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Sample records for voluntary isokinetic knee

  1. Isokinetic knee extension and vertical jumping: are they related?

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    Iossifidou, Anna; Baltzopoulos, Vasilios; Giakas, Giannis

    2005-10-01

    The aim of this study was to examine joint power generation during a concentric knee extension isokinetic test and a squat vertical jump. The isokinetic test joint power was calculated using four different methods. Five participants performed concentric knee extensions at 0.52, 1.57, 3.14 and 5.23 rad x s(-1) on a Lido isokinetic dynamometer. The squat vertical jump was performed on a Kistler force plate. Kinematic data from both tests were collected and analysed using an ELITE optoelectronic system. An inverse dynamics model was applied to measure knee joint moment in the vertical jump. Knee angular position data from the kinematic analysis in the isokinetic test were used to derive the actual knee angular velocity and acceleration, which, in turn, was used to correct the dynamometer moment for inertial effects. Power was measured as the product of angular velocity and moment at the knee joint in both tests. Significant differences (P knee joint power in the two tests (squat vertical jump: 2255 +/- 434 W; isokinetic knee extension: 771 +/- 81 W). Correlation analysis revealed that there is no relationship between the peak knee joint power during the vertical jump and the slow velocity isokinetic tests. Higher isokinetic velocity tests show better relationships with the vertical jump but only if the correct method for joint power calculation is used in the isokinetic test. These findings suggest that there are important differences in muscle activation and knee joint power development that must be taken into consideration when isokinetic tests are used to predict jumping performance.

  2. Knee Extensor Electromyographic Activity-to-Work Ratio is Greater With Isotonic Than Isokinetic Contractions.

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    Schmitz, Randy J.; Westwood, Kevin C.

    2001-12-01

    OBJECTIVE: To determine whether isotonic or isokinetic contractions produced greater electromyographic (EMG) activity per unit of work during isotonic and isokinetic knee-extension exercise. DESIGN AND SETTING: Subjects performed three 3-second maximal voluntary isometric contractions of the dominant knee extensors for EMG normalization. Exercise testing performed on the Biodex System 3 Dynamometer involved 10 isokinetic contractions at 180 degrees.s(-1) and 10 isotonic contractions with the resistance set at 50% of the previously recorded maximal voluntary isometric contraction. SUBJECTS: Recreationally active college students (10 men and 11 women). MEASUREMENTS: Surface EMG signals were collected from the vastus medialis and lateralis muscles and then integrated (IEMG) over the concentric phase of each repetition for both exercises. The IEMG was divided by the total work performed during the concentric phase for each exercise (IEMG/W). RESULTS: We analyzed the IEMG/W data using a 1-between (sex), 2-within (exercise and muscle) repeated-measures analysis of variance. There was a significant main effect for exercise, with the isotonic IEMG/W value being significantly greater than the isokinetic IEMG/W value. Additionally, the IEMG/W relationship did not appear to be affected by sex or individual muscle tested. CONCLUSIONS: Per unit of work performed, the isotonic contractions resulted in greater motor unit recruitment or an increased rate of firing, or both. This finding may have implications for the early phase of rehabilitation, when goals include complete motor unit recruitment of injured or atrophied muscles.

  3. Agonist muscle activity and antagonist muscle co-activity levels during standardized isotonic and isokinetic knee extensions.

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    Remaud, Anthony; Cornu, Christophe; Guével, Arnaud

    2009-06-01

    This study aimed to analyze the effects of the contraction mode (isotonic vs. isokinetic concentric conditions), the joint angle and the investigated muscle on agonist muscle activity and antagonist muscle co-activity during standardized knee extensions. Twelve healthy adult subjects performed three sets of isotonic knee extensions at 40% of their maximal voluntary isometric torque followed by three sets of maximal isokinetic knee extensions on an isokinetic dynamometer. For each set, the mean angular velocity and the total external amount of work performed were standardized during the two contraction modes. Surface electromyographic activity of vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), semitendinosus (ST) and biceps femoris (BF) muscles was recorded. Root mean square values were then calculated for each 10 degrees between 85 degrees and 45 degrees of knee extension (0 degrees =horizontal position). Results show that agonist muscle activity and antagonist muscle co-activity levels are significantly greater in isotonic mode compared to isokinetic mode. Quadriceps activity and hamstrings co-activity are significantly lower at knee extended position in both contraction modes. Considering agonist muscles, VL reveals a specific pattern of activity compared to VM and RF; whereas considering hamstring muscles, BF shows a significantly higher co-activity than ST in both contraction modes. Results of this study confirmed our hypothesis that higher quadriceps activity is required during isotonic movements compared to isokinetic movements leading to a higher hamstrings co-activity.

  4. Isokinetic evaluation of knee muscles in soccer players: discriminant analysis

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    Bruno Fles Mazuquin

    2015-10-01

    Full Text Available ABSTRACTIntroduction:Muscle activity in soccer players can be measured by isokinetic dynamometer, which is a reliable tool for assessing human performance.Objectives:To perform isokinetic analyses and to determine which variables differentiate the under-17 (U17 soccer category from the professional (PRO.Methods:Thirty four players were assessed (n=17 for each category. The isokinetic variables used for the knee extension-flexion analysis were: peak torque (Nm, total work (J, average power (W, angle of peak torque (deg., agonist/ antagonist ratio (%, measured for three velocities (60°/s, 120°/s and 300°/s, with each series containing five repetitions. Three Wilks' Lambda discriminant analyses were performed, to identify which variables were more significant for the definition of each of the categories.Results:The discriminative variables at 60°/s in the PRO category were: extension peak torque, flexion total work, extension average power and agonist/antagonist ratio; and for the U17s were: extension total work, flexion peak torque and flexion average power. At 120°/s for the PRO category the discriminant variables were: flexion peak torque and extension average power; for the U17s they were: extension total work and flexion average power. Finally at 300°/s, the variables found in the PRO and U17 categories respectively were: extension average power and extension total work.Conclusion:Isokinetic variables for flexion and extension knee muscles were able to significantly discriminate between PRO and U17 soccer players.

  5. EFFECTS OF BETWEEN-SET INTERVENTIONS ON NEUROMUSCULAR FUNCTION DURING ISOKINETIC MAXIMAL CONCENTRIC CONTRACTIONS OF THE KNEE EXTENSORS

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    Carole Cometti

    2011-12-01

    Full Text Available The presents study investigated the effects of between-set interventions on neuromuscular function of the knee extensors during six sets of 10 isokinetic (120°·s-1 maximal concentric contractions separated by three minutes. Twelve healthy men (age: 23.9 ± 2.4 yrs were tested for four different between-set recovery conditions applied during two minutes: passive recovery, active recovery (cycling, electromyostimulation and stretching, in a randomized, crossover design. Before, during and at the end of the isokinetic session, torque and thigh muscles electromyographic activity were measured during maximal voluntary contractions and electrically-evoked doublets. Activation level was calculated using the twitch interpolation technique. While quadriceps electromyographic activity and activation level were significantly decreased at the end of the isokinetic session (-5.5 ± 14.2 % and -2.7 ± 4.8 %; p < 0.05, significant decreases in maximal voluntary contractions and doublets were observed after the third set (respectively -0.8 ± 12.1% and -5.9 ± 9.9%; p < 0.05. Whatever the recovery modality applied, torque was back to initial values after each recovery period. The present results showed that fatigue appeared progressively during the isokinetic session with peripheral alterations occurring first followed by central ones. Recovery interventions between sets did not modify fatigue time course as compared with passive recovery. It appears that the interval between sets (3 min was long enough to provide recovery regardless of the interventions

  6. Isokinetic knee joint evaluation in track and field events.

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    Deli, Chariklia K; Paschalis, Vassilis; Theodorou, Anastasios A; Nikolaidis, Michalis G; Jamurtas, Athanasios Z; Koutedakis, Yiannis

    2011-09-01

    The purpose of this study was to evaluate maximal torque of the knee flexors and extensors, flexor/extensor ratios, and maximal torque differences between the 2 lower extremities in young track and field athletes. Forty male track and field athletes 13-17 years old and 20 male nonathletes of the same age participated in the study. Athletes were divided into 4 groups according to their age and event (12 runners and 10 jumpers 13-15 years old, 12 runners and 6 jumpers 16-17 years old) and nonathletes into 2 groups of the same age. Maximal torque evaluation of knee flexors and extensors was performed on an isokinetic dynamometer at 60°·s(-1). At the age of 16-17 years, jumpers exhibited higher strength values at extension than did runners and nonathletes, whereas at the age of 13-15 years, no significant differences were found between events. Younger athletes were weaker than older athletes at flexion. Runners and jumpers were stronger than nonathletes in all relative peak torque parameters. Nonathletes exhibited a higher flexor/extensor ratio compared with runners and jumpers. Strength imbalance in athletes was found between the 2 lower extremities in knee flexors and extensors and also at flexor/extensor ratio of the same extremity. Young track and field athletes exhibit strength imbalances that could reduce their athletic performance, and specific strength training for the weak extremity may be needed.

  7. Isokinetic assessment of the hip muscles in patients with osteoarthritis of the knee

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    Renata Alqualo Costa

    2010-01-01

    Full Text Available OBJECTIVES: To evaluate the difference in isokinetic strength of hip muscles between patients with knee osteoarthritis (OA and matched healthy controls, and to establish the correlation between this isokinetic strength and pain and function in patients with knee OA. METHODS: 25 patients with a diagnosis of unilateral knee OA, 25 patients with bilateral knee OA, and 50 matched controls were evaluated using the visual analog scale for pain, knee Lequesne index, Western Ontario and McMaster Universities questionnaire and an isokinetic test. RESULTS: The groups were matched for age, gender and body mass index. The results of the isokinetic test revealed lower peak torque of the hip in patients with OA of the knee than in the control group for all movements studied. Strong correlations were found between the peak torque, visual analog scale and function. CONCLUSIONS: Patients with OA of the knee exhibit lower isokinetic strength in the hip muscles than healthy control subjects. Strengthening the muscles surrounding the hip joint may help to decrease pain in people with knee OA. Some correlations between pain/function and peak torque were found.

  8. Effects of different stretching techniques on the outcomes of isokinetic exercise in patients with knee osteoarthritis.

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    Weng, Ming-Cheng; Lee, Chia-Ling; Chen, Chia-Hsin; Hsu, Jui-Jen; Lee, Wei-Der; Huang, Mao-Hsiung; Chen, Tien-Wen

    2009-06-01

    We recruited 132 subjects with bilateral knee osteoarthritis (Altman Grade II) to compare the effects of different stretching techniques on the outcomes of isokinetic muscle strengthening exercises. Patients were randomly divided into four groups (I-IV). The patients in Group I received isokinetic muscular strengthening exercises, Group II received bilateral knee static stretching and isokinetic exercises, Group III received proprioceptive neuromuscular facilitation (PNF) stretching and isokinetic exercises, and Group IV acted as controls. Outcomes were measured by changes in Lequesne's index, range of knee motion, visual analog pain scale, and peak muscle torques during knee flexion and extension. Patients in all the treated groups experienced significant reductions in knee pain and disability, and increased peak muscle torques after treatment and at follow-up. However, only patients in Groups II and III had significant improvements in range of motion and muscle strength gain during 60 degrees/second angular velocity peak torques. Group III demonstrated the greatest increase in muscle strength gain during 180 degrees/second angular velocity peak torques. In conclusion, stretching therapy could increase the effectiveness of isokinetic exercise in terms of functional improvement in patients with knee osteoarthritis. PNF techniques were more effective than static stretching.

  9. [Sincerity of effort: isokinetic evaluation of knee extension].

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    Colombo, R; Demaiti, G; Sartorio, F; Orlandini, D; Vercelli, S; Ferriero, G

    2008-01-01

    The aim of this study was to find a reliable method to evaluate the sincerity of the muscular maximal effort performed in a dynamometric isokinetic test of knee flexion-extension. The coefficient of variation of the peak torque (CV) and 3 new indices were analysed: (1) the average coefficient of variation calculated on the complete peak torque curve (CVM); (2) the slope of the regression line in an endurance test (PRR); (3) the correlation coefficient of the peak torques in the same endurance test (CCR). Twenty healthy subjects underwent assessment in two different trials, maximal (MX) and 50% submaximal (SMX), with 20 minutes of rest between trials. Each trial consisted of 4 tests, each of 3 repetitions, at angular speed of 30, 180, 30, and 180 degrees/s, respectively, and 1 test of 15 repetitions at 240 degrees/s. Our findings confirmed the ability of CV to detect a high percentage of sincere efforts: at 30 degrees/s Sensibility (Sns)=100% and Specificity (Spc)=70%; at 180 degrees/s Sns=75%, Spc=95%. The 3 new indices here proposed showed high characteristics of Sns and Spc, generally better than those of CV. CVM showed at 180 degrees/s Sns=90% and Spc=100%, while at 30 degrees/s Sns=90%, Spc=75%. PRR was the best index identifying all the efforts, except one (Sns=100%, Spc=95%). The CCR coefficient showed Sns and Spc values both of 90%.

  10. Effects of Lumbosacral Manipulation on Isokinetic Strength of the Knee Extensors and Flexors in Healthy Subjects: A Randomized, Controlled, Single-Blind Crossover Trial

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    Sanders, Grant D.; Nitz, Arthur J.; Abel, Mark G.; Symons, T. Brock; Shapiro, Robert; Black, W. Scott; Yates, James W.

    2015-01-01

    Objective The purpose of this study was to investigate the effect of manual manipulations targeting the lumbar spine and/or sacroiliac joint on concentric knee extension and flexion forces. Torque production was measured during isometric and isokinetic contractions. Methods This was a randomized, controlled, single-blind crossover design with 21 asymptomatic, college-aged subjects who had never received spinal manipulation. During 2 separate sessions, subjects’ peak torques were recorded while performing maximal voluntary contractions on an isokinetic dynamometer. Isometric knee extension and flexion were recorded at 60° of knee flexion, in addition to isokinetic measurements obtained at 60°/s and 180°/s. Baseline measurements were acquired before either treatment form of lumbosacral manipulation or sham manipulation, followed by identical peak torque measurements within 5 and 20 minutes posttreatment. Data were analyzed with a repeated measures analysis of variance. Results A statistically significant difference did not occur between the effects of lumbosacral manipulation or the sham manipulation in the percentage changes of knee extension and flexion peak torques at 5 and 20 minutes posttreatment. Similar, nonsignificant results were observed in the overall percentage changes of isometric contractions (spinal manipulation 4.0 ± 9.5 vs sham 1.2 ± 6.3, P = .067), isokinetic contractions at 60°/s (spinal manipulation − 4.0 ± 14.2 vs sham − 0.3 ± 8.2, P = .34), and isokinetic contractions at 180°/s (spinal manipulation − 1.4 ± 13.9 vs sham − 5.5 ± 20.0, P = .18). Conclusion The results of the current study suggest that spinal manipulation does not yield an immediate strength-enhancing effect about the knee in healthy, college-aged subjects when measured with isokinetic dynamometry. PMID:26793035

  11. Isokinetic Evaluation of Knee Extensor/Flexor Muscle Strength in Behcet’s Patients

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    Bekir Durmus

    2015-10-01

    Full Text Available Background: Behçet’s disease (BD is an idiopathic, multisystemic, progressive disease. The purpose of this study is to compare the knee flexor and extensor isokinetic muscle strengths of Behcet’s patients with that of healthy subjects. Methods: Twenty-five (13 male and 12 female patients with BD and 25 (15 male and 10 female healthy individuals were included in the study. Velocities of 90°/sec, 120°/sec, and 150°/sec were used for the isokinetic muscle strength testing. Patients with active inflammatory knee arthritis were excluded. Peak torque (Nm and peak torque adjusted to body weight (% were taken into consideration for comparison between study groups. Results: Compared to healthy controls, there was a statistically significant decrease in both the bilateral knee extensor and flexor muscle isokinetic peak torques(Nm as well as the peak torques adjusted to body weight (% at velocities of 90°/sec, 120°/sec and 150°/sec in patients with BD (p < 0.05. However, there was no significant difference in the agonist-antagonist ratio of the isokinetic peak torques of knee muscles between the two groups. Conclusion: In light of these findings, we have concluded that both knee flexor and extensor isokinetic muscle strengths are lower in BD. We therefore recommend careful monitoring of patients with BD in terms of muscle strength.

  12. Reliability of Concentric, Eccentric and Isometric Knee Extension and Flexion when using the REV9000 Isokinetic Dynamometer

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    de Carvalho Froufe Andrade, Alberto César Pereira; Caserotti, Paolo; de Carvalho, Carlos Manuel Pereira

    2013-01-01

    The aim of this study was to assess the reliability of isokinetic and ISO knee extensor and flexor muscle strength when using the REV9000 (Technogym) isokinetic dynamometer. Moreover, the reliability of several strength imbalance indices and bilateral ratios were also examined. Twenty......). The results of this study showed a high reproducibility in eccentric (0.95-0.97), concentric (0.95-0.96) and isometric (0.93-0.96), isokinetic strength for knee extensor and flexor muscles, thus indicating that the REV9000 isokinetic dynamometer can be used in future sports performance studies. A low...

  13. Knee Extensor and Flexor Torque Development with Concentric and Eccentric Isokinetic Training

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    Miller, Larry E.; Pierson, Lee M.; Nickols-Richardson, Sharon M.; Wootten, David F.; Selmon, Serah E.; Ramp, Warren K.; Herbert, William G.

    2006-01-01

    This study assessed muscular torque and rate of torque development following concentric (CON) or eccentric (ECC) isokinetic training. Thirty-eight women were randomly assigned to either CON or ECC training groups. Training consisted of knee extension and flexion of the nondominant leg three times per week for 20 weeks (SD = 1). Eccentric training…

  14. Knee Extensor and Flexor Torque Development with Concentric and Eccentric Isokinetic Training

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    Miller, Larry E.; Pierson, Lee M.; Nickols-Richardson, Sharon M.; Wootten, David F.; Selmon, Serah E.; Ramp, Warren K.; Herbert, William G.

    2006-01-01

    This study assessed muscular torque and rate of torque development following concentric (CON) or eccentric (ECC) isokinetic training. Thirty-eight women were randomly assigned to either CON or ECC training groups. Training consisted of knee extension and flexion of the nondominant leg three times per week for 20 weeks (SD = 1). Eccentric training…

  15. Reliability of isokinetic normalized peak torque assessments for knee muscles in post-stroke hemiparesis.

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    Noorizadeh Dehkordi, Shohreh; Talebian, Saeed; Olyaei, Gholamreza; Montazeri, Ali

    2008-05-01

    The purpose of this study was to establish test-retest reliability of measurement procedures for quantifying isokinetic concentric peak torque (PT) at the knee using normalization methods post-stroke. A second aim was to estimate the change required to show clinically significant improvements in knee muscles strength. The isokinetic normalized PT (NPT) values for the knee extensors and flexors were measured in each participant at two different angular velocities during two sessions 1 day apart. Thirty participants with mild to moderate hemiparesis after stroke who were able to walk were tested. The normalized PT measures for the knee muscles of the affected lower extremity were highly reliable (intraclass correlation coefficients ranged from 0.85 to 0.98; pknee flexors had more random variation than the knee extensors. This study supports the use of isokinetic dynamometers for the assessment of knee muscle strength in participants with chronic mild to moderate post-stroke hemiparesis and to measure clinical improvements. Established measurement error and smallest real differences in normalized PT will aid interpretation of real changes in muscle strength in this clinical population.

  16. The fatigue effect of a simulated futsal match protocol on isokinetic knee torque production.

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    Dal Pupo, Juliano; Detanico, Daniele; Santos, Saray Giovana Dos

    2014-11-01

    The objective of this study was to investigate the effects of a simulated futsal match protocol on isokinetic knee torque production. Twenty-one young futsal players participated in this study and performed a futsal-specific protocol comprising two blocks of 20-minute activities to simulate the match demands. At pre-protocol, half-time, and post-protocol, the concentric and eccentric isokinetic peak torque of the knee flexor and extensor muscles, the angle of peak torque, and the conventional and functional torque ratios were assessed. ANOVA was used to compare the variables (significance level p knee flexor and extensor eccentric torque and knee flexor concentric torque was found, in which the pre-protocol levels were higher than those at half-time, with both being larger than those at post-protocol. The knee extensor concentric torque reduced at half-time. The angle of eccentric torque of knee flexors increased, and the conventional and functional torque ratios decreased at post-protocol. In conclusion, the protocol produced a time-dependent reduction of knee flexor and extensor torque in both concentric and eccentric actions. These findings suggested a possible impairment of performance and the emergence of risk factors for hamstring strains during a futsal match.

  17. Comparison of knee laxity and isokinetic muscle strength in patients with a posterior cruciate ligament injury.

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    Jeon, Kyoungkyu

    2016-03-01

    [Purpose] The aim of this study was to compare knee laxity and isokinetic muscle strength in patients with an isolated posterior cruciate ligament injury. [Subjects and Methods] Twenty high school rugby players with a previous posterior cruciate ligament injury and abnormal findings higher than surgical grade I were included. Laxity with 132 N of pressure was measured using Kneelax 3 to assess the stability of the posterior cruciate ligament, and flexor and extensor torques were measured at 60°/sec, 180°/sec, and 240°/sec to measure the isokinetic muscle strength of the knee joint. The average and standard deviation values were extracted from all data to assess the measured data. [Results] Regarding the ipsilateral and contralateral laxity, the deviation value at the peak force and maximum manual drawer was statistically significant. The peak torque and peak torque per body weight in isokinetic measurements were significantly different only for knee extensor torque at 60°/sec, 180°/sec, and 240°/sec. [Conclusion] Return to normal activities post injury is important. Thus base data gathered by comparing patients' ipsilateral and contralateral sides will serve as essential criteria for structuring future rehabilitation programs to facilitate functional improvements.

