scholarly journals Effect of Three Half-Squat Protocols on the Tensiomyographic Twitch Response and Tissue Damage of the Rectus Femoris and the Biceps Femoris

2020 ◽  
Vol 75 (1) ◽  
pp. 15-27
Author(s):  
César Berzosa ◽  
Fernando Sanz-López ◽  
Oliver Gonzalo-Skok ◽  
Carlos Valero-Campo ◽  
José Luis Arjol-Serrano ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Training Session ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Physically Active ◽  
Concentric Exercise ◽  
Repeated Measures Analysis ◽  
Baseline Values ◽  
Eccentric Overload ◽  
Muscle Contractile

Abstract The aim of this study was to analyse the acute effects of a concentric exercise and two different eccentric overload exercises (EOEs) on blood markers of muscle damage (i.e. creatine kinase [CK], lactate dehydrogenase [LDH], myoglobin [Myo], and malondialdehyde [MDA]) and muscle contractile properties. Ten healthy, young (27 ± 1.5 years, 179 ± 6 cm, 78.7 ± 10.8 kg), physically active men (3.5 ± 1.9 h·w-1) randomly performed three training sessions using the following protocols: a half-squat (HS) as a concentric exercise, and exercises using Versapulley (VP) or YoYo isoinertial technology (YIT) as EOEs (4 x 7 repetitions with a 2 min rest interval between sets). Blood samples and tensiomyography measurements were obtained after each training session. Repeated measures analysis of variance (ANOVA) followed by the Tukey test was used to detect differences between the four time points of each variable. The standardized difference or effect size (ES, 90% confidence limit) in the selected variables was calculated using the basal SD. After all exercises, a greater activity of CK, LDH, and concentration of Myo, and MDA were found compared to baseline values (p < 0.05). A substantially greater activity of CK, LDH, and Myo concentration, but not MDA, were found after EOEs when compared to the HS protocol. Substantially lower tensiomyography results in the rectus femoris (RF) were reported, irrespective of the exercise mode performed. Also, no substantial differences were obtained in the biceps femoris (BF) between EOEs and the HS protocol. Time of contraction (Tc) in the RF was possibly to very likely lower in the HS in comparison to EOEs. Additionally, muscular displacement (Dm) in the RF was substantially lower in the HS compared to EOEs. VP produced higher concentrations of damage markers than YIT and concentric exercise did. Furthermore, tensiomyography variables showed similar activation in both exercises, although higher specific fatigue (in the RF) was registered in the traditional HS.

Comparison of Muscle Activity Using Unstable Devices During a Forward Lunge

2020 ◽  
Vol 29 (4) ◽  
pp. 394-399
Author(s):  
Lucinda E. Bouillon ◽  
Michael Hofener ◽  
Andrew O’Donnel ◽  
Amanda Milligan ◽  
Craig Obrock
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
Rectus Femoris ◽  
Random Order ◽  
Biceps Femoris ◽  
Lateral Gastrocnemius ◽  
Biceps Femoris Muscle ◽  
Repeated Measures Analysis ◽  
Closed Chain ◽  
Femoris Muscle

