scholarly journals Effects of training and detraining on muscle strength in rowers

2019 ◽  
Vol 72 (7-8) ◽  
pp. 223-227
Author(s):  
Nebojsa Janjic ◽  
Mina Maricic ◽  
Andrea Zubnar ◽  
Vedrana Karan ◽  
Miodrag Drapsin ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Muscle Adaptation ◽  
Contraction Rate ◽  
Lower Limb Muscles ◽  
Muscle Groups ◽  
Leg Extensor Power ◽  
Novi Sad ◽  
Periodized Training ◽  
Leg Extensors ◽  
Training And Detraining

Introduction. Annual and periodized training protocols significantly affect the muscle adaptation in rowers. Considering that the main goal of the training period is increasing specific muscle strength and of detraining period increasing general strength and active rest, the aim of this study was to compare the strength of different muscle groups between training and detraining periods. Material and Methods. The study was conducted at the Department of Physiology, Faculty of Medicine Novi Sad, and it included 34 male and female rowers, 15 to 18 years of age. The muscle strength was measured using a Concept 2 DYNO dynamometer. The strength of the arm extensors and flexors, as well as the leg extensors was measured twice, at the end of the competition season (peak of performance) and before the beginning of the preparation season (after detraining). Results. A statistically significant decrease was found in absolute and relative muscle strength, flexor and arm extensor contraction rate, as well as relative leg extensor strength and contraction rate during the training and detraining periods (p < 0.05). No difference was found in the absolute leg extensor power between the two measurements (p > 0.05). Conclusion. Periodization of the annual training program in rowers has a higher impact on differences in the upper limb muscle adaptation, compared to lower limb muscles in terms of absolute strength.

scholarly journals Recovery of early postoperative muscle strength after deep neuromuscular block by means of ultrasonography with comparison of neostigmine versus sugammadex as reversal drugs: study protocol for a randomised controlled trial

BMJ Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. e043935
Author(s):  
Xuan Wang ◽  
Yingyuan Li ◽  
Chanyan Huang ◽  
Wei Xiong ◽  
Qin Zhou ◽  
...  
Keyword(s):  
Randomised Controlled Trial ◽  
Muscle Strength ◽  
Neuromuscular Blockade ◽  
Postoperative Period ◽  
Controlled Trial ◽  
Complete Recovery ◽  
Early Postoperative Period ◽  
Time Points ◽  
Muscle Groups ◽  
Randomised Controlled

IntroductionDespite the use of quantitative neuromuscular monitoring together with the administration of reversal drugs (neostigmine or sugammadex), the incidence of residual neuromuscular blockade defined as a train-of-four ratio (TOFr) <0.9 remains high. Even TOFr >0.9 cannot ensure adequate recovery of neuromuscular function when T1 height is not recovered completely. Thus, a mathematical correction of TOFr needs to be applied because the return of a normal TOFr can precede the return of a normal T1 twitch height. On the other hand, different muscles have different sensitivities to neuromuscular blockade agents; thus, complete recovery of one specific muscle group does not represent complete recovery of all other muscles. Therefore, our study aims to assess the muscle strength recovery of respiratory-related muscle groups by ultrasound and evaluate global strength using handgrip dynamometry in the early postoperative period when TOFr=0.9 and corrected TOFr (cTOFr)=0.9 with comparison of neostigmine versus sugammadex as reversal drugs.Methods and analysisThis study will be a prospective, single-blinded, randomised controlled trial involving 60 patients with American Society of Anesthesiologists physical status I–II and aged between 18 and 65 years, who will undergo microlaryngeal surgery. We will assess geniohyoid muscle, parasternal intercostal muscle, diaphragm, abdominal wall muscle and handgrip strength at four time points: before anaesthesia, TOFr=0.9, cTOFr=0.9 and 30 min after admission to the post anaesthesia care unit. Our primary objective will be to compare the effects of neostigmine and sugammadex on the recovery of muscle strength of different muscle groups in the early postoperative period when TOFr=0.9 and cTOFr=0.9. The secondary objective will be to observe the difference of muscle strength between the time points of TOFr=0.9 and cTOFr=0.9 to find out the clinical significance of cTOFr >0.9.Ethics and disseminationThe protocol was reviewed and approved by the Ethics Committee of The First Affiliated Hospital, Sun Yat-sen University. The findings will be disseminated to the public through peer-reviewed scientific journals.Trial registration numberChiCTR2000033832.