  18. Comparison of knee laxity and isokinetic muscle strength in patients with a posterior cruciate ligament injury

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    Jeon, Kyoungkyu

    2016-01-01

    [Purpose] The aim of this study was to compare knee laxity and isokinetic muscle strength in patients with an isolated posterior cruciate ligament injury. [Subjects and Methods] Twenty high school rugby players with a previous posterior cruciate ligament injury and abnormal findings higher than surgical grade I were included. Laxity with 132 N of pressure was measured using Kneelax 3 to assess the stability of the posterior cruciate ligament, and flexor and extensor torques were measured at 60°/sec, 180°/sec, and 240°/sec to measure the isokinetic muscle strength of the knee joint. The average and standard deviation values were extracted from all data to assess the measured data. [Results] Regarding the ipsilateral and contralateral laxity, the deviation value at the peak force and maximum manual drawer was statistically significant. The peak torque and peak torque per body weight in isokinetic measurements were significantly different only for knee extensor torque at 60°/sec, 180°/sec, and 240°/sec. [Conclusion] Return to normal activities post injury is important. Thus base data gathered by comparing patients’ ipsilateral and contralateral sides will serve as essential criteria for structuring future rehabilitation programs to facilitate functional improvements. PMID:27134367

  19. Validity and reliability of isometric, isokinetic and isoinertial modalities for the assessment of quadriceps muscle strength in patients with total knee arthroplasty.

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    Lienhard, K; Lauermann, S P; Schneider, D; Item-Glatthorn, J F; Casartelli, N C; Maffiuletti, N A

    2013-12-01

    Reliability of isometric, isokinetic and isoinertial modalities for quadriceps strength evaluation, and the relation between quadriceps strength and physical function was investigated in 29 total knee arthroplasty (TKA) patients, with an average age of 63 years. Isometric maximal voluntary contraction torque, isokinetic peak torque, and isoinertial one-repetition maximum load of the involved and uninvolved quadriceps were evaluated as well as objective (walking parameters) and subjective physical function (WOMAC). Reliability was good and comparable for the isometric, isokinetic, and isoinertial strength outcomes on both sides (intraclass correlation coefficient range: 0.947-0.966; standard error of measurement range: 5.1-9.3%). Involved quadriceps strength was significantly correlated to walking speed (r range: 0.641-0.710), step length (r range: 0.685-0.820) and WOMAC function (r range: 0.575-0.663), independent from the modality (P torque (P > 0.05). In conclusion, isometric, isokinetic, and isoinertial modalities ensure valid and reliable assessment of quadriceps muscle strength in TKA patients.

  20. The comparison of knee isokinetic performances and anthropometric measurement of professional soccers who play different position

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    Enis Çolak

    2007-11-01

    Full Text Available The aim of our study is determine knee flexibility and knee isokinetic performance of soccer players who play different position. In this study nineteen professional soccer players who play in Kocaelispor were choosen as a subjects. Range of movement (ROMof knee and the knee flexion/extension muscle strengths were measured. In this measurement were used 60, 180 and 300 deg/sec con-con angular velocity protochol using biodex system III dynamometer.Statistically significant difference was found of total work of knee extensor in 60°/s between forwards and midfielders and also between forwards and defenders(p<0.05. Ekstansor muscle strength of forwards less than which of defenders and which of midfielders. Statistical differences were shown in 60°/s Peak Torque/body weight of between midfielders and defenders. Defenders have higher extensor muscle strength but lower values ROM. As the muscle strength and volume increase muscle get shorter. This can make risk for injures.While an exercise program is prepared play position must taken into consideration after isokinetic tests. Especially joint flexibility is indicator for future injures.

  1. The comparison of knee isokinetic performances and anthropometric measurement of professional soccers who play different position

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    Bergün Meriç

    2007-11-01

    Full Text Available The aim of our study is determine knee flexibility and knee isokinetic performance of soccer players who play different position. In this study nineteen professional soccer players who play in Kocaelispor were choosen as a subjects. Range of movement (ROMof knee and  the knee flexion/extension muscle strengths were measured. In this measurement were used  60, 180 and 300 deg/sec con-con angular velocity protochol using biodex system III dynamometer.Statistically significant difference was found of total work of knee extensor in 60°/s between forwards and midfielders and also between forwards and defenders(p<0.05. Ekstansor muscle strength of forwards less than which of defenders and which of midfielders. Statistical differences were shown in 60°/s Peak Torque/body weight of between midfielders and defenders. Defenders have higher extensor muscle strength but lower values ROM. As the muscle strength and volume increase muscle get shorter. This can make risk for injures.While an exercise program is prepared play position must taken into consideration after isokinetic tests. Especially joint flexibility is indicator for future injures.

  2. Effect of kinesio taping on the isokinetic muscle function in football athletes with a knee injury.

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    Hong, SoonKwon; Shim, JeMyung; Kim, SungJoong; Namkoong, Seung; Roh, HyoLyun

    2016-01-01

    [Purpose] The purpose of this study was to determine the difference in isokinetic muscle function in football athletes with a knee injury with and without kinesio taping. [Subjects] The subjects for this study were 10 football athletes (males) with a knee injury. [Methods] Measurements were performed by using Cybex dynamometer under uniform motion before and after the application of kinesio tape to the quadriceps and hamstring muscle. Maximal concentric knee extension and flexion at three angular velocities (60°/s, 120°/s, and 180°/s) were measured. [Results] A significant difference was found in peak torque and total work of the flexion at 120°/s and 180°/s, as well as in the average power of extension at 180°/s. [Conclusion] Though it is not the main therapy for muscle function in football athletes with injury, kinesio taping was an effective adjunct therapy.

  3. Effect of kinesio taping on the isokinetic muscle function in football athletes with a knee injury

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    Hong, SoonKwon; Shim, JeMyung; Kim, SungJoong; Namkoong, Seung; Roh, HyoLyun

    2016-01-01

    [Purpose] The purpose of this study was to determine the difference in isokinetic muscle function in football athletes with a knee injury with and without kinesio taping. [Subjects] The subjects for this study were 10 football athletes (males) with a knee injury. [Methods] Measurements were performed by using Cybex dynamometer under uniform motion before and after the application of kinesio tape to the quadriceps and hamstring muscle. Maximal concentric knee extension and flexion at three angular velocities (60°/s, 120°/s, and 180°/s) were measured. [Results] A significant difference was found in peak torque and total work of the flexion at 120°/s and 180°/s, as well as in the average power of extension at 180°/s. [Conclusion] Though it is not the main therapy for muscle function in football athletes with injury, kinesio taping was an effective adjunct therapy. PMID:26957761

  4. THE INFLUENCE OF BODY POSITION ON LOAD RANGE DURING ISOKINETIC KNEE EXTENSION/FLEXION

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    Brian W. Findley

    2006-09-01

    Full Text Available Isokinetic range of motion (ROM has three distinct phases: rate of velocity development (RVD, load range (LR, and deceleration (DCC. The purpose of this study was to determine if differences in isokinetic knee extension/flexion LR exist between body positions. Ten subjects (4 males and 6 females, age 29.3 ± 5.4 yrs, ht 1.71 ± 0.10 m, wt 71.9 ± 12.9 kg volunteered to participate in the seated vs. prone investigation and nine different subjects (4 males and 5 females, age 29.5 ± 6.9 yrs, ht 1.72 ± 0.09 m, wt 69.0 ± 13.8 kg volunteered to participate in the seated vs. supine study. Each subject completed 3 maximal reciprocal concentric/concentric repetitions of dominant knee extension/flexion on a Biodex System 2 isokinetic dynamometer at 60, 120, 180, 240 and 360 deg·sec-1 in the supine or prone and seated positions. Repeated measures ANOVA revealed that only seated flexion at 360 deg·sec-1 (57.6 ± 1.7 degrees elicited significantly (p < 0.05 greater LR than prone (49.2 ± 2.8 degrees. No significant differences in LR extension or flexion existed at any velocity between the supine vs. seated positions. ANOVA also demonstrated differences between seated vs. prone torque, work and power at most velocities while there was no difference between seated vs. supine. LR is the only phase of an isokinetic repetition where quantifiable resistance is maintained and this data appears to support that it may not be position-dependent but position may alter traditional performance variables

  5. Comparative assessment of knee extensor and flexor muscle strength measured using a hand-held vs. isokinetic dynamometer.

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    Muff, Guillaume; Dufour, Stéphane; Meyer, Alain; Severac, François; Favret, Fabrice; Geny, Bernard; Lecocq, Jehan; Isner-Horobeti, Marie-Eve

    2016-09-01

    [Purpose] To compare measurements of knee extensor and flexor muscle strength performed using a hand-held dynamometer and an isokinetic dynamometer in apparently healthy subjects. [Subjects and Methods] Thirty adult volunteers underwent knee muscle strength evaluation using an isokinetic or a hand-held dynamometer. [Results] Strong positive correlations were found between the 2 methods, with correlation coefficients r ranging from 0.72 (95% confidence interval [CI], 0.48-0.86) to 0.87 (95% CI, 0.75-0.94), depending on the muscle group and the isokinetic evaluation mode. The reproducibility of the hand-held dynamometer findings was good, judged by a coefficient of variation of 3.2-4.2%. However, the correlation between the 2 methods for the assessment of flexor/extensor ratios ranged from -0.04 to 0.46. [Conclusion] Knee extensor and flexor muscle strength recorded with a hand-held dynamometer is reproducible and significantly correlated with the isokinetic values, indicating that this method may in some cases be a useful replacement for isokinetic strength measurement. However, for strength ratio assessment, and when judged against the isokinetic standard, a hand-held dynamometer is not a valid option.

  6. Clinical assessment of the low-cost VariCom isokinetic knee exerciser.

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    Greenblatt, D; Diesel, W; Noakes, T D

    1997-04-01

    A low-cost isokinetic knee exerciser, known as the VariCom and developed with the emphasis on fulfilling the rehabilitation needs of developing countries, was subjected to a clinical evaluation. The evaluation was motivated by successful laboratory assessment of the exerciser as well as encouraging qualitative data acquired recently from a developing world hospital. The principal aim of this study was to demonstrate that the exerciser, employing a simple shock-absorber and lever mechanism, was capable of fulfilling the major criteria required from isokinetic equipment. Amongst the most important of these were attainment of a 'spectrum of velocities', patient safety, reliability, ease-of-use, patient comfort and estimation of the torque generated by the patient's knee-joint. It was ultimately demonstrated that the combination of design simplicity, durability and functionality renders the VariCom knee-exerciser technologically appropriate for use in developing countries. More generally, the success of the exerciser, combined with its low manufacturing cost, renders it a viable alternative to traditional up-market equipment.

  7. Comparative study on isokinetic capacity of knee and ankle joints by functional injury.

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    Jeon, Kyoungkyu; Seo, Byoung-Do; Lee, Sang-Ho

    2016-01-01

    [Purpose] To collect basic data for exercise programs designed to enhance functional knee and ankle joint stability based on isokinetic measurement and muscle strength evaluations in normal and impaired functional states. [Subjects and Methods] Twenty-four subjects were randomly assigned to the athlete group and the control group (n = 12 each). Data were collected of isokinetic knee extensor and flexor strength at 60°/sec, 180°/sec, and 240°/sec and ankle plantar and dorsiflexor strength at 30°/sec and 120°/sec. [Results] Significant intergroup differences were observed in peak torque of the right extensors at 60°/sec, 180°/sec, and 240°/sec and the right flexors at 240°/sec. Significant differences were observed in peak torque/body weight in the right extensors at 60°/sec, 180°/sec, and 240°/sec and in the right flexors at 180°/sec and 240°/sec. Significant peak torque differences were noted in the left ankle joint dorsiflexor at 30°/sec and 120°/sec, right plantar flexor at 120°/sec, left plantar flexor at 30°/sec, left dorsiflexor at 30°/sec and 120°/sec, and right dorsiflexor at 120°/sec. [Conclusion] Isokinetic evaluation stimulates muscle contraction at motion-dependent speeds and may contribute to the development of intervention programs to improve knee and ankle joint function and correct lower-extremity instability.

  8. The bilateral leg strength deficit is present in old, young and adolescent females during isokinetic knee extension and flexion.

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    Kuruganti, Usha; Seaman, Kenneth

    2006-06-01

    The bilateral limb deficit (BLD) describes the difference in maximal or near maximal force generating capacity of muscles when they are contracted alone or in combination with the contralateral muscles. A deficit occurs when the summed unilateral force is greater than the bilateral force. This study examined the presence of the BLD during isokinetic knee extensions and flexions in a group of adolescent females (n=8, mean of 15+/-1 years) and compared with previously reported data by this researcher of adult and older females. Data were collected from subjects during slow (45 deg/s) isokinetic knee extensions and flexions and it was found that a BLD exists during both extension and flexion regardless of age. Furthermore, this study is the first to examine the presence of the deficit in an adolescent population. Myoelectric signal (MES) data showed that there is no difference between bilateral and unilateral isokinetic knee extensions and flexions regardless of age group.

  9. Seasonal variation in isokinetic strength of knee flexors and extensors in soccer players

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    Michal Lehnert

    2015-06-01

    Full Text Available BACKGROUND: Muscle strength is an important factor in soccer from the performance and health perspective. There is a lack of knowledge about changes in muscle strength of the knee flexors and extensors and their ratios during annual training cycle. OBJECTIVES: The aim of this study was to evaluate the seasonal variability of the observed parameters of isokinetic strength of the knee flexors and extensors in soccer players, U19, from the performance and health perspective. METHODS: The strength of the knee flexors and extensors was measured in players U19 category (n = 9; the average age 18.5 ±0.4 years on the isokinetic dynamometer IsoMed 2000 in angular velocity 60° × s-1. Measurement was performed in concentric/concentric and excentric/excentric mode of muscle action at the beginning of the winter preparatory period, at the end of the preparatory period and at the end of the spring competitive period. Monitored parameters were absolute peak torque (PT, conventional H/Q ratio (H/QCON, functional H/Q ratio (H/QFUN and functional H/Q ratio in range 10-30° of knee flexion (H/QFUN_10-30. RESULTS: Significant change in PT (p < .05 was noted only in cases of the knee extensors of the nondominant leg in the concentric mode. The evaluation of imbalance of the knee flexors and extensors by H/QCON and H/QFUN ratios did not show any significant changes, but there was found a significant decrease of the H/QFUN_10-30 ratio in the dominant leg between measurements at the beginning and at the end of the winter preparatory period. CONCLUSIONS: The results of the current study indicate that throughout the monitored periods of the annual training cycle desirable changes in knee flexors and extensors strength did not occur. The values suggest the disruption of the dynamic stabilization of the knee joint and increase in injury risk. Different dynamics of the three observed ratios confirmed that they provide different information about the physical fitness of

  10. Reliability of isokinetic evaluation in passive mode for knee flexors and extensors in healthy children

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    Adriana N. Santos

    2013-04-01

    Full Text Available BACKGROUND: The isokinetic dynamometer has been considered the gold-standard measurement of muscle performance. However, the reliability for the passive mode in children has not been reported to date. OBJECTIVES: The purpose was to evaluate the reliability of the isokinetic dynamometer in passive mode in children. METHOD: Twenty-one healthy children (ten girls, eleven boys, aged 5 to 12 years (age: 8.5±2.2 years, were evaluated using an isokinetic dynamometer. Each participant was tested twice with a one-week interval and performed five consecutive cycles of knee extension and flexion. The test was performed at 60º/s in the concentric passive mode and the children performed maximal contractions. The measured variables were peak torque, average peak torque, total work, and average power, time to peak torque and angle of peak torque for dominant and non-dominant lower limbs. Reliabilities were determined using intraclass correlation coefficient (ICC3,1, standard error of measurement (SEM and SEM%, and coefficient of variation (CV. RESULTS: We found good reliability in both lower limbs for peak torque, average peak torque, total work and average power of knee flexors and extensors, with ICC3,1 values greater than 0.80; SEM ranging from 6.7 to 79.2; SEM% ranging from 10.4% to 16.8%; CV lower than 15%. Bland-Altman analysis showed that the bias was low than 10% and limits of agreement (LOAs ranging from 33.9% to 59.2%, and -28.8% and -52.8%, showing that measures tended to disagree. However, time to peak torque (ICC3,1 0.34; SEM%>37.4%; CV>41.7%; bias >24.0%; LOA>101.0% and angle of peak torque (ICC3,19.3; SEM%>27.6%; CV>15.3%; bias>11.0%; LOA>61.0% were not reliable. CONCLUSIONS: The findings indicate that isokinetic evaluation in passive mode for knee extensors and flexors of dominant and non-dominant lower limbs of children without disabilities was reliable for peak torque, average peak torque, work, and power. However, average time to peak

  11. Isokinetic and isometric muscle function of the knee extensors and flexors during simulated soccer activity: effect of exercise and dehydration.

    Science.gov (United States)

    Ali, Ajmol; Williams, Clyde

    2013-01-01

    This study investigated the influence of dehydration during soccer-type intermittent exercise on isokinetic and isometric muscle function. Eight soccer players performed two 90-min high-intensity intermittent shuttle-running trials without (NF) or with (FL) fluid ingestion (5 ml · kg(-1) before and 2 ml · kg(-1) every 15 min). Isokinetic and isometric strength and muscular power of knee flexors and knee extensors were measured pre-exercise, at half-time and post-exercise using isokinetic dynamometry. Sprint performance was monitored throughout the simulated-soccer exercise. Isokinetic knee strength was reduced at faster (3.13 rad · s(-1); P = 0.009) but not slower (1.05 rad · s(-1); P = 0.063) contraction speeds with exercise; however, there was no difference between FL and NF. Peak isometric strength of the knee extensors (P = 0.002) but not the knee flexors (P = 0.065) was significantly reduced with exercise with no difference between FL and NF. Average muscular power was reduced over time at both 1.05 rad · s(-1) (P = 0.01) and 3.14 rad · s(-1) (P = 0.033) but was not different between FL and NF. Mean 15-m sprint time increased with duration of exercise (P = 0.005) but was not different between FL and NF. In summary, fluid ingestion during 90 min of soccer-type exercise was unable to offset the reduction in isokinetic and isometric strength and muscular power of the knee extensors and flexors.

  12. Isokinetic Identification of Knee Joint Torques before and after Anterior Cruciate Ligament Reconstruction.

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    Adam Czaplicki

    Full Text Available The aim of this study was to evaluate the serial change of isokinetic muscle strength of the knees before and after anterior cruciate ligament reconstruction (ACLR in physically active males and to estimate the time of return to full physical fitness. Extension and flexion torques were measured for the injured and healthy limbs at two angular velocities approximately 1.5 months before the surgery and 3, 6, and 12 months after ACLR. Significant differences (p ≤ 0.05 in peak knee extension and flexion torques, hamstring/quadriceps (H/Q strength ratios, uninvolved/involved limb peak torque ratios, and the normalized work of these muscles between the four stages of rehabilitation were identified. Significant differences between extension peak torques for the injured and healthy limbs were also detected at all stages. The obtained results showed that 12 months of rehabilitation were insufficient for the involved knee joint to recover its strength to the level of strength of the uninvolved knee joint. The results helped to evaluate the progress of the rehabilitation and to implement necessary modifications optimizing the rehabilitation training program. The results of the study may also be used as referential data for physically active males of similar age.

  13. Isokinetic Identification of Knee Joint Torques before and after Anterior Cruciate Ligament Reconstruction.

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    Czaplicki, Adam; Jarocka, Marta; Walawski, Jacek

    2015-01-01

    The aim of this study was to evaluate the serial change of isokinetic muscle strength of the knees before and after anterior cruciate ligament reconstruction (ACLR) in physically active males and to estimate the time of return to full physical fitness. Extension and flexion torques were measured for the injured and healthy limbs at two angular velocities approximately 1.5 months before the surgery and 3, 6, and 12 months after ACLR. Significant differences (p ≤ 0.05) in peak knee extension and flexion torques, hamstring/quadriceps (H/Q) strength ratios, uninvolved/involved limb peak torque ratios, and the normalized work of these muscles between the four stages of rehabilitation were identified. Significant differences between extension peak torques for the injured and healthy limbs were also detected at all stages. The obtained results showed that 12 months of rehabilitation were insufficient for the involved knee joint to recover its strength to the level of strength of the uninvolved knee joint. The results helped to evaluate the progress of the rehabilitation and to implement necessary modifications optimizing the rehabilitation training program. The results of the study may also be used as referential data for physically active males of similar age.

  14. THE INFLUENCE OF VELOCITY OVERSHOOT MOVEMENT ARTIFACT ON ISOKINETIC KNEE EXTENSION TESTS

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    Fabiano Peruzzo Schwartz

    2010-03-01

    Full Text Available Exercise on an isokinetic device involves three distinct movement phases: acceleration, constant velocity, and deceleration. Inherent in these phases are unique occurrences that may confound test data and, thereby, test interpretation. Standard methods of data reduction like windowing and other techniques consist of removing the acceleration and deceleration phases in order to assure analysis under constant velocity conditions. However, none of these techniques adequately quantify the velocity overshoot (VO movement artifact which is a result of the devices resistance imposed to the limb. This study tested the influence of VO on isokinetic data interpretation. A computational algorithm was developed to accurately identify each movement phase and to delineate the VO segment. Therefore, the VO was then treated as a fourth and independent phase. A total of sixteen healthy men (26.8 ± 4.7 yrs, 1.76 ± 0.05 m, and 79.2 ± 9.4 kg performed two sets of ten maximal concentric extension repetitions of their dominant knee (at 60º·s-1 and 180º·s-1, on separate days and in a counterbalanced order, on a Biodex System 3 Pro dynamometer. All the phases of the isokinetic exercise were measured in terms of their biomechanical descriptors and according to the developed algorithm, the windowing method, and a data reduction technique that eliminates the first and last 10º of the total range of motion. Results showed significant differences (p < 0.05 between the constant velocity phases found by each method: the largest segment was obtained with the windowing method; the second one, with the algorithm; and the smallest, with data reduction technique. The point of peak torque was not affected by none of the techniques, but significant differences (p < 0.05 were found between the data including and not including the VO phase, concerning total work, time interval, and average length of load range: VO represents more than 10% of the amount calculated in constant

  15. Feasibility of estimating isokinetic knee torque using a neural network model.

    Science.gov (United States)

    Hahn, Michael E

    2007-01-01

    Many studies have investigated the relationships between electromyography (EMG) and torque production. A few investigators have used adjusted learning algorithms and feed-forward artificial neural networks (ANNs) to estimate joint torque in the elbow. This study sought to estimate net isokinetic knee torque using ANN models. Isokinetic knee extensor and flexor torque data were measured simultaneously with agonist and antagonist EMG during concentric and eccentric contractions at joint velocities of 30 degrees /s and 60 degrees /s. Age, gender, height, body mass, agonist EMG, antagonist EMG, joint position and joint velocity were entered as predictive variables of net torque. A three-layer ANN model was developed and trained using an adjusted back-propagation algorithm. Accuracy results were compared against those of forward stepwise regression models. Stepwise regression models included body mass, body height and joint position as the most influential predictors, followed by agonist EMG for concentric and eccentric contractions. Estimation of eccentric torque included antagonist EMG following the agonist activation. ANN models resulted in more accurate torque estimation (R=0.96), compared to the stepwise regression models (R=0.71). ANN model accuracy increased greatly when the number of hidden units increased from 5 to 10, continuing to increase gradually with additional hidden units. The average number of training epochs necessary for solution convergence and the relative accuracy of the model indicate a strong ability for the ANN model to generalize these estimations to a broader sample. The ANN model appears to be a feasible technique for estimating joint torque in the knee.

