFORMING LAW ENFORCEMENT-SPECIFIC BODY DRAGS

The use of surface electromyography (sEMG) wearable technology to measure training load (TL) during law enforcement-specific tasks (e.g. a body drag) requires investigation. This study determined muscle activation differences represented as TL during a 9.75-m drag with 74.84 kg and 90.72 kg dummies. Eight men and three women were fitted with a compression short or legging embedded with sEMG wearable technology to measure the quadriceps (QUAD; vastus medialis+vastus lateralis), biceps femoris (BF), and gluteus maximus (GM). After fitting on day one, participants completed maximal voluntary isometric contractions for each muscle to normalize the sEMG signal and calculate TL units. On days two and three, participants performed a 9.75 m body drag using either the 74.84 kg or the 90.72 kg dummy while wearing the technology. Participants lifted the dummy off the floor to a standing position and dragged it as quickly as possible over 9.75 m. Paired samples t-tests calculated between-drag differences for: time; QUAD, BF, GM, and total TL; and QUAD-BF, GM-BF, anterior-posterior (QUAD-GM+BF) ratios. QUAD TL was 9% greater (p=0.035), and GM TL was 8% lower (p=0.043), in the 90.72 kg body drag compared to the 74.84 kg drag. There were no between-mass differences in time, BF TL, total TL, or the ratios. QUAD TL increased while GM TL decreased when participants dragged a 90.72 kg dummy. As drag time was not different between the masses, drag mechanics may have changed leading to increased QUAD TL. sEMG wearable technology could be a useful method to measure TL in law enforcement-specific dragging tasks.

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Muscle Activation Differs between Three Different Knee Joint-Angle Positions during a Maximal Isometric Back Squat Exercise

Journal of Sports Medicine ◽

10.1155/2016/3846123 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 14

Author(s):

Paulo Henrique Marchetti ◽

Josinaldo Jarbas da Silva ◽

Brad Jon Schoenfeld ◽

Priscyla Silva Monteiro Nardi ◽

Silvio Luis Pecoraro ◽

...

Keyword(s):

Knee Joint ◽

Muscle Activation ◽

Specific Activity ◽

Vastus Lateralis ◽

Gluteus Maximus ◽

Rectus Femoris ◽

Biceps Femoris ◽

Joint Angles ◽

Back Squat ◽

Squat Exercise

The purpose of this study was to compare muscle activation of the lower limb muscles when performing a maximal isometric back squat exercise over three different positions. Fifteen young, healthy, resistance-trained men performed an isometric back squat at three knee joint angles (20°, 90°, and 140°) in a randomized, counterbalanced fashion. Surface electromyography was used to measure muscle activation of the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), semitendinosus (ST), and gluteus maximus (GM). In general, muscle activity was the highest at 90° for the three quadriceps muscles, yet differences in muscle activation between knee angles were muscle specific. Activity of the GM was significantly greater at 20° and 90° compared to 140°. The BF and ST displayed similar activation at all joint angles. In conclusion, knee position alters muscles activation of the quadriceps and gluteus maximus muscles. An isometric back squat at 90° generates the highest overall muscle activation, yet an isometric back squat at 140° generates the lowest overall muscle activation of the VL and GM only.

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Neuromuscular Responses of Elite Skaters During Different Roller Figure Skating Jumps

Journal of Human Kinetics ◽

10.2478/hukin-2014-0029 ◽

2014 ◽

Vol 41 (1) ◽

pp. 23-32

Author(s):

Patrícia Dias Pantoja ◽

André Mello ◽

Giane Veiga Liedtke ◽

Ana Carolina Kanitz ◽

Eduardo Lusa Cadore ◽

...

Keyword(s):

