Age- and sex-associated differences in isokinetic knee muscle endurance between young children and adults

2009 ◽  
Vol 34 (4) ◽  
pp. 725-731 ◽  
Author(s):  
Mark B.A. De Ste Croix ◽  
Martine A. Deighan ◽  
Sebastien Ratel ◽  
Neil Armstrong
Keyword(s):  
Young Children ◽  
Peak Torque ◽  
Knee Extension ◽  
Total Work ◽  
Adult Males ◽  
Significant Interaction Effect ◽  
Peak Knee ◽  
Knee Muscle ◽  
Main Effects ◽  
Age And Sex

The purpose of this study was to examine the age- and sex-associated differences of repeated isokinetic knee extension and flexion. Fifty one participants, 30 young children (16 boys and 14 girls; aged 11 and 12 years) and 21 adults (9 males and 12 females; aged 18–35 years), agreed to participate in the study. Isokinetic concentric peak knee extension (PET) and flexion (PFT) torque were measured using a calibrated Biodex System 3. Participants performed 4 concentric extension–flexion cycles with maximum effort; after a 2 min rest, 50 continuous concentric cycles were performed at 1.56 rad·s–1. Total work of the extensors (WKEX) and flexors (WKFL) for the complete 50 repetitions was recorded. Average peak torque and average work for the first and last 3 repetitions were calculated to represent the percentage decline in torque and work. There were no significant differences between groups in the peak torque generated during the pretrial and endurance task, suggesting that participants gave a maximal effort at the start of the endurance task. There was a significant interaction effect in the total work done for both extensors and flexors, with adult males producing the greatest amount of work (6622 and 3444 J, respectively). When total work was divided by body mass, there were no significant sex effects, only main effects for group. The percentage decline for PET (40% vs. 60%), PFT (50% vs. 65%), WKET (43% vs. 61%), and WKFL (60% vs. 69%) demonstrated significant main effects for group, with greater fatigue in adults. We found no significant sex effect for fatigue. This study concludes that females do not resist fatigue from repeated isokinetic muscle actions to a greater extent than males, and that the greater fatigue in adults than in children is probably a product of greater initial torque production and work performed.

The Reliability of an Isokinetic Knee Muscle Endurance Test in Young Children

2003 ◽  
Vol 15 (3) ◽  
pp. 313-323 ◽  
Author(s):  
Mark B.A. De Ste Croix ◽  
Neil Armstrong ◽  
Joanne R. Welsman
Keyword(s):  
Sex Differences ◽  
Young Children ◽  
Correlation Coefficients ◽  
Knee Extension ◽  
Muscle Endurance ◽  
Strong Positive Correlation ◽  
Intra Class Correlation ◽  
Isokinetic Muscle Actions ◽  
Knee Muscle ◽  
Muscle Actions

The purpose of this study was to examine the reliability of repeated isokinetic knee extension and flexion in young children and to examine sex differences in 30 untrained subjects (16 boys and 14 girls) aged 12.2 ± 0.3 years. Total work and the percentage decline in average torque and work were recorded during 50 repetitions. Intra-class correlation coefficients indicated a strong positive correlation between test 1 and 2 for all parameters ranging from 0.36–0.95. Coefficient of variation data ranged from ± 0% to ± 5.4%. Repeatability coefficients and limits of agreement indicated that the extensors were more reliable than the flexors for both torque and work. There were no significant sex differences in any of the parameters measured. This study suggests that repeated isokinetic muscle actions of the knee, as a function of muscle endurance, can be reliably assessed in young people.

scholarly journals Isokinetic evaluation of knee muscles in soccer players: discriminant analysis

2015 ◽  
Vol 21 (5) ◽  
pp. 364-368 ◽  
Author(s):  
Bruno Fles Mazuquin ◽  
Ligia Maxwell Pereira ◽  
Josilainne Marcelino Dias ◽  
João Pedro Batista Junior ◽  
Mônica Angélica Cardoso Silva ◽  
...  
Keyword(s):  
Human Performance ◽  
Average Power ◽  
Peak Torque ◽  
Knee Extension ◽  
Soccer Players ◽  
Total Work ◽  
Wilks Lambda ◽  
Discriminant Analyses ◽  
Definition Of ◽  
Flexion And Extension