  16. The determination of isokinetic performance values of knee joint and Hamstring (flexor/Quadriceps (extensor ratios differences in Volleyball players’

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    Özlem Yenigün

    2008-06-01

    Full Text Available The aim of this study was to determined the values of isokinetic performance in knee joint and the ratios of hamstring/quadriceps (H/Q between volleyball players and controls. 30 male volleyball players (age: 19,46±2,1 and 30 male controls (age: 19,66±2,0 were participated in this study. This study investigated hamstring and quadriceps muscles strength ratio obtained during concentric muscle contraction. The ratio of H/Q muscle strength which was an indicator of normal balance between the knee flexors and extensor and it is important to estimate of the capacity for stabilization of knee joint and the preventation of disability. Knee flexion and extension measurements were tested on biodex system–3 dynamometer in %60, %180 and %300 deg/sec test protocols. The range of motion of knee Joint was evaluated by biodex system–3 dynamometer. There was no statistical difference in the ROM of the knee joint between volleyball players and controls (p>0,05. The isokinetic values of volleyball players were significantly higher than controls (p<0,05. H/Q values must be determined to prevent disability. For the aim of get ready for the season and supply the continuity of performance level increases, preseason isokinetic testing of athletes may be helpful to test for strength imbalance and to determine the correct exercises which is suitable for remove the H/Q disproportion.

  17. Isokinetic knee strength qualities as predictors of jumping performance in high-level volleyball athletes: multiple regression approach.

    Science.gov (United States)

    Sattler, Tine; Sekulic, Damir; Spasic, Miodrag; Osmankac, Nedzad; Vicente João, Paulo; Dervisevic, Edvin; Hadzic, Vedran

    2016-01-01

    Previous investigations noted potential importance of isokinetic strength in rapid muscular performances, such as jumping. This study aimed to identify the influence of isokinetic-knee-strength on specific jumping performance in volleyball. The secondary aim of the study was to evaluate reliability and validity of the two volleyball-specific jumping tests. The sample comprised 67 female (21.96±3.79 years; 68.26±8.52 kg; 174.43±6.85 cm) and 99 male (23.62±5.27 years; 84.83±10.37 kg; 189.01±7.21 cm) high- volleyball players who competed in 1st and 2nd National Division. Subjects were randomly divided into validation (N.=55 and 33 for males and females, respectively) and cross-validation subsamples (N.=54 and 34 for males and females, respectively). Set of predictors included isokinetic tests, to evaluate the eccentric and concentric strength capacities of the knee extensors, and flexors for dominant and non-dominant leg. The main outcome measure for the isokinetic testing was peak torque (PT) which was later normalized for body mass and expressed as PT/Kg. Block-jump and spike-jump performances were measured over three trials, and observed as criteria. Forward stepwise multiple regressions were calculated for validation subsamples and then cross-validated. Cross validation included correlations between and t-test differences between observed and predicted scores; and Bland Altman graphics. Jumping tests were found to be reliable (spike jump: ICC of 0.79 and 0.86; block-jump: ICC of 0.86 and 0.90; for males and females, respectively), and their validity was confirmed by significant t-test differences between 1st vs. 2nd division players. Isokinetic variables were found to be significant predictors of jumping performance in females, but not among males. In females, the isokinetic-knee measures were shown to be stronger and more valid predictors of the block-jump (42% and 64% of the explained variance for validation and cross-validation subsample, respectively

  18. Explanatory models of muscle performance in acromegaly patients evaluated by knee isokinetic dynamometry: Implications for rehabilitation.

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    Lopes, Agnaldo José; Ferreira, Arthur Sá; Walchan, Evelyn Mendes; Soares, Mauricio Santos; Bunn, Priscila Santos; Guimarães, Fernando Silva

    2016-10-01

    To evaluate the effects of demographics and hormonal variations on knee muscle performance in patients with acromegaly and develop explanatory models of peripheral muscle function in these individuals. This was a cross-sectional study in which 53 acromegalics and 27 healthy subjects underwent knee isokinetic dynamometry to evaluate the peak torque value for leg extension at 75°/s (PTE75) and 240°/s (PTE240). Separate multivariable linear regression models for the prediction of PTE75 and PTE240 were tested using variables commonly used as predictors in the clinical setting and other specific variables related to acromegaly. The final prediction model for PTE75 (R(2)=0.888; adjusted R(2)=0.820, SE of bias=16.2Nm, p<0.001) was -0.221×growth hormone+36.791×sexmale=1-27.407×statusactive=1-0.690×age+148.071. The final prediction model for PTE240 (R(2)=0.816; adjusted R(2)=0.805, SE of bias=8.8Nm, p<0.001) was -0.174×growth hormone+12.522×sexmale=1-0.520×age+98.099. In acromegalics, high growth hormone levels, female gender, and older age are associated with reduced muscle strength and endurance. Additionally, active disease negatively affects peripheral muscle strength in these patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Knee-joint proprioception during 30-day 6 degrees head-down bed rest with isotonic and isokinetic exercise training

    Science.gov (United States)

    Bernauer, E. M.; Walby, W. F.; Ertl, A. C.; Dempster, P. T.; Bond, M.; Greenleaf, J. E.

    1994-01-01

    To determine if daily isotonic exercise or isokinetic exercise training coupled with daily leg proprioceptive training, would influence leg proprioceptive tracking responses during bed rest (BR), 19 men (36 +/- SD 4 years, 178 +/- 7 cm, 76.8 +/- 7.8 kg) were allocated into a no-exercise (NOE) training control group (n = 5), and isotonic exercise (ITE, n = 7) and isokinetic exercise (IKE, n = 7) training groups. Exercise training was conducted during BR for two 30-min periods.d-1, 5 d.week-1. Only the IKE group performed proprioceptive training using a new isokinetic procedure with each lower extremity for 2.5 min before and after the daily exercise training sessions; proprioceptive testing occurred weekly for all groups. There were no significant differences in proprioceptive tracking scores, expressed as a percentage of the perfect score of 100, in the pre-BR ambulatory control period between the three groups. Knee extension and flexion tracking responses were unchanged with NOE during BR, but were significantly greater (*p proprioceptive tracking was unchanged during BR with NOE, both isotonic exercise training (without additional proprioceptive training) and especially isokinetic exercise training when combined with daily proprioceptive training, significantly improved knee proprioceptive tracking responses after 30 d of BR.

  20. Influence of functional knee bracing on the isokinetic and functional tests of anterior cruciate ligament deficient patients.

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    Niyousha Mortaza

    Full Text Available Use of functional knee braces has been suggested to provide protection and to improve kinetic performance of the knee in Anterior cruciate ligament(ACL-injured patients. However, many athletes might refrain from wearing the braces because of the fear of performance hindrance in the playing field. The aim of this study was to examine the effect of three functional knee brace/sleeves upon the isokinetic and functional performance of ACL-deficient and healthy subjects. Six anterior cruciate ligament deficient (29.0 ± 5.3 yrs., 175.2 ± 5.4 cm, and 73.0 ± 10.0 kg and six healthy male subjects (27.2 ± 3.7 yrs., 176.4 ± 6.4 cm, and 70.3 ± 6.9 kg were selected. The effect of a custom-made functional knee brace, and two neoprene knee sleeves, one with four metal supports and one without support were examined via the use of isokinetic and functional tests in four sets (non-braced,wearing functional knee brace,and wearing the sleeves. Cross-over hop and single leg vertical jump test were performed and jump height, and hop distance were recorded. Peak torque to body weight ratio and average power in two isokinetic velocities(60°.s(-1,180°.s(-1 were recorded and the brace/sleeves effect was calculated as the changes in peak torque measured in the brace/sleeves conditions, expressed as a percentage of peak torque measured in non-braced condition. Frequency content of the isokinetic torque-time curves was also analyzed. Wilcoxon signed rank test was used to compare the measured values in four test conditions within each control and ACL-deficient group,and Mann-Whitney U test was used for the comparison between the two groups. No significant differences in peak torque, average power, torque-time curve frequency content, vertical-jump and hop measurements were found within the experimental and the non-braced conditions (p>0.05. Although the examined functional knee brace/sleeves had no significant effect on the knee muscle performance, there have been

  1. Knee-Joint Proprioception During 30-Day 6 deg Head-Down Bed Rest with Isotonic and Isokinetic Exercise Training

    Science.gov (United States)

    Bernauer, E. M.; Walby, W. F.; Ertl, A. C.; Dempster, P. T.; Bond, M.; Greenleaf, J. E.

    1994-01-01

    To determine if daily isotonic exercise or isokinetic exercise training coupled with daily log proprioceptive training, would influence log proprioceptive tracking responses during Bed Rest (BR), 19 men (36 +/- SD 4 years, 178 +/- 7 cm, 76.8 +/- 7.8 kg) were allocated into a NO-Exercise (NOE) training control group (n = 5), and IsoTanic Exercise (ITE, n = 7) and IsoKinetic Exercise (IKE, n = 7) training groups. Exercise training was conducted during BR for two 30-min period / d, 5 d /week. Only the IKE group performed proprioceptive training using a now isokinetic procedure with each lower extremity for 2.5 min before and after the daily exercise training sessions; proprioceptive testing occurred weekly for all groups. There were no significant differences in proprioceptive tracking scores, expressed as a percentage of the perfect score of 100, in the pro-BR ambulatory control period between the three groups. Knee extension and flexion tracking responses were unchanged with NOE during BR, but were significantly greater (*p less than 0.05) at the end of BR in both exercise groups when compared with NOE responses (extension: NOE 80.7 +/- 0.7%, ITE 82.9 +/- 0.6%, IKE 86.5* +/- 0.7%; flexion: NOE 77.6 +/- 1.50, ITE 80.0 +/- 0.8% (NS), IKE 83.6* +/- 0.8%). Although proprioceptive tracking was unchanged during BR with NOE, both lsotonic exercise training (without additional propriaceptive training) and especially isokinetic exercise training when combined with daily proprioceptive training, significantly improved knee proprioceptive tracking responses after 30 d of BR.

  2. Analysis of the association between isokinetic knee strength with offensive and defensive jumping capacity in high-level female volleyball athletes.

    Science.gov (United States)

    Sattler, Tine; Sekulic, Damir; Esco, Michael R; Mahmutovic, Ifet; Hadzic, Vedran

    2015-09-01

    Isokinetic-knee-strength was hypothesized to be an important factor related to jumping performance. However, studies examining this relation among elite female athletes and sport-specific jumps are lacking. This investigation determined the influence of isokinetic-knee flexor/extensor strength measures on spike-jump (offensive) and block-jump (defensive) performance among high-level female volleyball players. Cross-sectional laboratory study. Eighty-two female volleyball athletes (age = 21.3 ± 3.8 years, height = 175.4 ± 6.76 cm, and weight = 68.29 ± 8.53 kg) volunteered to participate in this study. The studied variables included spike-jump and block-jump performance and a set of isokinetic tests to evaluate the eccentric and concentric strength capacities of the knee extensors (quadriceps - Q), and flexors (hamstring - H) for both legs. Both jumping tests showed high intra-session reliability (ICC of 0.87 and 0.95 for spike-jump and block-jump, respectively). The athletes were clustered into three achievement-groups based on their spike-jump and block-jump performances. For the block-jump, ANOVA identified significant differences between achievement-groups for all isokinetic variables except the Right-Q-Eccentric-Strength. When observed for spike-jump, achievement-groups differed significantly in all tests but Right-H-Concentric-Strength. Discriminant canonical analysis showed that the isokinetic-strength variables were more associated with block-jump then spike-jump-performance. The eccentric isokinetic measures were relatively less important determinants of block-jump than for the spike-jump performance. Data support the hypothesis of the importance of isokinetic strength measures for the expression of rapid muscular performance in volleyball. The results point to the necessity of the differential approach in sport training for defensive and offensive duties. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  3. Physiological alterations of maximal voluntary quadriceps activation by changes of knee joint angle.

    Science.gov (United States)

    Becker, R; Awiszus, F

    2001-05-01

    The purpose of this study was to investigate the influence of different angles of the knee joint on voluntary activation of the quadriceps muscle, estimating the ability of a subject to activate a muscle maximally by means of voluntary contraction. Isometric torque measurement was performed on 6 healthy subjects in 5 degrees intervals between 30 degrees and 90 degrees of knee joint flexion. Superimposed twitches at maximal voluntary contraction (MVC) and at a level of 60% and 40% of the MVC were applied and the voluntary activation estimated. At between 30 degrees and 75 degrees of knee flexion, the maximal extension torque increased at an average rate of 2.67 +/- 0.6 Nm/degree, followed by a decline with further flexion. However, throughout the joint-angle range tested, voluntary activation increased on average by 0.37%/degree with a maximum at 90 degrees of flexion. Due to the influence of joint position it is not possible to generalize results obtained at the knee joint angle of 90 degrees of flexion, which is usually used for the quadriceps twitch-interpolation technique. Consequently, it is useful to investigate voluntary activation deficits in knee joint disorders at a range of knee joint angles that includes, in particular, the more extended joint angles used frequently during daily activity.

  4. Voluntary activation of human knee extensors measured using transcranial magnetic stimulation.

    Science.gov (United States)

    Goodall, S; Romer, L M; Ross, E Z

    2009-09-01

    The aim of this study was to determine the applicability and reliability of a transcranial magnetic stimulation twitch interpolation technique for measuring voluntary activation of a lower limb muscle group. Cortical voluntary activation of the knee extensors was determined in nine healthy men on two separate visits by measuring superimposed twitch torques evoked by transcranial magnetic stimulation during isometric knee extensions of varying intensity. Superimposed twitch amplitude decreased linearly with increasing voluntary torque between 50 and 100% of mean maximal torque, allowing estimation of resting twitch amplitude and subsequent calculation of voluntary activation. There were no systematic differences for maximal voluntary activation within day (mean +/- s.d. 90.9 +/- 6.2 versus 90.7 +/- 5.9%; P = 0.98) or between days (90.8 +/- 6.0 versus 91.2 +/- 5.7%; P = 0.92). Systematic bias and random error components of the 95% limits of agreement were 0.23 and 9.3% within day versus 0.38 and 7.5% between days. Voluntary activation was also determined immediately after a 2 min maximal voluntary isometric contraction; in four of these subjects, voluntary activation was determined 30 min after the sustained contraction. Immediately after the sustained isometric contraction, maximal voluntary activation was reduced from 91.2 +/- 5.7 to 74.2 +/- 12.0% (P knee extensors.

  5. ANALYSIS OF ISOKINETIC KNEE EXTENSION / FLEXION IN MALE ELITE ADOLESCENT WRESTLERS

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    Sanli Sadi Kurdak

    2005-12-01

    Full Text Available Wrestling requires strength of the upper and lower body musculature which is critical for the athletic performance. Evaluation of the adolescent's skeletal muscle is important to understand body movement, especially including those involved in sports. Strength, power and endurance capacity are defined as parameters of skeletal muscle biomechanical properties. The isokinetic dynamometer is an important toll for making this type of evaluation. However, load range phase of range of motion has to be considered to interpret the data correctly. With this in mind we aimed to investigate the lover body musculature contractile characteristics of adolescent wrestlers together with detailed analyses of load range phase of motion. Thirteen boys aged 12 - 14 years participated to this study. Concentric load range torque, work and power of knee extension and flexion were measured by a Cybex Norm dynamometer at angular velocities from 450°/sec to 30°/sec with 30°/sec decrements for each set. None of the wrestlers were able to attain load range for angular velocities above 390°/sec and 420°/sec for extension and flexion respectively. Detailed analyses of the load range resulted in statistically significant differences in the normalized load range peak torque for extension at 270°/sec (1.44 ± 0.28 Nm·kg-1 and 1.14 ± 0.28 Nm·kg-1 for total and load range peak torque respectively, p < 0.05, and for flexion at 300°/sec (1.26 ± 0.28 Nm·kg-1 and 1.03 ± 0.23 Nm·kg-1 for total and load range peak torque respectively, p < 0.05, compared to total peak torque data. Similarly, the significant difference was found for the work values at 90°/sec (1.91 ± 0.23 Nm·kg-1 and 1.59 ± 0.24 Nm·kg-1 for total and load range work respectively for extension and 1.73 ± 0.21 Nm·kg-1 and 1.49 ± 0.19 Nm·kg-1 for total and load range work respectively for flexion, p < 0.05, and was evident at higher angular velocities (p < 0.001 for both extension and flexion. At

  6. Isokinetic dynamometry of knee flexors and extensors: comparative study among non-athletes, jumper athletes and runner athletes

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    Siqueira Cássio Marinho

    2002-01-01

    Full Text Available Participation in intensive sports activities leads to muscular specializations that may generate alterations in involved articular forces and cause static (posture and dynamic changes (alterations of articular stability, coordination, etc.. Prevention of injury requires specific functional muscular evaluation in all athletes and for any kind of sport. OBJECTIVE: To dynamically evaluate, through isokinetic tests, the peak torque, total work, and average power of the knee flexor and extensor muscles of jumper and runner athletes and compare them to those of a non-athletic population, evaluating dominance and balance between agonistic and antagonistic muscle groups. RESULTS: In the non-athlete group, we noted a higher asymmetry between the dominant and nondominant members. The jumpers had the highest values of the evaluated parameters of all groups, whereas parameters for the runners were intermediate between non-athletes and jumpers.

  7. Correlation between the 8-repetition maximum test and isokinetic dynamometry in the measurement of muscle strength of the knee extensors: A concurrent validity study.

    Science.gov (United States)

    Taylor, J David; Fletcher, James P

    2013-05-01

    The 8-repetition maximum test has the potential to be a feasible, cost-effective method of measuring muscle strength for clinicians. The purpose of this study was to investigate the concurrent validity of the 8-repetition maximum test in the measurement of muscle strength by comparing the 8-repetition maximum test to the gold standard of isokinetic dynamometry. Thirty participants (15 males and 15 females, mean age = 23.2 years [standard deviation = 1.0]) underwent 8-repetition maximum testing and isokinetic dynamometry testing of the knee extensors (at 60, 120, and 240 degrees per second) on two separate sessions with 2-3 days between each mode of testing. Linear regression was used to assess the validity by comparing the findings between 8-repetition maximum testing and isokinetic dynamometry testing. Significant correlations were found between the 8-repetition maximum and isokinetic dynamometry peak torque at each testing velocity (r  =  0.71-0.85). The highest correlations were between the 8-repetition maximum and isokinetic dynamometry peak torques at 60 (r  =  0.85) and 120 (r  =  0.85) degrees per second. The findings of this study provide supportive evidence for the use of 8-repetition maximum testing as a valid, alternative method for measuring muscle strength.

  8. The relationship between previous hamstring injury and the concentric isokinetic knee muscle strength of irish gaelic footballers

    Directory of Open Access Journals (Sweden)

    O'Ceallaigh Brian

    2008-03-01

    Full Text Available Abstract Background Hamstring injury is one of the most common injuries affecting gaelic footballers, similar to other field sports. Research in other sports on whether residual hamstring weakness is present after hamstring injury is inconsistent, and no study has examined this factor in irish gaelic footballers. The aim of this study was to examine whether significant knee muscle weakness is present in male Irish gaelic footballers who have returned to full activity after hamstring injury. Methods The concentric isokinetic knee flexion and extension strength of 44 members of a university gaelic football team was assessed at 60, 180 and 300 degrees per second using a Contrex dynamometer. Results Fifteen players (34% reported a history of hamstring strain, with 68% of injuries affecting the dominant (kicking limb. The hamstrings were significantly stronger (p 0.05 using this comparison. The previously unilaterally injured hamstrings were significantly weaker (p Conclusion Hamstring muscle weakness was observed in male Irish gaelic footballers with a history of hamstring injury. This weakness is most evident when comparisons are made to multiple control populations, both within and between subjects. The increased strength of the dominant limb should be considered as a potential confounding variable in future trials. The study design does not allow interpretation of whether these changes in strength were present before or after injury.