scholarly journals Development of Lower Extremity Strength in Ambulatory Children With Bilateral Spastic Cerebral Palsy in Comparison With Typically Developing Controls Using Absolute and Normalized to Body Weight Force Values

2021 ◽  
Vol 12 ◽  
Author(s):  
Nicolaos Darras ◽  
Eirini Nikaina ◽  
Magda Tziomaki ◽  
Georgios Gkrimas ◽  
Antigone Papavasiliou ◽  
...  
Keyword(s):  
Body Weight ◽  
Cerebral Palsy ◽  
Muscle Strength ◽  
Lower Limb ◽  
Age Groups ◽  
Knee Extensors ◽  
Spastic Cerebral Palsy ◽  
Typically Developing ◽  
Antagonist Muscles ◽  
Muscle Groups

This cross-sectional study aimed to examine the development of lower limb voluntary strength in 160 ambulatory patients with bilateral spastic cerebral palsy (CP) (106 diplegics/54 quadriplegics) and 86 typically developing (TD) controls, aged 7–16 years. Handheld dynamometry was used to measure isometric strength of seven muscle groups (hip adductors and abductors, hip extensors and flexors, knee extensors and flexors, and ankle dorsiflexors); absolute force (AF) values in pounds were collected, which were then normalized to body weight (NF). AF values increased with increasing age (p &lt; 0.001 for all muscle groups), whereas NF values decreased through adolescence (p &lt; 0.001 for all muscle groups except for hip abduction where p = 0.022), indicating that increases in weight through adolescence led to decreases in relative force. Both AF and NF values were significantly greater in TD subjects when compared with children with CP in all muscle and all age groups (p &lt; 0.001). Diplegics and quadriplegics demonstrated consistently lower force values than TD subjects for all muscle groups, except for the hip extensors where TD children had similar values with diplegics (p = 0.726) but higher than quadriplegics (p = 0.001). Diplegic patients also exhibited higher values than quadriplegics in all muscles, except for the knee extensors where their difference was only indicative (p = 0.056). The conversion of CP subjects' force values as a percentage of the TD subjects' mean value revealed a pattern of significant muscle strength imbalance between the CP antagonist muscles, documented from the following deficit differences for the CP muscle couples: (hip extensors 13%) / (hip flexors 32%), (adductors 27%) / (abductors 52%), and (knee extensors 37%) / (knee flexors 53%). This pattern was evident in all age groups. Similarly, significant force deficiencies were identified in GMFCS III/IV patients when compared with TD children and GMFCS I/II patients. In this study, we demonstrated that children and adolescents with bilateral CP exhibited lower strength values in lower limb muscles when compared with their TD counterparts. This difference was more prevalent in quadriplegic patients and those with a more severe impairment. An important pattern of muscle strength imbalance between the antagonist muscles of the CP subjects was revealed.

Quantification of Muscle Strength and Imbalance in Neurogenic Pes Cavus, Compared to Health Controls, Using Hand-Held Dynamometry

2005 ◽  
Vol 26 (7) ◽  
pp. 540-544 ◽  
Author(s):  
Joshua Burns ◽  
Anthony Redmond ◽  
Robert Ouvrier ◽  
Jack Crosbie
Keyword(s):  
Muscle Strength ◽  
Healthy Controls ◽  
Foot And Ankle ◽  
Foot Deformity ◽  
Pes Cavus ◽  
Retest Reliability ◽  
Ankle Muscle ◽  
Cavus Foot ◽  
Muscle Groups ◽  
Test Retest Reliability