Tibialis Anterior ◽

Muscle Activation ◽

Vastus Lateralis ◽

Gluteus Maximus ◽

Rectus Femoris ◽

Biceps Femoris ◽

Figure Skating ◽

Vastus Medialis ◽

Lateral Gastrocnemius ◽

Neuromuscular Activity

AbstractThis study aimed to describe the neuromuscular activity of elite athletes who performed various roller figure skating jumps, to determine whether the muscle activation is greater during jumps with more rotations and in which phase the muscles are more active. This study also aimed to analyze if there is any difference in the muscle activity pattern between female and male skaters. Four elite skaters were evaluated, and each participated in two experimental sessions. During the first session, anthropometric data were collected, and the consent forms were signed. For the second session, neuromuscular data were collected during jumps, which were performed with skates at a rink. The following four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. The neuromuscular activity of the following seven muscles was obtained with an electromyograph which was fixed to the waist of each skater with a strap: biceps femoris, lateral gastrocnemius, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis and gluteus maximus. The signal was transmitted wirelessly to a laptop. During the roller figure skating jumps, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation during the jumps with more rotations, and the activation mainly occurred during the propulsion and flight phases. Female skaters demonstrated higher muscle activities in tibialis anterior, vastus lateralis, vastus medialis and gluteus maximus during the landing phase of the triple Mapes, when compared to their male counterparts. The results obtained in this study should be considered when planning training programs with specific exercises that closely resemble the roller figure skating jumps. This may be important for the success of elite skaters in competitions.

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Balance and Lower Limb Muscle Activation Between in-Line and Traditional Lunge Exercises

Journal of Human Kinetics ◽

10.1515/hukin-2017-0174 ◽

2018 ◽

Vol 62 (1) ◽

pp. 15-22 ◽

Cited By ~ 1

Author(s):

Paulo H. Marchetti ◽

Mauro A. Guiselini ◽

Josinaldo J. da Silva ◽

Raymond Tucker ◽

David G. Behm ◽

...

Keyword(s):

Lower Limb ◽

Muscle Activation ◽

Vastus Lateralis ◽

Gluteus Maximus ◽

Gluteus Medius ◽

Biceps Femoris ◽

Posterior Limb ◽

Gluteus Maximus Muscle ◽

Line P ◽

Posterior Position

Abstract In-line and traditional lunge exercises present differences in technique as lower limb positioning (anterioposterior), and medio-lateral (ML) balance may differentially affect primary and stabilizer muscles. The purposes of this study were to examine ML balance and muscle activation in anterior and posterior leg positions between in-line and traditional lunge exercises. Fifteen young, healthy, resistance-trained men (25 ± 5 years) performed 2 different lunge exercises (in-line and traditional) at their 10 repetition maximum in a randomized, counterbalanced fashion. Surface electromyography measured muscle activation of the vastus lateralis, biceps femoris, gluteus maximus, and gluteus medius. ML balance was measured with a Wii Fit Balance Board. The vastus lateralis activity was not significantly different between exercises or leg positions. The biceps femoris activity was not significantly different between exercises, however, it was significantly greater in the anterior compared to the posterior position for the in-line (p = 0.003), and traditional lunge (p < 0.001). The gluteus maximus activity was not significantly different between exercises, however, it was significantly greater in the anterior compared to posterior position for the in-line (p < 0.001) and traditional lunge (p < 0.001). ML balance was significantly greater in the in-line exercise in the anterior limb (p = 0.001). Thus, both in-line and traditional lunge exercises presented similar overall levels of muscle activation, yet the anterior limb generated the highest biceps femoral and gluteus maximus muscle activation when compared to the posterior limb. The in-line lunge presents greater ML balance when compared to the traditional lunge exercise.

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Muscle coordination in cycling: effect of surface incline and posture

Journal of Applied Physiology ◽

10.1152/jappl.1998.85.3.927 ◽

1998 ◽

Vol 85 (3) ◽

pp. 927-934 ◽

Cited By ~ 78

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.

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Differences in Gluteal and Quadriceps Muscle Activation Among Adults With and Without Lumbar Hyperlordosis

Journal of Sport Rehabilitation ◽

10.1123/jsr.2019-0112 ◽

2020 ◽

Vol 29 (8) ◽

pp. 1100-1105

Author(s):

Mohammad H. Izadi Farhadi ◽

Foad Seidi ◽

Hooman Minoonejad ◽

Abbey C. Thomas

Keyword(s):