  9. Simultaneous Knee Extensor Muscle Action Induces an Increase in Voluntary Force Generation of Plantar Flexor Muscles.

    Science.gov (United States)

    Suzuki, Takahito; Shioda, Kohei; Kinugasa, Ryuta; Fukashiro, Senshi

    2017-02-01

    Suzuki, T, Shioda, K, Kinugasa, R, and Fukashiro, S. Simultaneous knee extensor muscle action induces an increase in voluntary force generation of plantar flexor muscles. J Strength Cond Res 31(2): 365-371, 2017-Maximum activation of the plantar flexor muscles is required for various sporting activities that involve simultaneous plantar flexion and knee extension. During a multi-joint movement, activation of the plantar flexor muscles is affected by the activity of the knee extensor muscles. We hypothesized that coactivation of the plantar flexor muscles and knee extensor muscles would result in a higher plantar flexion torque. To test this hypothesis, 8 male volunteers performed maximum voluntary isometric action of the plantar flexor muscles with and without isometric action of the knee extensor muscles. Surface electromyographic data were collected from 8 muscles of the right lower limb. Voluntary activation of the triceps surae muscles, evaluated using the interpolated twitch technique, significantly increased by 6.4 percentage points with intentional knee extensor action (p = 0.0491). This finding is in line with a significant increase in the average rectified value of the electromyographic activity of the vastus lateralis, fibularis longus, and soleus muscles (p = 0.013, 0.010, and 0.045, respectively). The resultant plantar flexion torque also significantly increased by 11.5% of the predetermined maximum (p = 0.031). These results suggest that higher plantar flexor activation coupled with knee extensor activation facilitates force generation during a multi-joint task.

  10. Avaliação isocinética no joelho do atleta Isokinetic evaluation of athletes' knee

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    Antonio Sérgio A.P. Terreri

    2001-10-01

    power of muscle groups, and to determine relative values, that is, the agonist/antagonist proportion of such groups. Another valuable resource of this evaluation may be used as an auxiliary method in the rehabilitation of sports lesions. The examination is performed with a constant and preset angular speed, that is, low, intermediate, and/or high speed. Most isokinetic studies are applied to the knee. In the sports practice, the agonist/antagonist muscle balance, that is, the flexor/extensor balance represented, respectively, by the ischiotibial muscle/quadriceps plays an important role. On the other hand, the comparison between the absolute values of the muscle function for the left and right sides is also relevant. Changed results usually relate to sports lesions or their sequels. The development of an objective and safe method to evaluate the muscle functionality which provides for reliable and reproducible results is of utmost importance to athletes and to multidisciplinary teams. Also significant are the results obtained from isokinetic tests, which may be useful to establish criteria for athletes to resume and practice sports activities after lesions. This review aims at addressing some practical aspects of the isokinetic evaluation in the knee and its use in individuals performing sports activities.

  11. Knee Muscles Isokinetic Evaluation after a Six-Month Regular Combined Swim and Dry-Land Strength Training Period in Adolescent Competitive Swimmers

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    Dalamitros Athanasios A.

    2015-12-01

    Full Text Available Previous studies demonstrated significant increases in the shoulder internal rotators’ peak torque values and unilateral muscular imbalances of the shoulder rotators after a competitive swim period. However, there are no similar data concerning the knee muscles. The purpose of the current study was to examine the effects of a six-month training period on knee flexor and extensor peak torque values, examine a possible bilateral strength deficit and evaluate the unilateral strength balance in competitive swimmers. Eleven male adolescent swimmers (age: 14.82 ± 0.45 years were tested for concentric knee extension and flexion peak torque (60°/s with an isokinetic dynamometer, before and after a regular combined swim and dry-land strength training period. A trend towards greater improvements in the knee extensor compared to flexor muscles peak torque was observed. Furthermore, the bilateral strength deficit remained almost unchanged, whereas unilateral strength imbalance was increased for both limbs. However, all results were nonsignificant (p > 0.05. According to the data presented, a six-month regular combined swim and dry-land strength training period caused non-significant alterations for all the parameters evaluated during isokinetic testing. This study highlights the fact that competitive adolescent swimmers demonstrated unilateral knee strength imbalances throughout a long period of their yearly training macrocycle.

  12. Knee Muscles Isokinetic Evaluation after a Six-Month Regular Combined Swim and Dry-Land Strength Training Period in Adolescent Competitive Swimmers.

    Science.gov (United States)

    Dalamitros, Athanasios A; Manou, Vasiliki; Christoulas, Kosmas; Kellis, Spiros

    2015-12-22

    Previous studies demonstrated significant increases in the shoulder internal rotators' peak torque values and unilateral muscular imbalances of the shoulder rotators after a competitive swim period. However, there are no similar data concerning the knee muscles. The purpose of the current study was to examine the effects of a six-month training period on knee flexor and extensor peak torque values, examine a possible bilateral strength deficit and evaluate the unilateral strength balance in competitive swimmers. Eleven male adolescent swimmers (age: 14.82 ± 0.45 years) were tested for concentric knee extension and flexion peak torque (60°/s) with an isokinetic dynamometer, before and after a regular combined swim and dry-land strength training period. A trend towards greater improvements in the knee extensor compared to flexor muscles peak torque was observed. Furthermore, the bilateral strength deficit remained almost unchanged, whereas unilateral strength imbalance was increased for both limbs. However, all results were non-significant (p > 0.05). According to the data presented, a six-month regular combined swim and dry-land strength training period caused non-significant alterations for all the parameters evaluated during isokinetic testing. This study highlights the fact that competitive adolescent swimmers demonstrated unilateral knee strength imbalances throughout a long period of their yearly training macrocycle.

  13. Changes in voluntary quadriceps activation predict changes in muscle strength and gait biomechanics following knee joint effusion.

    Science.gov (United States)

    Pietrosimone, Brian; Lepley, Adam S; Murray, Amanda M; Thomas, Abbey C; Bahhur, Nael O; Schwartz, Todd A

    2014-09-01

    It has been hypothesized that arthrogenic muscle inhibition is responsible for altering physical function following knee injury. The association between the onset of arthrogenic muscle inhibition, measured using voluntary quadriceps activation, and changes in muscle strength and gait biomechanics are unknown. Outcomes were collected before and following a 60 ml experimental knee effusion in eighteen healthy participants. Voluntary quadriceps activation was the predictor variable, while the criterion variable included, maximal voluntary isometric strength, peak knee flexion angle, peak internal knee extension moment, and peak vertical ground reaction forces during the first half of stance phase upon stair descent. Percent change scores (Δ) were imputed into linear regression equations to determine associations between predictor and criterion variables. The variance in Δ voluntary quadriceps activation significantly predicted 87% the variance in the Δ strength (R(2)=0.87, Pknee flexion angle, Δ voluntary quadriceps activation predicted an additional 29% (Δ R(2)=0.29, P=0.007) of the variance in the Δ knee extension moment (R(2)=0.54, P=0.003, Δ knee extension moment=-10.79+0.74Δ knee flexion angle+1.64Δ voluntary quadriceps activation) following knee effusion. Immediate quadriceps activation deficits following joint effusion result in immediate alterations in muscle strength, knee extensor moment and vertical ground reaction force during gait. Published by Elsevier Ltd.

  14. Inter-machine reliability of the Biodex and Cybex isokinetic dynamometers for knee flexor/extensor isometric, concentric and eccentric tests.

    Science.gov (United States)

    de Araujo Ribeiro Alvares, João Breno; Rodrigues, Rodrigo; de Azevedo Franke, Rodrigo; da Silva, Bruna Gonçalves Cordeiro; Pinto, Ronei Silveira; Vaz, Marco Aurélio; Baroni, Bruno Manfredini

    2015-02-01

    To assess the inter-machine reliability of the Biodex System 3 Pro and Cybex Humac Norm Model 770 dynamometers for knee extensor and knee flexor peak torque measurements in isometric, concentric and eccentric tests. Randomized/crossover. Exercise Research Laboratory, Federal University of Rio Grande do Sul (Brazil). 25 healthy male subjects. Isometric, concentric and eccentric knee extensor and knee flexor peak torques recorded in the same test procedure performed on both isokinetic dynamometers. One-way ANOVA, intraclass correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of variation (CV) were used to verify significant differences, relative and absolute reliability between devices. No significant differences were found between tests performed on Biodex and Cybex (p > 0.05). ICC values indicated a high to very high reproducibility for isometric, concentric and eccentric peak torques (0.88-0.92), and moderate to high reliability for agonist-antagonist strength ratios (0.62-0.73). Peak torque did not show great difference between dynamometers for SEM (3.72-11.27 Nm) and CV (5.27-7.77%). Strength ratios presented CV values of 8.57-10.72%. Maximal knee extensor and knee flexor tests performed in isometric (60° of knee flexion), concentric and eccentric modes at 60°/s in Biodex and Cybex dynamometers present similar values. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Twitch potentiation induced by stimulated and voluntary isometric contractions at various torque levels in human knee extensor muscles.

    Science.gov (United States)

    Miyamoto, Naokazu; Yanai, Toshimasa; Kawakami, Yasuo

    2011-03-01

    The purpose of this study was to compare the extent of twitch potentiation (TP) after stimulated or voluntary contractions at identical intensities for the human knee extensor muscles. Isometric knee extensions of 10 s were performed at 20%, 40%, and 60% of maximal voluntary contraction (MVC) torque level, through percutaneous electrical stimulation of the quadriceps at 80 Hz or voluntary contraction. Twitch responses were evoked by stimulating the femoral nerve percutaneously with supramaximal intensity. The extent of TP after the stimulated contraction was greater than that after the voluntary contraction at the 20% MVC torque level, whereas a stimulated contraction induced a smaller extent of TP than did a voluntary contraction at contraction intensities higher than 40% MVC. We suggest that this contraction intensity dependence of differences in TP after stimulated and voluntary isometric conditioning contractions is responsible for differences in the recruitment pattern of motor units during the conditioning contractions.

  16. Isokinetic leg strength and power in elite handball players.

    Science.gov (United States)

    González-Ravé, José M; Juárez, Daniel; Rubio-Arias, Jacobo A; Clemente-Suarez, Vicente J; Martinez-Valencia, María A; Abian-Vicen, Javier

    2014-06-28

    Isokinetic strength evaluation of the knee flexion and extension in concentric mode of contraction is an important part of the comprehensive evaluation of athletes. The aims of this study were to evaluate the isokinetic knee peak torque in both the extension and flexion movement in the dominant and non-dominant leg, and the relationship with jumping performance. Twelve elite male handball players from the top Spanish handball division voluntary participated in the study (age 27.68 ± 4.12 years; body mass 92.89 ± 12.34 kg; body height 1.90 ± 0.05 m). The knee extensor and flexor muscle peak torque of each leg were concentrically measured at 60º/s and 180º/s with an isokinetic dynamometer. The Squat Jump and Countermovement Jump were performed on a force platform to determine power and vertical jump height. Non-significant differences were observed between legs in the isokinetic knee extension (dominant= 2.91 ± 0.53 Nm/kg vs non-dominant = 2.70 ± 0.47 Nm/kg at 60º/s; dominant = 1.90 ± 0.31 Nm/kg vs non-dominant = 1.83 ± 0.29 Nm/kg at 180º/s) and flexion peak torques (dominant = 1.76 ± 0.29 Nm/kg vs non-dominant = 1.72 ± 0.39 Nm/kg at 60º/s; dominant = 1.30 ± 0.23 Nm/kg vs non-dominant = 1.27 ± 0.35 Nm/kg at 180º/s). Low and non-significant correlation coefficients were found between the isokinetic peak torques and vertical jumping performance (SJ = 31.21 ± 4.32 cm; CMJ = 35.89 ± 4.20 cm). Similar isokinetic strength was observed between the legs; therefore, no relationship was found between the isokinetic knee flexion and extension peak torques as well as vertical jumping performance in elite handball players.

  17. Can a wearable strain sensor based on a carbon nanotube network be an alternative to an isokinetic dynamometer for the measurement of knee-extensor muscle strength?

    Science.gov (United States)

    Benlikaya, Ruhan; Ege, Yavuz; Pündük, Zekine; Slobodian, Petr; Meriç, Gökhan

    2017-04-01

    This study aimed to find out whether a wearable strain sensor including thermoplastic polyurethane composite with a multi-walled carbon nanotube network could be a viable alternative to an isokinetic dynamometer for the measurement of knee-extensor muscle strength. For the first time, the voltage-torque and angle–time relations of the sensor were determined to allow a comparison between the angle-dependent torque changes of the dynamometer and the sensor. This comparison suggested that the torque–angle relations of the dynamometer and the sensor did not have the same characteristics. In this regard, the sensor may be used in the torque measurements due to the moderate correlation between the torque values determined via the isokinetic dynamometer and the sensor and due to the significant difference between low and high torque values of the sensor. By the same token, the torque-angle graph of the sensor may be more informative than that of the dynamometer in evaluation of knee problems.

  18. Isokinetic and isometric muscle strength combined with transcutaneous electrical muscle stimulation in primary fibromyalgia syndrome

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Wildschiødtz, Gordon; Danneskiold-Samsøe, B

    1991-01-01

    Twenty women with primary fibromyalgia syndrome and 20 age matched healthy women were investigated. The subjects performed maximum voluntary isokinetic contractions of the right quadriceps in an isokinetic dynamometer. Maximum voluntary isometric contractions of the right quadriceps were performe...

  19. Effect of remote voluntary contractions on knee extensor torque and rate of velocity development.

    Science.gov (United States)

    Cherry, Emily A; Brown, Lee E; Coburn, Jared W; Noffal, Guillermo J

    2010-09-01

    Remote voluntary contractions (RVCs) are described as a muscle action of the prime mover while performing a simultaneous muscle action with another part of the body. Previous studies have shown that RVCs may elicit augmented performance of the prime mover. The purpose of this study was to evaluate the effect of RVCs on knee extensor rate of velocity development (RVD) and peak torque. Fourteen men and 16 women who were regularly active and free of any knee pathology for the past year took part in this study. Subjects performed 3 maximal dynamic knee extensions at 3 velocities with and without an RVC condition. The RVC condition consisted of holding hand dynamometers in each hand and maximally gripping while performing a maximal knee extension movement. The NO-RVC condition was the same only without gripping. Men produced greater peak torque and RVD than did women across speeds and conditions. Analysis demonstrated that RVC had no effect on knee extension peak torque, but RVD decreased in the RVC condition (NO-RVC 2,012.07 [46.52] degrees xs-1xs-1; RVC 1,882.61 [51.84] degrees xs-1xs-1). Grip strength of the left hand at 180 degrees xs-1decreased from 42.03 (14.40) to 38.83 (14.65) kg in the RVC condition. In conclusion, RVC should not be used when attempting to maximize RVD, because it may hinder results when performing a single joint movement.

  20. Isokinetic quadriceps and hamstring muscle strength and knee function 5 years after anterior cruciate ligament reconstruction: comparison between bone-patellar tendon-bone and hamstring tendon autografts.

    Science.gov (United States)

    Lautamies, Riitta; Harilainen, Arsi; Kettunen, Jyrki; Sandelin, Jerker; Kujala, Urho M

    2008-11-01

    Existing clinical studies have not proven which graft is to be preferred in anterior cruciate ligament (ACL) reconstruction. In recent years, bone-patellar tendon-bone and hamstring tendons have been the most frequently used graft types. Muscle strength deficit is one of the consequences after ACL reconstruction. The aim of this study was to evaluate possible differences in hamstring and quadriceps muscle strength and knee function 5 years after ACL reconstruction between the BPTB and the STG groups. The study group consisted of 288 patients (132 women, 156 men) with a unilateral ACL rupture who had received a BPTB (175 patients) or STG (113 patients) ACL reconstruction. Lower extremity concentric isokinetic peak extension and flexion torques were assessed at the angular velocities of 60 degrees /s and 180 degrees /s. The International Knee Documentation Committee (IKDC), the Tegner activity level, the Lysholm knee and the Kujala patellofemoral scores were also collected. Isokinetic quadriceps peak torque (percentage of the contralateral side) was 3.9% higher in the STG group than in the BPTB group at the velocity of 60 degrees /s and 3.2% higher at the velocity of 180 degrees /s and the isokinetic hamstring peak torque 2% higher in the BPTB group than in the STG group at the velocity of 60 degrees /s and 2.5% higher at the velocity of 180 degrees /s. In both groups the subjects had weaker quadriceps and hamstring muscle strength in the injured extremity compared with the uninjured one. In the single-leg hop test (according to the IKDC recommendations) there was a statistically significant difference (P = 0.040) between the groups. In the STG group, 68% of the patients had the single-leg hop ratio (injured vs. uninjured extremity) > or =90%, 31% of the patients 75-89% and 1% of the patients <75%, while in the BPTB group the corresponding percentages were 72, 21 and 7%. However, no statistically significant differences in clinical outcome were found between the

  1. The correlation between isokinetic strength of knee extensors and vertical jump performance in adolescent soccer players in an annual training cycle

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    Michal Lehnert

    2013-03-01

    Full Text Available BACKGROUND: Isokinetic testing is often used to provide coaches with important information about the physical status of athletes. Therefore, a number of studies focused on the assessment of the relationship between isokinetic and functional tests including soccer. The results of a limited number of studies indicate that the relationship changes in different training periods. OBJECTIVE: The aim of the study was to determine the relationship between the characteristics of the isokinetic strength of knee extensors and vertical jump performance in three different periods of the annual training cycle in adolescent soccer players. METHODS: A group of adolescent soccer players (n = 16; average age 16.7 ± 0.7 years was tested at the end of the competitive season, at the beginning of the off-season and during the sixth week of a new competitive season. The isokinetic concentric peak torque (PT, peak power (Pmax and time to peak torque (TPT of the dominant leg and non-dominant leg were measured at angular velocities of 60°•s–1, 180°•s–1, 360°•s–1. The explosive strength of the lower extremities was measured using the countermovement jump with free arms (CMJF method and countermovement jump with the arms crossed over the chest. Based on literary reviews, a logically significant value of the correlation was set at > 0.30. RESULTS: The correlations between the isokinetic strength characteristics and vertical jump performance irrespective of the training period were low to moderate; 56% of the correlations were > 0.30. In the different periods of the annual training cycle, the occurrence of correlations > 0.30 as well as their value varied – 67% at the end of the competitive season, 31% at the beginning of the off-season and 64% at the beginning of the competitive season. For both types of jumps, the correlations for Pmax and PT parameters were the lowest during the second measurement in most cases; no trend was observed for the TPT

  2. Voluntary Movement Frequencies in Submaximal One- and Two-Legged Knee Extension Exercise and Pedaling.

    Science.gov (United States)

    Stang, Julie; Wiig, Håvard; Hermansen, Marte; Hansen, Ernst Albin

    2016-01-01

    Understanding of behavior and control of human voluntary rhythmic stereotyped leg movements is useful in work to improve performance, function, and rehabilitation of exercising, healthy, and injured humans. The present study aimed at adding to the existing understanding within this field. To pursue the aim, correlations between freely chosen movement frequencies in relatively simple, single-joint, one- and two-legged knee extension exercise were investigated. The same was done for more complex, multiple-joint, one- and two-legged pedaling. These particular activities were chosen because they could be considered related to some extent, as they shared a key aspect of knee extension, and because they at the same time were different. The activities were performed at submaximal intensities, by healthy individuals (n = 16, thereof eight women; 23.4 ± 2.7 years; 1.70 ± 0.11 m; 68.6 ± 11.2 kg). High and fair correlations (R-values of 0.99 and 0.75) occurred between frequencies generated with the dominant leg and the nondominant leg during knee extension exercise and pedaling, respectively. Fair to high correlations (R-values between 0.71 and 0.95) occurred between frequencies performed with each of the two legs in an activity, and the two-legged frequency performed in the same type of activity. In general, the correlations were higher for knee extension exercise than for pedaling. Correlations between knee extension and pedaling frequencies were of modest occurrence. The correlations between movement frequencies generated separately by each of the legs might be interpreted to support the following working hypothesis, which was based on existing literature. It is likely that involved central pattern generators (CPGs) of the two legs share a common frequency generator or that separate frequency generators of each leg are attuned via interneuronal connections. Further, activity type appeared to be relevant. Thus, the apparent common rhythmogenesis for the two legs appeared

  3. Voluntary movement frequencies in submaximal one- and two-legged knee extension exercise and pedaling

    Directory of Open Access Journals (Sweden)

    Julie Sørbø Stang

    2016-02-01

    Full Text Available Understanding of behavior and control of human voluntary rhythmic stereotyped leg movements is useful in work to improve performance, function, and rehabilitation of exercising, healthy, and injured humans. The present study aimed at adding to the existing understanding within this field. To pursue the aim, correlations between freely chosen movement frequencies in relatively simple, single-joint, one- and two-legged knee extension exercise were investigated. The same was done for more complex, multiple-joint, one- and two-legged pedaling. These particular activities were chosen because they could be considered related to some extent, as they shared a key aspect of knee extension, and because they at the same time were different. The activities were performed at submaximal intensities, by healthy individuals (n=16, thereof 8 women; 23.4±2.7 years; 1.70±0.11 m; 68.6±11.2 kg.High and fair correlations (R-values of 0.99 and 0.75 occurred between frequencies generated with the dominant leg and the nondominant leg during knee extension exercise and pedaling, respectively. Fair to high correlations (R-values between 0.71 and 0.95 occurred between frequencies performed with each of the two legs in an activity, and the two-legged frequency performed in the same type of activity. In general, the correlations were higher for knee extension exercise than for pedaling. Correlations between knee extension and pedaling frequencies were of modest occurrence.The correlations between movement frequencies generated separately by each of the legs might be interpreted to support the following working hypothesis, which was based on existing literature. It is likely that involved central pattern generators (CPGs of the two legs share a common frequency generator or that separate frequency generators of each leg are attuned via interneuronal connections. Further, activity type appeared to be relevant. Thus, the apparent common rhythmogenesis for the two legs

  4. Effects of isokinetic eccentric training on knee extensor and flexor torque and on gait of individuals with long term ACL reconstruction: A controlled clinical trial

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    Heleodório Honorato dos Santos

    2014-12-01

    Full Text Available This study investigated the effects of the isokinetic eccentric training (IET on the knee extensor and flexor torque and kinematic gait parameters in individuals with ACL reconstruction. Sixteen men with ACL reconstructed (ACLr whose torque and the gait were evaluated, before and after 12 weeks of IET, was compared to a control group (14 individuals. Student t, MANOVA and ANOVA tests were performed with 5% of significance. The training increased the isometric, concentric at 30 and 120º/s (p < .05 and eccentric at 30º/s (p < .01 extensor torque on the affected limb (AL, and eccentric at 30 and 120º/s (p < .01, on the non-affected limb (NAL. In the flexors, there was an increase on the torque: isometric, concentric at 30º/s and eccentric at 30 and 120º/s (p < .01 in AL and in eccentric at 30 (p < .05 and 120º/s (p< .01 in NAL. With respect to the angular and spatio-temporal variables gait, there was no difference between pre-and post-training in LCAr group. Compared to control group, the cycle time, in two members, was lower in LCAr group, and stride length and cadence were higher in the AL of the LCAr (p < .05. Moreover, the knee flexion-extension angles (minimum and maximum remained lower in LCAr, pre- and post-training (p < .01. The torque gain associated with eccentric isokinetic training did not affect the kinematic parameters of gait in patients undergoing ACL reconstruction.