Background: Pes cavus foot deformity in neuromuscular disease is thought to be related to an imbalance of musculature around the foot and ankle. The most common cause of neurogenic pes cavus is Charcot-Marie-Tooth (CMT) disease. The aim of this investigation was to objectively quantify muscle strength and imbalance using hand-held dynamometry in patients diagnosed with CMT and pes cavus, compared to healthy controls. Methods: Muscles responsible for inversion, eversion, plantarflexion, and dorsiflexion of the foot and ankle were measured in 55 subjects (11 CMT patients with a frank pes cavus, and 44 healthy controls with normal feet) using the Nicholas hand-held dynamometer (HHD). Test-retest reliability of the HHD procedure also was determined for each of the four muscle groups in the healthy controls. Results: Test-retest reliability of the HHD procedure was excellent (ICC3,1 = 0.88 to 0.95) and the measurement error was low (SEM = 0.3 to 0.7 kg). Patients with CMT were significantly weaker than normal for all foot and ankle muscle groups tested ( p <0.001). Strength ratios of inversion-to-eversion and plantarflexion-to-dorsiflexion were significantly higher in the patients with CMT and pes cavus compared to individuals with normal foot types ( p > 0.01). Conclusions: Hand-held dynamometry is an objective and reliable instrument to measure muscle strength and imbalance in patients with CMT and a pes cavus foot deformity.

Zapateado Technique as an Injury Risk in Mexican Folkloric and Spanish Dance: An Analysis of Execution, Ground Reaction Force, and Muscle Strength

2013 ◽  
Vol 28 (2) ◽  
pp. 80-83 ◽  
Author(s):  
Soledad Echegoyen ◽  
Takeshi Aoyama ◽  
Cristina Rodríguez
Keyword(s):  
Risk Factors ◽  
Muscle Strength ◽  
Ground Reaction Force ◽  
Knee Flexion ◽  
Injury Risk ◽  
Reaction Force ◽  
Knee Injuries ◽  
Flat Foot ◽  
Lateral Plane ◽  
Muscle Groups

Zapateado is a repetitive percussive footwork in dance. This percussive movement, and the differences in technique, may be risk factors for injury. A survey on zapateado dance students found a rate of 1.5 injuries/1,000 exposures. Knee injuries are more frequent than in Spanish dancers than folkloric dancers. The aim of this research was to study the relationship between technique and ground reaction force between zapateado on Spanish and Mexican folkloric dancers. Ten female dance students (age 22.4 ± 4 yrs), six Spanish dancers and four Mexican folkloric dancers, were considered. Each student performed zapateado with a flat foot, wearing high-heeled shoes during 5 seconds on a force platform. Videotapes were taken on a lateral plane, and knee and hip angles in each movement phase were measured with Dartfish software. Additionally, knee and ankle flexor and extensor strength was measured with a dynamometer. Ground reaction forces were lower for Spanish dancers than Mexican folkloric dancers. Spanish dancers had less knee flexion when the foot contacted to the ground than did Mexican folkloric dancers. On Spanish dancers, the working leg had more motion in relation to hip and knee angles than was seen in folkloric dancers. The ankle extensors were stronger on folkloric dancers, and there were no differences for the other muscle groups. Knee flexion at foot contact and muscle strength imbalance could be risk factors for injuries. It is suggested that the technique in Spanish dance in Mexico be reviewed, although more studies are required to define more risk factors.

scholarly journals The Influence of 24-Hour Sleep Deprivation on the Strength of Lower Limb Muscles in Young and Physically Fit Women and Men

2020 ◽  
Vol 12 (7) ◽  
pp. 2762
Author(s):  
Karolina Kujawa ◽  
Marta Ołpińska-Lischka ◽  
Janusz Maciaszek
Keyword(s):  
Muscle Strength ◽  
Sleep Deprivation ◽  
Statistical Significance ◽  
Control Group ◽  
Education Students ◽  
Lower Limb Muscles ◽  
Physical Education Students ◽  
Flexor Muscles ◽  
And Control ◽  
Experimental Group

