Effects of Static, PNF Stretching and Dynamic Warm-up On Knee Peak Torque in Physically Active Females

2014 ◽  
Vol 46 ◽  
pp. 149
Author(s):  
Kent D. Johnson ◽  
Erin Gainey ◽  
Hannah DeWalt
Author(s):  
Daniel Boullosa ◽  
Boris Dragutinovic ◽  
Jan-Philip Deutsch ◽  
Steffen Held ◽  
Lars Donath ◽  
...  

Background: To the authors’ knowledge, there have been no studies comparing the acute responses to “all out” efforts in concentric (isoinertial) vs. eccentric (isovelocity) cycling. Methods: After two familiarization sessions, 12 physically active men underwent the experimental protocols consisting of a 2-min warm-up and 8 maximal efforts of 5 s, separated by 55 s of active recovery at 80 rpm, in concentric vs. eccentric cycling. Comparisons between protocols were conducted during, immediately after, and 24-h post-sessions. Results: Mechanical (Work: 82,824 ± 6350 vs. 60,602 ± 8904 J) and cardiometabolic responses (mean HR: 68.8 ± 6.6 vs. 51.3 ± 5.7% HRmax, lactate: 4.9 ± 2.1 vs. 1.8 ± 0.6 mmol/L) were larger in concentric cycling (p < 0.001). The perceptual responses to both protocols were similarly low. Immediately after concentric cycling, vertical jump was potentiated (p = 0.028). Muscle soreness (VAS; p = 0.016) and thigh circumference (p = 0.045) were slightly increased only 24-h after eccentric cycling. Serum concentrations of CK, BAG3, and MMP-13 did not change significantly post-exercise. Conclusions: These results suggest the appropriateness of the eccentric cycling protocol used as a time-efficient (i.e., ~60 kJ in 10 min) and safe (i.e., without exercise-induced muscle damage) alternative to be used with different populations in future longitudinal interventions.


2021 ◽  
Vol 27 (6) ◽  
pp. 610-615
Author(s):  
Guillermo Charneco Salguero ◽  
Francisco García-Muro San José ◽  
Arturo Pérez Gosalvez ◽  
Jose Miguel Cárdenas Rebollo ◽  
Isabel Brígido Fernández ◽  
...  

ABSTRACT Introduction: Isokinetics is a tool commonly used in professional soccer. There is ongoing debate among researchers as to the isokinetic reference values a player should have. Objectives: To determine the absolute peak torque (PT) and average work of professional soccer players in relation to their positions on the field, and to establish the reference values for these variables. Methods: Purposeful sampling was used to select 289 professional soccer players. The sample included 32 goalkeepers, 100 defenders, 98 midfielders, and 59 strikers. The participants were measured preseason. The players were asked to perform a 10-minute warm-up on an exercise bike, and then to perform 5 repetitions at low speed, 10 at medium speed, and 25 at high speed, with 30 to 40-s of rest between each set of repetitions. The contraction method was concentric-concentric in a dynamometer Isomed 2000. Results: The average age, weight, and height of the players was 21.9 years, 74.3 kilograms, and 1.8 meters, respectively. The goalkeepers presented higher PT at the 3 measured speeds, and the higher average work at 180°/s and 240°/s in relation to defenders and midfielders. The strikers presented higher average work at 240°/s in relation to midfielders, and higher PT in relation to the defenders and midfielders. Absolute values were shown and reference values were established. Conclusions: The goalkeepers and strikers were the players that showed the greatest differences in their favor in relation to the other positions. The peak torque values and average work were described in relation to the player's position on the field. This study resulted in the creation of a tool for health professionals working with professional soccer players, providing reference values for these players in relation to their position on the field that can be used as benchmarks, by health professionals, to optimize soccer players’ performance. Level of evidence II, Prospective comparative study.


