A Comparison of Concentric Knee Extension Performance Using the Cybex 6000 Nonpowered and Powered Mode for Work and Peak Torque Values

1993 ◽  
Vol 3 (4) ◽  
pp. 216-221
Author(s):  
Lori Jean Brown ◽  
Sonja Leah Wiberg Parker ◽  
Julie M. Chandler ◽  
Terry R. Malone
Keyword(s):  
Peak Torque ◽  
Knee Extension ◽  
Torque Values

Ability of Isokinetic Dynamometer to Predict Isotonic Knee Extension 1-Repetition Maximum

2020 ◽  
Vol 29 (5) ◽  
pp. 616-620
Author(s):  
Joseph B. Lesnak ◽  
Dillon T. Anderson ◽  
Brooke E. Farmer ◽  
Dimitrios Katsavelis ◽  
Terry L. Grindstaff
Keyword(s):  
Resistance Training ◽  
Knee Injury ◽  
Peak Torque ◽  
Knee Extension ◽  
Prediction Equation ◽  
Isokinetic Dynamometer ◽  
Physically Active ◽  
Repetition Maximum ◽  
Knee Rehabilitation ◽  
Torque Values

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.

Ultrasound Treatment Does Not Affect Postexercise Muscle Strength Recovery or Soreness

1999 ◽  
Vol 8 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Carrie Plaskett ◽  
Peter M. Tiidus ◽  
Lori Livingston
Keyword(s):  
Muscle Strength ◽  
Muscle Soreness ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Similar Treatment ◽  
Delayed Onset ◽  
Strength Recovery ◽  
Pulsed Mode ◽  
Torque Values

Ten volunteers (19-23 years old) performed 9 sets of 12 bilateral knee-extension exercises at 60% 1RM. Following exercise, 4 ultrasound treatments (5-cm transducer head, 1.0-MHz frequency, pulsed mode at 1.0 W/cm2) were applied for 8 min daily to the quadriceps muscle of a randomly selected treatment leg. The placebo leg received similar treatment with the ultrasound apparatus turned off. Knee-extension peak torque values and delayed onset muscle soreness (DOMS) were assessed on each leg prior to exercise and at 20 min and 24, 48, 72, and 96 hr postexercise. Postexercise peak torques declined to 60-70% of preexercise values and returned to normal by 96 hr. DOMS sensation peaked 24 hr postexercise and diminished thereafter. No significant differences in peak torque or DOMS were noted between ultrasound- or placebo-treated legs at any time postexercise. Hence ultrasound, as applied in this study, does not appear to be effective in enhancing postexercise muscle strength recovery or in diminishing DOMS.

scholarly journals Knee Muscles Isokinetic Evaluation after a Six-Month Regular Combined Swim and Dry-Land Strength Training Period in Adolescent Competitive Swimmers

2015 ◽  
Vol 49 (1) ◽  
pp. 195-200 ◽  
Author(s):  
Athanasios A. Dalamitros ◽  
Vasiliki Manou ◽  
Kosmas Christoulas ◽  
Spiros Kellis
Keyword(s):  
Strength Training ◽  
Knee Extensor ◽  
Peak Torque ◽  
Knee Extension ◽  
Training Period ◽  
Similar Data ◽  
Dry Land ◽  
Isokinetic Testing ◽  
Torque Values ◽  
Competitive Swimmers

Abstract Previous studies demonstrated significant increases in the shoulder internal rotators’ peak torque values and unilateral muscular imbalances of the shoulder rotators after a competitive swim period. However, there are no similar data concerning the knee muscles. The purpose of the current study was to examine the effects of a six-month training period on knee flexor and extensor peak torque values, examine a possible bilateral strength deficit and evaluate the unilateral strength balance in competitive swimmers. Eleven male adolescent swimmers (age: 14.82 ± 0.45 years) were tested for concentric knee extension and flexion peak torque (60°/s) with an isokinetic dynamometer, before and after a regular combined swim and dry-land strength training period. A trend towards greater improvements in the knee extensor compared to flexor muscles peak torque was observed. Furthermore, the bilateral strength deficit remained almost unchanged, whereas unilateral strength imbalance was increased for both limbs. However, all results were nonsignificant (p > 0.05). According to the data presented, a six-month regular combined swim and dry-land strength training period caused non-significant alterations for all the parameters evaluated during isokinetic testing. This study highlights the fact that competitive adolescent swimmers demonstrated unilateral knee strength imbalances throughout a long period of their yearly training macrocycle.

