bluuebunny/crossref_metadata_2025 huggingface dataset:
Side dominance does not affect dynamic control strength ratios in the shoulder
Authors: Gulick Dawn T. , Dustman Chrisa S. , Ossowski Laura L. , Outslay M. Duncan , Thomas Christine P. , Trucano Sean
Published: October 2018

{\it Purpose:} To examine the normal strength relationship between eccentric external rotation (EccER) and concentric internal rotation (ConIR) strength ratios of the shoulder in the dominant and non-dominant extremities of healthy subjects.

{\it Methods:} Fourteen men and sixteen women were tested in the scapular plane using two angular velocities: 90 and 120°/s. The dependent variables were: peak torque (PT), work per repetition (W/rep), and total work (TW) ratios.

{\it Results:} The EccER: ConIR ratio in a non-athletic population was significantly greater (p < 0.05) for the dominant than the non-dominant extremities for PT, W/rep, and TW. There was no significant difference in torque production between the two-isokinetic velocities. W/rep and TW ratios were significantly higher in females than in males. Although PT was not statistically significant, a similar relationship existed (p=0.069).

{\it Conclusion:} In a healthy, non-athletic population, when tested at 90 or 120°/s, the EccER is just slight greater than its ConIR counterpart in women and men alike.
Learning effect in isokinetic testing of ankle invertors and evertors
Authors: Cingel, van E.H.R. , Kleinrensink G.J. , Rooijens P.P.G.M. , Uitterlinden E.J. , Aufdemkampe G. , Stoeckart R.
Published: October 2018

The purpose of this study was to determine whether a motor learning effect exists during concentric isokinetic testing of the ankle invertor and evertor muscles of the dominant and non-dominant leg. Thirty-three subjects aged 22 to 57 years without any experience in isokinetic testing, were randomly assigned to one out of three test velocity groups (30, 60 or 120°/s). Each velocity group consisted of 11 subjects. Invertors and evertors of the dominant and non-dominant leg were tested. All subjects performed five sets of two maximal concentric inversion-eversion movements on a calibrated CYBEX 6000 dynamometer.

For the invertors of the dominant leg at 30 and 120°/s. the mean PKTQ%B the first set. For the evertors of the dominant leg and the invertors and evertors of the non-dominant leg no statistically significant difference was found.

To exclude possible bias of learning effects in concentric isokinetic testing of inversion-eversion muscles, we advise a practice session of two sets of two maximal inversion-eversion movements.
Isokinetic evaluation of the knee extensors and flexors anaerobic capacity
Authors: Tsaklis P.
Published: October 2018

This study focused on the design of an isokinetic test protocol for the evaluation of the anaerobic power-capacity of the knee extensors and flexors, and its validation using the Wingate 30'' anaerobic test. Twenty male track and field, sprint and jumping events athletes aged 17--28 years took part in the study. In the first session evaluation of lower limb anaerobic power took place. Following 48 hours their knee extensors and flexors were tested isokinetically (30 Reps at 240°/sec for 30s). The results have indicated a very high correlation coefficient r=0.927 between the values of the medium power for both tests, while the correlation coefficient between the fatigue indexes was relatively low r=0.485. Thus isokinetic testing of knee musculature could provide a valid measure of the anaerobic capacity of the knee extensors and flexors, particularly with respect to athletes who perform through the anaerobic glycolitic way. On the other hand, isokinetically-based fatigue could not be compared with the more common and is therefore not advisable as an alternative indicator to the Wingate test.
Concentric and eccentric strength of trunk in athletes
Authors: Weissland T. , Voisin P. , Tomaszewski A. , Delahaye H. , Vanvelcenaher J.
Published: October 2018

This Abstract was presented at the Second European Isokinetic Society Congress, Neuromuscular Performance in Research and Clinical Applications, March 15 and 16, 2002, Crans Montana, Switzerland.
The relationship between jumping performance and isokinetic strength of hip and knee extensors and ankle plantar flexors
Authors: Tsiokanos Athanasios , Kellis Eleftherios , Jamurtas Athanasios , Kellis Spiros
Published: October 2018

The purpose of this study was to examine the relationship between vertical jumping performance and isokinetic moment of force of knee extensors, hip extensors and ankle plantar flexors in adult males. Twenty-nine males performed squat and counter movement jumps on an Egrojump device. The peak jumping height and the total work (height × body mass) were used as indicators of vertical jump performance. The subjects also performed three submaximal and three maximal isokinetic efforts of the hip extensors, knee extensors and ankle plantarflexors at angular velocities of 60, 120 and 180°·s $^{-1}$ on Cybex Norm Dynamometer. Pearson's product correlation tests indicated that there was a significant (p<0.05) positive relationship between vertical jumping height and total work with hip and knee extension moments, whereas low correlation coefficients between isokinetic moment of the ankle plantarflexors and jumping performance were found p<0.05). Multiple regression analysis indicated that linear combinations of isokinetic torques accounted for 38% countermovement and squat jumping height variance, respectively. In contrast, regression models using isokinetic torques could predict jumping work accounting for 75% (squat jump) of the variance. The above results indicate that there is a moderate to high relationship between isokinetic knee and hip extension torques and vertical jump performance parameters, especially when jumping height is multiplied by subject's body weight. Furthermore, it appears that when using a linear combination of isokinetic torques from hip and knee joint muscle groups the multiple relationship between isokinetic tests and jumping performance is higher.
Test-retest reliability of an isokinetic muscle endurance test
Authors: Manou V. , Arseniou P. , Gerodimos V. , Kellis S.
Published: October 2018

