scholarly journals Acute Effects of Proprioceptive Neuromuscular Facilitation on Peak Torque and Muscle Imbalance

2018 ◽  
Vol 3 (4) ◽  
pp. 63 ◽  
Author(s):  
Cassio Ruas ◽  
Ryan McManus ◽  
Claudio Bentes ◽  
Pablo Costa
Keyword(s):  
Body Mass ◽  
Injury Risk ◽  
Peak Torque ◽  
Knee Extension ◽  
Acute Effects ◽  
Muscle Imbalance ◽  
Proprioceptive Neuromuscular Facilitation ◽  
Before And After ◽  
Angular Velocities ◽  
Muscle Actions

Background: The effects of proprioceptive neuromuscular facilitation (PNF) stretching on muscle imbalance are not fully understood. The aim of this study was to examine the acute effects of PNF stretching on knee extension and flexion peak torque (PT), as well as the conventional and functional hamstrings to quadriceps (H:Q) ratios. Methods: Fifteen men (age = 22 ± 1 years; body mass = 76 ± 12 kg; height = 176 ± 7 cm) and fifteen women (age = 22 ± 2 years; body mass = 63 ± 8 kg; height = 161 ± 5 cm) performed concentric quadriceps and hamstrings, and eccentric hamstrings muscle actions at different angular velocities (60, 180, and 300°·s−1 concentric; 60 and 180°·s−1 eccentric) before and after a bout of PNF stretching, and a control condition. Results: Neither PNF or control conditions affected concentric PT or H:Q ratios (p > 0.05), apart from knee extension at 60°·s−1 in men (p = 0.001). However, there was a reduction in hamstrings eccentric PT in both control and PNF conditions for men and women (p = 0.003). Conclusions: PNF stretching of the hamstrings may not adversely affect the H:Q ratios, and consequently not negatively affect injury risk associated with muscular strength imbalances.

Angle-Specific Eccentric Hamstring Fatigue After Simulated Soccer

2015 ◽  
Vol 10 (3) ◽  
pp. 325-331 ◽  
Author(s):  
Daniel D. Cohen ◽  
Bingnan Zhao ◽  
Brian Okwera ◽  
Martyn J. Matthews ◽  
Anne Delextrat
Keyword(s):  
Injury Risk ◽  
Test List ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Injury Incidence ◽  
Before And After ◽  
Muscle Balance ◽  
Length Changes ◽  
Torque Angle

Purpose:To evaluate the effect of simulated soccer on the hamstrings eccentric torque-angle profile and angle of peak torque (APTeccH), and on the hamstrings:quadriceps torque ratio at specific joint angles (ASHecc:Qcon).Methods:The authors assessed dominant-limb isokinetic concentric and eccentric knee flexion and concentric knee extension at 120°/s in 9 semiprofessional male soccer players immediately before and after they completed the Loughborough Intermittent Shuttle Test (LIST).Results:The LIST resulted in significant decreases in eccentric hamstrings torque at 60°, 50°, and 10° and a significant (21.8%) decrease in ASHecc:Qcon at 10° (P < .05). APTeccH increased from 7.1° ± 1.0° to 18.8° ± 4.2° (P < .05). Eccentric hamstrings peak torque significantly declined from 185.1 ± 70.4 N·m pre-LIST to 150.9 ± 58.5 N·m post-LIST (P = .002), but there were no significant changes in hamstrings or quadriceps concentric peak torque (P = .312, .169, respectively).Conclusions:Simulated soccer results in a selective loss of eccentric hamstrings torque and hamstrings-to-quadriceps muscle balance at an extended joint position and a shift in the eccentric hamstrings APT to a shorter length, changes that could increase vulnerability to hamstrings injury. These findings suggest that injury-risk screening could be improved by evaluating the eccentric hamstrings torque-angle profile and hamstrings strength-endurance and that the development of hamstrings fatigue resistance and long-length eccentric strength may reduce injury incidence.

The Acute Effects of Fast-Paced Walking on Isometric Peak Torque and Rate of Torque Development in Regularly Exercising and Inactive Older Women

2021 ◽  
pp. 1-7
Author(s):  
Ty B. Palmer ◽  
Jarrod Blinch ◽  
Ahalee C. Farrow ◽  
Chinonye C. Agu-Udemba ◽  
Ethan A. Mitchell
Keyword(s):  
Physical Activity ◽  
Older Women ◽  
Peak Torque ◽  
Knee Extension ◽  
Acute Effects ◽  
Rate Of Torque Development ◽  
Isometric Knee Extension ◽  
Before And After ◽  
Inactive Group ◽  
Torque Development