ABSTRACT Introduction: Muscle activity in soccer players can be measured by isokinetic dynamometer, which is a reliable tool for assessing human performance. Objectives: To perform isokinetic analyses and to determine which variables differentiate the under-17 (U17) soccer category from the professional (PRO). Methods: Thirty four players were assessed (n=17 for each category). The isokinetic variables used for the knee extension-flexion analysis were: peak torque (Nm), total work (J), average power (W), angle of peak torque (deg.), agonist/ antagonist ratio (%), measured for three velocities (60°/s, 120°/s and 300°/s), with each series containing five repetitions. Three Wilks' Lambda discriminant analyses were performed, to identify which variables were more significant for the definition of each of the categories. Results: The discriminative variables at 60°/s in the PRO category were: extension peak torque, flexion total work, extension average power and agonist/antagonist ratio; and for the U17s were: extension total work, flexion peak torque and flexion average power. At 120°/s for the PRO category the discriminant variables were: flexion peak torque and extension average power; for the U17s they were: extension total work and flexion average power. Finally at 300°/s, the variables found in the PRO and U17 categories respectively were: extension average power and extension total work. Conclusion: Isokinetic variables for flexion and extension knee muscles were able to significantly discriminate between PRO and U17 soccer players.

Effects of Hydraulic Resistance Strength Training on Isokinetic Measures of Leg Strength in Men with Mental Retardation

1995 ◽  
Vol 12 (4) ◽  
pp. 377-387 ◽  
Author(s):  
Rory Suomi ◽  
Paul R. Surburg ◽  
Peter Lecius
Keyword(s):  
Mental Retardation ◽  
Hydraulic Resistance ◽  
Peak Torque ◽  
Knee Extension ◽  
The Other ◽  
Isokinetic Strength ◽  
Total Work ◽  
Trained Subjects ◽  
Leg Strength ◽  
Hip Abduction

The purpose of this study was to determine the effects of hydraulic resistance (HR) training on total work and peak torque measures of isokinetic strength for tests of knee extension and hip abduction on men with mental retardation (MR). The subjects, 22 men with mild to moderate MR, were randomly assigned to two groups; 11 subjects trained three times a week for 12 weeks using HR exercise machines, while the other 11 served as controls. Prior to and after the 12 weeks of training, all subjects were assessed on isokinetic tests of knee extension at 60 deg/s and hip abduction at 30 deg/s. The strength trained subjects exhibited significant increases in total work scores on knee extension and hip abduction tests for both legs ranging from 25.0 to 177.1%. Significant increases ranging from 50.1 to 82.7% were also noted on two of the four peak torque measures. The control subjects did not exhibit significant changes in total work or peak torque scores on either muscle test between test sessions.

Effect of Ankle Position on EMG Activity and Peak Torque of the Knee Extensors and Flexors during Isokinetic Testing

1997 ◽  
Vol 6 (4) ◽  
pp. 335-342 ◽  
Author(s):  
John P. Miller ◽  
Kerriann Catlaw ◽  
Robert Confessore
Keyword(s):  
Female Athletes ◽  
Peak Torque ◽  
Knee Extension ◽  
Knee Extensors ◽  
Emg Activity ◽  
Isokinetic Testing ◽  
Surface Electrodes ◽  
Activity Peak ◽  
Peak Knee ◽  
Healthy Female

The purpose of this study was to examine the effect of ankle position on the electromyographic (EMG) activity, peak torque, and peak knee flexion to extension torque ratio during isokinetic testing of the knee. Twelve healthy female athletes performed six maximal knee extension and flexion repetitions with their dominant legs at 60 and 180°/s with the ankle in a plantar flexed position and again in a dorsiflexed position. Root mean square EMG (rmsEMG) activity was determined by placing bipolar surface electrodes on the quadriceps and the hamstrings. Ankle position had no effect on the rmsEMG activity of the quadriceps or the hamstrings at either 60 or 180°/s. Significant differences were noted for peak flexor torque at 607s (p <.001) and 180°/s (p<.01) and for peak torque flexor/extensor ratio (p <.01), with higher values observed with ankle dorsiflexion. This suggests that ankle position affects knee flexor torque and flexor/extensor ratio but not hamstring activity during isokinetic testing of the knee.