Context: Unstable devices in various forms are used as therapeutic adjuncts for prevention or following an injury. A slip-over-the-shoe design with inflatable domes (STEPRIGHT® Stability Trainer) was developed to improve balance. It is unknown how this unstable device affects muscle activity during a closed-chain exercise such as the forward lunge. Objective: To compare muscle activity across 3 surfaces (STEPRIGHT®, Both Sides Up [BOSU®] Balance Trainer, and firm) during a forward lunge. Design: Within-subject, repeated measures. Setting: University physical therapy research laboratory. Participants: A total of 20 healthy, recreationally active subjects (23.4 [1.47] y, 172.7 [14.7] cm, 71.6 [16.8] kg). Intervention: Each subject performed 1 set of 10 repetitions of forward lunge exercise in random order with STEPRIGHT®, BOSU®, and firm surface. Main Outcome Measures: Surface electromyography data, normalized to maximum voluntary isometric contractions (%MVIC), was used to assess muscle activity on rectus femoris, vastus medialis oblique (VMO), biceps femoris, lateral gastrocnemius, fibularis longus, and tibialis anterior. Results: The repeated-measures analysis of variance determined that there was a significant effect for surface type. During the descent of the lunge, the STEPRIGHT® elicited higher rectus femoris (33% [27%] MVIC) compared with BOSU® (22% [14%] MVIC) and VMO (44% [15%] MVIC) on STEPRIGHT® compared with firm (38% [11%] MVIC) (P < .05). During the ascent of the lunge, the rectus femoris (38% [27%] MVIC) using STEPRIGHT® was higher than BOSU® (24% [16%] MVIC), and STEPRIGHT® elicited higher VMO (65% [20%] MVIC) versus BOSU® (56% [19%] MVIC) (P ≤ .01). The STEPRIGHT® for fibularis longus was higher (descent: 51% [20%] MVIC, ascent: 52% [22%] MVIC) than BOSU® (descent: 36% [15%] MVIC, ascent: 33% [16%] MVIC) or firm (descent: 33% [12%] MVIC, ascent: 35% [15%] MVIC) (P < .001). Conclusions: Clinicians may choose to use the STEPRIGHT® for strengthening VMO and fibularis longus muscles, as these were over 41% MVIC or any of the 3 surfaces for endurance training (<25% MVIC) for biceps femoris muscle. This information may be helpful in exercise dosage for forward lunges when using STEPRIGHT®, BOSU®, or a firm surface.

scholarly journals Acute neuromuscular response during eccentric overload protocol by using a mechanical device to increase the load

2017 ◽  
Vol 19 (4) ◽  
pp. 375
Author(s):  
Marcel B Lanza ◽  
Antônio E M Pertence ◽  
André G P Andrade ◽  
Gustavo H Peixoto ◽  
Leonardo B Felix ◽  
...  
Keyword(s):  
Mechanical Load ◽  
Muscular Activity ◽  
Biceps Femoris ◽  
Mechanical Device ◽  
Neural Drive ◽  
Physically Active ◽  
Control Protocol ◽  
Neuromuscular Response ◽  
Eccentric Overload ◽  
Muscular Activation

DOI: http://dx.doi.org/10.5007/1980-0037.2017v19n4p375 The aim of this study was to propose a mechanical device that could increase the mechanical load during the entire eccentric (ECC) action on a knee flexor machine and to compare the muscular activity when the device was used during a testing protocol. Fifteen physically active women were recruited, and they performed two protocols: control and eccentric overload. Control protocol was performed with concentric (CON) and ECC actions with similar load (60% of one repetition maximum) whilst eccentric overload protocol consisted of ECC actions with 40% more load than CON actions. Muscular activation was measured using surface electromyography of the biceps femoris (BF) and the gastrocnemius medialis (GM) muscles. ECC actions presented a higher muscular activation during eccentric overload protocol than control protocol for BF (p = 0.032), but not for the GM (p = 0.439). The mechanical device increased the mechanical load during the ECC muscle action and consequently increased the amplitude of the neural drive to the BF muscle; however, it did not increase the amplitude of the neural drive to the GM muscle.

Is Tensiomyography-Derived Velocity of Contraction a Sensitive Marker to Detect Acute Performance Changes in Elite Team-Sport Athletes?

2020 ◽  
Vol 15 (1) ◽  
pp. 31-37
Author(s):  
Lucas A. Pereira ◽  
Rodrigo Ramirez-Campillo ◽  
Saul Martín-Rodríguez ◽  
Ronaldo Kobal ◽  
César C.C. Abad ◽  
...  
Keyword(s):  
Training Session ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Team Sport ◽  
Technical Training ◽  
Effect Sizes ◽  
Squat Jump ◽  
National Team ◽  
Before And After ◽  
Sensitive Marker