This study aimed to examine the acute effects of fast-paced walking on isometric peak torque and rate of torque development (RTD) in regular exercising and inactive older women. Ten regular exercising (67 ± 4 years) and 10 inactive (68 ± 4 years) older women performed three isometric knee extension contractions before and after a control condition (quiet resting) and an experimental condition of fast-paced walking for 6 min. Peak torque and early (RTD100), late (RTD200), and maximum (peak RTD) RTD measurements were obtained from each contraction. Results showed no significant changes in peak torque, peak RTD, or RTD200 after walking for either group (p > .050). A significant decrease in RTD100 was observed after walking for the inactive group (p = .005) but not for the regular exercisers (p = .909). These findings highlight the importance of physical activity and suggest that a task as simple as walking may impair the rapid strength capacities of inactive older women.

Two Stretching Treatments for the Hamstrings: Proprioceptive Neuromuscular Facilitation Versus Kinesio Taping

2013 ◽  
Vol 22 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Che-Hsiu Chen ◽  
Tsun-Shun Huang ◽  
Huei-Ming Chai ◽  
Mei-Hwa Jan ◽  
Jiu-Jenq Lin
Keyword(s):  
Outcome Measures ◽  
Peak Torque ◽  
Muscle Stiffness ◽  
Muscle Performance ◽  
Static Stretch ◽  
Kinesio Taping ◽  
Negative Results ◽  
Significant Difference ◽  
Proprioceptive Neuromuscular Facilitation ◽  
Before And After

Context:Recent studies have shown that the static stretch (SS) may adversely affect leg-muscle performance.Objectives:The authors examined the short-term effects of 2 stretching exercises on hamstrings muscle before and after exercise.Design:Crossover.Setting:Laboratory.Participants:9 healthy, physically active men.Interventions:There were 3 protocols in a randomized order with a 7-d interval: nonstretching (CON protocol), hamstrings static stretching (SS) with proprioceptive neuromuscular facilitation (PNF), and SS with kinesio-taping application on the hamstrings.Main Outcome Measures:Outcome measures included first-felt and maximum tolerant-felt range of motion (FROM and TROM), maximal knee-flexion peak torque (PT) at 180°/s, and hamstrings muscle stiffness.Results:Groups were not different at prestretching in terms of hamstrings flexibility, PT, and muscle stiffness. At poststretching, both stretching protocols showed significant increases in FROM and TROM (P < .05). Stiffer hamstrings muscle and decreased PT were found in both SS+PNF and CON protocols (P < .05). However, there was no significant difference in the SS+Taping protocol (P > .05).Conclusion:The stretching protocols improve hamstrings flexibility immediately, but after exercise hamstrings peak torque is diminished in the SS+PNF but not in the SS+Taping group. This means that SS+Taping can prevent negative results from exercise, which may prevent muscle injury.

Can Hip Joint Position affect Quadriceps Muscle Responses during Knee Extension Exercise?

2020 ◽  
Vol 41 (13) ◽  
pp. 929-935
Author(s):  
Denis César Leite Vieira ◽  
Marco Aurélio Araujo Dourado ◽  
Lucas Ugliara ◽  
Joao Luiz Quagliotti Durigan ◽  
Brad J. Schoenfeld ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Muscle Thickness ◽  
Rectus Femoris ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Knee Extensors ◽  
Work Output ◽  
Before And After ◽  
Knee Extension Exercise

AbstractThis study investigated the acute effects of seated and supine knee extension exercise on muscle swelling, torque, and work output. Twelve resistance-trained men performed two isokinetic concentric-only knee-extension training protocols at different hip positions in a counter-balanced order. They completed the knee extension exercise in the seated (hip angle at 85°) and supine (hip angle at 180°) positions. The torque and work output were assessed during each set. Moreover, muscle thickness of the middle and proximal vastus lateralis and rectus femoris were evaluated before and after each protocol and used as an indicator of muscle swelling. Middle rectus femoris and proximal vastus lateralis thickness increased significantly (p=0.01) with no difference between exercise variations. However, the middle vastus lateralis thickness increased (p=0.01) only after the seated knee extension exercise (~7%). Knee extensors’ peak torque and work output were approximately 8% higher (p=0.04) in the seated when compared to the supine hip position. There was a similar decrease in torque and work output throughout both protocols (p=0.98). In conclusion, seated knee extension exercises produced greater torque, work output, and muscle swelling in the vastus lateralis when compared to the supine knee extension exercise.

scholarly journals The Effect of Applying Rigid Taping to Quadriceps Muscles on Knee Extension Strength and Jumping Distance