Obese Youth Demonstrate Altered Landing Knee Mechanics Unrelated to Lower-Extremity Peak Torque When Compared With Healthy Weight Youth

2020 ◽  
pp. 1-9
Author(s):  
Matthew S. Briggs ◽  
Claire Spech ◽  
Rachel King ◽  
Mike McNally ◽  
Matthew Paponetti ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Knee Flexion ◽  
Peak Torque ◽  
Knee Extension ◽  
Knee Flexion Angle ◽  
Healthy Weight ◽  
Knee Mechanics ◽  
Landing Mechanics ◽  
Peak Knee ◽  
Hip Extension

Obese (OB) youth demonstrate altered knee mechanics and worse lower-extremity performance compared with healthy weight (HW) youth. Our objectives were to compare sagittal plane knee landing mechanics between OB and HW youth and to examine the associations of knee and hip extension peak torque with landing mechanics in OB youth. Twenty-four OB and 24 age- and sex-matched HW youth participated. Peak torque was measured and normalized to leg lean mass. Peak knee flexion angle and peak internal knee extension moment were measured during a single-leg hop landing. Paired t tests, Pearson correlation coefficients, and Bonferroni corrections were used. OB youth demonstrated worse performance and lower knee extension (OB: 12.76 [1.38], HW: 14.03 [2.08], P = .03) and hip extension (OB: 8.59 [3.13], HW: 11.10 [2.89], P = .005) peak torque. Furthermore, OB youth demonstrated lower peak knee flexion angles (OB: 48.89 [45.41 to 52.37], HW: 56.07 [52.59 to 59.55], P = .02) and knee extension moments (OB: −1.73 [−1.89 to −1.57], HW: −2.21 [−2.37 to −2.05], P = .0001) during landing compared with HW youth. Peak torque measures were not correlated with peak knee flexion angle nor internal knee extension moment during landing in either group (P > .01). OB youth demonstrated altered landing mechanics compared with HW youth. However, no associations among peak torque measurements and knee landing mechanics were present.

scholarly journals Relationship between Knee Muscle Strength and Fat/Muscle Mass in Elderly Women with Knee Osteoarthritis Based on Dual-Energy X-Ray Absorptiometry

2020 ◽  
Vol 17 (2) ◽  
pp. 573
Author(s):  
Xini Zhang ◽  
Xiaoyu Pan ◽  
Liqin Deng ◽  
Weijie Fu
Keyword(s):  
Muscle Strength ◽  
Knee Osteoarthritis ◽  
Muscle Mass ◽  
Elderly Women ◽  
Knee Extension ◽  
Mass Percentage ◽  
Peak Knee ◽  
Total Body ◽  
Knee Muscle ◽  
Knee Muscle Strength

Purpose: This study aimed to examine the characteristics and correlation of knee muscle strength and body composition (fat and muscle mass) among elderly women aged 60–70 years with knee osteoarthritis. The present study hypothesized that the muscle mass and the peak torques of the knee joints were considerably low in the knee osteoarthritis (KOA) group. Methods: A total of 47 elderly women aged 60–70 years were recruited from Yangpu District in Shanghai and assigned to the knee osteoarthritis (n = 25, KOA) or healthy control group (n = 22, CON). The knee extension/flexion isokinetic strength measurements were conducted on an isokinetic dynamometer at angular velocities of 90°/s. Dual-energy X-ray absorptiometry was used to measure the body composition (fat and muscle mass in the whole body and lower limbs). The independent sample t-test was employed to determine the effects of knee osteoarthritis on each variable, and the Pearson correlation analysis was used to investigate the correlation between the body composition and knee muscle strength. Results: Compared with the CON, the KOA exhibited the following: (1) Lower absolute peak knee extension torque (66.02 ± 10.57 vs. 56.61 ± 14.69 Nm), relative peak knee extension (1.11 ± 0.19 vs. 0.89 ± 0.26 Nm/kg), and flexion torque (0.62 ± 0.15 vs. 0.54 ± 0.16 Nm/kg, p < 0.05); (2) greater relative peak torque ratio of the knee extension and flexion (0.55 ± 0.08 vs. 0.62 ± 0.15, p < 0.05); and (3) lower total body muscle mass percentage (63.24% ± 4.50% vs. 59.36% ± 3.94%), particularly in the lower limbs (19.96% ± 1.51% vs. 18.47% ± 1.49%, p < 0.05). Furthermore, the total body fat mass percentage was negatively associated with the relative peak knee extension and flexion torque regardless of the group (p < 0.05). The total body muscle mass percentage was positively associated with the relative peak knee extension torque in the two groups and the relative peak knee flexion torque in the CON (p < 0.05). Conclusion: For elderly women with knee osteoarthritis, knee muscle strength decreases significantly, especially for the extensor strength. Moreover, compared with fat mass, the index of muscle mass is more sensitive in detecting the decrease in knee joint torque. Therefore, rather than weight loss alone, the quadriceps muscle and the rear-thigh muscles, which maintain the stability of knee joints during rehabilitation training, should be strengthened emphatically to improve muscle mass.