The purpose of this study was to investigate the test-retest reliability of an isokinetic muscle endurance test. The right legs of twelve healthy males were tested on the Cybex Norm isokinetic dynamometer. The protocol consisted of 40 consecutive concentric knee extensions and flexions, performed maximally at an angular velocity of 120°/s. The subjects performed the test twice, five days apart. Total work, endurance ratio, 50% fatigue work, 50% fatigue time and 50% fatigue repetitions were obtained. A one-way analysis of variance (ANOVA) with repeated measures was used to examine the differences between test and retest values. The reliability coefficient was also established using the ANOVA results. The results indicated that measurements demonstrated high reliability (r>0.819). It could be concluded that the protocol used in the present study can be used to evaluate muscle endurance.
ACL rehabilitation program using a combined isokinetic and isotonic strengthening protocol
Authors: Tsaklis P. , Abatzides G.
Published: October 2018

The purpose of this paper is to present a rehabilitation program following ACL reconstruction. This program consists of isotonic as well as isokinetic muscle strengthening components. Forty-five post-ACL surgery patients took part in this study. They were all male athletes participating in different events. Patients were divided randomly into 3 groups of 15 corresponding to 3 distinct rehabilitation programs which continued for 3 months after surgery. During the first month the groups followed the same paradigm. For the next two months, group A continued the practice by using only isotonic strengthening exercises, group B used exclusively isokinetic strengthening exercises and group C performed a combined program of isokinetic and isotonic exercises. The three groups appear to have improved until the 3rd post operative month, with highly significant pre-post differences in the various measured parameters. However, group C patients achieved the highest outcome scores and therefore our recommendation calls for a mixed isokinetic-isotonic program.
The influence of the range of motion on the isokinetic performances of the knee flexors and extensors
Authors: Croisier J.L. , Voisin P. , Elbouz L. , Forthomme B. , Vanvelcenaher J. , Crielaard J.M.
Published: October 2018

Article without abstract.
Comparative study of two isokinetics dynamometers: CYBEX NORM vs CON-TREX MJ
Authors: Cotte T. , Ferret J.-M.
Published: October 2018

Article without abstract.
Long term isokinetic evaluation of the knee flexor muscles after ACL reconstruction, using gracilis and semitendinosus tendon grafts
Authors: Parisaux J.-M. , Boileau P. , Desnuelle C. , Berg M.
Published: October 2018

Article without abstract.
The effect of eccentric contraction velocity on quadriceps oxygen dynamics
Authors: Okamoto Takanobu , Masuhara Mitsuhiko , Ikuta Komei
Published: October 2018

The purpose of this study was to investigate the effect of eccentric contraction velocity on quadriceps oxygen dynamics. Fifteen healthy male volunteers were tested eccentrically at 60 and 180°/s for a duration of 30 s. A probe for near infrared spectroscopy was placed on the rectus femoris allowing determination of muscle oxygenation (MO) levels and blood volume (BV). Higher MO and BV levels were observed at higher compared to the lower velocity. These results suggest that during eccentric knee extension at slow muscle contraction velocity, mechanical compression directed toward blood vessels is augmented resulting in blood flow disturbances and further evolving into hypoxic state within muscle tissues.
Test-retest reliability of measuring the passive stiffness of the Achilles tendon using ultrasonography
Authors: Mahieu N.N. , Witvrouw E. , Stevens V. , Willems T. , Vanderstraeten G. , Cambier D.
Published: October 2018

The purpose of this study was to examine the test-retest reliability for the real time ultrasonic measurement method that is used to determine the stiffness of the Achilles tendon. Twenty-one healthy men and women aged 20–50 years took part in the study. The subjects underwent three identical test sessions held seven days apart. The lengthening of the tendon during maximal isometric plantar flexion was determined using ultrasonography. A dynamometer was used to measure torque output during isometric plantar flexion. The relationship between the muscle force and the elongation of the tendon was calculated to become a measure of the stiffness of the Achilles tendon. The ICC for the stiffness of the right and the left Achilles tendon was 0.80 and 0.82 respectively, indicating a good reliability. The results demonstrate that this technique is reliable for the evaluation of the elastic properties of the Achilles tendon. This may be clinically important in the assessment of tendon properties.
Physical fitness levels of blind and visually impaired goalball team players
Authors: Çolak Tuncay , Bamaç Belgin , Aydin Mensure , Meriç Bergün , Özbek Aydin
Published: October 2018

The purpose of this study to verify the effect of playing goalball on some measures of motor fitness. One hundred and three children(age13–15 years) with varying degrees of blindness were assessed for motor fitness. All participants were male. The participants underwent motor fitness(balance, handgrip, flexibility, vertical jump, isokinetic concentric peak torque) assessments. There were significant differences between goalball players and non-goalball players regarding many motor fitness components. Non-goalball players were inferior in all motor fitness compared with goalball players. This study suggests that goalball may be considered effective option to improve motor skills in visually impaired children.
Influences of physical activity in stroke patients with hemiplegia on pulse wave velocity
Authors: Murakami Masahito , Kato Junich , Maeda Noriaki , Takahashi Kentarou , Furukawa Hiroshi
Published: October 2018

The objective of this study was three-fold: 1. To measure brachial-ankle PWV (baPWV) in fifteen stroke patients with hemiplegia (9 males and 6 females; 60±10 years old) 2. To examine changes in baPWV due to rehabilitation by physiotherapy; and 3. To evaluate the effects of an increase in physical activities on baPWV.