  5. Articulate torque and electromyographic activity of biceps femoris and semitendinosus muscles during isokinetic knee flexion movements in soccer athletes

    Directory of Open Access Journals (Sweden)

    Eduardo Bodnariuc Fontes

    2007-09-01

    Full Text Available The objective of the present study was to analyze the articulate torque (TO and the electromyographic activity (EMG of soccer athlete’s long head Biceps Femoris (BF and Semitendinosus (ST muscles during isokinetic knee fl exion movements (concentric-CON and eccentric-ECC actions at differing velocities, carried out in the ventral decubitus position. Fourteen soccer players aged 19 and 20 years old (71.2 ± 6.5 kg, 176.6 ± 6.4 cm were enrolled from the Associação Atlética Ponte Preta under- 20 team. They followed a protocol specifying 5 repetitions of fl exion (CON and ECC action of the knee at three velocities (60, 180 and 300º/s at random. The recovery interval between series adopted was 3 minutes. EMG Activity was recorded using surface electrodes and data were expressed in terms of root mean squares (RMS. Statistical analysis employed analysis of variance (Friedman test for repeated measures followed by the Wilcoxon test when necessary, with the level of signifi cance set at P ABSTRACT O objetivo do presente estudo foi analisar o torque articular (TO e a atividade eletromiográfi ca (EMG dos músculos Bíceps Femoral (BF cabeça longa e semitendíneo (ST durante movimentos isocinéticos de fl exão do joelho (ação concêntrica-CON e excêntrica-EXC, em diferentes velocidades de execução, na posição de decúbito ventral em atletas de futebol. Fizeram parte do estudo 14 atletas de futebol da equipe sub-20, da Associação Atlética Ponte Preta, com idade entre 19 e 20 anos (71,24 ± 6,53 kg, 176,59 ± 6,44 cm. Os atletas realizaram uma série de cinco repetições de fl exão (ação CON e EXC do joelho, em 3 velocidades (60, 180 e 300°/s, defi nidas anteriormente aleatoriamente. O intervalo de recuperação adotado entre as séries foi de 3 minutos. A atividade EMG foi coletada, utilizando-se eletrodos de superfície e os dados foram expressos em root mean square (RMS. Para análise estatística, foi empregada a análise de vari

  6. Avaliação isocinética em pacientes submetidos à artroplastia total de joelho Isokinetic evaluation of patients submitted to total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Marco Kawamura Demange

    2009-01-01

    Full Text Available OBJETIVOS: Tem-se afirmado que a via de acesso minimamente invasiva na artroplastia total de joelho (ATJ por não agredir o músculo quadríceps femoral permite reabilitação mais precoce. A fim de verificar a influência da preservação do aparelho extensor no ato cirúrgico, avaliou-se a força da musculatura extensora e flexora do joelho em pacientes submetidos à ATJ por duas vias de acesso diferentes. MATERIAIS E MÉTODOS: Este estudo comparou, no período de janeiro de 2005 a julho de 2006, os valores de torque máximo e de trabalho total obtidos por dinamometria isocinética aos seis meses de pós-operatório. Foram avaliados 12 indivíduos submetidos a ATJ por via de acesso minimamente invasiva e 8 indivíduos submetidos a ATJ por via de acesso transquadricipital. RESULTADOS: A análise estatística dos valores de torque máximo e de trabalho total absolutos e corrigidos pelo peso corporal não demonstrou diferença entre os dois grupos. CONCLUSÃO: Não há diferença de força da musculatura extensora e flexora do joelho aos seis meses de cirurgia.OBJECTIVE: In total knee arthroplasty, the minimally-invasive approach has been claimed to enable earlier rehabilitation because it spares the femoral quadriceps muscle. To check the influence of preserving the extensor apparatus during surgery, the strength of knee extension and flexion muscles was evaluated in patients submitted to total knee arthroplasty with different approaches. MATERIALS AND METHODS: The values of maximum torque and total work obtained by isokinetic dynamometry six months after surgery were compared for the Minimally invasive surgery group constituted of 12 individuals submitted to total knee arthroplasty by the minimally invasive surgical approach and the Control group, constituted of eight patients submitted to total knee arthroplasty by the transquadricipital approach, between January 2005 and July 2006. RESULTS: Statistical analysis of the absolute values for

  7. Nonlinear relationship between isokinetic muscle strength and activity limitations in patients with knee osteoarthritis: Results of the Amsterdam-Osteoarthritis cohort.

    Science.gov (United States)

    Edelaar, Lisa M; van Dieën, Jaap H; van der Esch, Martin; Roorda, Leo D; Dekker, Joost; Lems, Willem F; van der Leeden, Marike

    2017-07-07

    To investigate whether relationships between upper leg muscle strength and activity limitations are non-linear in patients with knee osteoarthritis, and, if so, to determine muscle strength thresholds for limitations in daily activities. Baseline data were used for 562 patients with knee osteoarthritis in the Amsterdam-Osteoarthritis cohort. Upper leg muscle strength (Nm/kg) was measured isokinetically. Activity limitations were measured with the timed Get Up and Go test and timed Stair Climb Test, subdivided into stair-ascent and stair-descent. Linear and non-linear relationships between muscle strength and activity limitations were evaluated, and thresholds were determined. Non-linear models improved model fit compared with linear models. The improvement in percentage variance accounted for was 5.9, 8.2 and 5.2 percentage points for the timed Get Up and Go, stair-ascent and stair-descent times, respectively. Muscle strength thresholds were 0.93 Nm/kg (95% confidence interval (95% CI) 0.82-1.04), 0.89 Nm/kg (95% CI 0.77-1.02) and 0.97 Nm/kg (95% CI 0.85-1.11) for relationships with timed Get Up and Go, stair-ascent and stair-descent times, respectively. In patients with knee osteoarthritis, relationships between muscle strength and activity limitations are non-linear. Patients with muscle strength below the described thresholds might benefit more from muscle strength training to reduce limitations in daily activities than would patients with muscle strength above the thresholds. Further research is needed to assess the clinical value of the thresholds determined.

  8. Strength Training to Contraction Failure Increases Voluntary Activation of the Quadriceps Muscle Shortly After Total Knee Arthroplasty

    DEFF Research Database (Denmark)

    Mikkelsen, Elin Karin; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders;

    2016-01-01

    OBJECTIVE: The objective of this study was to investigate voluntary activation of the quadriceps muscle during one set of knee extensions performed until contraction failure in patients shortly after total knee arthroplasty. DESIGN: This was a cross-sectional study of 24 patients with total knee...... arthroplasty. One set of knee extensions was performed until contraction failure, using a predetermined 10 repetition maximum loading. In the operated leg, electromyographic (EMG) activity of the lateral and medial vastus, semitendinosus, and biceps femoris muscles was recorded during the set. Muscle activity...... (%EMGmax) and median power frequency of the EMG power spectrum were calculated for each repetition decile (10%-100% contraction failure). RESULTS: Muscle activity increased significantly over contractions from a mean of 90.0 and 93.6 %EMGmax (lateral vastus and medial vastus, respectively) at 10...

  9. Within- and between-session reliability of the maximal voluntary knee extension torque and activation.

    Science.gov (United States)

    Park, Jihong; Hopkins, J Ty

    2013-01-01

    A ratio between the torque generated by maximal voluntary isometric contraction (MVIC) and exogenous electrical stimulus, central activation ratio (CAR), has been widely used to assess quadriceps function. To date, no data exist regarding between-session reliability of this measurement. Thirteen neurologically sound volunteers underwent three testing sessions (three trials per session) with 48 hours between-session. Subjects performed MVICs of the quadriceps with the knee locked at 90° flexion and the hip at 85°. Once the MVIC reached a plateau, an electrical stimulation from superimposed burst technique (SIB: 125 V with peak output current 450 mA) was manually delivered and transmitted directly to the quadriceps via stimulating electrodes. CAR was calculated by using the following equation: CAR = MVIC torque/MVIC + SIB torque. Intraclass correlation coefficients (ICC) were calculated within- (ICC((2,1))) and between-session (ICC((2,k))) for MVIC torques and CAR values. Our data show that quadriceps MVIC and CAR are very reliable both within- (ICC((2,1)) = 0.99 for MVIC; 0.94 for CAR) and between-measurement sessions (ICC((2,k)) = 0.92 for MVIC; 0.86 for CAR) in healthy young adults. For clinical research, more data of the patients with pathological conditions are required to ensure reproducibility of calculation of CAR.

  10. Isokinetic Strength of Knee Flexors and Extensors and Relationship with Functions in Patients with Knee Osteoarthritis%膝骨关节炎患者膝屈伸肌群等速肌力及其与功能的相关性

    Institute of Scientific and Technical Information of China (English)

    王剑雄; 周谋望; 宫萍; 付桂敏; 李筱雯; 杨延砚; 丛卉; 吴同绚

    2014-01-01

    目的:观察膝关节骨关节炎(KOA)患者膝屈伸肌群等速肌力变化及其与膝关节功能的关系。方法23例双侧KOA患者及14名正常人进行膝屈伸肌等速肌力检查、五次坐-起试验(FTSST)、静态平衡测试、步态分析。KOA组还完成疼痛视觉模拟评分(VAS)及WOMAC骨关节炎指数评定。结果 KOA组伸肌及屈肌峰力矩、峰力矩均值、平均功率、单次最佳做功及总功主患侧均小于对侧(P0.05)。结论 KOA患者伸肌及屈肌等速肌力主患侧较对侧减弱,伸肌等速肌力较正常人减弱,膝伸屈肌肌力变化不同步。KOA患者伸肌等速肌力峰力矩与膝关节疼痛、功能之间存在相关性。%Objective To investigate the isokinetic strength of knee extensors and flexors in patients with knee osteoarthritis (KOA), and to establish the correlation between the isokinetic strength and function in patients with KOA. Methods 23 patients with bilateral KOA and 14 matched normal controls finished the isokinetic test of knee extensors and flexors, the Five Times Sit-to-Stand Test (FTSST), Gait analy-sis, and Balance test. The KOA patients were evaluated with Visual Analog Scale (VAS) for pain and Western Ontario and McMaster Univer-sity Osteoarthritis Index (WOMAC). Results It was less of the peak torque, average peak torque, average power, max rep total work, total work of knee extensors and flexors in the mainly involved limbs than the contralateral limbs (P0.05). Conclusion It is weak of the isokinetic strength of knee extensors and flexors in patients with KOA in the mainly involved limb, as well as the isokinetic strength of knee extensors compared with the normal controls. The changes in the ex-tensors and flexors are not equivalent. The peak torque of knee extensors significantly correlated with the pain and functions of the knee.

  11. 小学生膝关节屈伸肌力的等速测试%Isokinetic test of flexor and extensor strength in primary student knees

    Institute of Scientific and Technical Information of China (English)

    及化娟; 魏孟田; 王丽霞

    2011-01-01

    背景:以往对小学生下肢力量发育的评估,主要局限于立定跳远和纵跳摸高等身体素质的测量,缺乏对其肌肉功能的定量性研究.目的:通过小学生膝关节屈伸肌力发展现状进行测试分析,正确认识小学生关节肌肉力量发育特征.方法:运用"Kinitech "等速肌力测试系统对随机抽取石家庄市年龄为9~12 岁的54 名健康小学生(男25 例、女29 例)膝关节屈伸肌群进行60,120,240 (°)/s 三种速度测试.结果与结论:小学生膝关节屈、伸肌群峰力矩均呈现随测试速度增加而下降的现象;男、女生左侧屈肌群在60,120 (°)/s 时及右侧屈肌群在60 (°)/s 时,峰力矩低于伸肌群峰力矩(P < 0.01 或P < 0.05).同一测试速度下,在测试速度为240 (°)/s 时,男生左侧屈、伸肌群及右侧屈肌群峰力矩明显高于女生(P < 0.01 或P < 0.05).%BACKGROUND: Previous evaluation for lower limb strength in primary students are limited for physical quality measurement,such as standing long jump or jump touching, which lack of quantitative studies.OBJECTIVE: To learn the characteristic of development in muscle strength in primary students using isokinetic testing system. METHODS: The flexion and extension strength of knee joints in 54 healthy primary students aged 9-12 (25 boys and 29 girls)were measured by using Kinitech Isokinetic testing system with 3 angular velocities: 60 (°)/s, 120 (°)/s and 240 (°)/s.RESULTS AND CONCLUSION: The peak torque (PT) of primary students was decreased with angular velocities increasing; The PT value of left side at speed of 60 (°)/s and 120 (°)/s, and right side at speed of speed of 60(°)/s was lower than that of the extensors in both genders (P < 0.01 or P < 0.05). At the same speed, the PT value of flexor and extensor in left side and flexor in the right side of boys were obviously higher than that of girls at 240 (°)/s (P < 0.01 or P <0.05).

  12. Effect of Isokinetic Training on Stiff Knees after Fracture Immobilization of Femur%等速训练在股骨骨折制动后膝关节僵硬康复中的应用

    Institute of Scientific and Technical Information of China (English)

    沈良册; 杨秋红; 吴玉玲; 吴立红; 林建强

    2012-01-01

    Objective To investigate the effect of isokinetic training on stiff knees after fracture arrest. Methods 38 fracture patients were divided into observation group (n=19) and control group (n=19) by the medical number. Both 2 groups received the Chinese herbs fumigation and joint mobilization. Besides, the observation group received the isokinetic training, while the control group received the instrument training. The range of motion (ROM), maximum peak torque (PT), peak torque/body weight (PT/BW), average power (AP), and hamstrings/quadriceps (H/Q) were tested before and 16 weeks after training. Results The flexion, straightness and flexion radian became significantly better after training. The flexion and the increase of the flexion radian were significantly better in observation group than in control group after training. All indexes of the isokinetic test significantly improved after training (P0.05). RO1VU PT% PT/ BW and AP of the knees joint were significantly better in the observation group than in the control group (P0.05) after training. Conclusion Isokinetic training can promote recovery of stiff knees of femur fracture.%目的 探讨等速训练在骨折制动后膝关节僵硬康复中的效果.方法 选择本科住院及门诊骨折患者38例,按就诊顺序分为观察组(n=19)和对照组(n=19).两组均采用中药熏蒸和关节松动术治疗.观察组在此基础上加等速训练,对照组在此基础上加器械训练(股四头肌训练椅).治疗前及治疗16周后,观察两组膝关节活动度、屈伸肌群最大峰力矩、峰力矩与体重比、平均功率、屈伸肌肌力比值的变化情况.结果 治疗后两组关节屈曲度、伸直度、屈伸弧均显著优于治疗前(P0.05).结论 等速训练在骨折制动后膝关节僵硬的康复中有很好的治疗作用.

  13. 等速训练对膝半月板损伤关节镜手术后膝关节功能恢复及关节周围肌肉力量的影响%The Impact of Knee Function and Muscles Strength of Isokinetic for Patients with Knee Meniscus after Arthroscopic Surgery

    Institute of Scientific and Technical Information of China (English)

    邵正海; 张玉发; 吕宏; 毕霞; 高亮亮; 刘小垒; 黄鑫凝

    2014-01-01

    目的:回顾性分析等速训练康复方案对膝半月板损伤患者术后关节功能恢复及关节周围肌肉力量的影响。方法:对25例膝半月板损伤患者关节镜术后采取等速康复训练,与对照组行常规训练进行比较。结果:经治疗二个疗程后,观察组单次最大做功、力矩加速能、屈膝伸肌峰力矩测试和平均做功率各指标均优于对照组(P<0.05),差异有统计学意义。结论:等速康复训练对膝半月板损伤关节镜手术后患者具有较好的改善,能够明显改善患者的预后状况,值得临床推广应用。%Objective:Retrospective analysis impact of knee function and muscles strength of Isokinetic for patients with knee meniscus after arthroscopic surgery. Methods:25 cases of arthroscopic knee meniscus injury patients were taken isokinetic rehabilitation after surgery, and the efficacy of the control group were compared. Results:After two courses of treatment, the maximum single acting, torque acceleration energy, knee extensor peak torque test and the average power of the observation group were all better than the control group(P<0.05). Conclusion:The isokinetic method for knee meniscus injury patients’ rehabilitation after arthroscopic surgery was helpfui and could significantly improve the patient's prognosis, worthy of clinical application.

  14. The Relationships Among Isokinetic Endurance, Initial Strength Level, and Fiber Type.

    Science.gov (United States)

    Clarkson, Priscilla M.; And Others

    1982-01-01

    Knee extension isokinetic peak torque was assessed at four angular velocities, and isokinetic endurance was assessed in eight college age men. Muscle fiber type was determined and related to isokinetic strength and fatigability. Results indicate that factors other than fiber type and initial strength level must influence the rate of isokinetic…

  15. Combined effects of myofeedback and isokinetic training on hand ...

    African Journals Online (AJOL)

    Khaled A. Olama

    2012-04-25

    Apr 25, 2012 ... physical therapy program with isokinetic training for the triceps brachii muscle for 60 min, in addition group B ... The knee is extended. The foot is planter ..... movement with increased eccentric muscular control, and im-.

  16. 等速运动训练对膝关节损伤后功能恢复的影响研究%Clinical research on the effect of isokinetic training on knee injury patients’ recovery function

    Institute of Scientific and Technical Information of China (English)

    杨丽; 周军; 罗伟

    2014-01-01

    目的:分析等速运动训练对膝关节损伤后功能恢复的影响。方法:选择98例膝关节损伤患者,根据康复训练方式不同将其随机分为接受常规训练的对照组和接受等速运动训练的观察组,每组49例,检测训练前后患者的膝关节功能、伸屈肌肌力及关节活动度等情况。结果:两组患者训练后Lysholm膝关节功能评分均高于训练前,且观察组患者的Lysholm膝功能评分明显高于对照组;两组患者训练后伸屈肌肌力水平均高于治疗前,且观察组患者的伸屈肌PT、AP和MRTW水平高于对照组;训练后8周及16周,观察组患者的伸膝、屈膝最大角度均明显高于对照组。结论:等速运动训练可以有效改善膝关节损伤患者的关节功能,提高其肌力同时扩大关节活动度,有效提高患者的生活质量。%Objective: To analyze the Effect of isokinetic training on knee injury patients’ recovery function. Methods: Choose knee injury patients between October 2012 to October 2013 as research object, randomly divided into control group received conventional training, and observe group received isokinetic training, each with 49 cases, detecting knee function after training, stretching flexor muscle strength, range of motion. Results: 1) After training ,both groups of patients inflammation Lysholm knee function scores were higher than before,and observation group patients Lysholm knee function score were significantly higher; 2)After training, both groups extensor flexor muscle strength were higher than before,and the observation group patients’ stretched flexor PT, AP, MRTW level were higher; 3)After eight weeks of training and 16 weeks, observation group patients’ knee extension, knee flexion angles were significantly higher.Conclusion:Isokinetic exercise training can improve knee joint function in patients, improve muscle strength while expanding its range of motion, improve the quality of life

  17. Knee Isokinetic Characteristics of Chinese Women Basketball Players%中国女子篮球运动员膝关节等速肌力测试分析

    Institute of Scientific and Technical Information of China (English)

    罗安民; 李珺晖; 洪平

    2012-01-01

    目的:了解中国国家女子篮球队运动员膝关节等速肌力特征.方法:选用IsoMed 2000等速测试系统,采用60°/s、180°/s、240°/s三种角速度,测试18名中国女篮国家队运动员膝关节等速肌力.根据场上位置将运动员分为三组:后卫组7人(1、2号位),前锋组6人(3、4号位),中锋组5人(5号位),比较分析三组运动员的测试结果.结果:(1)女篮运动员双侧膝关节慢速测试时(60°/s)屈伸肌峰力矩(PT)显著高于快速测试(180°/s,240°/s),膝关节屈伸肌蜂力矩比值(H/Q)随测试速度增加递增,左右膝H/Q无显著性差异.(2)慢速测试时(60°/s),左右膝关节峰力矩、峰力矩/体重比值、平均功率、H/Q无显著差异.(3)快速测试(240°/s)时,左膝屈肌PT、峰力矩/体重比值(PT/BW)显著高于右膝.180°/s测试时,左膝屈肌平均功率显著高于右膝.(4)60°/s测试时,后卫、前锋、中锋运动员PT、PT/BW组间比较无显著性差别.180°/s测试时,后卫运动员左膝屈肌PT与前锋、中锋运动员比较有显著性差异(P=0.02),各组间伸肌PT未见显著差异.240°/s测试时,后卫运动员右膝屈、伸肌PT/BW和中锋运动员比较均存在显著差异;后卫、前锋、中锋三组运动员平均功率、H/Q、总功与峰值功率组间比较均无显著性差别.结论:(1)女篮运动员快速测试(240°/s)时左膝屈肌力量强于右膝,反映快速运动时左右膝关节肌力不平衡.(2)不同场上位置女篮运动员膝关节等速肌力快速测试结果有差异性,提示力量训练应根据场上位置进行特异性训练.(3)女篮运动员需加强屈肌快速力量训练,以提高H/Q,预防膝关节损伤.%Objective To understand Chinese national women basketball players knee joint isokinet-ic feature,and to provide quantitive basis for scientific selecting women basketball talents and developing rehabilitation programe. Methods Knee joints of eighteen players from Chinese National Women

  18. THE EFFECT OF CREATINE SUPPLEMENTATION ON ATHLETE ISOKINETIC PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Erkan Faruk ŞİRİN

    2009-12-01

    Full Text Available The purpose of this study is to find the effects of Creatin Monohydrate (CrH2O on athlete performance (isokinetic power measured as a total workout used as an ergojenic aid in long-term (6 weeks supplementation. There are 38 participants willing to join to the study. Their ages are between 20 and 27. All of them are choosed from active athletes. From the findings of this study; all the participants’ in the creatin group have increased the total workout production in all cycles of isokinetic exercise. The difference between the values in the first and fifth cycles, (both before and after loading are statistically significant. In the creatin group the difference between before loading and 15th day values are statistically significant. But the difference between before loading and 50th day values does not have statistical difference. In placebo group, before and after values in all 5 cycles, there is no statistical difference between the total workout production values. There is also no statistical difference between the before loading and 15th day values. As the same there is no statistical difference between the before loading and the 50th day values. The most important finding in this study is that, there is no affect of long term creatin loading (50 days on maximal voluntary knee extansion, as a total muscle workout values. But the change in values before loading day and 15th day are significantly improved. And so we understand that, for getting better results in total workout production, we better use two weeks period loading instead of long term loading. Key Words: Ergogenic aid, creatine supplementation, isokinetic performance

  19. Characteristics of fast voluntary and electrically evoked isometric knee extensions during 56 days of bed rest with and without exercise countermeasure.