2013 ◽  
Vol 26 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Grasiéla Nascimento Correia ◽  
Cristine Homsi Jorge Ferreira ◽  
Mariana Chaves Aveiro ◽  
Vanessa Santos Pereira ◽  
Patricia Driusso

INTRODUCTION: The pelvic floor muscle (PFM) training is the most common treatment for urinary incontinence (UI), however many women performed the contraction of PFM with associated contraction of abdominal, gluteus and hip adductors muscles. OBJECTIVE: To assess the effects of pelvic floor muscle (PFM) training on isometric and isokinetic hip adductors peak torque (PT) among women suffering from urinary incontinence (UI). MATERIALS AND METHODS: It is a longitudinal and prospective exploratory study. This study included 15 physically active women aged 45 years old and over, who presented complaints of UI. The PFM function (digital evaluation and perineometry), isometric and isokinetic hip adductors PT and one hour pad test were performed before and after treatment. The PFM training was performed in group, one hour once a week for 12 sessions. RESULTS: Significant improvement of PFM function and pressure level (p = 0.003), and significant decrease of hip adductors isometric PT and one-hour pad test, were found post-treatment. Moderate negative correlations between PFM contraction pressure and hip adductors isokinetic PT for dominant side (DS) (r = -0.62; p = 0.03) and non-dominant side (NDS) (r = -0.64; p = 0.02); and between PFM fast fibers contraction and hip adductors isometric PT for DS (r = -0.60; p = 0.03) and NDS (r = -0.59; p = 0.04) were also found. CONCLUSIONS: The PFM training decreased hip adductors PT and improved PFM functions and UI.


1994 ◽  
Vol 3 (3) ◽  
pp. 245-254 ◽  
Author(s):  
David H. Perrin

This paper reviews the concepts associated with isokinetic open chain assessment and exercise of the quadriceps and hamstring muscle groups. Following a review of the isokinetic concept of exercise, the paper addresses principles of assessment and exercise of the knee, including the importance of musculoskeletal and cardiovascular screening, warm-up, body position, stabilization, and joint alignment. Gravity correction, test and exercise velocity, and duration of exercise are also addressed. Interpretation of an isokinetic evaluation of the knee is also addressed within the context of force-velocity relationships, peak torque relative to body weight, and bilateral and reciprocal muscle group relationships. Joint range of motion and test velocity are also discussed with respect to patellofemoral and tibiofemoral joint forces. Finally, recommended protocols for isokinetic assessment and exercise of the quadriceps and hamstring muscle groups are presented.


Author(s):  
Haiko B. Zimmermann ◽  
Débora Knihs ◽  
Fernando Diefenthaeler ◽  
Brian MacIntosh ◽  
Juliano Dal Pupo

Purpose: The objective of this study was to analyze the effects of a conditioning activity (CA) composed of continuous countermovement jumps on twitch torque production and 30-m sprint times. Methods: A total of 12 sprint athletes, 10 men (23.5 [7.7] y) and 2 women (23.0 [2.8] y), volunteered to participate in this study. The participants were evaluated in 2 sessions as follows: (1) to determine the effects of the CA (3 sets of 5 continuous vertical jumps with a 1-min interval between sets) on 30-m sprint performance over time (2, 4, 6, 8, and 10 min) and (2) to evaluate twitch peak torque to determine the magnitude and time course of the induced postactivation potentiation at the same recovery intervals. Results: Mixed-model analysis of variance with Bonferroni post hoc verified that there was a decrease on the 30-m sprint time at 2 minutes (P = .01; Δ = 2.78%; effect size [ES] = 0.43) and 4 minutes (P = .02; Δ = 2%, ES = 0.30) compared with pre when the CA preceded the sprints. The peak torque of quadriceps also showed significant increase from pretest to 2 minutes (P < .01; Δ = 17.0% [12.2%]; ES = 0.45) and 4 minutes (P = .02; Δ = 7.2% [8.8%]; ES = 0.20). Conclusion: The inclusion of CA composed of continuous countermovement jumps in the warm-up routine improved 30-m sprint performance at 2- and 4-minute time intervals after the CA (postactivation performance enhancement). Since postactivation potentiation was confirmed with electrical stimulation at the time when sprint performance increased, it was concluded that postactivation potentiation may have contributed to the observed performance increases.