BaPWV decreased significantly from 1,885±374 before rehabilitation to 1,770±374 cm/sec after rehabilitation (p<0.0005) on the paralyzed side and from 1,714±374 to 1,568±364 cm/sec(p<0.001) on the non-paralyzed side. The serum total cholesterol level did not evidence significant change. The FIM, which represents the degree of functional independence, increased significantly from 52±21 to 75±29 (p<0.0005). A significant positive correlation (r=0.58, p<0.05) was observed between ΔFIM and ΔbaPWV on the paralyzed side.

In stroke patients with motor disorders due to hemiplegia, baPWV was significantly higher on the paralyzed side than on the non-paralyzed side, suggesting a decrease in the arterial extensibility due to motor paralysis. Furthermore, baPWV was improved by rehabilitation, and this improvement was related to an increase in physical activities. It is hence concluded that baPWV may be considered an effective index of the rehabilitation.
The reproducibility of peak isokinetic torque and EMG activity in unfamiliarised subjects on repeated days
Authors: Howatson G. , van Someren K.A.
Published: October 2018

The aim of this investigation was to examine the intra-subject and group reproducibility of isokinetic muscle function testing and the associated surface electromyography (EMG) signal on repeated days testing. Fifteen subjects who were unfamiliar with isokinetic dynamometry completed maximal isokinetic elbow flexor contractions at 60°/s and 210°/s on five consecutive days. Surface electromyography was recorded from the biceps brachii to examine the electrical activity associated with the peak torque. The intra-subject reproducibility was moderate for isokinetic torque: mean coefficient of variation (CV) of 8.93% at 60°/s and 9.14% at 210°/s, however the EMG and EMG:torque ratio were somewhat more variable: mean CV of 15.18% and 18.42% at 60°/s, respectively and 11.97% and 14.50% at 210°/s, respectively. The group reproducibility for all variables at both isokinetic speeds were high with intraclass correlation coefficients ranging from 0.92 and 0.99. In addition, the group CV for isokinetic peak torque, EMG and EMG:torque ratio for both contraction speeds ranged from 1.47% to 5.12%. These results illustrate that individual subjects can show large day-to-day variations in torque and EMG, however when group data are examined, both torque and the associated EMG activity demonstrate high reproducibility. Practitioners should therefore express caution when interpreting longitudinal changes in an individual's isokinetic data.
Isokinetic evaluation of shoulder internal and external rotators concentric strength and endurance in baseball players: Variations from pre-pubescence to adulthood
Authors: Huang Tung-Fu , Wei Shun-Hwa , Jung-Chi Chiu , Hsu Miao-Ju , Chang Hsiao-Yun
Published: October 2018

This study compared the strength and endurance of shoulder internal rotators (IR) and external rotators (ER) among baseball pitchers of four age levels. Eighty baseball pitchers aged 10–23 years participated this study. Strength was assessed by the average peak torque of the middle 3 out of 5 repetitions. Endurance was assessed by thirty concentric internal and external contractions. Percentage of strength loss, initial and final torque ratio were used to assess endurance ability. The results showed that IR strength was greater than the ERs for all groups. The ER/IR ratio ranged 0.71–0.77. In endurance assessment, the players were found to have 70% strength loss in the IRs. Adolescent and pre-pubescent players had larger p<0.05) strength loss in the ERs. Compared with adult pitchers, adolescent and pre-pubescent baseball pitchers had relatively weaker shoulder ERs especially after high repetition muscle contraction. In order to prevent shoulder injury in adolescent and pre-adolescent baseball throwers, muscle endurance in ER should be emphasized.
Explosive strength-related isokinetic parameters in high-level sprinters and long-distance runners: The relative power index
Authors: Olmo J. , Castilla N.
Published: October 2018

Strength is an important factor in athletic performance. Although maximal strength is readily measurable using isokinetic dynamometry other parameters are needed to assess the specific explosive component of muscular strength. To identify these parameters, 41 high-level long-distance runners (17 female and 24 male) and 65 high-level sprinters (22 female and 43 male) performed maximal isokinetic knee flexion/extension exertions at 60°/s and 300°/s using the dominant limb. Multiple strength parameters of hamstrings and quadriceps were studied including peak torque (PT) at both velocities, %PT at 0.2 s of contraction initiation at 60°/s, average explosive work at 300°/s, average power at 300°/s, average power at 300°/s divided by the PT at 60°/s (Relative Power Index – RPI), and average power at 300°/s divided by the PT at 300°/s. The only parameter which did not significantly correlate with (PT60) was the RPI in both flexion and extension. Irrespective of gender, this parameter was also significantly higher in sprinters compared with long-distance runners, and higher in the hamstrings than in the quadriceps. Therefore the use of this parameter is recommended for measuring explosive strength related to sprinting performance in the athlete. Reference data for the RPI in high-level sprinters are provided.
Isokinetic and functional parameters in patients following reconstruction of the anterior cruciate ligament
Authors: Jamshidi A.A. , Olyaei G.R. , Heydarian K. , Talebian S.
Published: October 2018