    NARCIS (Netherlands)

    Mulder, E.R.; Gerrits, K.H.; Rittweger, J.; Felsenberg, D.; Stegeman, D.F.; Haan, A. de

    2008-01-01

    The contractile characteristics of fast voluntary and electrically evoked unilateral isometric knee extensions were followed in 16 healthy men during 56 days of horizontal bed rest and assessed at bed rest days 4, 7, 10, 17, 24, 38 and 56. Subjects were randomized to either an inactive control group

  20. Relation of selective voluntary motor control of the lower extremity and extensor strength of the knee joint in children with spastic diplegia.

    Science.gov (United States)

    Kusumoto, Yasuaki; Takaki, Kenji; Matsuda, Tadamitsu; Nitta, Osamu

    2016-06-01

    [Purpose] The aim of this study was to investigate differences in selective voluntary motor control of the lower extremities by objective assessment and determine the relationship between selective voluntary motor control and knee extensor strength in children with spastic diplegia. [Subjects and Methods] Forty individuals who had spastic cerebral palsy, with Gross Motor Function Classification System levels ranging from I to III, were assessed using the Selective Control Assessment of the Lower Extremity and by testing the maximum knee extensor strength. The unaffected side was defined as the lower limb with the higher score, and the affected side was defined as the lower limb with the lower score. [Results] The Selective Control Assessment of the Lower Extremity score on the affected side had a lower average than that on the unaffected side. The scores showed a significant inverse correlation with the maximum knee extensor strength. [Conclusion] There was bilateral difference in the selective voluntary motor control of the lower extremities in children with spastic diplegia, and the selective voluntary motor control of the lower extremity was related to maximum knee extensor strength.

  1. Effect of isokinetic training on the function recovery of knee meniscus injuries following arthroscope%关节镜术后等速训练对膝半月板损伤恢复的影响

    Institute of Scientific and Technical Information of China (English)

    李兴海; 任延波; 席国平

    2006-01-01

    training on the functional recovery of knee flexors and extensors and the muscle force around the joint after knee meniscus injuries receiving arthroscopy.DESIGN: Case-control observation SETTING: Department of Police Training, Liaoning Advanced Police Officer School PARTICIPANTS: A total of 20 patients with acute meniscus injury of lateral knee joint were selected from the Department of Surgery, Affiliated Hospital of Dalian Medical University between September 2004 and January 2005. They were randomly divided into experimental group and control group,including 11 cases respectively. METHODS: All the patients were treated with arthroscope operation, additionally the control patients received routine blocking, physiotherapy and massage, etc. To recover the function. From the 2nd to 4th days postoperative, the patients of experimental group began to carry out the functional rehabilitation, and received isokinetic exercise in both knees flexors and extensors with the Cybex-6000 isokinetic dynamometer 3 weeks later.MAIN OUTCOME MEASURES: Peak torque values, total work, torque accelerating energy and average power in both knee flexors and extensors at different angular velocities [60, 120 and 180(°)/s].RESULTS: A total of 22 patients were involved in the result analysis.①After arthroscope operation and isokinetic training, the range of joint movement were extended, and the maximum flexion angle changed from (132±25)° to (158±21)°. There were significant differences before and after training by t test (P < 0.01).②The experimental group had statistical significance compare with control group in the test index at 60, 120 and 180(°)/s(P < 0.05).CONCLUSION: The arthroscope combining with isokinetic training can speed up the rehabilitation after knee meniscus injury, enhance the muscle force around knee joint and maintain the stability of knee joint and motor ability.

  2. Analysis On Isokinetic Test Of Flexion And Extension Muscle Strength Of Knee Joints In Young Fencers%青少年击剑运动员膝关节屈伸肌群等速肌力测试分析

    Institute of Scientific and Technical Information of China (English)

    宣磊; 江海魁

    2011-01-01

    By using the methods of documentary、 experiments and statistics,the article analyzes isokinetic strength of flexion and extension muscle of lower extremities knee in youth fencers of Anhui,and objectively evaluates the differences in bilateral peak torque of flexors and extensors of knee between adult and youth fencers.Besides,the author also offers the theory basis and puts forward suggestions and countermeasures in special force training for the young fencers.%运用文献资料法、实验法、数据统计法,对安徽省击剑队青少年运动员下肢膝关节屈伸肌群等速肌力进行分析研究,客观评价青少年与成年击剑运动员在下肢膝关节屈伸肌群力量特征方面存在的差异,同时为青少年击剑专项力量训练提供理论依据和针对性建议。

  3. Isokinetic Testing in Evaluation Rehabilitation Outcome After ACL Reconstruction

    Science.gov (United States)

    Cvjetkovic, Dragana Dragicevic; Bijeljac, Sinisa; Palija, Stanislav; Talic, Goran; Radulovic, Tatjana Nozica; Kosanovic, Milkica Glogovac; Manojlovic, Slavko

    2015-01-01

    Introduction: Numerous rehab protocols have been used in rehabilitation after ACL reconstruction. Isokinetic testing is an objective way to evaluate dynamic stability of the knee joint that estimates the quality of rehabilitation outcome after ACL reconstruction. Our investigation goal was to show importance of isokinetic testing in evaluation thigh muscle strength in patients which underwent ACL reconstruction and rehabilitation protocol. Subjects and methods: In prospective study, we evaluated 40 subjects which were divided into two groups. Experimental group consisted of 20 recreational males which underwent ACL reconstruction with hamstring tendon and rehabilitation protocol 6 months before isokinetic testing. Control group (20 subjects) consisted of healthy recreational males. In all subjects knee muscle testing was performed on a Biodex System 4 Pro isokinetic dynamo-meter et velocities of 60°/s and 180°/s. We followed average peak torque to body weight (PT/BW) and classic H/Q ratio. In statistical analysis Student’s T test was used. Results: There were statistically significant differences between groups in all evaluated parameters except of the mean value of PT/BW of the quadriceps et velocity of 60°/s (p>0.05). Conclusion: Isokinetic testing of dynamic stabilizers of the knee is need in diagnostic and treatment thigh muscle imbalance. We believe that isokinetic testing is an objective parameter for return to sport activities after ACL reconstruction. PMID:25870471

  4. Isokinetic dynamometry in elderly women undergoing total knee arthroplasty: a comparative study Dinamometria isocinética na determinação da evolução da artroplastia total do joelho em mulheres idosas: um estudo comparativo

    Directory of Open Access Journals (Sweden)

    Marcos de Amorim Aquino

    2006-06-01

    Full Text Available OBJECTIVE: The present study assessed the reliability and validity of isokinetic dynamometry in the qualitative determination of the evolution of total knee arthroplasty. Cases: 20 patients whose mean age was 71.35 years, undergoing knee arthroplasty, and 25 controls whose mean age was 71.36 years. METHOD: Computerized isokinetic assessment of flexor and extensor muscles using a CYBEX® 6000 dynamometer. RESULTS: The total flexor/extensor effort ratio for the treated side of patients vs the nondominant side of controls was not significantly different. The flexion/extension ratio concerning maximum torque for the treated side of patients vs the nondominant side of controls was significantly different. CONCLUSION: By detecting deficiencies in the balance of flexor and extensor muscles (a balance that is required for uniform gait, it will be possible to select specific rehabilitation exercises according to the individual needs of each patient undergoing surgery.OBJETIVO: O presente estudo avaliou a dinamometria isocinética na determinação qualitativa da evolução da artroplastia total do joelho. CASUÍSTICA E MÉTODO: Vinte pacientes com média de 71, 35 anos, submetidas a artroplastia de joelho e 25 controles com média de 71,36 anos. Foi utilizada avaliação isocinética computadorizada para os músculos flexores e extensores dos joelhos num dinamômetro marca CYBEX® 6000. RESULTADOS: A análise estatística dos valores da relação entre o trabalho total flexor e extensor não demonstrou diferenças significativas entre o lado operado das pacientes e o lado não dominante das voluntárias. A relação flexão/extensão do torque máximo demonstrou uma diferença significativa entre o lado operado das pacientes e o lado não-dominante das voluntárias. CONCLUSÃO: Por detecção de deficiências do equilíbrio dos músculos flexores e extensores (equilíbrio este necessário para uma marcha uniforme, poderão ser enfatizados exercícios de

  5. 等速肌力训练对全膝关节置换术后髌骨轨迹异常的影响%A clinical evaluation of isokinetic training for correcting patellar tracking after total knee replacement

    Institute of Scientific and Technical Information of China (English)

    张颖; 袁红; 曹建刚; 李益平; 王勇军; 杜金刚

    2011-01-01

    目的 探讨股四头肌不同角度等速肌力训练对全膝关节置换术后髌骨轨迹异常者的影响.方法 入选全膝关节置换术患者52例,共66个膝关节,其中男9例10膝,女43例56膝,平均年龄58.3岁.按接诊顺序分为3组,即0~30°组、30~60°组和60~90°组进行股四头肌训练,每组22个膝关节.采用德国lsomed 2000型等速肌力训练系统对各组(膝关节屈曲范围分别为0~30°、30~60°及60~90°)进行3个月的股四头肌向心性收缩训练,测试速度为30°/s.治疗前、后拍摄膝关节负重正侧位及屈膝45°轴位片,测量髌骨指数、外侧髌骨角及髌骨协调角;记录每个膝关节的峰力矩、总功率及平均功率;治疗前、后采用美国特种外科医院(HSS)膝关节功能评分评定膝关节功能.结果 0~30°组治疗前、后的髌骨指数、外侧髌骨角及髌骨协调角比较,差异有统计学意义(P<0.01),30~60°组及60~90°组治疗前、后相关指标差异无统计学意义(P>0.05);治疗后,各组峰力矩、总功率及平均功率均较治疗前增大(P<0.05).治疗前后反映髌骨轨迹的指标,即髌骨指数、外侧髌骨角及髌骨协调角差值均与0~30°组股四头肌肌力指标,即峰力矩、总功率及平均功率的差值呈正相关(P<0.05),但与30~60°组及60~90°组的各项肌力指标差值无相关性(P>0.05).治疗后0~30°组HSS评分与治疗前比较,差异有统计学意义,而30~60°组及60~90°组治疗前、后HSS评分差异无统计学意义.结论 膝关节屈曲范围0~30°的股四头肌等速训练可有效改善全膝关节置换术后髌骨轨迹异常,提高膝关节功能.%Objective To evaluate the effects of isokinetic quadriceps training with different ranges of motion for improving mal-patellar tracking after total knee replacement (TKR). Methods Isokinetic quadriceps training was administered to 52 TKR cases, involving 66 knee joints with poor patellar

  6. Neuromuscular Changes and Damage after Isoload versus Isokinetic Eccentric Exercise.

    Science.gov (United States)

    Doguet, Valentin; Nosaka, Kazunori; Plautard, Mathieu; Gross, Raphaël; Guilhem, GaËL; Guével, Arnaud; Jubeau, Marc

    2016-12-01

    This study compared the effects of isoload (IL) and isokinetic (IK) knee extensor eccentric exercises on changes in muscle damage and neuromuscular parameters to test the hypothesis that the changes would be different after IL and IK exercises. Twenty-two young men were paired based on their strength and placed in the IL (N = 11) or the IK (N = 11) group. The IL group performed 15 sets of 10 eccentric contractions with a 150% of predetermined one-repetition maximum load. The IK group performed 15 sets of several maximal eccentric contractions matched set by set for the total amount of work and mean angular velocity with the IL group. Muscle damage markers (voluntary isometric peak torque, muscle soreness, and creatine kinase activity) and neuromuscular variables (e.g., voluntary activation, H-reflex, M-wave, and evoked torque) were measured before, immediately after, and 24, 48, 72, and 96 h postexercise. Voluntary isometric peak torque decreased to the same extent (P = 0.94) in both groups immediately after (IL = -40.6% ± 13.8% vs IK = -42.4% ± 10.2%) to 96 h after the exercise (IL = -21.8% ± 28.5% vs IK = -26.7% ± 23.5%). Neither peak muscle soreness (IL = 48.1 ± 28.2 mm vs IK = 54.7 ± 28.9 mm, P = 0.57) nor creatine kinase activity (IL = 12,811 ± 22,654 U·L vs IK = 15,304 ± 24,739 U·L, P = 0.59) significantly differed between groups. H-reflex (IL = -23% vs IK = -35%) and M-wave (IL = -10% vs IK = -17%) significantly decreased immediately postexercise similarly between groups. The changes in muscle damage and neuromuscular function after the exercise are similar between IL and IK, suggesting that resistance modality has little effects on acute muscle responses.

  7. Isokinetic training for knee extensor and flexor after partial denervation or hemiplegia%神经功能异常屈伸膝肌的等速运动训练

    Institute of Scientific and Technical Information of China (English)

    郑光新; 邹毅; 瞿玮

    2001-01-01

    Objective To study the effect of isokinetic training on knee extensor and flexor with nerve function abnormality caused by partial denervation or hemiplegia.Methods Both knees of 16 cases with nerve function abnormality and 16 cases with traumatic osteoarthropathy were evaluated by Cybex 300(60°/s) before and after isokinetic training.The angular velocity began at 60°/s,90°/s,120°/s,150°/s to 180°/s,from here the velocity was gradually descended to 60°/s.Each speed repeated 10 times.Before and after training,peak torque-flexor(PT-F),peak torque-extensor(PT-E),F/Q ratio and difference in % of involved knees were recorded.The change rate of mean muscle strength per week was calculated.The design method was repeatedly measured using analysis of variance to compare the difference in both groups.Results After training:1.The PT-F and PT-E were enhanced.The change rate of PT-F and PT-E in involved knees per week was greater than that of uninvolved knees,but that of abnormal nerve group was obviously lower than that of the control group(PT-F:F=8.82,P<0.01;PT-E:F=4.99,P<0.05).2.The difference in % of PT-F and PT-E in involved knees all was decreased,the reducing amplitude in abnormal nerve group was respectively 3.7% and 4.4% vs. the 11.0% and 13.4% of control group.The difference in % of PT-F and PT-E in control group after training was markedly lower than before(PT-F:F=6.40,P<0.01;PT-E:F=22.69,P<0.01).3.F/Q ratio all was significantly decreased in two groups,but there wasn't obvious difference(F=0.95,P>0.05).Conclusion The study suggests that isokinetic training can improve the muscle strength of nerve function abnormality and stabilize the knee joints in partial denervation and hemiplegia.%目的 了解常用等速肌力训练方案对伴神经异常性屈、伸膝肌力的影响。方法 伴神经异常和单纯骨关节伤病后的患者各16例,用Cybex330型等速运动仪评定(60°/s)双侧膝关节,用60°/s~180

  8. EFFICACY OF ISOKINETIC STRENGTH TRAINING AND BALANCE EXERCISES ON LOWER LIMB MUSCLES IN SUBJECTS WITH STROKE

    OpenAIRE

    Dr.P.Keerthi Chandra Sekhar; Dr K. Madhavi; Dr. V.Srikumari; Dr. Patchava Appa Rao; Dr. A.Chathurvedi .P

    2013-01-01

    Background:To evaluate the efficacy of isokinetic strength training and balance exercises on lower limb musclesamong the subjects suffering with stroke.Materials and Methods:40 subjects who are suffering from strokewere divided into two groups, Experimental group received Isokinetic strength training and balance exercises(n=20) and Control group received conventional physiotherapy, results were measured withIsokinetic deviceand Berg balance scale for peak torque of knee extensors on paretic l...

  9. 四川省优秀自由式摔跤运动员膝关节等速力量测试的分析%Research on Isokinetic Muscle Strength Test of Sichuan Excellent Freestyle Wrestler Players' Knee Joints

    Institute of Scientific and Technical Information of China (English)

    陈星强; 程亮; 常书婉

    2012-01-01

    Using IsoMed 2000 Isokinetic testing equipment which is made in German, did quantitative testing and analysis of knee joint at the slow speed of 60° / S and at the fast speed of 240° / S for two outstanding freestyle wrestler ,then feedback the test results to the athletes timely, so that training become more scientific.The results showed that: their before and aider muscles of lefc and right knees" relative strength are poor;the left and right leg flexor, extensor force developed imbalances,the right leg muscle's endurance was better than the leR .In the test of 240° / S ,the two players" left, right leg flexor PT value decreased slower than the extensors.%采用德国产IsoMed2000等速肌力测试仪器,对2名四川省优秀自由式摔跤运动员左、右膝关节进行慢速60°/s和快速240°/S的定量测试及分析,并将测试结果及时反馈给运动员,从而使训练更加科学化.结果显示:2名运动员表现为左、右膝关节前后肌群相对力量较差;左、右腿的屈、伸肌力发展不平衡;同时右腿的肌肉耐力均比左腿好.在进行240°/S的测试中,两名运动员的左.右腿屈肌群PT值下降慢于伸肌群.

  10. Shanghai Elite young runners hip and knee isokinetic analysis%上海优秀男子青少年中跑运动员髋、膝关节等速肌力测试分析

    Institute of Scientific and Technical Information of China (English)

    於鹏; 刘敏; 唐宝军; 顾益民

    2011-01-01

    Through testing hip and knee isokinetic strength of young men distance runners, itfound out young middle distance runners'hip and knee muscle strength characteristics and weak muscles. Methods: Test unilateral hip and knee isokinetic strength of sixteen young runners at isokinetic concentric 60°/s×6 and 240°/s×6 . Record test peak torque, maximum power,flexion and extension muscle peak torque ratio. Results: The hip flexor peak torque and relative peak torque at two speeds were significantly different (P 〈 0.05 ) ;extensor peak torque and relative peak torque speed had highly significant difference ( P 〈 0.01 ), peak torque of flexorand extensor Ratios were significantly different ( P 〈 0.05 ), knee flexor peak torque and relative peak torque were of no difference, while the extensor peak torque and relative peak torque at two speeds were significantly different ( P 〈 0.05 ), flexion and extension peak torque ratio of muscle were no difference. Hip flexor maximum power and relative maximum power hadhighly significant difference ( P 〈 0.01 ), extensor maximum power and relative maximum power were significantly different ( P 〈 0.05 ), maximum power of knee flexor and extensor power at two speed had significant difference (P 〈 O. 01 ). Conclusion: The peak torque of hip show a downward trend with test speed increases, high -speed test flexor peak torque/ extension of hip was decreased. Hip flexor power needs to be improved;Knee extensor peak torque decreased with increasing test speed, and peak flexor Moment of flexion / extension values did not change significantly.%通过对男子青少年中跑运动员进行髋、膝关节等速肌力测试,发现男子青少年中跑运动员髋、膝关节肌力特点及薄弱肌群。方法:对16名上海优秀男子青少年中跑运动员进行髋、膝关节单侧等速向心60°/s×6和240°/s×6测试记录测试峰力矩、最大功率、屈伸肌峰力矩比

  11. Properties of Isokinetic Fatigue at Various Movement Speeds in Adult Males.

    Science.gov (United States)

    Clarke, David H.; Manning, James M.

    1985-01-01

    Eighteen male subjects, aged 20 to 28 years, engaged in three fatigue bouts using an isokinetic dynamometer to measure knee extension contractions. Peak torque varied inversely with movement speed, and the pattern of decrement was independent of speed. Time to peak torque did not change significantly across trials in isokinetic fatigue. (Author/MT)

  12. Study of rehabilitation program on the isokinetic muscle strength test of patients with knee osteoarthritis after total knee arthroplasty%应用等速肌力测试对膝骨性关节炎患者全膝关节置换术后康复的研究

    Institute of Scientific and Technical Information of China (English)

    武亮; 李毅; 姚建锋

    2012-01-01

    Objective: To study the function change of quadriceps femoris muscle of knee osteoarthritis (KOA)Patients who were accepted total knee arthroplasty . Method: 30 patients with severe osteoarthritis of knce, who had been performed to total knee arthroplasty (the prosthescs posterior-stabilized artificial knee joint). All the patients were followed up 6 months ,Thc peak torquc(PT) , total work(TW) of quadriceps were tested at 60 ° / s and 180 ° / s before and after the operation , the result was analyzed. Results: ALL 30 patients underwent total knee arthroplasty, no complications were found postopcrativcly. The incision was healed at the primary stage. The muscle strength (PT、 TW)of 30 patients was no significant difference in early postopcration compared with prcopcration, There was statistically significant difference in muscle strength at 3and 6 months after total knee arthroplasty. Conclusion; rehabilitation is of importance for restoring muscle power of quadriceps femoris after total knee arthroplasty . For knee osteoarthritis patients,isokinetic muscle testing is an effective means in evaluating the effect of rehabilitation program .%目的:研究接受全膝关节置换的膝骨关节炎患者(KOA)股四头肌功能的变化.方法:选用晚期KOA患者30例,均行表面全膝人工关节(后稳定型)单膝置换.所有患者进行6个月的随访,在慢速(60°/ s)和快速(180°/ s)两种速度下,进行等速肌力测试包括峰力矩(PT)、作功量(TW)对其结果进行比较分析.结果:30例患者术后无并发症、合并症出现,伤口均为一期愈合.根据统计学分析,术后早期 PT、TW较术前无显著差异,3个月~6个月后较术前有显著性差异.结论:康复训练对全膝关节置换术后股四头肌的肌力恢复有明显作用,等速肌力测试是评价骨关节炎患者康复疗效的有效手段.

