scholarly journals L-Glutamine Supplementation Enhances Strength and Power of Knee Muscles and Improves Glycemia Control and Plasma Redox Balance in Exercising Elderly Women

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 1025
Author(s):  
Gislene R. Amirato ◽  
Juliana O. Borges ◽  
Daniella L. Marques ◽  
Juliana M. B. Santos ◽  
Carlos A. F. Santos ◽  
...  
Keyword(s):  
Uric Acid ◽  
Elderly Women ◽  
Average Power ◽  
Knee Extensor ◽  
Thiobarbituric Acid ◽  
Glutamine Supplementation ◽  
Flexor Muscle ◽  
Physical Exercises ◽  
Isokinetic Test ◽  
Plasma Antioxidant Capacity

We investigated the effects of oral L-glutamine (Gln) supplementation, associated or not with physical exercises, in control of glycemia, oxidative stress, and strength/power of knee muscles in elderly women. Physically active (n = 21) and sedentary (n= 23) elderly women aged 60 to 80 years were enrolled in the study. Plasma levels of D-fructosamine, insulin, reduced (GSH) and oxidized (GSSG) glutathione, iron, uric acid, and thiobarbituric acid-reactive substances (TBARs) (lipoperoxidation product), as well as knee extensor/flexor muscle torque peak and average power (isokinetic test), were assessed pre- and post-supplementation with Gln or placebo (30 days). Higher plasma D-fructosamine, insulin, and iron levels, and lower strength/power of knee muscles were found pre-supplementation in the NPE group than in the PE group. Post-supplementation, Gln subgroups showed higher levels of GSH, GSSG, and torque peak, besides lower D-fructosamine than pre-supplementation values. Higher muscle average power and plasma uric acid levels were reported in the PE + Gln group, whereas lower insulin levels were found in the NPE + Gln than pre-supplementation values. TBARs levels were diminished post-supplementation in all groups. Gln supplementation, mainly when associated with physical exercises, improves strength and power of knee muscles and glycemia control, besides boosting plasma antioxidant capacity of elderly women.

Isokinetic Strength After ACL Reconstruction: Influence of Concomitant Anterolateral Ligament Reconstruction

2021 ◽  
pp. 194173812110054
Author(s):  
Benoit Gillet ◽  
Yoann Blache ◽  
Isabelle Rogowski ◽  
Grégory Vigne ◽  
Bertrand Sonnery-Cottet ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Ligament Reconstruction ◽  
Knee Extensor ◽  
Anterolateral Ligament ◽  
Flexor Muscle ◽  
Knee Flexor ◽  
Strength Recovery ◽  
Flexor Muscles ◽  
Knee Muscle ◽  
Knee Muscle Strength

Background: To reduce the rate of anterior cruciate ligament (ACL) graft rupture, recent surgeries have involved anterolateral ligament reconstruction (ALLR). This reconstruction procedure harvests more knee flexor muscle tendons than isolated ACL reconstruction (ACLR), but its influence on knee muscle strength recovery remains unknown. This study aimed to assess the influence of ALLR with a gracilis graft on the strength of the knee extensor and flexor muscles at 6 months postoperatively. Hypothesis: The additional amount of knee flexor harvest for ALLR would result in impairment in knee flexor muscle strength at 6 months postoperatively. Study Design: Retrospective cohort study. Level of Evidence: Level 2. Methods: A total of 186 patients were assigned to 2 groups according to the type of surgery: ACL + ALLR (graft: semitendinosus + gracilis, n = 119) or isolated ACLR (graft: semitendinosus, n = 67). The strength of the knee extensor and flexor muscles was assessed using an isokinetic dynamometer at 90, 180, and 240 deg/s for concentric and 30 deg/s for eccentric contractions and compared between groups using analysis of variance statistical parametric mapping. Results: Regardless of the surgery and the muscle, the injured leg produced significantly less strength than the uninjured leg throughout knee flexion and extension from 30° to 90° for each angular velocity (30, 90, 180, and 240 deg/s). However, the knee muscle strength was similar between the ACL + ALLR and ACLR groups. Conclusion: The addition of ALLR using the gracilis tendon during ACLR does not alter the muscle recovery observed at 6 months postoperatively. Clinical Relevance: Although more knee flexor muscle tendons were harvested in ACL + ALLR, the postoperative strength recovery was similar to that of isolated ACLR.