Effect of Submaximal Repetitive Exercise on Knee Coactivation in Young and Middle-Aged Women

2014 ◽  
Vol 30 (2) ◽  
pp. 269-275 ◽  
Author(s):  
Joanne N. Hodder ◽  
Tova E. Plashkes ◽  
Regan A. Franklin ◽  
Heather K. Hickey ◽  
Monica R. Maly
Keyword(s):  
Young Women ◽  
Biceps Femoris ◽  
Peak Torque ◽  
Young Group ◽  
Knee Extension ◽  
Contact Forces ◽  
Knee Extensors ◽  
Middle Aged ◽  
Peak Knee ◽  
Coactivation Ratios

Coactivation of the knee extensors and flexors increases knee joint contact forces, which may lead to degradation of the articular surfaces. This study investigated the effect of neuromuscular fatigue induced by submaximal, repetitive, dynamic contractions on coactivation of knee musculature in young and middle-aged women. Data from 10 young women (24.6 ± 1.8 years) and 8 middle-aged women (55.4 ± 4.2 years) were analyzed. Measures included peak knee extension and flexion torques and the average amplitude of surface electromyography of rectus femoris and biceps femoris. Coactivation ratios were calculated from these activations. To induce fatigue, participants completed up to ten sets of 50 concentric knee extension and flexion contractions at 60°/s. A two-factor analysis of variance was used to determine the effect of age and fatigue. The young group showed higher peak torque compared with the middle-aged group (P< .001). During flexion, biceps femoris activity increased after fatigue when both groups were considered together (P= .018). During extension, biceps femoris activity was higher in the middle-aged than young group (P= .043). Middle-aged women exhibited a trend for greater coactivation during knee extension compared with young women (P= .066). This coactivation likely contributed to extension torque decrements in middle-aged women.

scholarly journals A 12-Week Randomized Double-Blind Placebo-Controlled Clinical Trial, Evaluating the Effect of Supplementation with a Spinach Extract on Skeletal Muscle Fitness in Adults Older Than 50 Years of Age

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4373
Author(s):  
Silvia Pérez-Piñero ◽  
Vicente Ávila-Gandía ◽  
Jacobo A. Rubio Arias ◽  
Juan Carlos Muñoz-Carrillo ◽  
Pilar Losada-Zafrilla ◽  
...  
Keyword(s):  
Spinacia Oleracea ◽  
Peak Torque ◽  
Knee Extension ◽  
Muscle Quality ◽  
Moderate Intensity ◽  
Total Work ◽  
Double Blind ◽  
Repetition Maximum ◽  
Spinacia Oleracea L ◽  
Muscle Fitness