Purpose: To examine the variations in the velocity of contraction (Vc) assessed using tensiomyography, vertical jumping ability, and sprinting speed induced by 4 different exercise protocols (ie, strength, sprint, plyometric, and technical training sessions) in 14 male national-team rugby players (age 21.8 [2.6] y, weight 83.6 [8.5] kg, and height 177.4 [6.7] cm). Methods: Physical tests were conducted immediately before and after 4 distinct workouts in the following order: tensiomyography in the rectus femoris and biceps femoris muscles, squat and countermovement jumps, and 30-m sprint velocity. To analyze the differences in the assessed variables before and after each training session, the differences based on magnitudes were calculated. Results: After strength and plyometric workouts, the players presented possible to almost certain impairments in sprint and jump performance and in the Vc of the rectus femoris (effect sizes 0.26–0.64). After the sprint-training session, possible to very likely decreases were observed in the squat jump, 30-m sprint, and Vc of the biceps femoris (effect sizes 0.21–0.44). By contrast, after the technical training, athletes demonstrated a possible increase in the squat jump and Vc in both muscles examined (effect sizes 0.13–0.20). Conclusions: The main finding of this research is that, for the vast majority of results, the direction of changes observed in Vc were the same as those observed in performance assessments. This suggests that Vc might be used as a sensitive marker of acute variations in speed and power performance of elite team-sport athletes.

Isosulfan Blue Affects Pulse Oximetry

2000 ◽  
Vol 93 (4) ◽  
pp. 1002-1003 ◽  
Author(s):  
Lindsey Vokach-Brodsky ◽  
Stefanie S. Jeffrey ◽  
Harry J. M. Lemmens ◽  
John G. Brock-Utne
Keyword(s):  
Breast Cancer ◽  
Pulse Oximetry ◽  
Pulse Oximeter ◽  
Repeated Measures ◽  
Isosulfan Blue ◽  
Vital Dyes ◽  
Repeated Measures Analysis ◽  
Baseline Values ◽  
Significant Interference ◽  
Tumor Area

Background Certain vital dyes are known to cause pulse oximetry (Spo2) desaturation. The authors studied the effect of isosulfan blue (IB) on Spo2. Methods Thirty-three women, aged 34-81 yr, who were undergoing surgery for breast cancer were studied. IB, 5 ml (50 mg), was injected intraparenchymally around the tumor area by the surgeon. A pulse oximeter was used to continuously record Spo2 values up to 130 min after IB injection. Friedman repeated-measures analysis of ranks was used to analyze the baseline Spo2 and values at 5, 10, 20, 30, 40, 50, and 60 min. Results Spo2 values were significantly different from baseline values at 5, 10, 20, 30, 40, 50, and 60 min (P &lt; 0.05). In a typical patient, a maximum Spo2 decrease of 3% can be anticipated 25 min after injection of IB. Conclusions After peritumoral administration of IB, 50 mg, a significant interference with Spo2 will occur.

Explosivkraftsteigerung durch sensomotorisches Training: Eine Untersuchung akuter Effekte

2016 ◽  
Vol 64 (1) ◽  
Keyword(s):  
Intervention Group ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Control Group ◽  
Time Interval ◽  
Sensorimotor Training ◽  
Force Output ◽  
Physically Active ◽  
Explosive Strength ◽  
Voluntary Contractions

The knowledge of the effects of conditioning muscle activities on the following performances is highly relevant in professional sports. In this paper, an attempt was made to analyse the direct effects of a sensorimotor training (SMT) on the explosive leg strength. Therefore 28 physically active subjects were randomly assigned to either an intervention group (IG) or a control group (CG). Subjects were tested on two separate days. Isometric maximum voluntary contractions were investigated in a leg press. Maximum rate of force development RFDmax as well as neuromuscular activation of the quadriceps and hamstring muscles were analysed in all subjects and compared between days. Subjects of the CG repeated the same procedure without any modifications of the testing protocol, while the IG underwent a single conditioning SMT before the posttesting session. In the posttest compared to the pretest RFDmax improved significantly only for the IG (+15%, p < 0.05). These improvements in explosive strength are accompanied with a significant reduction of the early integrated m. biceps femoris electromyogram (IEMG) for the time intervals 50–100 ms (p < 0.01) and 100–200 ms (p < 0.05) relative to the onset of contraction and a significant increase in m. rectus femoris IEMG for the time interval 30–50 ms (p < 0.05). It is thus suggested that SMT results in a reduced antagonistic co-activation along with an increased agonistic muscle activity and that this changes are responsible for the gain in force output at the onset of a contraction. An immediate potentiation of the explosive strength at this level is believed to be of high significance in all sports that require fast and explosive movements of the legs.

