scholarly journals Isokinetic Strength Profile of Elite Female Handball Players

2015 ◽  
Vol 49 (1) ◽  
pp. 257-266 ◽  
Author(s):  
Zuzana Xaverova ◽  
Johannes Dirnberger ◽  
Michal Lehnert ◽  
Jan Belka ◽  
Herbert Wagner ◽  
...  

Abstract Systematic assessment of muscle strength of the lower extremities throughout the annual training cycle in athletes is crucial from a performance perspective for the optimization of the training process, as well as a health perspective with regard to injury prevention. The main aim of the present study was to determine isokinetic muscle strength of the knee flexors and extensors in female handball players at the beginning of a preparatory period and to assess whether there were any differences between players of different performance levels. The performance level was expressed by means of membership of the Women’s Junior National Handball Team (JNT, n=8) or the Women’s National Handball Team (NT, n=9). The isokinetic peak torque during concentric and eccentric single-joint knee flexion and extension was measured at angular velocities of 60, 180, 240°/s (concentric) and 60°/s (eccentric). The Mann- Whitney test showed no significant differences in the peak torques or ipsilateral ratios between the two groups. The bilateral force deficit (BFD) for concentric extension at 240°/s was significantly higher in the JNT compared with the NT (p=0.04; d=1.02). However, the results of individual evaluation show that the BFD was more frequent in the NT in most measurements. A high BFD was evident in the eccentric mode in both groups highlighting a need for particular strengthening. With regard to low strength ratios a prevention programme should be suggested for both observed groups of professional female handball players to reduce the risk of injury.

2017 ◽  
Vol 14 (2) ◽  
pp. 2111
Author(s):  
Tuğba Kocahan ◽  
Bihter Akınoğlu ◽  
Çağlar Soylu ◽  
Necmiye Ün Yıldırım ◽  
Adnan Hasanoğlu

