scholarly journals Morphology of the Patellar Tendon and the Contractility Response of the Quadriceps: Symmetry and Gender Analysis

2021 ◽  
Vol 18 (10) ◽  
pp. 5309
Author(s):  
Pablo Abián ◽  
Fernando Martínez ◽  
Fernando Jiménez ◽  
Javier Abián-Vicén
Keyword(s):  
Patellar Tendon ◽  
Rectus Femoris ◽  
Quadriceps Strength ◽  
Isometric Strength ◽  
Knee Extensors ◽  
Isokinetic Strength ◽  
Gender Analysis ◽  
Physically Active ◽  
Absolute Strength ◽  
And Gender

The purpose of the study was to describe the differences between the dominant and non-dominant leg regarding contractility response and quadriceps strength and the morphology and stiffness of the patellar tendon (PT) in a group of physically active men and women. Fifty physically active subjects (36 men and 14 women) were evaluated for morphology and stiffness of the PT, contractility response of the rectus femoris of the quadriceps, isometric strength of the quadriceps and hamstrings, and isokinetic strength (concentric and eccentric) at 60°/s of the knee extensors. The measurements were made on the subject’s dominant and non-dominant leg. The men showed a greater thickness of the PT in both legs compared to the women. Regarding the contractility response, the women recorded a 10.1 ± 16.2% (p = 0.038) greater contraction time (ct) in the dominant versus the non-dominant leg and the men recorded 11.9% (p = 0.040) higher values in the dominant leg compared to the women. In all the absolute strength measurements the men recorded higher values (p < 0.05) than the women, however, when the values were normalised with respect to the muscle mass of the leg these differences disappeared. The dominant leg showed values of isometric strength and eccentric strength at 60°/s (p < 0.05) greater than the non-dominant leg. The reference values provided in this study of the knee extensors and PT may be useful for detecting possible muscular or tendinous anomalies.

Spatial muscle activation patterns during different leg exercise protocols in physically active adults using muscle functional MRI: a systematic review

2020 ◽  
Vol 129 (4) ◽  
pp. 934-946
Author(s):  
Katherine Dooley ◽  
Suzanne J. Snodgrass ◽  
Peter Stanwell ◽  
Samantha Birse ◽  
Adrian Schultz ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Assessment Tool ◽  
Meta Analysis ◽  
Lumbar Vertebra ◽  
Rectus Femoris ◽  
Physically Active ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Research Questions ◽  
Active Adults

An emerging method to measure muscle activation patterns is muscle functional magnetic resonance imaging (mfMRI), where preexercise and postexercise muscle metabolism differences indicate spatial muscle activation patterns. We evaluated studies employing mfMRI to determine activation patterns of lumbar or lower limb muscles following exercise in physically active adults. Electronic systematic searches were conducted until March 2020. All studies employing ≥1.5 Tesla MRI scanners to compare spatial muscle activation patterns at the level of or inferior to the first lumbar vertebra in healthy, active adults. Two authors independently assessed study eligibility before appraising methodological quality using a National Institutes of Health assessment tool. Because of heterogeneity, findings were synthesized without meta-analysis. Of the 1,946 studies identified, seven qualified for inclusion and pertained to hamstring ( n = 5), quadriceps ( n = 1) or extrinsic foot ( n = 1) muscles. All included studies controlled for internal validity, with one employing assessor blinding. MRI physics and differing research questions explain study methodology heterogeneity. Significant mfMRI findings were: following Nordic exercise, hamstrings with previous trauma (strain or surgical autograft harvest) demonstrated reduced activation compared with unharmed contralateral muscles, and asymptomatic individuals preferentially activated semitendinosus; greater biceps femoris long head to semitendinosus ratios reported following 45° hip extension over Nordic exercise; greater rectus femoris activation occurred in “flywheel” over barbell squats. mfMRI parameters differ on the basis of individual research questions. Individual muscles show greater activation following specific exercises, suggesting exercise specificity may be important for rehabilitation, although evidence is limited to single cohort studies comparing interlimb differences preexercise versus postexercise.