  13. Effectiveness of isokinetic training and Maitland mobilization technique for traumatic stiff knee%等速运动训练结合 Maitland 手法对创伤性膝关节僵直的疗效观察

    Institute of Scientific and Technical Information of China (English)

    徐远红; 王俊华; 万超; 刘飞

    2015-01-01

    Objective:To observe the effects of isokinetic training and Maitland mobilization technique on the knee functions and muscle strength in the traumatic stiff knee .Methods :Forty cases of the traumatic stiff knee were ran‐domly divided into research group and control group .The research group received the isokinetic training and Mait‐land mobilization technique ,and the control group only received the Maitland mobilization technique .Besides ,both two groups received regular exercise therapy and symptom control therapy .Visual analog scale (VAS ) ,range of motion (ROM) ,HSS index ,maximum peak torque (PT) ,and peak torque/body weight (PT/BW) were assessed before and after the treatments in two groups .Results:The VAS score was significantly reduced in the research group after treatment as compared with that before treatment and in control group (P<0 .05) .The flexion degree , extention degree and flexion radian were significantly increased after treatments in both two groups ( P< 0 .05 ) , more significantly in the research group than in the control group (P<0 .05) .The HSS index was significantly in‐creased after treatments in both two groups (P<0 .05) ,more significantly in the research group than in the control group (P<0 .05) .PT and PT/BW were significantly increased after treatments in both two group (P<0 .05) ,more significantly in the research group than in the control group (P<0 .05) .Conclusion:The effectiveness of isokinetic training and the Maitland mobilization technique for the traumatic stiff knee is satisfactory ,which can effectively re‐lieve pain ,increase the range of joint motor ,enhance the muscle strength ,and finally improve the knee functions .%目的:探讨分析等速运动训练结合M aitland手法对创伤性膝关节僵直患者关节功能及关节周围肌肉力量恢复的影响。方法:将40例创伤性膝关节僵直患者随机分为研究组和对照组各20例。研究组行等速运动训练及M aitland

  14. Effects of concentric isokinetic strength training on joint function of patients with knee osteoarthritis%等速向心肌力训练对膝关节骨性关节炎患者关节功能水平的影响

    Institute of Scientific and Technical Information of China (English)

    杨俊兴; 袁颖嘉; 李田珂; 张华; 曾屹峰; 李雪; 樊粤光

    2012-01-01

    Objective: To investigate the effect of concentric isokinetic strength training on joint function of patients with knee osteoarthritis. Method: A total of 100 patients(168 knees) suffered from knee osteoarthritis were divided into isokinetic group(50 cases,83 knees) and comparison group(50 cases,85 knees).All 100 patients received the same conventional rehabili-tation(eontaining the patella inside pushing, quadriceps trainings, and wedge-shaped cushion walking) for 8 weeks. In addition, isokinetic group patients received concentric isokinetic strength training for 8 weeks. The Lysholm scores of knee function and the parameters of peak torque(PT), total work(TW), average power(AP)and max rep total work(MRTW) were utilized to evaluate the effectiveness. Result: All the patients' Lysholm scores and the parameters of PT, TW, AP, MRTW increased significantly after therapy, but the isokinetic group were better than the comparison group, and there was statistically significance(P< 0.01). Conclusion: The concentric isokinetic strength training can significantly increase the patients' leg muscles strength, and improved the function of knee joint.%目的:研究腿部肌群等速向心肌力训练对提高膝关节骨性关节炎患者关节功能水平的作用.方法:将膝关节骨性关节炎患者100例(168膝)随机分为两组,对照组50例(85膝),进行推髌骨、股四头肌训练及楔形垫行走训练等常规康复治疗;等速组50例(83膝),在常规康复治疗的基础上进行患腿肌群等速运动训练.所有患者均在治疗前和治疗后8周时接受等速肌力测试及采用Lysholm膝关节功能评分作为康复疗效判定标准.结果:经过8周的系统康复治疗,等速组与对照组患者的屈、伸肌峰力矩(PT)、总功量(TW)、平均功率(AP)和伸屈肌单次最大作功量(MRTW)均较前有改善,等速组改善较对照组更明显(P<0.01).两组的患者的Lysholm评分均较前有改善,等速组Lysholm评

  15. Isokinetic assessment of knee flexor/extensor muscular strength in elderly women Avaliação isocinética do torque muscular flexor-extensor do joelho em mulheres com idade entre 75-83 anos

    Directory of Open Access Journals (Sweden)

    Marcos de Amorim Aquino

    2002-08-01

    Full Text Available OBJECTIVE: To assess knee flexor-extensor muscular strength in elderly women with no previous history of musculoskeletal disorders on the lower limbs using an isokinetic dynamometer, in order to obtain data that could be used as a comparative parameter in the evaluation of elderly women with knee disorders, thus facilitating a better rehabilitation of these patients. METHODS: Twenty-six volunteers aged 75 to 83 years were studied using a Cybex® 6000 isokinetic dynamometer. The chosen angular velocity was 60 º/s, and concentric exercise was used for either flexion or extension. The studied parameters were: peak torque, angle of peak torque, and flexor-extensor torque rate. RESULTS: There were no differences between dominant (D and nondominant (ND knee peak torque values. This was true for both flexor (D = 42.46 ± 9.09 Nm / ND = 40.65 ± 9.38 Nm and extensor (D = 76.92 ± 13.97 Nm / ND = 77.65 ± 15.21 Nm movements. The descriptive statistical analysis of the values obtained for the flexor-extensor peak torque rate and for the angle of occurrence of peak torque was the same for the dominant and nondominant sides. CONCLUSIONS: The values of peak torque for the contralateral side can be used as a reference during rehabilitation of elderly women with acute disease of the knee, and the angular velocity of 60 º/s is proper and safe for isokinetic assessment of elderly people.OBJETIVO: Avaliar, isocineticamente, o torque dos músculos flexores e extensores dos joelhos de mulheres idosas sem afecções do sistema músculo-esquelético em membros inferiores, obtendo dados que possam servir como parâmetro de comparação na avaliação de mulheres idosas portadoras de afecções nos joelhos, colaborando para uma melhor reabilitação dessas pacientes. CASUÍSTICA E MÉTODOS: Vinte e seis voluntárias foram avaliadas. O estudo foi realizado através de um dinamômetro isocinético marca CYBEXâ modelo 6000 na velocidade angular de 60º/s. O tipo do

  16. Effects of short-term isokinetic training with reciprocal knee extensors agonist and antagonist muscle actions: A controlled and randomized trial

    Directory of Open Access Journals (Sweden)

    Rafael Cunha

    2013-04-01

    Full Text Available BACKGROUND: Previous studies have shown that preloading an antagonist muscle may increase the acute agonist neuromuscular performance. In addition, studies have suggested that very short-term resistance exercise (RE programs may also be useful to increase strength and muscular performance. OBJECTIVES: To evaluate the effects of three days of RE using a reciprocal action method on the muscular performance of healthy men and to compare these effects with those of a traditional RE group. METHOD: Thirty-three men (21.1 ± 2.3 years were randomly assigned to one of three groups: 1 reciprocal (REC; knee flexion immediately followed by a knee extension exercise; 2 traditional (TRA; non-preload; a concentric knee extension exercise; and 3 control (CON; no exercise. The REC and TRA subjects performed four sets of 10 repetitions at 60º/s with one minute of rest. The pre- and post-RE tests included two sets of four maximal concentric repetitions at 60º/s and 180º/s. A 3x2 ANOVA with Tukey post-hoc was used to analyze the differences in peak torque (PT, rating of acceleration development (RAD and time to peak torque (TIMEtorque. RESULTS: A significant PT increase was found for REC and TRA (p CONTEXTUALIZAÇÃO: Estudos demonstraram que a pré-ativação de músculos antagonistas pode aumentar o desempenho neuromuscular agonista. Além disso, estudos sugerem que programas de exercício resistido (ER de curta duração podem ser úteis para aumentar a força muscular e o desempenho. OBJETIVOS: Avaliar os efeitos de três sessões de ER por meio do método de ações recíprocas no desempenho muscular de homens sadios e comparar com um grupo de ER tradicional. MÉTODO: Trinta e três homens (21,1 ± 2,3 anos foram randomicamente alocados em três grupos: Recíproco (REC: uma repetição de flexão do joelho imediatamente seguida por uma de extensão do joelho; Tradicional (TRA: exercício concêntrico de extensão do joelho e Controle (CON: não realizaram

  17. Effects of Neuromuscular Electrical Stimulation and Resistance Training on Knee Extensor/Flexor Muscles.

    Science.gov (United States)

    Pantović, Milan; Popović, Boris; Madić, Dejan; Obradović, Jelena

    2015-07-01

    Neuromuscular electrical stimulation (NMES) has recently drawn a lot of attention as means for strengthening of voluntary muscle contraction both in sport and rehabilitation. NMES training increases maximal voluntary contraction (MVC) force output through neural adaptations. On the other hand, positive effects of resistance training (RT) on muscle strength are well known. The aim of this study was to investigate effects of a 5-week program of NMES compared to RT program of same duration. Sample of 15 students' of faculty of sport and physical education (age 22 ± 2) were randomized in two groups: NMES (N = 7) and RT (N = 8). NMES group performed NMES superimposed over voluntary muscle contraction, RT group performed resistance training with submaximal loads. Subjects were evaluated for knee isokinetic dynamometry on both sides (60° and 180° s). After intervention no significant difference between groups were observed in isokinetic dynamometry (p = 0.177). However, applying pair sample t test within each group revealed that peak torque increased in NMES-group (p = 0.002 for right knee extensors muscles, p = 0.003 for left, respectively, at 60° and p = 0.004 for left knee extensors muscles, at angular velocity 180°). In RT group (p = 0.033 for right knee extensors muscles, p = 0.029 for right knee flexor muscles, at angular velocity 60°). Our results indicate that NMES has equal potential if not in some way better than classical RT having in mind that overload on locomotor apparatus during NMES is minimal and force of muscle contraction is equal on both sides, for enhancement of knee muscles concentric peak torque.

  18. Comparitive Assessment of Isokinetic and Pneumatic Lower Limb Strength in Functionally-Limited Elderly Subjects

    Science.gov (United States)

    The purpose of this study was to investigate the relationship between isokinetic and pneumatic knee extensor strength in functionally-limited elders and to compare the respective changes in knee extensor peak torque and one repetition maximum strength (1RM) after a randomized controlled progressive ...

  19. A study of isokinetic strength and laxity with and without anterior cruciate ligament injury

    OpenAIRE

    Kim, Kewwan; Jeon, Kyoungkyu; Mullineaux, David R.; Cho, Eunok

    2016-01-01

    [Purpose] The purpose of this study was to provide useful information for future treatments and to organize rehabilitation programs for anterior cruciate ligament injury by assessing isokinetic muscle strength and laxity of knee joints in athletes with anterior cruciate ligament injuries. [Subjects and Methods] Thirty-one high school athletes with anterior cruciate ligament injuries participated in this study. Isokinetic muscle strength at 60°/sec and anterior cruciate ligament laxity for non...

  20. A study of isokinetic strength and laxity with and without anterior cruciate ligament injury

    OpenAIRE

    Kim, Kewwan; Jeon, Kyoungkyu; Mullineaux, David R.; Cho, Eunok

    2016-01-01

    The purpose of this study was to provide useful information for future treatments and to organize rehabilitation programs for anterior cruciate ligament injury by assessing isokinetic muscle strength and laxity of knee joints in athletes with anterior cruciate ligament injuries. [Subjects and Methods] Thirty-one high school athletes with anterior cruciate ligament injuries participated in this study. Isokinetic muscle strength at 60°/sec and anterior cruciate ligament laxity for non-involved ...

  1. Proprioceptive isokinetic exercise test

    Science.gov (United States)

    Dempster, P. T.; Bernauer, E. M.; Bond, M.; Greenleaf, J. E.

    1993-01-01

    Proprioception, the reception of stimuli within the body that indicates position, is an important mechanism for optimal human performance. People exposed to prolonged bed rest, microgravity, or other deconditioning situations usually experience reduced proprioceptor and kinesthetic stimuli that compromise body balance, posture, and equilibrium. A new proprioceptive test is described that utilizes the computer-driven LIDO isokinetic ergometer. An overview of the computer logic, software, and testing procedure for this proprioceptive test, which can be performed with the arms or legs, is described.

  2. Isokinetic sampler; Amostrador isocinetico

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Luis Cesar C. de; Santos, Antonio Carlos dos [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil); Barrio, Lara B.A. del [AZ Armaturen do Brasil Ltda., Itatiba, SP (Brazil); Silva, Claudio B. da C. e; Silva, Ricardo R. da [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2005-07-01

    The Center of Research Leopoldo A. Miguez de Melo - CENPES - in association with AZ Armaturen Company do Brasil and TRANSPETRO developed and tested an Isokinetic sampler. This work presents the sampling principles and the results and performance of the tests realized in the 'Sitio de Testes de Atalaia' and in one of the terminals of bunker transfer of TRANSPETRO - 'Terminal Aquaviario da Baia de Guanabara'. In the 'Sitio de Testes' the products used were oil and water with BSW from 5% to 97% and in the terminal were tested samplings of bunker with ranges viscosities between (MF 180 to 380). (author)

  3. Isometric and isokinetic muscle strength in patients with fibrositis syndrome. New characteristics for a difficult definable category of patients

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Danneskiold-Samsøe, B

    1987-01-01

    A common complaint among patients with fibrositis syndrome is exhaustion and fatique. It was therefore felt desirable to evaluate the muscle strength of these patients compared with normal subjects. Maximum isometric and isokinetic strength of knee extension was measured in 15 patients and 15...... healthy matched subjects, using an isokinetic dynamometer (Cybex II). Maximum isometric strength at various knee extension angles (90 degrees, 60 degrees and 30 degrees degrees) was significantly (p less than 0.001) lower in the fibrositis group than in controls, a reduction of approximately 58......-66%. Maximum isokinetic strength at various knee extension velocities (30-240 degrees per second) was also significantly (p less than 0.01) lower in the fibrositis group than in controls, the reduction being approximately 41-51%. In conclusion, isometric and isokinetic muscle strength is found to be lower...

  4. The isokinetic study of different surgical procedures for the treatment of patients with arthroscopic knee meniscus%膝半月板损伤后关节镜手术不同术式的等速肌力测试分析

    Institute of Scientific and Technical Information of China (English)

    邵正海; 张玉发; 吕宏; 毕霞; 高亮亮; 刘小垒; 黄鑫凝

    2014-01-01

    目的:回顾性分析关节镜下行半月板缝合修整成型术和射频消融术的疗效差异,以向临床推广合适的术式。方法:对60例膝半月板损伤患者关节镜术后采取半月板缝合修整成型术和射频消融术,采用等速肌力测试比较两组治疗的差异。结果:观察组屈膝60°、120°时膝关节单次最大做功、力矩加速能、屈膝伸肌峰力矩测试和平均做功率均优于对照组,差异有统计学意义(P<0.05)。结论:半月板缝合修整成型术对膝半月板损伤关节镜手术后患者具有较好的改善,能够明显改善患者的预后状况。%Objective:Retrospective analysis of the isokinetic study of different surgical procedures for the treatment of arthroscopic meniscal suture repair angioplasty and radiofrequency ablation for patients with arthroscop-ic knee meniscus ,in order to promote the appropriate surgery methods for clinical treatment .Methods :60 cases of patients with knee meniscus injury were treated by the treatment of arthroscopic meniscal suture repair angioplasty and radiofrequency ablation and the isokinetic treatment were used to compared the difference between the two groups .Results :The knee maximum single acting ,torque acceleration energy ,knee extensor peak torque testing and average power of the observation group were better than those in the control group and all P <0 .05 .Conclu-sion:The treatment of arthroscopic meniscal suture repair angioplasty for the patients can significantly improve the patient's prognosis ,and worthy of clinical application .

  5. An analysis of influence factors during isokinetic eccentric test of knee joint%影响膝关节等速离心收缩测试的相关因素探讨

    Institute of Scientific and Technical Information of China (English)

    成鹏; 毕霞; 郎海涛

    2001-01-01

    Objective: To analyze some influence factors during isokinetic eccentric test. Method: Twenty normal males were tested by Biodex isokinetic test and rehabilitation system. Their peak torque(PT) and peak torque to body weight (PT/BW) were analyzed under different conditions. Result: It was found that velocity and contraction mode influence the results significantly( P<0.01). Conclusion: Many factors must be considered during isokinetic eccentric test and training.%目的:探讨影响膝关节等速离心收缩测试和训练的因素,为进一步深入研究提供客观的依据。方法:利用Biodex等速测试及康复系统测试20健康男性的峰力矩及相对峰力矩,观察速度、惯用肢和功能运动对峰力矩和相对峰力矩的影响。结果:速度和功能运动对峰力矩和相对峰力矩影响显著,而对惯用肢的影响比较复杂。结论:离心等速测试和训练过程中,必须考虑速度、惯用肢和收缩方式等因素。

  6. Isokinetic testing and analysis of flexor-extensor muscle of the knee joint of women field hockey athletes%女子曲棍球运动员膝关节屈伸肌群等速测试与分析

    Institute of Scientific and Technical Information of China (English)

    曹峰锐; 邹亮畴; 彭森

    2011-01-01

    BACKGROUND: In recent years, isokinetic test has been widely used by scientific research personnel to evaluate the strengthcharacter of athletes of different sport events. However, there are few reports describing the characteristics of the field hockeyplayer by isokinetic test.OBJECTIVE: This study tested the flexor and extensor torque of the knee joint of women field hockey athletes from Guangdongprovince to provide some results for the training of sport teams and scientific research.METHODS: The flexor and extensor torque of knee joint of 14 women field hockey athletes from Guangdong province wasperformed isokinetic test using CON-TREX isokinetic testing machine. Detection indices include peak torque/body weight, peaktorgue ratio of hamstring to quadriceps, average power, total work and fatigue index.RESULTS AND CONCLUSION: Under the testing velocity of 60° per second, the peak torque/body weight values of extensorwere significantly greater than those of the flexor (P < 0.01). Under three different velocities, the hamstring/quadriceps ratio of theleft knee joint was 66%-77%, and the ratio of the right knee joint was 82%-88%. The average power of the extensor of left kneejoint was significantly greater than that of the flexor (P < 0.01). The total work of the extensor of the left and right flexor wassignificantly greater than that of the flexor (P < 0.01). The fatigue index of extensor and flexor of the knee joint was 0.24-0.48.The most strength of knee joint extensor was greater than that of the flexor. The peak torgue ratio of hamstring to quadriceps ofthe left knee joint was slightly low at 240°/s, while the peak torgue ratio of hamstring to quadriceps of the right knee joint wasslightly high at low speed. The results showed that the speed strength of the left knee joint of the women field hockey athleteswas slightly low, the maximum strength of the right knee joint extensor was relatively low, the speed strength of the extensor wasgreater than

  7. Peak torque and knee kinematics during gait after eccentric isokinetic training of quadriceps in healthy subjects O pico de torque e a cinemática do joelho durante a marcha após treino isocinético excêntrico do quadríceps em sujeitos saudáveis

    Directory of Open Access Journals (Sweden)

    PR Poletto

    2008-08-01

    Full Text Available OBJECTIVE: To evaluate the effects of eccentric isokinetic training on knee range of motion (ROM of healthy subjects. METHODS: The knee extensor and flexor isokinetic peak torques and ROM of flexion/extension and varus/valgus knee movements during gait of 18 healthy men (21.7±2.2 years; 1.73±0.10m; 68.7±9.4kg; body mass index: 22.6±2kg/m² were analyzed, before and after six weeks of bilateral eccentric isokinetic training of the knee extensors at 30º/s. RESULTS: The knee extensor torque increased in both limbs (right, from 229±54 to 304±53Nm; pOBJETIVO: Avaliar os efeitos do treino isocinético excêntrico sobre a amplitude de movimento (ADM do joelho em sujeitos saudáveis. MÉTODOS: Foram analisados os picos de torque isocinético dos extensores e flexores do joelho e a ADM de flexo/extensão e valgo/varo, durante a marcha, de 18 homens saudáveis (21,7±2,2 anos; 1,73±0,10m; 68,7±9,4kg; índice de massa corpórea: 22,6±2kg/m² antes e após seis semanas de treino isocinético excêntrico bilateral dos extensores do joelho a 30º/s. RESULTADOS: O torque extensor do joelho aumentou em ambos os membros, direito (de 229±54 para 304±53Nm; p<0,01 e esquerdo (de 228±59 para 311±63Nm; p<0,01 sem diferença de ganho de torque entre eles. O pico de torque flexor aumentou (de 114±30 para 123±22Nm; p<0,05, mas a razão isquiotibiais/quadríceps (I/Q diminuiu (de 0,5±0,08 para 0,39±0,07; p<0,01 após o treino. Não houve diferença para os movimentos de flexo/extensão e valgo/varo após o treino, exceto uma pequena mudança (4° no valgo para o joelho esquerdo. CONCLUSÕES: O treino isocinético excêntrico dos extensores do joelho aumentou o torque extensor e diminuiu a razão I/Q, entretanto o efeito sobre o padrão da marcha parece desprezível em sujeitos saudáveis. Um treino associado dos flexores, complementar ao treino dos extensores parece ser necessário para o equilíbrio entre agonistas e antagonistas do joelho.