Purpose: The aim of this study is to determine the isokinetic muscle strength profile of knee flexor and extensor muscles of visually impaired long distance running athletes and compare them with the literature.Methods: The study consisted of 7 male visually impaired long distance running athletes aged between 19-28 (means 24,14±3,23), who complied with the criteria and voluntarily participated in the study. İsokinetic measurement was performed with Isomed 2000® device. İn isokinetic evaluation, maximal muscle strength, muscle strength ratios, percentage of right-left strength difference ratio of knee flexors and extensors were recorded. İsokinetic testing protocol; before the test all athletes performed the knee flexion and extension isokinetic test with the 5 repeating at 90 º/sec as a warm-up and for comprehenting the test. Then, knee flexion and extension concentric-concentric strength measurements were performed with the 5 repeating at 60 º/sec and with the 15 repeating at 180 º/sec with the angle between 90 degrees of knee flexion and 10 degrees of knee extension. The evaluations were performed bilaterally, first dominant side and after 3 minutes non dominant side was evaluated.Results: The H / Q peak torque ratio of the athletes is 53.55% for the dominant side and 55.47% for the non-dominant side at 60º / sec. velocity while 59.05% for the dominant side and 61.34% for the non-dominant side at 180º / sec. velocity. When the H / Q peak torque ratio of the athletes was compared between dominant and non-dominant sides, there was no difference in both angular velocities (p>0.05). Knee flexion and extension isokinetic muscle strength’s difference were determined lower than %10 for both angular angles when compared to the asymmetry of the right and left extremities. It was found that this was in accordance with the literature and there was no asymmetry between the right and left sides.Conclusion: In visually impaired long distance runners, having H/Q ratio lower than normal borders against knee flexors for both sides at 180°/sec. angular velocity poses a risk for injuries. In terms of prevention of sports injuries, it is necessary for the athletes to maintain muscle force balance which is specific to each angular velocity and to exercise with sports-specific exercises.Extended English abstract is in the end of PDF (TURKISH) file.ÖzetAmaç: Bu çalışmanın amacı görme engelli uzun mesafe atletizm sporcularının diz fleksör ve ekstansör kaslarının izokinetik kas kuvvet profilini belirlemek ve literatürdeki bilgilerle karşılaştırmaktır.Method: Çalışmamıza; 19-28 (Ort. 24,14±3,23) yaş aralığında 7 erkek görme engelli uzun mesafe atletizm sporcusu dâhil edildi. İzokinetik kas kuvveti Isomed 2000® cihazı ile değerlendirildi. İzokinetik değerlendirmede diz fleksör ve ekstansörlerinin maksimum kas kuvveti, kas kuvvet oranları, sağ-sol kuvvet farkı oranı yüzdesi kaydedildi. Değerlendirmede 90-10 º fleksiyon açılarında konsantrik-konsantrik kuvvet ölçümü yapıldı. İzokinetik test protokolü olarak; 5 tekrarlı 90º/sn. hızla testi anlama ve submaksimal ısınma hareketinden sonra, 5 tekrarlı 60º/sn. hızla ve 15 tekrarlı 180º/sn. hızla maksimal diz fleksiyon ve ekstansiyon hareketleri yaptırıldı. Değerlendirmeler bilateral olarak gerçekleştirildi ve öncelikle dominant taraf, 3 dk sonra non-dominant taraf değerlendirildi.Bulgular: Sporcuların H/Q peak tork oranı 60º/sn. hızda dominant taraf için % 53.55, non-dominant taraf için % 55.47 bulunurken 180º/sn. hızda dominant taraf için % 59.05, non-dominant taraf için % 61.34 bulundu. H/Q peak tork oranı dominant ve non-dominant taraf arasında karşılaştırıldığında her iki açısal hızda da farklılık bulunmadı (p>0,05). Sağ ve sol ekstremiteler asimetri açısından karşılaştırıldığında diz fleksiyon ve ekstansiyon izokinetik kas kuvveti farkının her iki açısal hızda da %10 un altında olduğu belirlendi. Bu durumun literatür ile uyumlu olduğu ve sağ-sol taraf arasında bir asimetri olmadığı sonucuna varıldı.Sonuç: Çalışmamız sonucunda Görme engelli uzun mesafe koşucularında 180º/sn. açısal hızda H/Q oranının normal sınırlardan daha düşük ve her iki tarafta diz fleksörleri aleyhinde olması yaralanma açısından risk oluşturmaktadır. Spor yaralanmalarının önlenmesi açısından sporcuların her açısal hıza özgü olan kas kuvvet dengesinin korunması ve spora özgü egzersizlerle çalıştırılması gereklidir.


Author(s):  
Omer Ayik ◽  
Mehmet Demirel ◽  
Fevzi Birisik ◽  
Ali Ersen ◽  
Halil I. Balci ◽  
...  

AbstractThe present randomized controlled study aims to evaluate whether tourniquet application during total knee arthroplasty (TKA) has an effect on (1) thigh muscle strength (quadriceps and hamstring muscle strength) and (2) clinical outcomes (postoperative knee range of motion [ROM], postoperative pain level, and Knee Society Score [KSS]). The effects of tourniquet application during TKA were investigated in 65 patients randomly allocated to one of two groups: TKA with a tourniquet and TKA without a tourniquet. Patients in both groups were comparable in terms of the demographic and clinical data (p > 0.05 for age, number of patients, sex, radiographic gonarthrosis grade, American Society of Anesthesiologists [ASA] classification, and body mass index [BMI]). All patients in both groups were operated by the same surgeon using one type of prosthesis. Isokinetic muscle strength (peak torque and total work) of knee extensors (quadriceps) and flexors (hamstrings) was measured in Newton meters (Nm) using a CYBEX 350 isokinetic dynamometer (HUMAC/CYBEX 2009, Stoughton, MA). The combined KSS (knee score + function score), visual analog scale (VAS), and knee ROM were measured preoperatively and at 1 and 3 months postoperatively to evaluate clinical outcomes. There were no significant differences between the two groups in preoperative and postoperative values of isokinetic muscle strength (peak torque and total work) and aforementioned clinical outcomes (p < 0.05). The present study has shown that quadriceps strength and clinical outcomes were not improved in the early postoperative period (3 months) when a tourniquet was not used during TKA.