Both isokinetic testing and functional tests are commonly used to evaluate patients following reconstruction of the anterior cruciate ligament(ACLR). To determine the relationship of scores on an isokinetic test to scores on a variety of lower extremity functional tests ten healthy subjects and eleven ACLR patients at least six months after surgery performed knee isokinetic test at 60 and 180 deg/sec and three functional tests: leg vertical jump, single hop, and triple cross-over hop for distance. Correlation coefficients of isokinetic peak torque to body weight and functional testing were not significant at the P<0.05 level in patients or control subjects, whi1e ratio of involved to uninvolved knee quadriceps isokinetics peak torque and Limb Symmetry Index (LSI) of functional test were significant at the P<0.05 level (r=0.54 to 0.97). These results indicate a significant relationship between the LSI of various functional tests and side-to-side ratio of isokinetic testing just in ACLR patients.
Reproducibility analysis of isokinetic strength measurements of shoulder and elbow muscles in subjects with spinal cord injury
Authors: Kakebeeke T.H. , Lechner H.E. , Handschin C.
Published: October 2018

In this study we tested the reproducibility for torque measurements of the shoulder musculature in subjects with spinal cord injury (SCI) on an isokinetic dynamometer. Ten subjects with motor and sensory complete SCI (ASIA A) were studied. The subjects were asked to produce maximal torque for flexion/extension in the elbow, adduction/abduction and internal/external rotation in the shoulder. They were recruited four times – twice by two investigators separately – on which occasions three contraction modes(concentric, eccentric and isometric) were tested. The intra class correlations of the shoulder isometric strength were the highest (range: 0.71–0.88). The smallest real differences were lower for the shoulder (range: 5.5– 21.4 Nm) in comparison to the elbow measurements (range: 17.3–38.4 Nm) as were the coefficients of variation, 4.4–19.4% and 9.0–21.7%, respetively. This implies that measurements in the elbow were less reproducible than those in the shoulder. The coefficients of variation were higher for the inter- than the intra-tester measurements. This study demonstrates that among the muscles tested the most reproducible strength was obtained during isometric effort of shoulder rotators when these were performed by the same experimenter.
A principal component analysis of sport-specific isometric evaluation
Authors: Rousanoglou Elissavet N. , Karteroliotis Konstantinos , Boudolos Konstantinos D.
Published: October 2018

The purpose of the study was to identify the sport-specific range of joint angles for the knee extensors' muscular strength during isometric evaluation. Twenty young female track and field jumpers (J) and 21 volleyball players (V), aged 13–19 years, participated in the study. The values of torque at the initial 200 ms (T $_{INIT}$ ) and of maximum torque (T $_{MAX}$ ) were determined from the torque-time curve at each knee angle. A 2 (Group) × 9 (Angle) ANOVA was applied to examine the between group differences of T $_{INIT}$ and $_{MAX}$ . Principal component analysis (PCA) followed by varimax rotation was performed to investigate the angle sport-specificity of $_{INIT}$ and T $_{MAX}$ . Track and field jumpers demonstrated higher torque values, however, these values did not yield statistical significance at all knee angles (p> 0.05), either for T $_{INIT}$ or T $_{MAX}$ . PCAs revealed an angle sport-specific loading of $_{INIT}$ and T $_{MAX}$ , which were heavier loaded on the first component at the angles closer to full knee extension and at the angles closer to knee flexion, in the track and field jumpers and the volleyball players, respectively. These findings provide evidence for the knee angles to be included in a more specialized sport-specific isometric evaluation.
Athletic specialization of young males and relationships of elbow extensor and flexor muscular strength
Authors: Nikolaidou Maria-Elisavet , Rousanoglou Elissavet N. , Bayios Ioannis A. , Boudolos Konstantinos D.
Published: October 2018

The study examined the relationships among isokinetic, isometric and dynamic measures of the elbow extensor (EE) and elbow flexor (EF) strength, in junior throwing athletes. The isokinetic torque (T $_{ISOK}$ )(90, 210, 300°/s) and the isometric torque (T $_{ISOM}$ )(10, 40, 90°) of the EE and EF, and the maximum force(Fz $_{max}$ ) during the push-up test were measured in tennis(TP, n=7) and handball players (HP, n=8) (13 to 16 yrs). Statistics included 2(Group) × 3 (Angular velocity or Joint angle) ANOVA for group differences and the Pearson coefficient (r) for the relationships between strength measures. Handball players developed higher T $_{ISOK}$ and T $_{ISOM}$ (p < 0.05), however, when normalized to body mass, differences were not always significant. Fz $_{max}$ was the same between groups (p > 0.05). The angle-specificity of the strong relationships between T $_{ISOK}$ and T $_{ISOM}$ (p< 0.05) reflected sport specialization. All relationships between EE and EF were significant in TP(p>0.05), whereas, T $_{ISOK}$ and T $_{ISOM}$ relationships with Fz $_{max}$ were significant in HP (p < 0.05). In conclusion, athletic specialization has an impact on the relationships between isokinetic, isometric and dynamic measures of elbow strength in junior tennis and handball players.
Inter-session, inter-tester and inter-site reproducibility of isometric trunk muscle strength measurements
Authors: Demoulin C. , Grosdent S. , Debois I. , Mahieu G. , Maquet D. , Jidovsteff B. , Croisier J.-L. , Crielaard J.M. , Vanderthommen M.
Published: October 2018

