Absolute Reliability of Hamstring to Quadriceps Strength Imbalance Ratios Calculated Using Peak Torque, Joint Angle-Specific Torque and Joint ROM-Specific Torque Values

2012 ◽  
Vol 33 (11) ◽  
pp. 909-916 ◽  
Author(s):  
F. Ayala ◽  
M. De Ste Croix ◽  
P. Sainz de Baranda ◽  
F. Santonja
Keyword(s):  
Joint Angle ◽  
Peak Torque ◽  
Quadriceps Strength ◽  
Torque Values ◽  
Absolute Reliability

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 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 STRONGER THAN EVER! ADOLESCENT ATHLETES SHOW STRENGTH GAINS WITHIN THE UNINJURED LEG AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0005
Author(s):  
Elliot Greenberg ◽  
Joshua Bram ◽  
Theodore Ganley
Keyword(s):  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Reconstruction ◽  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Cohort Analysis ◽  
Peak Torque ◽  
Quadriceps Strength ◽  
Strength Assessment ◽  
Cruciate Ligament Reconstruction ◽  
Anterior Cruciate

Background: The restoration of quadriceps strength after anterior cruciate ligament reconstruction (ACLR) is critical to restore optimal patient function and reduce the incidence of secondary ACL injury. Strength is typically quantified during return to sport assessments, by comparing the strength in the involved limb to that of the uninvolved limb. A limb symmetry index (LSI) is calculated and used to determine if any residual strength deficits persist. Recent evidence demonstrates that the uninvolved limb may lose strength during ACLR recovery and suggests that pre-operative uninvolved limb strength values may offer a better representation and more stringent indicator of strength recovery after ACLR. However, this body of literature is limited and no studies have specifically evaluated this occurrence within youth athletes. Purpose: To evaluate the change in strength in the uninvolved limb from pre-operative to 6 months post-ACLR, and assess the effect of pre-operative strength comparison on 6-month post-op LSI. Methods: A retrospective cohort analysis of pediatric patients (≤18 years) undergoing primary ACLR from 1/2018-1/2020 without concomitant multi-ligamentous reconstruction was conducted. Isokinetic peak torque values for the uninvolved and involved quadriceps were extracted at pre-operative (uninvolved only) and 6 months post-operative. Strength changes were analyzed using paired-samples t-test. Results: Complete data was available for a total of 17 subjects (mean age 15.1±1.7, 53% female). Pre-operative strength assessment was performed a mean of 11.5 days (range 1-26) prior to surgery. The mean 6-month post-operative assessment occurred at 177 days (range 127-246). The uninvolved limb was significantly stronger (p<0.001) at 6 months compared to preoperatively, with a mean improvement of 12.1ft/lbs (95%CI 18.3 – 7.2) with a change from 82.4ft/lbs to 95.1 ft/lbs. The LSI was calculated using both pre-operative and 6-month post-operative uninvolved limb values and demonstrated substantially lower LSI values when using concurrent 6-month data (LSIpre 91.3% vs LSI6M 76.9%). Conclusions: Among this sample, the uninvolved limb got stronger during post-ACLR recovery and comparison to concurrently assessed strength values led to a more stringent determination of LSI. Differences in rehabilitation programming, adolescent physiology, and pre-injury training patterns may explain why these results differ than those found in older cohorts.

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 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 A Novel Noninvasive Method for Measuring Fatigability of the Quadriceps Muscle in Noncooperating Healthy Subjects

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jesper B. Poulsen ◽  
Martin H. Rose ◽  
Kirsten Møller ◽  
Anders Perner ◽  
Bente R. Jensen
Keyword(s):  
Healthy Subjects ◽  
Functional Limitations ◽  
Regression Line ◽  
Intraclass Correlation ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Fatigue Index ◽  
Minimum Detectable Change ◽  
Torque Values ◽  
Index Ratio