2018 ◽  
Vol 63 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Zuzana Gonosova ◽  
Petr Stastny ◽  
Jan Belka ◽  
Lucia Bizovska ◽  
Michal Lehnert

Abstract Monitoring seasonal variations in strength performance and the relative risk of injury indicators related to strength of hamstring (H) and quadriceps (Q) in female elite athletes is beneficial for the training process. The aim of this study was to examine and compare the level of muscle strength, the conventional ratio (HCONC/QCONC) as well as two functional and strength ratios reflecting the movement of knee extension (HECC/QCONC) and flexion (HCONC/QECC), and the bilateral percentage strength deficit (BSD) in elite female handball players. The concentric and eccentric isokinetic peak torque was measured at an angular velocity of 60°/s on three occasions (in-season cessation, 4 weeks of rest followed by 4 weeks of individual conditioning and 6 weeks of group conditioning) in eleven female handball players (age: 23.1 ± 3.5 years, body height: 1.73 ± 0.6 m). According to ANOVA results, the BSD of H muscles in the concentric mode decreased between the in-season cessation and the end of the pre-season, and HCONC/QCONC increased at the beginning of the pre-season and at the end of the pre-season in comparison with inseason cessation measurement. The effect size analyses showed that the off-season rest followed by 10 weeks of the conditioning programme increased Q and H strength in comparison with the previous season with a large effect. Coaches should include progressive conditioning in the pre-season phase to decrease the bilateral strength deficit and to support further conditioning development.


2014 ◽  
Vol 42 (1) ◽  
pp. 175-185 ◽  
Author(s):  
Michal Lehnert ◽  
Zuzana Xaverová ◽  
Mark De Ste Croix

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.


2017 ◽  
Vol 5 (2_suppl2) ◽  
pp. 2325967117S0007
Author(s):  
Bihter Akınoğlu ◽  
Tuğba Kocahan ◽  
Necmiye Ün Yıldırım ◽  
Çağlar Soylu ◽  
Adnan Hasanoğlu

Aim: The purpose of this study is to determine the relationship between isokinetic wrist muscle strenght and grip strength in tennis players aged between 12-14. Methods: This study was carried out with the participation of 9 (3 female and 6 male) tennis players aged between 12-14 (means 13,22±0,83). Weight, height, body mass index and dominant extremity of the players were recorded. İsokinetic measurement was performed with Isomed 2000® device. İsokinetic testing protocol; before the test all players performed the wrist flexion and extension isokinetic test with the 5 repeating at 90 º/sec as a warm-up and for comprehenting the test. Then, wrist flexion and extension concentric-concentric strength measurements were performed with the 5 repeating at 60 º/sec and with the 15 repeating at 240 º/sec with the angle between 50 degrees of wrist flexion and 60 degrees of wrist extension and peak torque values were recorded. Standard Jamar® Dynamometer was used for grip strength measurements. Grip strenght was performed firstly in sitting position, which is the position of standard measurement. Secondly, in standing position, the elbow was in full ekstansion and the forearm was in neutral position. Thirdly, in standing position the wrist was positioned approximately 30° extension and 10° ulnar deviation. This test was repeated 3 times in all test position and the mean of three scores were recorded. Firstly, the dominant hand, then the non-dominant hand was evoluated. They were allowed to rest for 30 seconds between each grip measurement. Correlation between peak tork of isokinetic muscle strenght and grip strength was done having been used Spearman correlation test. Findings: It was determined that there was a significant positive relation between wrist flexion-extension isokinetic muscle strength and grip strenght in tennis players aged between 12-14. Clinically, grip strength measured in the standard sitting position was found more as compared to the other positions but these values were not statistically significant (p>0,05). Accordingly, grip strength measured in the standard sitting position correlated with much more of the parameters which we evaluated for isokinetic muscle strength comparing to grip strenght measured in the other two positions (p<0,05). Results: It was concluded that isokinetic muscle strength of wrist can be affected by grip strength, therefore measurement needs to be done in the sitting position which maximum grip strength may reveal. [Table: see text]


2009 ◽  
Vol 34 (4) ◽  
pp. 609-615 ◽  
Author(s):  
Bareket Falk ◽  
Charlotte Usselman ◽  
Raffy Dotan ◽  
Laura Brunton ◽  
Panagiota Klentrou ◽  
...  