The purpose of this study was to investigate the inter-session, inter-tester and inter-site reproducibility of trunk muscle strength scores in flexion, extension, lateral flexion and rotation. Ten healthy students were tested on four apparatus with a 7–10 day break between sessions. The first two sessions were identical while the other two differed either by the tester or by the site. Furthermore, 10 patients with chronic low back dysfunction (CLBD) were assessed with the four apparatus, once only. For all tests, CV ranged from 3.4% to 7.6% and from 3.9% to 8.1% in the inter-session and inter-tester studies, respectively (p>0.05 except for inter-session reproducibility of trunk flexor strength). Peak torque (PT) was more variable from site to site with a CV ranging from 4.2% to 12.7%, particularly in extension and left lateral flexion (p< 0.05). No statistically significant difference in the strength ratios (flexion/extension, right/left lateral-flexion and right/left rotation) were found between sessions or testers (4.9% < CV < 9.7%. The inter-site reproducibility of ratios was lower. Comparison between the CLBD patients and the healthy subjects with regard to PT normalized to body weight indicated significantly decreased performance for the former except for flexion and rotation scores in males. We conclude that in the case of healthy subjects, inter-session and inter-tester trunk strength measurements derived from these devices are reproducible. The low inter-site reproducibility suggests that caution should be exercised when interpreting findings originating from different sites. The lower extension strength scores in CLBD patients test lends some validity to the system. However, further studies focusing on reproducibility and validity of this system in CLBD patients are critical before any conclusion regarding their clinical viability may be drawn.
Influence of rest period duration between successive muscular strength sets on acute modifications of blood pressure and heart rate in the healthy subject
Authors: Lamotte M. , Fournier F. , Vanissum A. , van de Borne Ph
Published: October 2018

Objective. To measure the impact of different recovery periods on systolic blood pressure (SBP) and heart rate (HR) during classical resistance training (RT) modalities

Background. Resistance training was introduced into rehabilitation programs to improve the efficiency of traditional training. The impact of different RT modalities on muscular performance is well known but the recovery periods between successive RT sets recommended in the literature varied between 30 s and 5 min.

Method. Twenty one healthy subjects were tested while performing a classical RT paradigm: 3 sets of 10 repetitions at 75% of 1-RM, with recovery periods of 30, 60, 90 and 120 s.

Results. A recovery period of 30 or 60 s did not allow a return of SBP and HR to resting values. A progressive drift of the values was observed in the successive rests as well as in the successive efforts. A recovery period longer than 60 s (90 and 120 s) allowed a return of SBP and HR to resting values.

Conclusions. A recovery period of 90 s or more between successive classical RT sets is recommended in order to avoid excessive SBP and HR elevation.
The effect of combined visual feedback and verbal encouragement on isokinetic concentric performance in healthy females
Authors: O'Sullivan Anita , O'Sullivan Kieran
Published: October 2018

The purpose of this study was to compare isokinetic concentric quadriceps and hamstring performance in healthy females in the absence of feedback versus combined visual feedback and verbal encouragement at 60, 180 and 300°/s. A repeated-measures randomised cross-over design was used. Twenty two asymptomatic females were tested at the three test velocities under two randomly ordered conditions: (a) combined visual feedback and verbal encouragement; and (b) no feedback. The two sessions were separated by seven days. Examination of results revealed that with feedback there was a statistically significant increase in peak torque at the three test velocities(p<0.05) for both muscles. This study demonstrated that combined feedback can result in increased concentric muscle performance in females at three test velocities.
Knee flexibility and knee muscles isokinetic strength in swimmers and soccer players
Authors: Ozcaldiran Bahtiyar
Published: October 2018

Our purpose was to compare muscle flexibility and strength for lower extremities in the different groups determined by sport and to investigate the relationship between these parameters. We evaluated a total 62 subjects consisting of 19 swimmers, 23 soccer players and 20 controls with four flexibility tests. Isokinetic muscle evaluation of knee flexors and extensors was carried out for all subjects. All the results were significantly different among the groups without a difference between the athletes. The results showed that there was no significant relationship between the strength and flexibility in the athletes. A relationship between flexibility and strength at 60°/s was also indicated in swimmers and soccer players.
The relationship between anaerobic performance, muscle strength and sprint ability in American football players
Authors: Kin-İsler Ayse , Ariburun Bayrak , Ozkan Ali , Aytar Aydan , Tandogan Reha
Published: October 2018