Muscle Activation ◽

Vastus Lateralis ◽

Gluteus Maximus ◽

Gluteus Medius ◽

Quadriceps Muscle ◽

Functional Activities ◽

Level Of Activity ◽

Lumbar Hyperlordosis ◽

Single Leg Squat ◽

The Moment

Context: Many factors have been reported contributing to altering the neuromuscular function of hip and knee muscles. The lumbar hyperlordosis, as a poor posture in some athletes, is thought to be associated with the alteration of the hip and knee muscles activity. Objective: To examine the activation of selected hip and knee muscles in athletes with and without lumbar hyperlordosis during functional activities. Design: Case-control study. Setting: University laboratory. Participants: Twenty-six college male athletes (n = 13 with and n = 13 without lumbar hyperlordosis). Interventions: Surface electromyography of gluteus maximus (GMAX), gluteus medius (GMED), vastus medialis oblique (VMO), and vastus lateralis (VL) were recorded during single-leg squat and single-leg jump landing (SLJL) tasks. Main Outcome Measure: Preactivity; reactivity; and onset muscle during SLJL and eccentric activity during single-leg squat (GMAX, GMED, VMO, and VL along with the ratio of VMO:VL) were assessed. Results: Athletes with lumbar hyperlordosis had a higher level of activity in their GMAX (P = .003), VMO (P = .04), and VL (P = .01) muscles at the moment before foot contact during SLJL. These athletes also demonstrated a higher level of GMAX activity (P = .01) immediately after foot contact. Finally, athletes with lumbar hyperlordosis activated their GMAX sooner (P = .02) during the SLJL. Athletes with normal lumbar lordosis had more activity in their GMED muscle (P = .001) in the descending phase of the single-leg squat task and a higher VMO:VL (P = .01) at the moment after the foot contact during the SLJL. Conclusion: The altered activation of GMAX, GMED, VMO, VL, and VMO:VL can reveal the role of lumbar hyperlordosis in the knee and hip muscles’ alteration in athletes. Further study is needed to identify whether these alterations in the hip and knee muscles contribute to injury in athletes.

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Evaluation of the Electromyography Test for the Analysis of the Aerobic-Anaerobic Transition in Elite Cyclists during Incremental Exercise

Applied Sciences ◽

10.3390/app9030589 ◽

2019 ◽

Vol 9 (3) ◽

pp. 589

Author(s):

Iban Latasa ◽

Alfredo Cordova ◽

Gregorio Quintana-Ortí ◽

Ana Lavilla-Oiz ◽

Javier Navallas ◽

...

Keyword(s):

Linear Regression ◽

Vastus Lateralis ◽

Gluteus Maximus ◽

Biceps Femoris ◽

Incremental Exercise ◽

Linear Regression Method ◽

Validity And Reliability ◽

Time Curve ◽

Invasive Method ◽

Elite Cyclists

(1) Background: The aim of this study was to investigate the validity and reliability of surface electromyography (EMG) for automatic detection of the aerobic and anaerobic thresholds during an incremental continuous cycling test using 1 min exercise periods in elite cyclists. (2) Methods: Sixteen well-trained cyclists completed an incremental exercise test (25 W/1 min) to exhaustion. Surface bipolar EMG signals were recorded from the vastus lateralis, vastus medialis, biceps femoris, and gluteus maximus, and the root mean square (RMS) were assessed. The multi-segment linear regression method was used to calculate the first and second EMG thresholds (EMGT1 and EMGT2). During the test, gas exchange data were collected to determine the first and second ventilatory thresholds (VT1 and VT2). (3) Results: Two breakpoints (thresholds) were identified in the RMS EMG vs. time curve for all muscles in 75% of participants. The two breakpoints, EMGT1 and EMGT2, were detected at around 70%–80% and 90%–95% of VO2MAX, respectively. No significant differences were found between the means of VT1 and EMGT1 for the vastii and biceps femoris muscles (p > 0.05). There were no significant differences between means of EMGT2 and VT2 (p > 0.05). (4) Conclusions: It is concluded that the multi-segment linear regression algorithm is a valid non-invasive method for analyzing the aerobic-anaerobic transition during incremental tests with 1 min stage durations.

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Pelvic Limb Kinematics and Surface Electromyography of the Vastus Lateralis, Biceps Femoris, and Gluteus Medius Muscle in Dogs with Hip Osteoarthritis

Veterinary Surgery ◽

10.1111/j.1532-950x.2011.00932.x ◽

2011 ◽

Vol 41 (1) ◽

pp. 54-62 ◽

Cited By ~ 17

Author(s):

Barbara Bockstahler ◽

Cordula Kräutler ◽

Peter Holler ◽

Alexander Kotschwar ◽

Angela Vobornik ◽

...