The aim of a 12-week randomized double-blind placebo-controlled study was to assess the effect of daily supplementation with a natural extract of Spinacia oleracea L. (4 × 500 mg capsules/day; total 2 g per day) combined with a moderate-intensity training program (1 h session/3 times a week) on skeletal muscle fitness in adults over 50 years of age. Muscle strength assessed by isokinetic and isometric dynamometry improved significantly in the experimental (n = 23) and the placebo (n = 22) groups, but the magnitude of improvement was higher in the experimental group, with between-group differences in almost all variables, including isokinetic at 60° s−1 in knee extension, peak torque (p < 0.007); total work per repetition maximum (p < 0.009); isokinetic at 180°s−1 in knee extension, peak torque (p < 0.002); total work (p < 0.007); total work per repetition maximum (p < 0.005); average power (p < 0.027); isometric in knee extension, peak torque (p < 0.005); and average peak torque (p < 0.002). Similar findings were observed for muscle quality. Changes in quality of life (SF-36) were not found, except for improvements in the role physical (p < 0.023) and role emotional (p < 0.001) domains, likely as a result of the physical training sessions. A nutritional survey did not revealed changes in dietary habits. No adverse events were recorded. In subjects over 50 years of age, moderate-intensity strength training combined with daily supplementation for 12 weeks with a natural extract of Spinacia oleracea L. improved muscle-related variables and muscle quality. Maintaining muscle health is a key component of healthy aging.

scholarly journals Alterations in peak torque occur without hematological changes after muscle fatigue

2017 ◽  
Vol 23 (3) ◽  
pp. 180-183
Author(s):  
Frank Shiguemitsu Suzuki ◽  
Marcelo Martins Kalytczak ◽  
Rodrigo Augusto Ferreira Palomares ◽  
Marcos Rodolfo Paunksnis ◽  
Sergio Matias Silva ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Hematological Parameters ◽  
Peak Torque ◽  
Knee Extension ◽  
Muscular Fatigue ◽  
Adult Males ◽  
Fatigue Protocol ◽  
Isometric Torque ◽  
Hematological Changes ◽  
Inactive Group

ABSTRACT Introduction: Muscular fatigue during voluntary muscle contractions is a complex and multifactorial phenomenon associated with central changes and adaptations of the neuromuscular system. Objective: The aim of this study was to analyze the changes in both peak torque and hematological parameters in active and inactive healthy subjects following a muscular fatigue protocol. Methods: Twenty-one healthy adult males performed a muscle fatigue protocol (10 sets, 10 repetitions of knee extension at 75% of the maximal isometric torque (MIT), 120º s-1 and 40 seconds of rest). Hematocrit (Ht), red blood cells (RBC) and leukocytes (L) analysis were evaluated before (B) and after (A) a fatigue test. Results: The inactive group presented impairment only in concentric muscular action of -41±4% in relation to the active (-23±3%) group. No differences were found in hematological parameters in inactive group (Ht, B: 45.00±0.01 vs. A: 47.00±0.01; RBC, B: 442±40 vs. A: 487±41; L, B: 7,565±2,878 vs. A: 8,015±4,224) and the active group (Ht, B: 45.00±0.63 vs. A: 47.00±0.01; RBC, B: 477±30 vs. A: 559±37; L, B: 6,418±3,557 vs. A: 6,632±4,460). Conclusion: Differences were found only in concentric actions between groups. Additionally, there were no relationships found in hematological parameters between groups.

Relationships among Muscle Endurance, Explosiveness, and Strength in Circum-Pubertal Boys

1998 ◽  
Vol 10 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Kensaku Suei ◽  
Leslie McGillis ◽  
Randy Calvert ◽  
Oded Bar-Or
Keyword(s):  
Body Mass ◽  
Vertical Jump ◽  
Peak Torque ◽  
Knee Extension ◽  
Muscle Performance ◽  
Muscle Endurance ◽  
Total Work ◽  
Endurance Strength ◽  
Isometric Knee Extension ◽  
Pubertal Boys

We assess relationships among muscle endurance, strength, and explosiveness in forty-eight 9.6- to 17.0-year-old males divided into 3 maturational groups (Tanner Stages I, II-IV, and V). Peak torque during isometric knee extension and flexion was averaged to reflect strength. Mechanical power in the Sargent vertical jump was taken as explosiveness, and total work in the Wingate test reflected muscle endurance. Correlations (3 groups combined) among the variables, expressed in absolute terms, were r = .82 to .92, but only -.11 to .70 when expressed per body mass or lean thigh size. These correlations were distinctly lower in the Tanner V boys than in the 2 less-mature groups, which may suggest that specialization into discrete muscle performance characteristics does not occur before late puberty.

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