scholarly journals Associations of the Stair Climb Power Test With Muscle Strength and Functional Performance in People With Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study

2010 ◽  
Vol 90 (12) ◽  
pp. 1774-1782 ◽  
Author(s):  
Marc Roig ◽  
Janice J. Eng ◽  
Donna L. MacIntyre ◽  
Jeremy D. Road ◽  
W. Darlene Reid
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Muscle Strength ◽  
Functional Performance ◽  
Knee Extensor ◽  
Chronic Obstructive ◽  
Flexor Muscle ◽  
Cross Sectional ◽  
Obstructive Pulmonary Disease ◽  
Power Test ◽  
Muscle Torque

Background The Stair Climb Power Test (SCPT) is a functional test associated with leg muscle power in older people. Objective The purposes of this study were to compare the results of the SCPT in people with chronic obstructive pulmonary disease (COPD) and people who were healthy and to explore associations of the SCPT with muscle strength (force-generating capacity) and functional performance. Design The study was a cross-sectional investigation. Methods Twenty-one people with COPD and a predicted mean (SD) percentage of forced expiratory volume in 1 second of 47.2 (12.9) and 21 people who were healthy and matched for age, sex, and body mass were tested with the SCPT. Knee extensor and flexor muscle torque was assessed with an isokinetic dynamometer. Functional performance was assessed with the Timed “Up & Go” Test (TUG) and the Six-Minute Walk Test (6MWT). Results People with COPD showed lower values on the SCPT (28%) and all torque measures (∼32%), except for eccentric knee flexor muscle torque. In people with COPD, performance on the TUG and 6MWT was lower by 23% and 28%, respectively. In people with COPD, the SCPT was moderately associated with knee extensor muscle isometric and eccentric torque (r≥.46) and strongly associated (r=.68) with the 6MWT. In people who were healthy, the association of the SCPT with knee extensor muscle torque tended to be stronger (r≥.66); however, no significant relationship between the SCPT and measures of functional performance was found. Limitations The observational design of the study and the use of a relatively small convenience sample limit the generalizability of the findings. Conclusions The SCPT is a simple and safe test associated with measures of functional performance in people with COPD. People with COPD show deficits on the SCPT. However, the SCPT is only moderately associated with muscle torque and thus cannot be used as a simple surrogate for muscle strength in people with COPD.

scholarly journals Physical exercises and weight loss in obese patients help to improve uric acid

Oncotarget ◽  
2017 ◽  
Vol 8 (55) ◽  
pp. 94893-94899 ◽  
Author(s):  
Jun Zhou ◽  
Yu Wang ◽  
Fan Lian ◽  
Dongying Chen ◽  
Qian Qiu ◽  
...  
Keyword(s):  
Weight Loss ◽  
Uric Acid ◽  
Obese Patients ◽  
Physical Exercises

CHANGES IN THE FLEXOR AND EXTENSOR MUSCLES AT DIFFERENT SPEEDS

2021 ◽  
Vol 27 (7) ◽  
pp. 686-688
Author(s):  
Rui Ma ◽  
Wenyan Li
Keyword(s):  
Knee Joint ◽  
Peak Torque ◽  
Muscle Group ◽  
Lower Limbs ◽  
Flexor Muscle ◽  
Level Of Evidence ◽  
Isokinetic Test ◽  
Extensor Muscles ◽  
Test Velocity ◽  
The Difference