The aim of this study was to investigate the influence of 24-h sleep deprivation on the muscle strength of young, healthy and physically fit people. The research material consisted of physical education students. In total, 67 people participated in the study, including 38 women and 29 men. Respondents were divided into an experimental group “E” of 44 persons subjected to 24-h sleep deprivation and a control group “C” of 23 persons. Students completed the Epworth Sleepiness Scale (ESS) measuring daytime sleepiness. Students performed measurements of the maximum strength of knee joint extensor and flexor muscles. Measurements of muscle strength of flexors and extensors of the knee were taken on a UPR-02 A/S chair with Moment II by Sumer software. ANOVA (analysis of variance) was used to determine the significance of differences between experimental “E” and control “C” group. Statistical significance was defined at the level of p ≤ 0.05. Statistically significant differences were observed in the change of strength levels between groups at the strength moments of right (p < 0.05, η2p = 0.16) and left (p < 0.05, η2p = 0.08) knee muscles extensor. Changes in extensor muscle strength are significant for students with left dominant legs.

Magnitude and Reliability of Measurements of Muscle Strength across Trials for Individuals with Mental Retardation

1993 ◽  
Vol 77 (2) ◽  
pp. 643-649 ◽  
Author(s):  
Michael Horvat ◽  
Ron Croce ◽  
Glenn Roswal
Keyword(s):  
Mental Retardation ◽  
Muscle Strength ◽  
Muscle Group ◽  
Extensor Muscle ◽  
Reliable Measure ◽  
Muscle Groups ◽  
Sufficient Magnitude ◽  
Individuals With Mental Retardation

The purpose of this investigation was to examine the magnitude and reliability of strength measures on the Nicholas Manual Muscle Tester for individuals with mental retardation. 17 subjects were given six trials with the dominant and nondominant flexor and extensor muscle groups. No significant differences were found between dominant and nondominant muscle groups by side or by muscle group. Interclass correlations ranged from .96 to .98 for six and three trials, respectively. It was concluded that the test was appropriate for reliably assessing strength in this population and that these individuals can achieve a sufficient magnitude on three trials for a reliable measure of strength.

A cross-sectional study of muscle strength and mass in 45- to 78-yr-old men and women

1991 ◽  
Vol 71 (2) ◽  
pp. 644-650 ◽  
Author(s):  
W. R. Frontera ◽  
V. A. Hughes ◽  
K. J. Lutz ◽  
W. J. Evans
Keyword(s):  
Muscle Strength ◽  
Peak Torque ◽  
Cross Sectional Study ◽  
Fat Free Mass ◽  
Knee Extensors ◽  
Cross Sectional ◽  
Men And Women ◽  
Age Related ◽  
Muscle Groups ◽  
Old Men

The isokinetic strength of the elbow and knee extensors and flexors was measured in 200 healthy 45- to 78-yr-old men and women to examine the relationship between muscle strength, age, and body composition. Peak torque was measured at 60 and 240 degrees/s in the knee and at 60 and 180 degrees/s in the elbow by use of a Cybex II isokinetic dynamometer. Fat-free mass (FFM) was estimated by hydrostatic weighing in all subjects, and muscle mass (MM) was determined in 141 subjects from urinary creatinine excretion. FFM and MM were significantly lower (P less than 0.001) in the oldest group. Strength of all muscle groups at both testing speeds was significantly (P less than 0.006) lower (range 15.5–26.7%) in the 65- to 78- than in the 45- to 54-yr-old men and women. When strength was adjusted for FFM or MM, the age-related differences were not significant in all muscle groups except the knee extensors tested at 240 degrees/s. Absolute strength of the women ranged from 42.2 to 62.8% that of men. When strength was expressed per kilogram of MM, these gender differences were smaller and/or not present. These data suggest that MM is a major determinant of the age- and gender-related differences in skeletal muscle strength. Furthermore, this finding is, to a large extent, independent of muscle location (upper vs. lower extremities) and function (extension vs. flexion).