Keyword(s):

Surface Electromyography ◽

Vastus Lateralis ◽

Hip Osteoarthritis ◽

Gluteus Medius ◽

Biceps Femoris ◽

Gluteus Medius Muscle ◽

Limb Kinematics ◽

Pelvic Limb

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Effects of Short-Term Training With Uncoupled Cranks in Trained Cyclists

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.7.2.113 ◽

2012 ◽

Vol 7 (2) ◽

pp. 113-120 ◽

Cited By ~ 1

Author(s):

Jack M. Burns ◽

Jeremiah J. Peiffer ◽

Chris R. Abbiss ◽

Greig Watson ◽

Angus Burnett ◽

...

Keyword(s):

Muscle Activation ◽

Vastus Lateralis ◽

Biceps Femoris ◽

Training Group ◽

Recovery Phase ◽

Muscle Recruitment ◽

Short Term ◽

Activation Patterns ◽

Gross Efficiency ◽

Muscle Activation Patterns

Purpose:Manufacturers of uncoupled cycling cranks claim that their use will increase economy of motion and gross efficiency. Purportedly, this occurs by altering the muscle-recruitment patterns contributing to the resistive forces occurring during the recovery phase of the pedal stroke. Uncoupled cranks use an independent-clutch design by which each leg cycles independently of the other (ie, the cranks are not fixed together). However, research examining the efficacy of training with uncoupled cranks is equivocal. The purpose of this study was to determine the effect of short-term training with uncoupled cranks on the performance-related variables economy of motion, gross efficiency, maximal oxygen uptake (VO2max), and muscle-activation patterns.Methods:Sixteen trained cyclists were matched-paired into either an uncoupled-crank or a normal-crank training group. Both groups performed 5 wk of training on their assigned cranks. Before and after training, participants completed a graded exercise test using normal cranks. Expired gases were collected to determine economy of motion, gross efficiency, and VO2max, while integrated electromyography (iEMG) was used to examine muscle-activation patterns of the vastus lateralis, biceps femoris, and gastrocnemius.Results:No significant changes between groups were observed for economy of motion, gross efficiency, VO2max, or iEMG in the uncoupled- or normal-crank group.Conclusions:Five weeks of training with uncoupled cycling cranks had no effect on economy of motion, gross efficiency, muscle recruitment, or VO2max compared with training on normal cranks.

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Quadriceps and hamstrings coactivation in exercises used in prevention and rehabilitation of hamstring strain injury in young soccer players

10.1101/574210 ◽

2019 ◽

Author(s):

Gonzalo Torres ◽

David Chorro ◽

Archit Navandar ◽

Javier Rueda ◽

Luís Fernández ◽

...

Keyword(s):

Muscle Activation ◽

Vastus Lateralis ◽

Rectus Femoris ◽

Biceps Femoris ◽

Activation Pattern ◽

Male Youth ◽

Maximum Voluntary Isometric Contraction ◽

Hamstring Strain ◽

Exercise Muscle ◽

Injury Recovery

AbstractThis study aimed to study the co-activation of hamstring-quadriceps muscles during submaximal strength exercises without the use of maximum voluntary isometric contraction testing and compare (i) the inter-limb differences in muscle activation, (ii) the intra-muscular group activation pattern, and (iii) the activation during different phases of the exercise. Muscle activation was recorded by surface electromyography of 19 elite male youth players. Participants performed five repetitions of the Bulgarian squat, lunge and the squat with an external load of 10 kg. Electrical activity was recorded for the rectus femoris, vastus medialis, vastus lateralis, biceps femoris and semitendinosus. No significant inter-limb differences were found (F1, 13=619; p=0.82; partial η2=0.045). Significant differences were found in the muscle activation between different muscles within the muscle group (quadriceps and hamstrings) for each of the exercises: Bulgarian squat (F1,18=331: p<0.001; partial η2=0.80), lunge (F4,72=114.5; p<0.001; partial η2=0.86) and squat (F1,16=247.31; p<0.001; partial η2=0.93).Differences were found between the concentric, isometric and eccentric phases of each of the exercises (F2, 26=52.27; p=0.02; partial η2=0.80). The existence of an activation pattern of each of the muscles in the three proposed exercises could be used for muscle assessment and as a tool for injury recovery.

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THE EFFECT OF LOCAL VIBROSTIMULATION ON ELECTROMYOGRAPHY PARAMETERS IN ROWERS

SOCIETY INTEGRATION EDUCATION Proceedings of the International Scientific Conference ◽

10.17770/sie2017vol3.2321 ◽

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).

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