2014 ◽  
Vol 2 (11_suppl3) ◽  
pp. 2325967114S0017
Author(s):  
Burak Yasin Yasar ◽  
Tuba Kaplan ◽  
Sabriye Ercan ◽  
Erkan Alp ◽  
Cem Cetin
Keyword(s):  
Lower Limb ◽  
Performance Enhancement ◽  
Knee Extensor ◽  
Peak Torque ◽  
Knee Extension ◽  
Knee Extension Strength ◽  
Jump Distance ◽  
Before And After ◽  
Isokinetic Torque ◽  
Work Done

Objectives: The scientific literature is insufficient to support the use of elastic or rigid taping for the prevention or treatment of musculoskeletal injury or performance enhancement. The aim of this study was to analyze the effects of applying rigid taping on the knee extension strength and lower limb function in healthy subjects. Methods: Twenty eight healthy volunteers (age: 20.9 ± 1.1 years) were randomly assigned to two groups of 14 subjects each: Placebo/sham tape and rigid tape (Rigid tape application over the same muscles). All individuals were assessed for single and double leg hops and peak isometric and concentric isokinetic torque before and after interventions. Results: There were no statistically significant differences in jumping distances, isometric peak torque, isokinetic peak torque and total work done between groups. Conclusion: Application of rigid tape to quadriceps muscles did not significantly change lower limb functions, jump distance and knee extensor peak torque in healthy sedentary subjects.

scholarly journals The acute effects of high-intensity jack-knife stretching on the flexibility of the hamstrings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kosuke Takeuchi ◽  
Kazunori Akizuki ◽  
Masatoshi Nakamura
Keyword(s):  
High Intensity ◽  
Rating Scale ◽  
Numerical Rating Scale ◽  
Knee Extension ◽  
Acute Effects ◽  
Safe Method ◽  
Passive Torque ◽  
Before And After ◽  
Numerical Rating ◽  
Healthy Participants

AbstractThe purpose of the present study was to examine the acute effects of high-intensity jack-knife stretching for 60 s on flexibility of the hamstrings. Twelve healthy participants underwent jack-knife stretching for 60 s (3 repetitions of 20 s stretching with 30 s intervals) at two different intensities based on the point of discomfort (POD and PODmax). To examine any change in flexibility, knee extension range of motion (ROM), passive torque at end ROM, and muscle–tendon unit stiffness were measured before and after stretching. To evaluate hamstrings pain, a numerical rating scale (NRS) was described. The knee extension ROM (p < 0.01) and passive torque at end ROM (p < 0.05) were significantly increased at both intensities. The muscle–tendon unit stiffness was significantly decreased in PODmax intensity (p < 0.01), but there was no change in POD intensity (p = 0.18). The median values of NRS during the stretching were 0 and 6–7 in POD and PODmax intensity, respectively, although it was 0 immediately after the stretching protocol in both intensities. These data suggested that high-intensity jack-knife stretching is an effective and safe method to decrease muscle–tendon unit stiffness of the hamstrings.

scholarly journals Skeletal Muscle Characteristics and Motor Performance After 2-Year Growth Hormone Treatment in Adults With Prader-Willi Syndrome

2014 ◽  
Vol 99 (5) ◽  
pp. 1816-1824 ◽  
Author(s):  
Claudio L. Lafortuna ◽  
Alessandro Minocci ◽  
Paolo Capodaglio ◽  
Luca A. Gondoni ◽  
Alessandro Sartorio ◽  
...  
Keyword(s):  
Body Mass ◽  
Motor Performance ◽  
Gh Deficiency ◽  
Handgrip Strength ◽  
Peak Torque ◽  
Knee Extension ◽  
Gh Treatment ◽  
Cross Sectional ◽  
Walking Tests ◽  
Exercise Endurance

Context: In adults with Prader-Willi syndrome (PWS), abnormal body composition with decreased lean body mass and skeletal muscle (SM) volume has been related to altered GH secretion and may possibly contribute to greatly reduced motor capacity. Objective: The scope of the study was to test the hypothesis that GH treatment has favorable effects on SM characteristics and motor performance in adults with PWS. Design, Setting, and Participants: Fifteen obese PWS subjects (nine males and six females; age range, 19–35 y; body mass index, 37.7–59.9 kg/m2) were investigated before and after 12 (GH12) and 24 (GH24) months of GH treatment. Main Outcome Measures: SM cross-sectional area and SM attenuation were determined with computed tomography at the lumbar and midthigh levels. Maximal isometric handgrip strength and isokinetic knee extension peak torque were measured. Motor performance was evaluated with different indoor walking tests, whereas exercise endurance was assessed with a treadmill incremental test to exhaustion. Results: A condition of severe GH deficiency was found in six patients (40%). GH treatment significantly increased lean body mass (GH12, P &lt; .05; GH24, P &lt; .05), reduced percentage of body fat (GH12, P &lt; .05; GH24, P &lt; .05), and augmented SM cross-sectional area and SM attenuation of both lumbar (GH12, P &lt; .01; GH24, P &lt; .001) and thigh muscles (GH24, P &lt; .05). Handgrip strength increased by 7% at GH12 (P &lt; .05) and by 13% at GH24 (P &lt; .001). Peak torque of knee extension extrapolated at zero angular velocity was significantly higher at GH24 (P &lt; .01), and exercise endurance rose by 13% (P &lt; .05) and 17% (P &lt; .05) before exhaustion at GH12 and GH24, respectively, whereas no change was detected with walking tests. No significant difference in the response to GH treatment was detected between patients with and without GH deficiency. Conclusion: Long-term GH treatment in adult PWS patients improves body composition and muscle size and quality and increases muscle strength and exercise tolerance independently from the GH secretory status.