Muscle strength and activation were compared in boys and men during maximal voluntary elbow flexion and extension contractions. Peak torque, peak rate of torque development (dτ/dτmax), rate of muscle activation, and electromechanical delay (EMD) were measured in 15 boys (aged 9.7 ± 1.6 years) and 16 men (aged 22.1 ± 2.8 years). During flexion, peak torque was significantly lower in boys than in men (19.5 ± 5.8 vs. 68.5 ± 11.0 Nm, respectively; p < 0.05), even when controlling for upper-arm cross-sectional area (CSA), and peak electromyography activity. Boys also exhibited a lower normalized dτ/dτmax (7.2 ± 1.7 vs. 9.5 ± 1.6 (Nm·s–1)·(Nm–1), respectively; p < 0.05) and a significantly longer EMD (75.5 ± 28.4 vs. 47.6 ± 17.5 ms, respectively). The pattern was similar for extension, except that group differences in peak torque were no longer significant when normalized for CSA. These results suggest that children may be less able to recruit or fully utilize their higher-threshold motor units, resulting in lower dimensionally normalized maximal torque and rate of torque development.


2017 ◽  
Vol 5 (2_suppl2) ◽  
pp. 2325967117S0006
Author(s):  
Bihter Akınoğlu ◽  
Tuğba Kocahan ◽  
Necmiye Ün Yıldırım ◽  
Çağlar Soylu ◽  
Ufuk Apur ◽  
...  

Aim: The aim of this study was to compare isokinetic muscle strength of wrist flexor and extensor muscles in paralympic athletes. Methods: This study was carried out with the participation of 9 (4 females and 5 males) wheelchair (WC) table tennis players aged 24+3 and 8 male WC basketball players aged 26+3, met the criteria and voluntarly participate in the study. Body weight, height, body mass index and dominant extremity of the study subjects were recorded. İsokinetic measurement were performed with Isomed 2000® device. İsokinetic testing protocol; before the test all players performed the wrist flexion and extension isokinetic test with the 5 repeating at 90º/sec as a warm-up and comprehending the test. Then, wrist flexion and extension concentric-concentric strength measurements were performed with the 5 repeating at 60º/sec and with the 15 repeating at 240º/sec with the angle between 50 degrees of wrist flexion and 60 degrees of wrist extension and peak torque, peak torque/kg values and flexion/extension ratios were recorded. Mann-Whitney U test was used to compare isokinetic muscle strength quantitative variables in athletes. Findings: Isokinetic muscle strength of wrist flexors and extensors was higher in both sides in WC table tennis players with 60º/sec speed (p<0,05). İsokinetic muscle strength of wrist flexors and extensors was higher in both sides in WC basketball players with 240º/sec speed (p<0,05). There was no significant difference statistically between the groups in isokinetic wrist flexion and extansion peak torque/kg ratio in all speeds (p>0,05). Wrist flexion/extension peak torque ratios were similar in both groups. When examining the athletes flexion/extension ratios, wrist extensor muscles were weaker than flexor muscles and flexor muscles were average twice stronger than extensor muscles in both sports ( Table1 ). [Table: see text] Results: We thought that imbalance of muscle strength in the wrist may have occurred because of the use of a WC and requiring the intensive wrist flexors in playing sports. In both groups wrist ekstansor muscles were found to be weaker than wrist flexors and flexor/extensor ratio was found to be imbalance. We believe that all athletes using WC such as WC table tennis and WC basketball players have a strenght imbalance in the muscle of the wrist and as a result, this situation will increase the possibility of injury. Therefore, our study showed that weakness of wrist extensors and imbalance of muscle stenght should be taken into account in WC athletes in athletic training and exercise programs.