The purpose of this study was to investigate the relationship between, isokinetic knee strength, anaerobic performance and sprinting ability in American football players. Twenty-eight male amateur American football players participated in this study voluntarily. Knee extension and flexion strengths were evaluated at 60, 150 and 240°/s, anaerobic performance was evaluated by Wingate anaerobic power test and sprint ability was determined by single- (20 m) and repeated-sprint (12 × 20 m) tests. Extension strength was significantly correlated with peak and mean power in all contraction velocities; however the only significant correlation between flexion strength and peak power was indicated at 240°/s. In the case of sprinting ability, there was a significant but weak correlation between 240°.s $^{-1}$ knee flexion strength and percentage of performance decrement from 10–20 m (r=0.381, p< 0.05). No measure of strength was significantly related to single-sprint and other measures of repeated-sprint ability (p> 0.05). Hence, although maximal knee extension strength is a crucial component in anaerobic performance of American football players, lack of its association with single- and repeated-sprint performance indicates that factors other than strength might be involved in single-and repeated-sprint performance in this group of athletes.
Test-retest reproducibility of isokinetic lifting strength measurements
Authors: Yuzer Serdil , Aydog Ece , Gurcay Eda , Unlu Ece , Cakci Aytul
Published: October 2018

Objectives: To determine the intra-rater reproducibility of normalized lifting strength (NLS) measurements.

Methods: 30 healthy male volunteers with a mean age of 28.16 ± 7.59 years participated in this study. Each subject was tested by the same physician twice in a week, with at least 48 hours between the test sessions. For the evaluation of intra-rater reproducibility, intraclass correlation coefficients (ICC), the standard error of measurement (SEM) and the smallest real difference (SRD) and Bland and Altman method were used.

Results: Intra-rater ICCs of the NLS were 0.77 and 0.67 at 19.4 and 38.9 cm/s, respectively. The SEM% were 13.2% and 20.1% while the SRD% were 36.6% and 55.8% at these velocities, respectively.

Conclusions: The reproducibility of NLS using the Biodex Lift Simulation Attachment was moderate in terms of the ICC and low in terms of the SRD. Thus the test, as described and applied is not sufficiently sensitive to detect clinically relevant changes.
A comparative study of the Jamar® and the Grippit® for measuring handgrip strength in clinical practice
Authors: Svantesson Ulla , Nordé Maria , Svensson Sandra , Brodin Elisabeth
Published: October 2018

Objectives: The objectives of the study were to measure and compare handgrip strength using two instruments, Jamar® and Grippit® and to assess the validity and evaluate the test-retest reliability of each instrument. Thirty-four participants were recruited from University of Gothenburg, Sweden. Included were apparently healthy women, right handed and aged 20–29 years. Handgrip strength was measured with Jamar® and Grippit® on two occasions 4–11 days apart. Three measurements were made with each hand and instrument on two separate occasions. The test-retest reliability of both instruments showed very high correlations (ICC 0.87–0.95) and SRD% ranged from 12–15%. When comparing the results obtained from both instruments, high correlations (r = 0.78–0.83) were found between all the analysed variables. The test-retest reliability of both Jamar® and Grippit® was very high as was the concurrent validity between the two instruments.
Effect of eight weeks of strength training on fatigue resistance in men and women
Authors: Salvador Emanuel Péricles , Dias Raphael Mendes Ritti , Gurjão André Luiz Demantova , Avelar Ademar , Pinto Luiz Gustavo , Cyrino Edilson Serpeloni
Published: October 2018

The purpose of the present study was to compare the effects of eight weeks of strength training on fatigue resistance in men and women. Thirty-three men and twenty-three women performed eight weeks of strength training in three weekly sessions. Subjects performed four sets using 80% of 1-RM tests on bench press, squat and arm curl. Fatigue index (FI) was used for analysis of decline in motor performance along the sets. The sum of the number of repetitions accomplished in the four sets in each exercise was used to indicate the fatigue resistance. Anova or Ancova two-way (time x gender) was employed for statistical analysis (P < 0.05). Eight weeks of strength training increased significantly 1-RM strength, fatigue resistance and total number of repetitions in both genders. FI decreased significantly in both genders after training (men = 50% vs. women = Time x gender interaction was observed in the total number of repetitions in squat (P = 0.04) and arm curl exercises, regarding gains to women (P = 0.01). In conclusion, eight weeks of ST improved strength, FR, FI and total number of repetitions performed. However, women obtained greater adaptations than men.
Quadriceps insufficiency in patients with knee compromise: How many velocities should an isokinetic test protocol consist of?
Authors: Zemach L. , Almoznino S. , Barak Y. , Dvir Z.
Published: October 2018

The objective of this study was to find out whether the use of multiple velocity (30, 60, 90 and 120°/s) isokinetic as well as a single angle isometric testing was justified for assessing unilateral muscular weakness. Twenty one unilateral knee patients (16 men, 5 women), mostly with ACL pathology, with a mean post-injury time of 36 ± 33 m, were conveniently sampled. All patients filled in a functional questionnaire which indicated good recovery. The relative weakness of the involved (I) side was determined using the uninvolved (U) side as reference. Patients were also asked to rank the difficulty in performing the tests. The mean (based on the 4 velocities) eccentric weakness (19.7%) was significantly higher than in both the concentric (14.9%) or the isomteric (13.9%) modes. However within either the concentric or eccentric modes no between-velocity differences were noted. Side dominance had a significant effect on quadriceps weakness in all test modes. In conclusion, and with respect to the specific patient group, the use of one or, at most, two test velocities is sufficient to portray muscular insufficiency.
Responsiveness of measurements of knee extension force obtained by hand-held dynamometry: A preliminary analysis
Authors: Bohannon Richard W.
Published: October 2018