scholarly journals Knee Muscle Strength Recovery in the Early Period After ACL Reconstruction

2014 ◽  
Vol 2 (11_suppl3) ◽  
pp. 2325967114S0014
Author(s):  
Gulcan Harput ◽  
Hasan Erkan Kılınc ◽  
Hamza Özer ◽  
Gül Baltacı ◽  
Carl G. Mattacola
Keyword(s):  
Acl Reconstruction ◽  
Early Period ◽  
Quadriceps Strength ◽  
Isometric Strength ◽  
Time Points ◽  
Hamstring Muscles ◽  
Significant Difference ◽  
Isometric Torque ◽  
Over Time ◽  
Time Point

Objectives: The aim of this study was to investigate quadriceps and hamstrings isometric strength at 4, 8 and 12 week time points following ACL Reconstruction (ACLR) and to document the strength changes of these muscles over time. The primary hypothesis was that there would be significant increases in quadriceps and hamstring muscle strengths between the 4th, 8th and 12th weeks following ACLR. The secondary hypothesis was that the quadriceps index would be higher than hamstring index at 12th week after ACLR. Methods: Thirty patients (Mean ± SD [age, 29.1±2.3yrs; weight, 77.3±13.2kg; height, 172.1±7.1cm; BMI, 21.2±3.5kg/m2, time to surgery: 7.1±7.2 months]) who underwent ACLR with Hamstring Tendon Autograft (HTG) were enrolled in this study. The isometric strength of quadriceps and hamstring muscles was measured on an isokinetic dynamometer at 60° knee flexion angle at 4th, 8th and 12th weeks after surgery. The recovery of quadriceps and hamstring muscles strength following rehabilitation was expressed as a Quadriceps Index (QI) and Hamstring Index (HI) and calculated with the following formula:[(maximum voluntary isometric torque of the involved limb / maximum voluntary isometric torque by uninvolved limb) × 100]. Torque output of the involved and uninvolved limbs and quadriceps and hamstring indexes were used for the statistical analysis. A repeated measures of ANOVA was used to determine the strength changes of quadriceps and hamstrings over time. Results: Quadriceps and Hamstrings strengths significantly increased over time for both involved (Quadriceps: F (2,46)=58.3, p<0.001, Hamstring: F (2,46)=35.7, p<0.001) and uninvolved limb (Quadriceps: F(2,46)=17.9, p<0.001, Hamstring: F(2,46)=56.9, p=0.001 ). Quadriceps strength was higher at 12th week when compared to the 8 and 4 week time points for the involved limb (p<0.001), and it was higher at 8th week when compared to 4 week time point for the involved limb (p<0.001). For the uninvolved limb, quadriceps strength was also higher at 12th week when compared to the 8 (p=0.02) and 4 week time point (p<0.001), and higher at 8 week when compared to the 4 week time point (p=0.02). Hamstring strength was higher at 12 week when compared to the 8 and 4 week time points (p<0.001) and it was higher at 8 week when compared to 4 week time point for the involved limb (p<0.001). For the uninvolved limb hamstring strength was also higher at 12 week when compared to 4 week time point (p=0.01). There was no significant difference between the 4 and 8 week time points (p>0.05) or between the 8 and 12 week time points (p=0.07). Quadriceps and hamstring indexes significantly changed from 4th weeks (QI:57.9, HI:54.4 ) to 8th weeks (QI:78.8, HI:69.9 ) and from 8th weeks to 12th weeks (QI:82, HI:75.7 ) (p<0.001); however, there was no difference between indexes at the 12-week time point (p=0.17). Conclusion: Isometric strength of quadriceps and hamstring muscles for the involved and uninvolved limb increased during the early period of ACLR. The results of this study could be a baseline for clinicians while prescribing a rehabilitation protocol for ACLR patients with HTG to better appreciate expected strength changes of the muscles in the early phase.

scholarly journals Kinesio Taping Does Not Alter Quadriceps Isokinetic Strength and Power in Healthy Nonathletic Men: A Prospective Crossover Study