scholarly journals 602 THE EFFECT OF BILATERAL ISOKINETIC KNEE EXTENSION/FLEXION ON JOINT ANGLE AT PEAK TORQUE

1993 ◽  
Vol 25 (Supplement) ◽  
pp. S108 ◽  
Author(s):  
J. R. Bryant ◽  
L. E. Brown ◽  
M. Whitehurst
Keyword(s):  
Joint Angle ◽  
Peak Torque ◽  
Knee Extension

scholarly journals Reliability of a New Portable Dynamometer for Assessing Hip and Lower Limb Strength

2021 ◽  
Vol 11 (8) ◽  
pp. 3391
Author(s):  
Jan Marušič ◽  
Goran Marković ◽  
Nejc Šarabon
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Peak Torque ◽  
Knee Extension ◽  
Lower Limb Muscles ◽  
Lower Limb Strength ◽  
Flexion Extension ◽  
Strength Tests ◽  
Hip Abduction ◽  
Maximal Peak

The purpose of this study was to evaluate intra- and inter-session reliability of the new, portable, and externally fixated dynamometer called MuscleBoard® for assessing the strength of hip and lower limb muscles. Hip abduction, adduction, flexion, extension, internal and external rotation, knee extension, ankle plantarflexion, and Nordic hamstring exercise strength were measured in three sessions (three sets of three repetitions for each test) on 24 healthy and recreationally active participants. Average and maximal value of normalized peak torque (Nm/kg) from three repetitions in each set and agonist:antagonist ratios (%) were statistically analyzed; the coefficient of variation and intra-class correlation coefficient (ICC2,k) were calculated to assess absolute and relative reliability, respectively. Overall, the results display high to excellent intra- and inter-session reliability with low to acceptable within-individual variation for average and maximal peak torques in all bilateral strength tests, while the reliability of unilateral strength tests was moderate to good. Our findings indicate that using the MuscleBoard® dynamometer can be a reliable device for assessing and monitoring bilateral and certain unilateral hip and lower limb muscle strength, while some unilateral strength tests require some refinement and more extensive familiarization.

Validity of Isokinetic and Isometric Testing modalities for Assessing Short-term Resistance Exercise Strength Gains

1992 ◽  
Vol 1 (4) ◽  
pp. 275-283 ◽  
Author(s):  
Andrew C. Fry ◽  
Dawn R. Powell ◽  
William J. Kraemer
Keyword(s):  
Resistance Exercise ◽  
Human Performance ◽  
Peak Torque ◽  
Quadriceps Strength ◽  
Short Term ◽  
Isokinetic Testing ◽  
Leg Extension ◽  
Leg Flexion ◽  
Isokinetic Torque ◽  
Torque Values

Although it is generally accepted that human performance must be assessed in a manner specific to the training, previous studies have violated this principle. In order to determine the validity of evaluating short-term resistance training programs with isometric and isokinetic measures, 23 recreationally active males participated in an 8-week training program. Subjects were randomly divided into barbell squat, hip sled, leg extension, and control groups. Pre- and posttesting of quadriceps strength was performed with a Cybex isokinetic dynamometer. Six angle-specific torques (N.m) were determined at 0 rad-s-1 and 1.05 rad-s-1. Ten RM training loads increased significantly for all groups that trained. Isometric torque values differed significantly from isokinetic torque values at 30, 60, 75, and 90° of leg flexion for all groups. No significant torque increases from pre- to posttest were observed for any group at any limb angle for either isometric or isokinetic testing, or for isokinetic peak torque. This indicates that strength increases during short-term dynamic external resistance exercise are not adequately assessed with either isometric or isokinetic evaluations.

scholarly journals Isokinetic strength of shoulder internal and external rotators in cricket bowlers

2002 ◽  
Vol 58 (2) ◽  
Author(s):  
X.M. Mabasa ◽  
A. Stewart ◽  
C. Fleishman
Keyword(s):  
External Rotation ◽  
Peak Torque ◽  
Isokinetic Strength ◽  
Neutral Position ◽  
Joint System ◽  
Rotational Strength ◽  
Significant Difference ◽  
Position Data ◽  
Torque Values ◽  
Rotation Strength

The strength of the shoulder internal and external rotators incricket bowlers, may not be sufficient to cope with the demands of bowling.As very little research has been done on cricketers, this study was done to establish the isokinetic strength profile of the shoulder internal andexternal rotators in cricket bowlers.Isokinetic, shoulder rotational strength was evaluated in thirty malecricket volunteers with a mean age of 23.9 years and mean body weight of 70.3 kgs. The Cybex 340 dynamometer multi joint system was used to collect data on shoulder rotation strength in a standing neutral position. Data were collected at four different speeds (60,90,180 and 300deg/sec) and were computed for peak torque values for internal and external ratios for both dominant and non dominant shoulders.The results showed no statistically significant difference in the mean shoulder rotational torque between the bowlingand non-bowling shoulders for external rotation (p>0.05), and indicated statistically significant differences in themean shoulder rotational torque between the bowling and non-bowling shoulders for internal rotation (p<0.05). Therewas a significant decrease in isokinetic peak torque production for the external/internal rotator muscles as the speedof contraction increased (p<0.05). The peak torque ratio for the external/internal rotator muscles of the bowling armwere significantly less than of the non-bowling arm (p<0.05). These findings suggest that the strength ratios of thebowling arm need to be considered when managing young cricketers and their injuries.