Acute Effects of a Loaded Warm-Up Protocol on Change of Direction Speed in Professional Badminton Players

2014 ◽  
Vol 30 (5) ◽  
pp. 637-642 ◽  
Author(s):  
Sean J. Maloney ◽  
Anthony N. Turner ◽  
Stuart Miller
Keyword(s):  
Body Mass ◽  
Recovery Time ◽  
Vertical Jump ◽  
Acute Effects ◽  
Countermovement Jump ◽  
Jump Performance ◽  
Warm Up ◽  
Change Of Direction ◽  
Before And After ◽  
Weighted Vest

It has previously been shown that a loaded warm-up may improve power performances. We examined the acute effects of loaded dynamic warm-up on change of direction speed (CODS), which had not been previously investigated. Eight elite badminton players participated in three sessions during which they performed vertical countermovement jump and CODS tests before and after undertaking the dynamic warm-up. The three warm-up conditions involved wearing a weighted vest (a) equivalent to 5% body mass, (b) equivalent to 10% body mass, and (c) a control where a weighted vest was not worn. Vertical jump and CODS performances were then tested at 15 seconds and 2, 4, and 6 minutes post warm-up. Vertical jump and CODS significantly improved following all warm-up conditions (P< .05). Post warm-up vertical jump performance was not different between conditions (P= .430). Post warm-up CODS was significantly faster following the 5% (P= .02) and 10% (P< .001) loaded conditions compared with the control condition. In addition, peak CODS test performances, independent of recovery time, were faster than the control condition following the 10% loaded condition (P= .012). In conclusion, the current study demonstrates that a loaded warm-up augmented CODS, but not vertical jump performance, in elite badminton players.

scholarly journals Caffeinated Gel Ingestion Enhances Jump Performance, Muscle Strength, and Power in Trained Men

Nutrients ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 937 ◽  
Author(s):  
Sandro Venier ◽  
Jozo Grgic ◽  
Pavle Mikulic
Keyword(s):  
Vertical Jump ◽  
Average Power ◽  
Peak Torque ◽  
Knee Extension ◽  
Peak Power Output ◽  
Knee Extensors ◽  
Jump Performance ◽  
Squat Jump ◽  
Rowing Ergometer ◽  
Angular Velocities

We aimed to explore the effects of caffeinated gel ingestion on neuromuscular performance in resistance-trained men. The participants (n = 17; mean ± standard deviation (SD): age 23 ± 2 years, height 183 ± 5 cm, body mass 83 ± 11 kg) completed two testing conditions that involved ingesting a caffeinated gel (300 mg of caffeine) or placebo. The testing outcomes included: (1) vertical jump height in the squat jump (SJ) and countermovement jump (CMJ); (2) knee extension and flexion peak torque and average power at angular velocities of 60°·s−1 and 180°·s−1; (3) barbell velocity in the bench press with loads corresponding to 50%, 75%, and 90% of one-repetition maximum (1RM); and (4) peak power output in a test on a rowing ergometer. Compared to the placebo, caffeine improved: (1) SJ (p = 0.039; Cohen’s d effect size (d) = 0.18; +2.9%) and CMJ height (p = 0.011; d = 0.18; +3.3%); (2) peak torque and average power in the knee extensors at both angular velocities (d ranged from 0.21 to 0.37; percent change from +3.5% to +6.9%), peak torque (p = 0.034; d = 0.24; +4.6%), and average power (p = 0.015; d = 0.32; +6.7%) at 60°·s−1 in the knee flexors; (3) barbell velocity at 50% 1RM (p = 0.021; d = 0.33; +3.5%), 75% 1RM (p < 0.001; d = 0.42; +5.4%), and 90% 1RM (p < 0.001; d = 0.59, +12.0%). We conclude that the ingestion of caffeinated gels may acutely improve vertical jump performance, strength, and power in resistance-trained men.

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