A retrospective review of patient records was undertaken to establish the responsiveness of measurements of knee extension force obtained by hand-held dynamometry. Of particular interest was a minimal clinically important difference (MCID). A transition of dependence to independence in sit-to-stand was considered clinically important. Patients who experienced such a transition had a mean increase in bilateral knee extension force of 83 N(43%), whereas patients who remained dependent in sit-to stand demonstrated a decrease in bilateral knee extension force of 7 N (3%). Although a difference of 43% is contextual, it provides the first clue of an MCID in knee extension force indicative of responsiveness for the measurement.
Manual muscle testing overlooks many knee extension strength deficits among older adults
Authors: Bohannon Richard W.
Published: October 2018

This retrospective study examined the adequacy of manual muscle testing (MMT) as a measure of knee extension force among home-care patients. The knee extension strength of 31 patients was measured by MMT, hand-held dynamometry (HHD), and the five-repetition sit-to-stand-test (FRSTST). Although most patients were identified as weak by MMT, neither the sensitivity nor the specificity of MMT relative to HHD or FRSTST justifies its use as a sole measure of muscle strength among home care patients.
Combined sensorimotor and resistance training for young short track speed skaters: A case study
Authors: Behrens Martin , Mau-Möller Anett , Laabs Henrike , Felser Sabine , Bruhn Sven
Published: October 2018

The purpose of the study was to investigate the effects of a combined sensorimotor – resistance training on muscle strength and neuromuscular activation of selective muscles of the right ankle joint. Both treatments were performed successively in each training session. Seven short track speed skaters participated in the study. The training was performed twice a week for 12 weeks. Maximum peak torque during inversion/eversion, the associated neuromuscular activation of soleus and peroneus longus as well as eversion/inversion ratio were measured in a pre- and post-test, respectively. After the training the athletes revealed a significantly increased maximum peak torque during inversion (17.47 ± 4.37N · m vs. 23.57 ± 3.58N ˙ m; p =0.006) associated with a significantly increased root mean square of the EMG signal in the soleus (12.42 ± 6.09mV vs. 24.00± 9.37mV; p = 0.009). The eversion/inversion ratio was significantly decreased after training (0.96 ± 0.12 vs. 0.77 ± 0.11; p = 0.034). Eversion training adaptations were lower than inversion training adaptations probably due to the fact that resistance training did not contain an exercise for peroneus longus. Based on these the combined sensorimotor-resistance training is an attractive option for athletes where maximum strength, active joint stabilization and postural control plays a decisive role.
Feasibility and reproducibility of muscular strength measures in gymnastics-specific body positions using hand-held dynamometry
Authors: Siatras Theophanis A. , Douka Ioanna D. , Milosis Dimitrios C.
Published: October 2018

This study aimed to determine feasibility and reproducibility of muscular strength measurements in young gymnasts, using hand-held dynamometry in gymnastics-specific body positions. A group of 32 male and female young gymnasts 8–11 years-old, performed different strength tests using a Nicholas Manual Muscle Tester (NMMT). The measurements were collected in 4 major muscle groups (shoulder flexors and extensors, hip flexors and extensors) at 22 different joint angular positions, with the active elbow or knee joint in full extension. The maximal strength was obtained by placing the NMMT in a distal forearm or shank position, with the gymnast in supine or prone position stabilized on a vault. A Myrin goniometer, attached on the sagittal plane near elbow or knee joint, was used to specify the shoulder and hip joint angular positions. In the majority of the measurements (18 out of 22 angular positions) the intra-class correlation coefficients revealed a good level of test-retest reliability (R = 0.80–0.88). In four cases (3 in shoulder flexors and 1 in shoulder extensors) intra-class reliability was fair, with R-values ranging from 0.70 to 0.78. The low coefficients of variation and standard errors of measurements affirmed the reproducibility of measurements. In conclusion, this study showed the feasibility and the reproducibility of shoulder and hip flexor and extensor muscles maximal strength measurements using NMMT in gymnastics-based settings.
Isokinetic norms for ankle, knee, shoulder and forearm muscles in young South African men
Authors: Lategan Leon
Published: October 2018

Background and objectives: Isokinetic test results are often evaluated against a norm or normal value. Previous research on isokinetics is prolific however, different populations present with different "normal" values. Thus, the aim of the present study was to establish isokinetic norms for the ankle, knee, shoulder, elbow and forearm joints in young, South African men.

Methods: Four hundred and thirty eight (N=438) young male participants (19.06 ± 1.86 yrs) were evaluated in terms of isokinetic peak torque of the ankle, knee, shoulder and forearm. A Cybex 340 isokinetic dynamometer was used to evaluate their concentric peak torque at a low velocity(30 or 60°/s); gravity was not corrected for. The data was tested for normality and the descriptive statistics were calculated. Percentile scores were subsequently constructed.