ABSTRACT Introduction: Centrifugal strength is an important element for strength quality. Developing muscle centrifugal strength can effectively increase the stability of lower limbs and reduce the risk of injury. Objective: To explore the characteristics of contractile force of flexor ahods in strength training and rehabilitation training, and the extensor muscles of the knee joint in athletes with different speeds of centripetal force. Methods: The knee joint muscle group of 8 first-level male high jumpers and 8 second-level male high jumpers were tested by isokinetic centrifugal contraction; the angular test velocity was 60 °/s, 120 °/s, 240 °/s, and the indexes included peak torque, relative peak torque (peak torque/body weight), and the peak torque flexural extension ratio. Results: With the centrifugal contraction of the knee joint muscle group (P < 0.05), the second-level high jumpers should increase the ability of the knee flexor muscle group of the take-off leg. In the case of constant velocity centrifugal contraction (P < 0.01), taking off time must be reduced, that is, taking off speed must be accelerated. Conclusions: The difference in the knee joint muscle isokinetic test results is one of the reasons for the difference in knee joint flexor and extensor muscle contractility under the different speed forces of high jumpers. Level of evidence II; Therapeutic studies - investigation of treatment results.

Hamstring Flexibility Is Not Correlated with Isokinetic Knee Muscle Strength in Female Modern Dancers

2018 ◽  
Vol 33 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Ani Agopyan
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Flexor Muscle ◽  
Work Production ◽  
University Level ◽  
Modern Dancers ◽  
Hamstring Flexibility ◽  
Knee Muscle ◽  
The Right

OBJECTIVE: To evaluate bilateral isokinetic knee extensor and flexor muscle strength relative to hamstring flexibility in female modern dancers. METHODS: 20 trained university-level female modern dance students (mean age 23.8±3.8 yrs) volunteered for the study. Concentric isokinetic peak torque (PT, in Nm), peak torque % of body weight (PT%BW, in Nm/kg), and total work (TW, in J) of the knee extensor and flexor muscles for each leg were measured with a dynamometer at a velocity of 60, 180, and 300°/s. Hamstring flexibility of both limbs was assessed by a goniometer with the subjects in a supine position using the active straight leg raise (SLR) test. Participants were divided into flexible (n=10) and highly flexible (n=10) groups based on their hamstring flexibility. RESULTS: The flexible and highly flexible groups had significant differences (p≤0.05) for the right (flexible, 119.7±4.3°; highly flexible, 137.7±2.6°) and left active SLR tests (flexible, 120.6±5.3°; highly flexible, 138.3±4.5°). No significant differences were found between the flexible and highly flexible dancers for concentric knee extensor and flexor muscle strength in all selected parameters (p≤0.05). There were also no significant correlations between flexibility and bilateral PT, PT%BW, and TW scores (60, 180, and 300°/s) of dancers at the concentric contraction (p≤0.05). CONCLUSION: These findings indicate that hamstring flexibility (for both the flexible and highly flexible groups) is not correlated with knee strength and has no impact on torque and work production during maximal concentric isokinetic knee muscle action in university-level female modern dancers.

scholarly journals Effects of strength training and detraining on knee extensor strength, muscle volume and muscle quality in elderly women

AGE ◽  
2012 ◽  
Vol 35 (5) ◽  
pp. 1899-1904 ◽  
Author(s):  
Cleiton Silva Correa ◽  
Bruno Manfredini Baroni ◽  
Régis Radaelli ◽  
Fábio Juner Lanferdini ◽  
Giovani Dos Santos Cunha ◽  
...  
Keyword(s):  
Strength Training ◽  
Elderly Women ◽  
Knee Extensor ◽  
Muscle Volume ◽  
Muscle Quality ◽  
Knee Extensor Strength ◽  
Training And Detraining

Decreased hepatosplanchnic antioxidant uptake during hepatic ischaemia/reperfusion in patients undergoing liver resection

2008 ◽  
Vol 114 (8) ◽  
pp. 553-560 ◽  
Author(s):  
Marcel C. G. van de POLL ◽  
Cornelis H. C. Dejong ◽  
Marc A. J. G. Fischer ◽  
Aalt Bast ◽  
Ger H. Koek
Keyword(s):  
Oxidative Stress ◽  
Uric Acid ◽  
Liver Resection ◽  
Xanthine Oxidase ◽  
Oxidase Activity ◽  
Ischaemic Preconditioning ◽  
Xanthine Oxidase Activity ◽  
Ischaemia Reperfusion ◽  
Plasma Antioxidant Capacity ◽  
Plasma Antioxidant