scholarly journals Single-Leg Squat Delicacies—The Position of the Nonstance Limb is an Important Consideration

2019 ◽  
Vol 28 (4) ◽  
pp. 318-324
Author(s):  
Benita Olivier ◽  
Samantha-Lynn Quinn ◽  
Natalie Benjamin ◽  
Andrew Craig Green ◽  
Jessica Chiu ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
Inertial Sensors ◽  
Center Of Mass ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Trunk Flexion ◽  
Repeated Measures Design ◽  
Mass Displacement ◽  
Single Leg Squat

Context: The single-leg squat task is often used as a rehabilitative exercise or as a screening tool for the functional movement of the lower limb. Objective: To establish the effect of 3 different positions of the nonstance leg on 3-dimensional kinematics, muscle activity, and center of mass displacement during a single-leg squat. Design: Within-subjects, repeated-measures design. Setting: Movement analysis laboratory. Participants: A total of 10 participants, aged 28.2 (4.42) years performed 3 squats to 60° of knee flexion with the nonstance (1) hip at 90° flexion and knee at 90° flexion, (2) hip at 30° flexion with the knee fully extended, or (3) hip in neutral/0° and the knee flexed to 90°. Main Outcome Measures: Trunk, hip, knee and ankle joint angles, and center of mass displacement were recorded with inertial sensors while muscle activity was captured through wireless electromyography. Results: Most trunk flexion (21.38° [18.43°]) occurred with the nonstance hip at 90° and most flexion of the stance hip (23.10° [6.60°]) occurred with the nonstance hip at 0°. Biceps femoris activity in the 90° squat was 40% more than in the 0° squat, whereas rectus femoris activity in the 0° squat was 29% more than in the 90° squat. Conclusion: The position of the nonstance limb should be standardized when the single-leg squat is used for assessment and be adapted to the aim when used in rehabilitation.

Construction and Validation of the Mills Inventory of Preferred Leisure Activities

1981 ◽  
Vol 52 (2) ◽  
pp. 479-483 ◽  
Author(s):  
Helen H. Mills ◽  
Joseph C. Bledsoe
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Leisure Activities ◽  
Total Variance ◽  
Physically Active ◽  
Repeated Measures Analysis ◽  
Main Effects ◽  
Insight Into

A 55-item inventory of preferences for leisure activities mentioned in the literature was administered to 235 conference participants and responses factor analyzed. Six factors accounted for 47.2% of the total variance. Four items were discarded. A repeated-measures analysis of variance indicated no significant differences in preferences for Passive, Physically Active, Social, and Learning-related activities, but these four factors were preferred to mental activities, which in turn were preferred over creative activities. Main effects for general (undifferentiated) activities of age, income, sex, race, occupation, and education were non-significant, but significant interactions between these main effects and the six activities factors indicated that the inventory may provide insight into preferences related to these effects.

scholarly journals The Use of Session RPE to Monitor the Intensity of Weight Training in Older Women: Acute Responses to Eccentric, Concentric, and Dynamic Exercises

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sandro S. Ferreira ◽  
Kleverton Krinski ◽  
Ragami C. Alves ◽  
Mariana L. Benites ◽  
Paulo E. Redkva ◽  
...  
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Weight Training ◽  
Training Session ◽  
Rating Of Perceived Exertion ◽  
Training Experience ◽  
Repeated Measures Analysis ◽  
Acute Responses ◽  
Muscle Actions

The rating of perceived exertion (RPE) is ability to detect and interpret organic sensations while performing exercises. This method has been used to measure the level of effort that is felt during weight-training at a given intensity. The purpose of this investigation was to compare session RPE values with those of traditional RPE measurements for different weight-training muscle actions, performed together or separately. Fourteen women with no former weight-training experience were recruited for the investigation. All participants completed five sessions of exercise: familiarization, maximum force, concentric-only (CONC-only), eccentric-only (ECC-only), and dynamic (DYN = CONC + ECC). The traditional RPE method was measured after each series of exercises, and the session RPE was measured 30 min after the end of the training session. The statistical analyses used were the pairedt-test, one-way analysis of variance, and repeated measures analysis of variance. Significant differences between traditional RPE and session RPE for DYN, CONC, and ECC exercises were not found. This investigation demonstrated that session RPE is similar to traditional RPE in terms of weight-training involving concentric, eccentric, or dynamic muscle exercises, and that it can be used to prescribe and monitor weight-training sessions in older subjects.