Results: Normative values for peak torque, peak torque per body mass and agonist-antagonist ratios were constructed for the ankle, knee, shoulder and forearm.

Conclusions: Results from this study might provide useful norms for the clinical evaluation of low-velocity, concentric peak torque in young males, when gravity correction is not performed.
Effect of ascending vs. descending velocity order on peak torque during isokinetic testing in males
Authors: Warren Barbara L. , Wright Kevin J.
Published: October 2018

The vast majority of previous research with isokinetic machines has used only ascending or random velocity sets during testing. The purpose of this study was to investigate the effect velocity order (ascending vs. descending order) had on peak torque of knee extension during isokinetic testing and to examine the differences in peak torque in collegiate and recreational athletes. Thirty healthy, college aged males (15 collegiate athletes (CA): mean Age 20.27 yrs, Ht 178.99 cm, Mass 85.00 kgs and 15 recreational athletes (RA): Age 21.2 yrs, Ht 183.39 cm, Mass 89.06 kgs) performed two familiarization trials and four randomly assigned experimental trials. Subjects performed four knee extension repetitions at five velocities in either ascending (60, 120, 180, 240, and 300°/sec) or descending (300, 240, 180, 120, 60°/sec) order. There was no significant(p< 0.05) difference between the order of velocities and peak torque or between CA and RA groups. Although not statistically significant, RA produced greater peak torque than CA. This may be a result of numerous RAs in this study being former collegiate athletes. In conclusion, the order of velocities may not be pertinent when establishing a protocol for testing peak torque of the knee extensors in healthy college-aged males.
Muscular activation patterns during the soccer in-step kick
Authors: Cerrah Ali Onur , Gungor Elvin Onarıcı , Soylu Abdullah Ruhi , Ertan Hayri , Lees Adrian , Bayrak Coşkun
Published: October 2018

The aim of the study was to define activation characteristics of knee muscles of the kicking leg during the in-step kick and interpret these in relation to isokinetic strength parameters and ball velocity in professional(N=14) compared to amateur (N=17) soccer players. Electromyographic (EMG) recordings were taken from the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), long head of biceps femoris (BF) and medial gastrocnemius (GAS) as players performed three successful maximal in-step kicks using a 0° approach angle with two steps to a stationary ball towards a target. Kicks were also recorded with high speed video and ball velocity was measured by a radar gun. Afterward the bilateral concentric isokinetic strength of the knee extensors and flexors was recorded. Results suggest that during the swing phase, BF activation occurred significantly earlier, RF showed reduced activation and an earlier and greater muscle activity occurred in VL and VM in professionals compared to amateur players. During knee extension, VL and VM showed a markedly greater magnitude of muscle activity in professionals; during the follow through, GAS showed reduced activity in professionals. Relationships between muscle strength and performance (ball speed) were found for amateurs but not for professionals (r=0.57 to r=0.72, p< 0.05). The findings of this study indicate that the superior performance of professional players compared to amateurs appears not to be due to muscle strength factors but rather to subtle differences in technique, as indicated by EMG data, throughout both the build up and execution of the kick.
Age and sex variations of the index finger flexion and extension strength in adult Bengalee population
Authors: De Sujaya , Sengupta Piyali , Maity Payel , Pal Amitava , Dhara Prakash C.
Published: October 2018

This investigation was aimed to assess age and sex related variation in the index finger flexion and extension strength and its association with some anthropometric characteristics. A total of 400 subjects (200 male and 200 female), 18–60 years were selected at random and divided into three age groups: 18–34, 35–50 and 51–60 years. Strength was measured using a dedicated device. Results revealed that finger flexion and extension strength was significantly greater (p < 0.001) in men than in women. Irrespective of gender the right hand was significantly stronger(p< 0.001) than that of left hand. A significant variation in finger extension strength with age was noted for both genders. Positive correlations between strength and some anthropometry were indicated only in case of male subjects.
What is normal isokinetic shoulder strength or strength ratios? A systematic review
Authors: Land Helen , Gordon Susan
Published: October 2018

Purpose: To systematically review the literature regarding isokinetic testing to identify values for isokinetic shoulder strength and agonist/antagonist ratios in the general population which may be used as reference values when assessing, planning and implementing shoulder rehabilitation.

Methods: Electronic databases were systematically searched and reference lists of all retrieved papers were hand searched and nine relevant studies were identified. Two independent reviewers assessed methodological quality and extracted data.

Results: Seven studies reported the effect of limb dominance on strength with four reporting no significant difference between the dominant and non-dominant limbs. The studies which compared muscle strength with gender concluded that men were significantly stronger than women at all speeds in all directions. Age was reported to have no significant effect on muscle strength. Four studies agreed that adduction and extension muscle strength were greater than other directions and flexion, abduction, internal rotation and external rotation were the next strongest in that order.

Conclusions: Nine low and moderate quality research papers have attempted to establish isokinetic shoulder strength in a general population. Poor consistency with respect to sample sizes, randomization and selection of testing velocities and positions did not allow direct comparison of the results. Future research involving symptomatic subjects will need to be matched to a group of subjects from the general population of the same age, gender and physical profile with adequate sample sizes representative of the symptomatic population.