Background. Critical illness is associated with muscle weakness leading to long-term functional limitations.Objectives. To assess the reliability of a novel method for evaluating fatigability of the quadriceps muscle in noncooperating healthy subjects.Methods. On two occasions, separated by seven days, nonvoluntary isometric contractions (twitch and tetanic) of the quadriceps femoris muscle evoked by transcutaneous electrical muscle stimulation were recorded in twelve healthy adults. For tetanic contractions, the Fatigue Index (ratio of peak torque values) and the slope of the regression line of peak torque values were primary outcome measures. For twitch contractions, maximum peak torque and rise time were calculated. Relative (intraclass correlation, ICC3.1) and absolute (standard error of measurement, SEM) reliability were assessed and minimum detectable change was calculated using a 95% confidence interval (MDC95%).Results. The Fatigue Index (ICC3.1, 0.84; MDC95%, 0.12) and the slope of the regression line (ICC3.1, 0.99; MDC95%, 0.03) showed substantial relative and absolute reliability during the first 15 and 30 contractions, respectively.Conclusion. This method for assessing fatigability of the quadriceps muscle produces reliable results in healthy subjects and may provide valuable data on quantitative changes in muscle working capacity and treatment effects in patients who are incapable of producing voluntary muscle contractions.

scholarly journals THE EFFECT OF AGE AND CONCOMITANT SURGERY ON STRENGTH IN ADOLESCENT ATHLETES WITH PRIMARY QUADRICEPS TENDON ACL RECONSTRUCTION

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0020
Author(s):  
Sarah E. Reinking ◽  
Kaitlyn A. Flynn ◽  
Alexia G. Gagliardi ◽  
Cassidy J. Hallagin ◽  
Melissa N. Randall ◽  
...  
Keyword(s):  
Acl Reconstruction ◽  
Return To Sport ◽  
Quadriceps Tendon ◽  
Peak Torque ◽  
Quadriceps Strength ◽  
Steady Increase ◽  
Isokinetic Testing ◽  
Concomitant Surgery ◽  
Effect Of Age ◽  
Meniscus Surgery

Background: Knee extensor strength deficits occur after ACL reconstruction (ACLR). Prior studies have reported that age affects quadriceps strength after ACLR, however strength deficits in relation to age have not been assessed among adolescents. Isokinetic dynamometric strength testing is a tool frequently used to assess strength post-operatively in order to identify these deficits. Purposes: 1) To examine the effect of age on isokinetic extensor and flexor deficits among adolescents who were 5-10 months post-ACLR. We hypothesized that age would be inversely related to extensor strength deficit. 2) To determine if extensor or flexor strength deficits exist between adolescents post-ACLR with and without concomitant meniscus surgery. We hypothesized that those with concomitant meniscus surgery would demonstrate greater deficits in flexor and extensor strength. Methods: Study participants completed isokinetic testing within 5-10 months after primary quadriceps tendon ACLR, but before return to sport. The protocol consisted of assessing peak torque at 60, 180, and 300 degrees/s, through a limited range of knee extension and flexion. Our primary outcome variables were peak torque percent deficit of involved leg compared to uninvolved leg for flexion and extension. To address purpose 1, we constructed a series of multivariable regression models, where age was the independent variable, peak torque flexor/extensor deficits at each testing speed was the dependent variable, and sex and weight were covariates. To address purpose 2, we compared peak torque extensor and flexor deficits between those with and without concomitant meniscus surgery using independent samples t-tests. Results: A total of 44 completed the study protocol. There were no significant demographic differences between those with and without concomitant meniscus surgery (Table 1). The relationship between age at surgery and peak torque extensor deficits at 300d/s demonstrated a linear but non-significant association (Table 2; Figure 1). For every year increase in age, the expected deficit at 300d/s increased by approximately 3%. Patients who underwent isolated ACLR demonstrated significantly greater flexor deficits than those who underwent ACLR with concomitant meniscus surgery when tested at 180d/s and 300d/s (Table 3). Conclusion: Contrary to our first hypothesis, extensor deficits at 300d/s demonstrated an apparent association with older age. We observed a steady increase in strength deficit at 300d/s associated with increasing age. Contrary to our second hypothesis, no significant differences were found in extensor strength between those with and without meniscus surgery. Additionally, those with concomitant meniscus surgery demonstrated significantly less flexor deficit than those without meniscus surgery. [Table: see text][Table: see text][Figure: see text][Table: see text]