scholarly journals Tensiomyographic Responses to Warm-Up Protocols in Collegiate Male Soccer Athletes

2021 ◽  
Vol 6 (4) ◽  
pp. 80
Author(s):  
Michael J. Redd ◽  
Tristan M. Starling-Smith ◽  
Chad H. Herring ◽  
Matt S. Stock ◽  
Adam J. Wells ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Warm Up ◽  
Performance Variables ◽  
Leg Muscles ◽  
Main Effect ◽  
Before And After ◽  
Main Effects ◽  
Knee Flexors

The mechanical properties of knee flexors and extensors in 15 collegiate male soccer players following different warm-up protocols [small-sided games (SSG), dynamic (DYN), and plyometric (PLY)] were evaluated. Tensiomyography (TMG) was used to assess contraction time (Tc), delay time (Td) and maximal displacement (Dm) of the rectus femoris (RF) and biceps femoris (BF) of both legs before and after each warm-up, while countermovement jump height variables, 20 m sprint, t-test and sit-and-reach were measured following the warm-ups. TMG was analyzed using a three-way [condition × time × leg] ANOVA, while performance variables were analyzed with a repeated measures ANOVA. Main effects of time were observed for BF-Tc (p = 0.035), RF-Td (p < 0.001), and BF-Td, (p = 0.008), and a main effect of condition was seen for RF-Tc (p = 0.038). Moreover, participants’ 20 m sprint improved following SSG (p = 0.021) compared to DYN and PLY. Sit-and-reach was greater following PLY (p = 0.021). No significant interactions were noted for the measured TMG variables. Warm-up-specific improvements were demonstrated in sprint speed and flexibility following SSG and PLY, respectively. The present study revealed changes in certain TMG measures following the warm-ups that suggest enhanced response of lower leg muscles regardless of specific activities used.

Early Ambulation After Injury Is Associated With Increased Muscle Size and Strength

2020 ◽  
Vol 22 (4) ◽  
pp. 527-535
Author(s):  
Jacob T. Higgins ◽  
Susan K. Frazier ◽  
Terry Lennie ◽  
Mary Kay Rayens ◽  
Jacob Avila
Keyword(s):  
Skeletal Muscle ◽  
Repeated Measures ◽  
Major Trauma ◽  
Injury Severity ◽  
Rectus Femoris ◽  
Muscle Size ◽  
Early Ambulation ◽  
Repeated Measures Analysis ◽  
Trauma Injury ◽  
And Gender

Background: Trauma and management of injuries can result in reduction or loss of mobility, which can lead to skeletal muscle deconditioning and sustained disability. Prior investigators have examined changes in skeletal muscle due to injury and immobility separately. The muscular consequences of combined immobility and trauma have not been systematically investigated. Objective: The purpose of this study was to explore the association of time to first ambulation with skeletal muscle size and strength in patients after major trauma. Methods: Adults ( N = 19) admitted for major trauma (Injury Severity Score [ISS] > 15) provided daily measures of muscle size (ultrasound) and strength (dynamometry) during hospitalization. Participants were grouped based on time to first ambulation. Repeated measures analysis of variance was used to compare muscle measures between the groups across 5 days while controlling for age and gender. Results: Participants were primarily male (63%) aged 40 ± 17 years with a mean ISS of 21 ± 4. Early ambulation was associated with a 10% increase from baseline in bicep size on Days 3 and 4 and a 15% increase from baseline on Day 5. There were no changes in rectus femoris size in either group. The early ambulation group was significantly stronger than the delayed ambulation group throughout the study in measures taken with the biceps (22%–37%) and quadriceps (26%–46%). Conclusion: Early ambulation following major trauma was associated with increased bicep size and greater muscle strength in the biceps and quadriceps muscles over time.

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