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Paweł Korman ◽  
Anna Straburzyńska-Lupa ◽  
Radosław Rutkowski ◽  
Jakub Gruszczyński ◽  
Jacek Lewandowski ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Knee Extensors ◽  
Isokinetic Strength ◽  
Acute Effects ◽  
Isokinetic Dynamometer ◽  
Mean Power ◽  
Concentric Contractions ◽  
Kinesio Taping

Objectives. The effects of Kinesio Taping (KT) on muscular performance remain largely unclear. This study aimed to investigate the acute effects of KT on the maximum concentric and eccentric quadriceps isokinetic strength.Study Design. This is a single-blinded, placebo crossover, repeated measures study.Methods. Maximum isokinetic concentric/eccentric extension torque, work, and power were assessed by an isokinetic dynamometer without taping (NT) and with KT or placebo taping (PT) in 17 healthy young men. Repeated measures one-way analysis of variance (ANOVA) was used for statistical analyses.Results. Testing concentric contractions at 60°/s or 180°/s isokinetic speed, no significant differences in peak torque (Nm), total work (J), or mean power (W) were noted among the application modes under different conditions. Testing eccentric contractions at 30°/s or 60°/s isokinetic speed, no significant differences in mentioned parameters were noted, respectively. KT on the quadriceps neither decreased nor increased muscle strength in the participants.Conclusion. KT application onto the skin overlying the quadriceps muscle does not enhance the strength or power of knee extensors in healthy men.

Women in Low Status Part-Time Jobs: A Class and Gender Analysis

2000 ◽  
Vol 4 (4) ◽  
pp. 152-170 ◽  
Author(s):  
Tracey Warren
Keyword(s):  
Life Cycle ◽  
Social Contexts ◽  
Gender Analysis ◽  
Working Lives ◽  
Lower Status ◽  
Time Work ◽  
Part Time ◽  
Gender Based ◽  
And Gender ◽  
Part Time Work

Why, given all the problems associated with part-time employment in Britain, do women work part-time at all? Does the answer to this question lie in gender-based explanations which focus on womenís caring responsibilities? This paper addresses these issues by focusing on the relative experiences of the largest group of part-timers, women working in low status occupations. It is concluded that a gender-informed analysis of womenís part-time employment is clearly vital, but an awareness of further dimensions of social inequality is required if we are to understand diversity amongst part-timers. Relative to full-timers, part-timers are similar in their life-cycle positions, their marital status and motherhood status. However, incorporating a class analysis shows that part-timers in lower status jobs stand apart in that they are disproportionately likely to have been brought up in working class households and, as adults, they are more likely to be living in very low waged households with partners who are also in low paid manual occupations. It is concluded that women go into the lowest status part-time jobs in specific social contexts and, as a result, we cannot lump together into one unified group, women working part-time in manual and higher status occupations, and then talk sensibly about part-time work and its impact on women. It is essential to examine the interaction of gender and class inequalities to better understand these womenís working lives.

scholarly journals Regional and muscle-specific adaptations in knee extensor hypertrophy using flywheel versus conventional weight-stack resistance exercise

2019 ◽  
Vol 44 (8) ◽  
pp. 827-833 ◽  
Author(s):  
Tommy R. Lundberg ◽  
Maria T. García-Gutiérrez ◽  
Mirko Mandić ◽  
Mats Lilja ◽  
Rodrigo Fernandez-Gonzalo
Keyword(s):  
Resistance Exercise ◽  
Muscle Hypertrophy ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Knee Extensors ◽  
Cross Sectional ◽  
Proximal Site ◽  
Before And After