Comparison of Isometric Portable Fixed Dynamometry to Isokinetic Dynamometry for Assessment of Hip Strength

2013 ◽  
Vol 18 (6) ◽  
pp. 1-6 ◽  
Author(s):  
Roger O. Kollock ◽  
Bonnie Van Lunen ◽  
Jennifer L. Linza ◽  
James A. Onate
Keyword(s):  
Outcome Measures ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Peak Torque ◽  
Hip Strength ◽  
Isokinetic Testing ◽  
Testing Procedures ◽  
Hip Motion ◽  
Torque Values ◽  
Isokinetic Peak Torque

Context:Assessment of hip strength can be performed with either isokinetic or isometric testing procedures, but the degree of association between values derived from the alternative testing methods has not been previously documented.Objective:To investigate the relationship between isometric peak torque and isokinetic peak torque at 60°·s-1 for various hip motions.Participants:Eighteen physically active males (N = 9) and females (N = 9) participated (22 ± 3 years, 173.0 ± 10.5 cm, 73.8 ± 16.7 kg).Intervention(s):Three isokinetic repetitions at 60°·s-1 and three isometric contractions of 5 s each for the hip fexors (HFs), hip extensors (HEs), hip abductors (ABs), hip adductors (ADs), hip external rotators (ERs), and hip internal rotators (IRs).Outcome Measures:Pearson correlation coefficients and coefficients of determination were calculated for both absolute and allometric-scaled peak torque values.Results:Meaningful associations between isometric and isokinetic peak torque values were found for each hip motion. Allometric-scaled strength values demonstrated stronger correlations than absolute strength values.Conclusions:The results suggest that portable fixed isometric testing of hip strength is an alternative to isokinetic testing at 60°·s-1.

scholarly journals Changes in Muscle Strength in U19 Soccer Players During an Annual Training Cycle

2014 ◽  
Vol 42 (1) ◽  
pp. 175-185 ◽  
Author(s):  
Michal Lehnert ◽  
Zuzana Xaverová ◽  
Mark De Ste Croix
Keyword(s):  
Peak Torque ◽  
Quadriceps Strength ◽  
Soccer Players ◽  
Muscle Action ◽  
Strength Assessment ◽  
Training Cycle ◽  
Competitive Season ◽  
Post Hoc ◽  
Testing Range ◽  
Knee Flexors

Abstract The aim of the study was to investigate the seasonal variation in isokinetic strength of the knee flexors and extensors, and conventional (H/QCONV) and functional (H/QFUNC) hamstring to quadriceps strength ratios in highly trained adolescent soccer players. The players (n=11; age 17.8±0.3) were measured at the end of the competitive season (autumn), at the beginning and the end of pre-season (winter) and during the sixth week of a new competitive season. Isokinetic peak torque (concentric and eccentric) was measured at 60°•s-1 in a sitting position with the hip flexed at 100°. The testing range of motion was set from 10 - 90° of knee flexion. The players performed a set of five maximum repetitions for both the dominant and non-dominant leg. Statistically significant differences (p<0.001) between the four seasonal measurements were noted for peak torque of the dominant leg knee flexors in concentric muscle action only. A post hoc analysis revealed a statistically significant increase in peak torque from the 1st to the 4th measurement (p<0.001; d=0.692) and from the 2nd to the 4th (p<0.01; d=0.564). The differences in the changes of peak torque of the knee flexors and extensors depending on type of muscle action and tendencies found in the H/Q ratios throughout the annual training cycle indicate that strength assessment of the knee flexors and extensors and their balance throughout the annual training cycle could be beneficial for elite male adolescent soccer players both in terms of performance and risk of injury.

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