Oxidative stress mediates cell injury during ischaemia/reperfusion. On the other hand, experimental findings suggest that ROS (reactive oxygen species) induce processes leading to ischaemic preconditioning. The extent and source of oxidative stress and its effect on antioxidant status in the human liver during intermittent ischaemia and reperfusion remains ill-defined. Therefore the aim of the present study was to investigate the occurrence of oxidative stress in humans undergoing liver resection. Liver biopsies, and arterial and hepatic venous blood samples were taken from ten patients undergoing hepatectomy with an intermittent Pringle manoeuvre. Plasma MDA (malondialdehyde) and hepatic GSSG levels were measured as markers of oxidative stress and plasma uric acid as a marker of xanthine oxidase activity. In addition, changes in hepatosplanchnic consumption of plasma antioxidants and hepatic levels of carotenoids and glutathione (GSH) were measured. After ischaemia, hepatosplanchnic release of MDA and increased hepatic GSSG levels were found. This was accompanied by the release of uric acid, reflecting xanthine oxidase activity. During reperfusion, ongoing oxidative stress was observed by further increases in hepatic GSSG content and hepatosplanchnic MDA release. Uric acid release was minimal during reperfusion. A gradual decrease in plasma antioxidant capacity and net hepatosplanchnic antioxidant uptake was observed upon prolonged cumulative ischaemia. Oxidative stress occurs during hepatic ischaemia in man mainly due to xanthine oxidase activity. Interestingly, the gradual decline in plasma antioxidant capacity and net hepatosplanchnic antioxidant uptake during prolonged cumulative ischaemia, preserved both hydrophilic and lipophilic hepatic antioxidant levels. Decreasing plasma levels and net hepatosplanchnic uptake of plasma antioxidants may warrant antioxidant supplementation, although it should be clarified to what extent limitation of oxidative stress compromises ROS-dependent pathways of ischaemic preconditioning.

scholarly journals Velocity-specific knee strength between professional and under-17 female volleyball player

2019 ◽  
Vol 75 (1) ◽  
Author(s):  
Alexandre R.M. Pelegrinelli ◽  
Laís F. Dela Bela ◽  
Mariana F. Silva ◽  
Lucas C.R. Rodrigues ◽  
João P. Batista ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Total Work ◽  
Flexor Muscle ◽  
Mean Power ◽  
Cross Sectional ◽  
Significant Group ◽  
Surface Maps ◽  
Volleyball Players

Background: Many studies have investigated isokinetic performance in volleyball players but not through surface maps.Objectives: The goals of this study were to assess velocity-specific isokinetic knee extensor–flexor muscle strength and to compare the isokinetic knee extensor–flexor muscles between professional (PRO) and under-17 (U17) female volleyball players.Method: This cross-sectional laboratory study was developed with two groups: PRO (n = 12), medianage = 21.3 years, and U17 (n = 9), medianage = 15 years. Peak torque, total work, mean power, angle of peak torque, hamstring–quadriceps torque ratio (H–Q ratio) and torque–angle–velocity surface maps were analysed from knee extension–flexion at 60, 120 and 300 degrees per second (°/s).Results: Significant differences were identified for extensor peak torque between PRO x = 202.3 Newton metre (N·m) (standard deviation [SD] = 24.4) and U17 x = 141.6 N·m (30.1) at 60 °/s (p < 0.001; d = 2.21) as well as flexor peak torque (PRO x = 75.7 N·m [10.3] and U17 x = 57.7 N·m [11.4]) at 120 °/s (p < 0.001; d = 1.65) for the dominant limb. There were also significant group differences for total work and mean power at all velocities for extension and flexion. Surface maps demonstrated higher torque at lower speeds for both groups with smaller torque changes across velocities for flexion.Conclusion: Different groups of female volleyball players showed contrasting concentric knee muscle strength across isokinetic velocities.Clinical implications: These results demonstrate the importance of specific strength training for different age groups, even within the same sport, and provide insight into muscle strength.

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