scholarly journals Muscle Strength Variations of Knee Joint Muscles in Elite Female Handball Players after Pre-Season Conditioning

2018 ◽  
Vol 63 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Zuzana Gonosova ◽  
Petr Stastny ◽  
Jan Belka ◽  
Lucia Bizovska ◽  
Michal Lehnert
Keyword(s):  
Muscle Strength ◽  
Elite Athletes ◽  
Body Height ◽  
Peak Torque ◽  
Knee Extension ◽  
Training Process ◽  
Strength Performance ◽  
Risk Of Injury ◽  
Previous Season ◽  
Isokinetic Peak Torque

Abstract Monitoring seasonal variations in strength performance and the relative risk of injury indicators related to strength of hamstring (H) and quadriceps (Q) in female elite athletes is beneficial for the training process. The aim of this study was to examine and compare the level of muscle strength, the conventional ratio (HCONC/QCONC) as well as two functional and strength ratios reflecting the movement of knee extension (HECC/QCONC) and flexion (HCONC/QECC), and the bilateral percentage strength deficit (BSD) in elite female handball players. The concentric and eccentric isokinetic peak torque was measured at an angular velocity of 60°/s on three occasions (in-season cessation, 4 weeks of rest followed by 4 weeks of individual conditioning and 6 weeks of group conditioning) in eleven female handball players (age: 23.1 ± 3.5 years, body height: 1.73 ± 0.6 m). According to ANOVA results, the BSD of H muscles in the concentric mode decreased between the in-season cessation and the end of the pre-season, and HCONC/QCONC increased at the beginning of the pre-season and at the end of the pre-season in comparison with inseason cessation measurement. The effect size analyses showed that the off-season rest followed by 10 weeks of the conditioning programme increased Q and H strength in comparison with the previous season with a large effect. Coaches should include progressive conditioning in the pre-season phase to decrease the bilateral strength deficit and to support further conditioning development.

scholarly journals ISOKINETIC PROFILES AND REFERENCE VALUES OF PROFESSIONAL SOCCER PLAYERS

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 ◽  
...  
Keyword(s):  
Reference Values ◽  
Health Professionals ◽  
High Speed ◽  
Peak Torque ◽  
Soccer Players ◽  
Level Of Evidence ◽  
Warm Up ◽  
Professional Soccer ◽  
Average Work ◽  
Torque Values

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.

scholarly journals ROLE OF HAMSTRING MUSCLES IN KNEE JOINT STABILITY PROVIDING AND INJURY PREVENTION

2016 ◽  
Vol 3 ◽  
pp. 522
Author(s):  
Inese Pontaga
Keyword(s):  
Stance Phase ◽  
Knee Extension ◽  
Swing Phase ◽  
Joint Stability ◽  
Distance Runners ◽  
Leg Extension ◽  
Hamstring Muscles ◽  
Extreme Extension ◽  
Torque Values

The aim of our investigation was to determine the ratio of maximal torque values and the torques in the certain positions of range of movements (ROM) between hamstring (H) and quadriceps femoris (Q) muscles at medium and high velocity of movement in concentric (CC) and eccentric (ECC) action of hamstring muscles. The knee muscles of 15 amateur female short and middle distance runners were tested by the dynamometer system in the isokinetic movements with the angular velocity of 90º/s and 240º/s in CC and at the velocity of 90º/s in ECC H/ CC Q muscles contractions. The torque values produced by the muscles are detected at the different angular positions of the ROM with the step of 10º. The ratios of H/ Q muscles torques are calculated. The H/Q muscles maximal torques ratio is 0.51 ± 0.13 at the velocity of 90º/s in CC and 0.60 ± 0.09 in ECC H/ CC Q muscles contractions, and 0.59 ± 0.09 CC at the velocity of 240º/s. The H/Q maximal torques ratio and this ratio in the knee extreme extension and flexion at the ECC contraction of H is higher due to greater torques produced by the H in comparison with Q muscle. The H must be stronger to decelerate the thigh and lower leg extension in the late swing phase of running and to extend the hip in early stance phase to provide powerful sprint running and prevent the knee and H injury. The H/Q muscles torques ratio in extended knee positions are similar in medium (90º/s) and fast (240º/s) velocity of motions because CC action of H muscles cannot prevent extreme knee extension.

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