This study compared the effects of the most frequently employed protocols of flywheel (FW) versus weight-stack (WS) resistance exercise (RE) on regional and muscle-specific adaptations of the knee extensors. Sixteen men (n = 8) and women (n = 8) performed 8 weeks (2–3 days/week) of knee extension RE employing FW technology on 1 leg (4 × 7 repetitions), while the contralateral leg performed regular WS training (4 × 8–12 repetitions). Maximal strength (1-repetition maximum (1RM) in WS) and peak FW power were determined before and after training for both legs. Partial muscle volume of vastus lateralis (VL), vastus medialis (VM), vastus intermedius (VI), and rectus femoris (RF) were measured using magnetic resonance imaging. Additionally, quadriceps cross-sectional area was assessed at a proximal and a distal site. There were no differences (P > 0.05) between FW versus WS in muscle hypertrophy of the quadriceps femoris (8% vs. 9%), VL (10% vs. 11%), VM (6% vs. 8%), VI (5% vs. 5%), or RF (17% vs. 17%). Muscle hypertrophy tended (P = 0.09) to be greater at the distal compared with the proximal site, but there was no interaction with exercise method. Increases in 1RM and FW peak power were similar across legs, yet the increase in 1RM was greater in men (31%) than in women (20%). These findings suggest that FW and WS training induces comparable muscle-specific hypertrophy of the knee extensors. Given that these robust muscular adaptations were brought about with markedly fewer repetitions in the FW compared with WS, it seems FW training can be recommended as a particularly time-efficient exercise paradigm.

scholarly journals Profil izokinetickej sily extenzorov a flexorov kolena u mladých futbalových hráčov

2012 ◽  
Vol 6 (1) ◽  
pp. 53-60
Author(s):  
Tomáš Malý ◽  
František Zahálka ◽  
Lucia Malá ◽  
Jaroslav Teplan
Keyword(s):  
Angular Velocity ◽  
Research Group ◽  
Eccentric Contraction ◽  
Baseline Data ◽  
Soccer Players ◽  
Knee Extensors ◽  
Isokinetic Strength ◽  
Concentric Contraction ◽  
Angular Velocities

Th e aim of the study was to present isokinetic strength profi le of knee fl exors and extensors during concentric contraction in young soccer players. Particularly in knee fl exors was evaluated also strength during eccentric contraction. Research group was state from young soccer players U17 category (n=19, age=16,4±0,3 years). All of them are the participant of highest junior soccer league. Isokinetic strength was evaluated by isokinetic dynamometr Cybex Humac Norm in following angular velocities: 30, 60 and 120°/s in eccentric contraction and 60, 180, 240 and 300 °/s in concentric contraction. Th e results did not revealed signifi cant diff erences at three diff erent speed levels of knee fl exors’ strength during eccentric contraction (p>0,05). Regarding the concentric contraction we found signifi cant diff erences for strength production depending on angular velocity for both knee extensors and fl exors (p<0,01). Knee fl exors generated more strength during eccentric contraction compared to concentric contraction. Th e strength profi les developed in the present study can assist in the establishment of baseline data in young soccer players or for comparison values with other researchers.

scholarly journals Gender Analysis in Indonesia's Legislation Regarding Political Laws

Lentera Hukum ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 337
Author(s):  
Erlina Erlina ◽  
Nika Normadilla
Keyword(s):  
Political Parties ◽  
Social Life ◽  
Equal Opportunity ◽  
Gender Mainstreaming ◽  
Gender Analysis ◽  
Election Law ◽  
The Government ◽  
And Gender ◽  
Electoral Law ◽  
Gain Access

This paper examines Indonesia's current legislation on politics, inter alia, Political Parties Law, Election Law, and Parliament Law, by using gender analysis. This paper considers how these laws ensure equitable access, participation, control, and benefits for men and women. Under the justice and gender equality approach, these laws are not optimal, especially under the control and benefit indicators. In this context, Political Parties Law contributes more to the indicator of access, while Electoral Law provides access and participation indicators. At the same time, Parliament Law is expected to contribute the most to the control and benefit indicators. However, it is regrettable that Parliament Law does not comply with these two indicators. Also, the Constitutional Court's interpretation was not followed in a series of legislative revisions of Parliament Law. Therefore, the gender approach in the legislative revision of these three laws should be encouraged to benefit from social life with more just and non-discriminatory. It should also provide equal opportunity for every citizen to gain access, participatory rights, control, and benefits in development. Hence, it is inevitable to the importance of the government commitment in gender mainstreaming in policy, harmonization, and synchronization of laws and regulations. KEYWORDS: gender justice and equality, political laws, women's representation.

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