2010 ◽  
Vol 35 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Iain M. Fletcher ◽  
Mathew M. Monte-Colombo

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.


2012 ◽  
Vol 26 (5) ◽  
pp. 1296-1301 ◽  
Author(s):  
Kristianna M. Altamirano ◽  
Jared W. Coburn ◽  
Lee E. Brown ◽  
Daniel A. Judelson

2020 ◽  
Vol 29 (5) ◽  
pp. 616-620
Author(s):  
Joseph B. Lesnak ◽  
Dillon T. Anderson ◽  
Brooke E. Farmer ◽  
Dimitrios Katsavelis ◽  
Terry L. Grindstaff

Context: Resistance training exercise prescription is often based on exercises performed at a percentage of a 1-repetition maximum (1RM). Following knee injury, there is no consensus when a patient can safely perform 1RM testing. Resistance training programs require the use of higher loads, and loads used in knee injury rehabilitation may be too low to elicit gains in strength and power. A maximum isometric contraction can safely be performed during early stages of knee rehabilitation and has potential to predict an isotonic knee extension 1RM. Objective: To determine whether a 1RM on an isotonic knee extension machine can be predicted from isometric peak torque measurements. Design: Descriptive laboratory study. Setting: University research laboratory. Participants: A total of 20 (12 males and 8 females) healthy, physically active adults. Main Outcome Measures: An isokinetic dynamometer was used to determine isometric peak torque (in N·m). 1RM testing was performed on a knee extension machine. Linear regression was used to develop a prediction equation, and Bland–Altman plots with limits of agreement calculations were used to validate the equation. Results: There was a significant correlation (P < .001, r = .926) between peak torque (283.0 [22.6] N·m) and the knee extension 1RM (69.1 [22.6] kg). The prediction equation overestimated the loads (2.3 [9.1] kg; 95% confidence interval, −15.6 to 20.1 kg). Conclusions: The results show that isometric peak torque values obtained on an isokinetic dynamometer can be used to estimate 1RM values for isotonic knee extension. Although the prediction equation tends to overestimate loads, the relatively wide confidence intervals indicate that results should be viewed with caution.


2009 ◽  
Vol 18 (3) ◽  
pp. 438-447 ◽  
Author(s):  
Blaine C. Long ◽  
J. Ty Hopkins

Context:It is reported that thermotherapy decreases motoneuron-pool recruitment. Any decrease in recruitment might have a significant impact on an athlete’s ability to return to competition.Objective:To determine whether moist heat application influences involuntary motoneuron-pool recruitment or voluntary plantar-flexion peak torque of the soleus muscle immediately or 30 min after application.Design:A 3 × 3 crossover design.Setting:Biomechanics laboratory.Participants:Eighteen healthy subjects with no history of lower extremity surgery or injury 12 months before the study volunteered.Intervention:A series of short-duration, high-intensity stimuli was delivered to the tibial nerve to find the Hmax and Mmax measures. Immediately after the Hmax and Mmax measures, subjects were positioned on an isokinetic dynamometer where they performed 5 submaximal warm-up repetitions. Immediately after the warm-up, 5 maximum-intensity peak plantar-flexion torque repetitions were performed. After the dynamometer measures, subjects returned to the table, where a moist heat pack, no heat pack, or a dry nonheated heat pack was applied.Main Outcome Measures:Hmax, Mmax, peak plantar-flexion torque, surface temperature (°C), and ambient temperature (°C).Results:Moist heat did not influence the H:Mmax ratio or peak plantar-flexion torque. Temperature increased with moist heat pack. Ambient temperature remained constant.Conclusions:Moist heat did not influence involuntary motoneuron-pool recruitment or voluntary peak plantar-flexion torque of the soleus muscle immediately or 30 min after application.


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