scholarly journals Association between walking and strength of lower limbs after chronic stroke

2020 ◽  
Vol 27 (3) ◽  
pp. 131-138
Author(s):  
Brenno Belchior Cordeiro Silva ◽  
Iza de Faria-Fortini ◽  
Pollyana Helena Vieira Costa ◽  
Camila Torriani-Pasin ◽  
Janaine Cunha Polese
Keyword(s):  
Muscle Strength ◽  
Lower Limb ◽  
Walking Speed ◽  
Chronic Stroke ◽  
Community Dwelling ◽  
Lower Limbs ◽  
Average Strength ◽  
Paretic Side ◽  
The Difference ◽  
Muscle Groups

Certain muscle groups strength directly influence walking speed (WS), and the lower strength of the paretic side is significantly associated with lower WS of individuals after stroke. Studies that have investigated the association between the average of lower limb strength and the WS in individuals are scarce. Therefore, it is important to determine whether the strength could explain walking performance due to some muscle weakness could be compensated by the strength of others, mainly because all muscles act in group, not isolated. Objective: To investigate the association between WS and lower limbs muscle strength, and to identify whether an individual muscle group or the average strength of lower limb would best predict WS and walking speed reserve (WSR) in individuals with stroke. Methods: Sixty-four community-dwelling individuals with chronic stroke have their maximum isometric strength (hip flexors/extensors/abductors, knee flexors/extensors, and ankle dorsiflexors/plantarflexors) and self-selected and fast WS (10m walk test) measured. WSR was considered as the difference between the fast and self-selected speed. Results: Average strength of the paretic limb accounted for 19% and 20% of the variance in self-selected and fast WS, respectively. Plantarflexor strength of the paretic, knee and hip flexors of the non-paretic side explained alone 27% of the WSR scores and plantarflexor strength of the paretic side alone explained 15%.Conclusion: Average muscle strength of the paretic side contributed to self-selected and fast WS. Plantarflexor strength of the paretic side, knee and hip flexors of the non-paretic side contributed with the WSR of chronic stroke individuals.

scholarly journals FORCE-VELOCITY RELATIONSHIP OF LEG EXTENSORS OBTAINED FROM THREE DIFFERENT TYPES OF LOAD

2018 ◽  
Vol 15 (3) ◽  
pp. 467
Author(s):  
Marko Ćosić ◽  
Saša Đurić ◽  
Milena Živković ◽  
Aleksandar Nedeljković
Keyword(s):  
Concurrent Validity ◽  
Isometric Force ◽  
Maximal Velocity ◽  
Muscle System ◽  
Different Types ◽  
Force Velocity ◽  
Muscle Groups ◽  
Leg Extensors ◽  
Relationship Of ◽  
The Impact

The first aim of this study was to evaluate the shape of force-velocity (F-V) relationships in case of gravitational (W), inertial (I) and combined (W+I) type of load assessed from squat jump (SJ) performed on a modified Smith machine. The second aim was to determine whether there were differences between the same parameters (maximal force, F0; maximal velocity, V0; maximal power, P0) obtained from linear F-V relationship among three different loads. The third aim was to evaluate the concurrent validity of the parameters F0 obtained from different types of load in SJ, with maximum isometric force in squat (Fiso), as well as one repetition maximum in squat (1RM). Fifteen male participants were tested in SJ with three different types of load, squat for obtaining 1RM and isometric squat for obtaining the Fiso. The observed F-V relationships were exceptionally strong and approximately linear (median r ≥ 0.98) independently of used load. The differences between same parameters of different types of load were determined in parameters F0 and V0, while there were no differences between P0. Regarding third aim, concurrent validity for F0 showed to be moderate to high and significant in all 3 types of load (r ≥ 0.56), except between F0 and Fiso in W type of load, where it was non-significant (r ≥ 0.47). The significance of the study reflects in better understanding of the mechanisms of the functioning of muscle system in case of different types of load. Future studies should investigate the impact of different types of load to kinetic and kinematic parameters in case of different motoric tasks and muscle groups.

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