2012 ◽  
Vol 31 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Niyazi Eniseler ◽  
Çağatay Şahan ◽  
Hikmet Vurgun ◽  
Hasan Mavi

Isokinetic Strength Responses to Season-long Training and Competition in Turkish Elite Soccer PlayersThere are not enough studies that describe the isokinetic strength of professional soccer players at high angular velocities. The purpose of this study was to evaluate the seasonal changes in isokinetic strength of Turkish professional soccer players (n=14) over the course of a 24-week soccer season. The isokinetic strength of players who underwent usual soccer training and weekly competition throughout the soccer season was assessed by means of the Biodex System 3 dynamometer with the knee attachment. The peak torque of knee extensor and flexor muscles were measured at angular velocities of 60°/s, 300°/s and 500°/s. Players were tested at the beginning and end of the competitive season. While the first- and second-test measurements did not show significant changes at 60°/s and 300°/s angular velocities, at the end of the training period, players' knee strength changed significantly at 500°/s angular velocities. In addition, the H/Q ratio improved significantly for the dominant as well as non-dominant leg at 500°/s. Significant bilateral strength improvements for knee flexors were also observed at 500°/s. The findings of this study suggest that usual daily soccer training (technical, tactical, power, strength, endurance, flexibility, etc.) and weekly competition might produce changes in knee strength at high angular velocities.


2018 ◽  
Vol 18 (08) ◽  
pp. 1840036 ◽  
Author(s):  
YU-RI KWON ◽  
YOON-HYEOK CHOI ◽  
GWANG-MOON EOM ◽  
JUNGHYUK KO ◽  
JI-WON KIM

A higher fall rate has been reported in elderly women than in elderly men. Muscle strength is one of the key fall risk factors. The aim of this study was to investigate gender differences associated with maximal voluntary hip flexion and extension torque in concentric, isometric and eccentric contractions among the elderly subjects. A total of 20 healthy elderly subjects (10 men and 10 women) participated in this study. A dynamometer was used to measure hip joint torque during various modes of isokinetic contraction in frontal plane. The peak torque was normalized according to each subject’s body mass. Independent [Formula: see text]-tests were conducted to compare elderly women with elderly men. Elderly women exhibited weaker normalized peak torque during flexion and extension compared with elderly men in isometric contraction mode ([Formula: see text]). Eccentric strength of elderly women was significantly lower than in elderly men primarily in hip extension ([Formula: see text]). In contrast, no significant differences were observed in concentric contraction mode between the two genders ([Formula: see text]). These results suggest that the decreased muscle strength per body mass, especially in isometric and eccentric contraction, may be associated with a higher frequency of falls in elderly women than in elderly men. This study suggests the need for effective muscle strength training and intervention for fall prevention in elderly women.


2021 ◽  
Vol 11 (11) ◽  
pp. 4951
Author(s):  
Tuğba Kocahan ◽  
Bihter Akınoğlu ◽  
Ayfer Ezgi Yilmaz ◽  
Thomas Rosemann ◽  
Beat Knechtle

This study aimed to evaluate the intra- and inter-rater reliability of a well-used and a less-used IsoMed-2000 dynamometer for knee flexion and extension peak torque (PT) measurements in a concentric test in athletes. Two IsoMed-2000 isokinetic dynamometers were used, an old one that was well-used and a new one that was less-used. Thirty-seven weight-lifting athletes (12 female, 25 male) were included in this study. Both legs of each athlete were tested twice on each isokinetic dynamometer at 60°/s and 180°/s. The Intraclass Correlation Coefficients (ICC), Standard Error Measurement (SEM), Smallest Detectable Change (SDC), SDC% and 95% limits of agreement were calculated to evaluate the intra- and inter-rater reliability of a well-used and a less-used IsoMed 2000 dynamometer for knee flexion and extension peak torque in athletes. Intra-rater reliability was moderate to excellent (ICCs: 0.516–0.928) for knee muscle strength parameters, and the highest SDC and SEM values were 0.76 N/kg and 0.28 N/kg, respectively. Inter-rater reliability was moderate to excellent (ICCs: 0.519–915) for knee muscle strength parameters, and the highest SDC and SEM values were 0.81 N/kg and 0.29 N/kg, respectively. At least 89.2% of the obtained values of parameters fell within the 95% limits of agreement. Our findings demonstrate the intra and inter-rater reliability of a Well-Used and a Less-Used IsoMed 2000 Dynamometer for Knee Flexion and Extension Peak Torque in Athletes.


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