  8. Lower-extremity isokinetic strength profiling in professional rugby league and rugby union.

    Science.gov (United States)

    Brown, Scott R; Brughelli, Matt; Griffiths, Peter C; Cronin, John B

    2014-03-01

    While several studies have documented isokinetic knee strength in junior and senior rugby league players, investigations of isokinetic knee and hip strength in professional rugby union players are limited. The purpose of this study was to provide lower-extremity strength profiles and compare isokinetic knee and hip strength of professional rugby league and rugby union players. 32 professional rugby league and 25 professional rugby union players. Cross-sectional analysis. Isokinetic dynamometry was used to evaluate peak torque and strength ratios of the dominant and nondominant legs during seated knee-extension/ flexion and supine hip-extension/flexion actions at 60°/s. Forwards from both codes were taller and heavier and had a higher body-mass index than the backs of each code. Rugby union forwards produced significantly (P rugby league forwards. Rugby league backs produced significantly greater hip-extension peak torque in the dominant and nondominant legs (ES = 0.83 and 0.77) compared with rugby union backs. There were no significant differences in hamstring-to-quadriceps ratios between code, position, or leg. Rugby union forwards and backs produced significantly greater knee-flexion-to-hip-extension ratios in the dominant and nondominant legs (ES = 1.49-2.26) than rugby union players. It seems that the joint torque profiles of players from rugby league and union codes differ, which may be attributed to the different demands of each code.

  9. Selective hypertrophy of the quadriceps musculature after 14 weeks of isokinetic and conventional resistance training.

    Science.gov (United States)

    Matta, Thiago Torres; Nascimento, Francisco Xavier; Trajano, Gabriel S; Simão, Roberto; Willardson, Jeffrey Michael; Oliveira, Liliam Fernandes

    2017-03-01

    One of the fundamental adaptations observed with resistance training (RT) is muscle hypertrophy. Conventional and isokinetic machines provide different forms of mechanical stress, and it is possible that these two training modes could promote differing degrees of hypertrophic adaptations. There is a lack of data comparing the selective hypertrophy of the quadriceps musculature after training with a conventional knee extension machine versus an isokinetic machine. The purpose of this study was to evaluate the selective hypertrophy of the quadriceps musculature and knee extension maximal isometric torque after 14 weeks of conventional versus isokinetic RT. Thirty-five men were assigned to three groups: control group and training groups (conventional and isokinetic) performed three sets of unilateral knee extensions per session with a progressive loading scheme twice a week. Prior to and following the intervention, maximal isometric knee extensor torque was measured using an isokinetic dynamometer, and muscle thickness (MT) of quadriceps femoris muscles was assessed via ultrasound. The results indicated non-uniform changes in MT between the muscles that comprise the quadriceps femoris group. For the conventional group, significantly greater increases in rectus femoris thickness were evident versus all other quadriceps muscles (14%). For the isokinetic group, increases in RF thickness (11%) were significantly greater in comparison with the vastus intermedius only. Although the muscle thickness did not increase for all the quadriceps femoris muscles, the relative rectus femoris adaptation suggested a selective hypertrophy favouring this portion. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  10. Neural and morphological adaptations of vastus lateralis and vastus medialis muscles to isokinetic eccentric training

    Directory of Open Access Journals (Sweden)

    Rodrigo de Azevedo Franke

    2014-09-01

    Full Text Available Vastus lateralis (VL and vastus medialis (VM are frequently targeted in conditioning/rehabilitation programs due to their role in patellar stabilization during knee extension. This study assessed neural and muscular adaptations in these two muscles after an isokinetic eccentric training program. Twenty healthy men underwent a four-week control period followed by a 12-week period of isokinetic eccentric training. Ultrasound evaluations of VL and VM muscle thickness at rest and electromyographic evaluations during maximal isometric tests were used to assess the morphological and neural properties, respectively. No morphological and neural changes were found throughout the control period, whereas both muscles showed significant increases in thickness (VL = 6.9%; p .05 post-training. Isokinetic eccentric training produces neural and greater morphological adaptations in VM compared to VL, which shows that synergistic muscles respond differently to an eccentric isokinetic strength training program

  11. An adequate interset rest period for strength recovery during a common isokinetic test.

    Science.gov (United States)

    Blazquez, Ivan N; Warren, Barbara L; O'Hanlon, Ann M; Silvestri, Lynette R

    2013-07-01

    Isokinetic testing is used in rehabilitation settings on a regular basis; yet, there is a lack of consistency in rest period usage among protocols. Furthermore, the allotment of rest periods has been arbitrary (e.g., 30, 60, 90 seconds or more). This investigation examines the work:rest ratio as an effective method of standardizing rest periods in isokinetic testing. The purpose of this study was to establish an adequate rest period that would allow reproducibility of strength during a common isokinetic strength test. Twenty-seven healthy college-aged men (age, 23 ± 3.8 years; body weight, 79.54 ± 11.09 kg) were tested on 5 separate occasions: 2 familiarization sessions and 3 experimental sessions. Each subject performed a knee extension/flexion isokinetic strength protocol (Cybex NORM; Lumex, Inc., Ronkonkoma, NY, USA) to determine peak torque by performing 5 maximal reciprocal repetitions at each ascending velocity of 60, 180, and 300°·s. Work:rest ratios of 1:3, 1:8, and 1:12 were counterbalanced between sets. A 3 × 3 repeated measures analysis of variance was used to analyze the data. A significance level of α ≤ 0.05 was used for all tests. There was no significant difference in either knee extension or knee flexion peak torque when comparing work:rest ratios. These findings suggest that a 1:3 work:rest ratio is sufficient during a common isokinetic strength test.

  12. Association of isokinetic strength with pain and functional status in knee osteoarthritis patients aged 80 years and over%80岁及以上膝骨性关节炎患者等速肌力与疼痛和功能状态的关系

    Institute of Scientific and Technical Information of China (English)

    瓮长水; 郭燕梅; 陈蔚; 黎春华; 王娜

    2014-01-01

    目的 评估80岁及以上膝骨性关节炎(OA)患者膝关节等速肌力与疼痛和功能状态之间的关系. 方法 32例膝OA患者和10例健康受试者作为对照组.对膝OA患者进行视觉模拟评分法(VAS)疼痛强度评分、Lequesne指数.对膝OA组和对照组受试者进行膝关节伸肌和屈肌标准化等速向心收缩测试程序,角速度为60°/s和180°/s,进行功能性移动能力测试:5次坐到站测试(FTSST)、3 m计时起立行走测试(TUGT)和10m计时步行测试(TWT). 结果 膝OA组与对照组受试者在两个角速度的伸肌和屈肌的相对峰力矩之间的比较差异有统计学意义(t=2.747,P<0.05).伸肌相对峰力矩与年龄、Liquesce指数总分、FTSST、TUGT和TWT之间呈负相关(r=-0.39~-0.75,均P<0.05).伸肌相对峰力矩与VAS得分和Lequesne指数疼痛评分之间无相关(r=-0.23~ 0.31,均P>0.05).伸肌相对峰力矩和VAS得分两者是Liquesce指数的重要预测因子,可解释Liquesce指数41%的变异量(adjusted R2=0.41). 结论 80岁及以上膝OA患者肌力损害程度与其功能表现密切关联,股四头肌肌力和疼痛强度是预测失能的重要指标.%Objective To evaluate the difference in isokinetic strength of the knee muscles between knee osteoarthritis (KOA) patients aged 80 years and over and matched healthy controls,and to establish the association of isokinetic strength with pain and functional status in patients with KOA.Methods The study enrolled 32 patients aged 80 and over diagnosed with unilateral knee OA and 10 matched controls.Pain was evaluated by the visual analogue scale (VAS),the pain intensity scale and the Lequesne index for patients with knee OA.Functional status was assessed by the Timed Up and Go Test (TUGT),the Five Times Sit to Stand Test (FTSST) and the Timed 10 Meter Walk Test (TWT).Muscle strength was measured using the isokinetic dynamometer Biodex System 4 Pro.Bilateral isokinetic (concentric) knee flexion and extension with

  13. Using Evolved Fuzzy Neural Networks for Injury Detection from Isokinetic Curves

    Science.gov (United States)

    Couchet, Jorge; Font, José María; Manrique, Daniel

    In this paper we propose an evolutionary fuzzy neural networks system for extracting knowledge from a set of time series containing medical information. The series represent isokinetic curves obtained from a group of patients exercising the knee joint on an isokinetic dynamometer. The system has two parts: i) it analyses the time series input in order generate a simplified model of an isokinetic curve; ii) it applies a grammar-guided genetic program to obtain a knowledge base represented by a fuzzy neural network. Once the knowledge base has been generated, the system is able to perform knee injuries detection. The results suggest that evolved fuzzy neural networks perform better than non-evolutionary approaches and have a high accuracy rate during both the training and testing phases. Additionally, they are robust, as the system is able to self-adapt to changes in the problem without human intervention.

  14. Electromyographic features of agonists and antagonist muscles of the knee joints during maximal and submaximal isokinetic fatigue%膝关节最大和次最大等速运动至疲劳过程中主动肌与拮抗肌肌电特征分析

    Institute of Scientific and Technical Information of China (English)

    张肃; 高峰

    2015-01-01

    背景:人体关节力量输出主要取决于关节周围主动肌与拮抗肌的激活效果,而拮抗肌通过共激活形式参与肢体活动,从而协助维持关节稳定性。但是肌肉不同收缩模式下拮抗肌共激活的不同中枢策略的报道较少。目的:观察健康受试者膝关节伸肌在最大和次最大等速运动至疲劳过程中主动肌与拮抗肌表面肌电信号的特征与差别。方法:对16名在校学生使用Biodex等速训练仪诱发下肢右侧膝关节伸肌等速屈伸运动直至疲劳,同时使用表面肌电仪采集单侧股内侧肌、股外侧肌以及股二头肌的表面肌电信号。分析时域指标均方根振幅百分比以及频域指标平均频率的变化规律。结果与结论:在膝关节最大等速屈伸运动中峰值力矩下降了40.3%(P 0.05)。结果提示,在不同强度的等速疲劳运动中中枢神经系统对主动肌和拮抗肌采取了不同神经支配策略。%BACKGROUND:The power output of the human joints depends on the activation of agonists and antagonist muscles around the joints, and the antagonist muscle is involved in physical activity in a co-activated manner, thereby helping to maintain joint stability. But there are less reports on the central nervous system strategies of antagonist co-activation under different muscle contraction modes. OBJECTIVE:To observe the characteristics and differences of surface electromyography (sEMG) of agonists and antagonist muscles of the knee joints during maximal and submaximal isokinetic exercises until fatigue. METHODS:Sixteen students were enroled, who developed the right knee joint fatigue induced by the Biodex isokinetic equipment, and simultaneously sEMG activities of vastus medialis, vastus lateralis and biceps femoris were recorded by the myoelectrical equipment. The RMS (%) and mean frequency were selected to analyze sEMG characteristics. RESULTS AND CONCLUSION:In the maximal isokinetic fatigue, the peak

  15. Analysis on Concentric Isokinetic Test of Flexion and Extension Muscle Strength of Knee Joints in Chon-dromalacia Patellae%髌骨软骨病患者的膝屈伸肌群等速向心肌力分析

    Institute of Scientific and Technical Information of China (English)

    徐卫华; 赵彦; 王鸿; 王家祥; 孙强

    2015-01-01

    目的::运用等速肌力测试方法分析髌骨软骨病患者的膝关节屈伸肌群等速向心肌力特征,为髌骨软骨病的防治和康复提供参考。方法:对30例髌骨软骨病单膝患者和与之相应的年龄、体型相差不大的24位正常成人进行双膝等速向心肌力测试,测得其在60°/s的峰力矩,运用统计学方法分析。结果:患膝屈伸肌峰力矩均减弱,与健侧及正常人双膝相比,P<0.01,具有统计学意义;伸肌PT值下降更为明显,双侧同名伸肌差异比,显著( P<0.05)高于髌骨软骨病组的屈肌和正常对照组的屈伸肌;同时患侧 H/Q 比值也显著( P<0.05)高于健侧及对照组。结论:髌骨软骨病患者的患膝屈伸肌群力量减弱、主动肌与拮抗肌比例失衡、双膝同名伸肌力量差异明显,提示髌骨软骨病患者的诊断和康复治疗应注意峰力矩、拮抗比和双侧差异的检测以及患膝关节肌肉力量和平衡的恢复。%Objective An analysis of flexion and extension muscle strength characters of knee in Chondromalacia Pa-tellae( CP) by means of isokinetic test was performed to provide a basis for CP prevention and rehabilitation. Meth-ods 30 patients with CP and 24 matched controls who cor-responding age,size finished the concentric isokinetic test of knee flexion and extension,using statistical methods to analyze its peak torque measured at 60°/s. Results Peak torques of flexion and extension muscles of the patient knee are reduced, and are statistically significant by P<0. 01 compared with the healthy side and normal knee;PT of extension decreased more significantly, and difference ratio of bilateral homonymous extensor muscle is significantly ( P<0. 05 ) higher than flexor of chondro-malacia patellae group and flexor and extensor of normal control group;At the same time,the H/Q ratio of the pa-tient side was significantly higher than that of the control group ( P<0. 05 ) . Conclusion The flexion and

  16. Acute effects of two different stretching techniques on isokinetic strength and power

    Directory of Open Access Journals (Sweden)

    F. Ayala

    2015-09-01

    Conclusions: Short pre-exercise static and dynamic lower-limb stretching routines did not elicit stretching-induce reductions or improvements in knee flexor and knee extensor isokinetic concentric and eccentric strength. In addition, the findings of the current study support the claim that dynamic stretching may be preferable to static stretching as part of a warm-up designed to prepare for physical activity.

  17. Short-term effects of kinesio tape on joint position sense, isokinetic measurements, and clinical parameters in patellofemoral pain syndrome

    OpenAIRE

    Kurt, Emine Eda; Büyükturan, Öznur; Erdem, Hatice Rana; Tuncay, Figen; Sezgin, Hicabi

    2016-01-01

    [Purpose] To evaluate the short-term effects of kinesio tape on joint position sense, isokinetic measurements, kinesiophobia, symptoms, and functional limitations in patients with patellofemoral pain syndrome. [Subjects and Methods] A total of 90 patients (112 knees) with patellofemoral pain syndrome were randomized into a kinesio tape group (n=45) or placebo kinesio tape group (n=45). Baseline isokinetic quadriceps muscle tests and measurements of joint position sense were performed in both ...

  18. 膝骨关节炎患者临床症状与等速肌力测试指标的关系%Study on the relationship between clinical symptoms and isokinetic test indexes of myodynamia in patients with knee osteoarthritis

    Institute of Scientific and Technical Information of China (English)

    周文琪; 罗小兵; 王小勇; 虞亚明; 何栩; 高丕明; 蒋晴

    2014-01-01

    Objective:To explore the relationship between clinical symptoms and isokinetic myodynamia test indexes in patients with knee osteoarthritis(KOA). Methods:One hundred and twelve patients with KOA were enrolled in the study. Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)scores were assessed with guidance from three trained evaluation staff. Peek torque,relative peek torque,peek power and relative peek power of knee extensors and flexors at 60° / sec and 180° / sec were measured by using an ISOMED-2000 isokinetic dynamomete. Then spearman correlation analysis and multiple linear regression analysis were applied to study the relation-ship between WOMAC and isokinetic myodynamia test indexes. Results:The results of spearman correlation analysis showed that most inde-xes of WOMAC were negatively correlated with peek torque,relative peek torque,peek power and relative peek power at 60° / sec and 180° / sec of knee extensors(p 0. 05)and only a few indexes of WOMAC were negatively correlated with relative peek torque and relative peek power(p 0.05),仅有少部分临床症状指标与相对峰力矩、相对峰功呈负相关(p <0.05)。多重线性回归分析结果显示,60(°)·s ﹣1时的伸膝相对峰功与西安大略和麦克马斯特大学骨关节炎指数中的疼痛评分、僵硬评分、行动障碍评分及总分均存在负线性关系(r =﹣0.271,p =0.001;r =﹣0.308,p =0.000;r =﹣0.263,p =0.001;r =﹣0.296,p =0.000);180(°)·s ﹣1时的伸膝相对峰功与疼痛评分存在负线性关系(r =﹣0.214,p =0.010),180(°)·s ﹣1时的伸膝峰功与僵硬评分存在负线性关系( r =﹣0.202,p =0.015)。结论:在等速肌力测试指标中,伸膝指标对膝骨关节炎患者临床症状的影响大于屈膝指标,其中60(°)·s ﹣1时的伸膝相对峰功最能反映膝骨关节炎患者的临床症状,可将其作为定量评价膝骨关节炎患者临床症状的指标之一。

  19. Effect of Isokinetic Training Concentrically and Eccentrically on Knee Peak Torque and Hamstring/Quadricep Ratio%等速向心/离心训练对膝关节峰力矩和屈/伸肌峰力矩比影响的比较

    Institute of Scientific and Technical Information of China (English)

    柳华; 杨翼; 黄晓琳

    2015-01-01

    目的:分别进行4周膝关节的等速向心(c)/离心(e)训练后,比较屈膝肌(H)和伸膝肌(Q)在训练前后向心/离心收缩峰力矩(Hc、He、Qc、Qe)及其比值的变化及性别差异,为膝关节肌肉康复训练运动处方的制定提供参考。方法2014年5~6月本校无任何训练基础的28名大学生分为向心组(n=14)和离心组(n=14),分别在BIODEX等速肌力评估训练系统4上进行每周3次、共4周的右膝等速向心/离心训练。测量向心30°/s、60°/s、90°/s和离心60°/s、90°/s、120°/s训练前后峰力矩。结果向心组训练后60°/s、90°/s的Hc、He增加(P0.05)。向心组He/Qc在90°/s、Hc/Qc在30°/s均下降(P0.05)。向心组Qc/Qe在60º/s和90º/s,Hc/He在90º/s均提高(P0.05)。女性Hc、He、Qc、Qe、He/Qc与男性比较有显著性差异(P0.05). After concentric isokinet-ic training, the He/Qc ratio decreased at 90 °/s (P0.05). The Qc/Qe ratio increased at 60 °/s and 90 °/s (P0.05). There were significant differences in Hc, He, Qc, Qe and He/Qc ratio between different genders (P<0.05). Conclusion Concentric training and ec-centric training have different influences on the muscle strength after 4 weeks training. Eccentric training only can reduce the knee stability. Hc/He ratio and Qc/Qe ratio can be used to evaluate the knee muscle function. Gender should be considered into training.

  20. The therapeutic effects of isokinetic strength training combined with intra-articular injection of hyaluronate and joint mobilization for patients with knee osteoarthritis%等速肌力训练联合关节腔内注射及关节松动术治疗膝骨性关节炎的疗效观察

    Institute of Scientific and Technical Information of China (English)

    雒晓甜; 梁英; 李鹏; 邓剑伟

    2014-01-01

    Objective To observe any effects of using isokinetic strengthening exercises combined with intra-articular injection of sodium hyaluronate and joint mobilization in treating patients with knee osteoarthritis (KOA).Methods Eighty-one KOA patients were divided into a combined treatment group,a conventional treatment group and a control group.The combined treatment group received isokinetic strengthening training,intra-articular injections of sodium hyaluronate and joint mobilization therapy; the conventional treatment group received the injections and mobilization only; the control group was instructed to do ankle pumps at home on their own.Before the start of treatment and after 4 weeks,knee pain was self-assessed [using a visual analogue scale (VAS) for pain] along with knee range of motion (ROM),quality of life (using the WOMAC condensed health survey rating scale) and indexes of isokinetic strength [including the knee flexors,extensor peak torque (PT),and the flexion and extension angles corresponding peak torque (AOPT)] in both groups.Results After 4 weeks of treatment,statistically significant improvements compared to the baseline values were observed in both groups.The combined treatment group,however,improved to a significantly greater extent than the conventional treatment group in terms of all of the measures.Conclusion Isokinetic strength training combined with intra-articular injections of sodium hyaluronate and joint mobilization has a synergistic effect in enhancing knee stability and improving the performance in activities of daily life of KOA patients.%目的 观察等速肌力训练联合玻璃酸钠关节腔内注射及关节松动术治疗膝骨性关节炎(KOA)的疗效.方法 采用随机数字表法将81例KOA患者分为联合治疗组、常规治疗组及对照组.联合治疗组给予等速肌力训练、玻璃酸钠关节腔内注射及关节松动术治疗,常规治疗组给予玻璃酸钠关节腔内注射及关节松动术治疗,对照

  1. Effect of anterior cruciate ligament rupture on hamstring∶quadriceps ratio during isokinetic knee extension and flexion at 30 degrees of flexion%膝关节30闭时前交叉韧带断裂对等速屈伸肌力比值的影响

    Institute of Scientific and Technical Information of China (English)

    黄红拾; 蒋艳芳; 杨洁; 于媛媛; 王懿; 徐雁; 敖英芳

    2015-01-01

    目的:研究膝关节30°时前交叉韧带(anterior cruciate ligament,ACL)断裂对股四头肌(quadriceps,Q)和腘绳肌(hamstring,H)的肌力及其动态平衡的影响。方法:应用等速肌力测试系统(Con-Trex MJ)对25例男性单侧单纯ACL断裂患者在60°/s进行开链向心(concentric,c)和离心(eccentric,e)测试。选择膝关节30°时股四头肌或腘绳肌的等速向心和离心平均力矩,并计算其比值,包括股四头肌离心和向心比值( Qe∶Qc)、腘绳肌离心和向心比值( He∶Hc)、腘绳肌与股四头肌的向心比值( Hc∶Qc)、腘绳肌离心与股四头肌向心比值( He∶Qc)、腘绳肌向心与股四头肌离心比值( Hc∶Qe)。采用配对符号秩检验分析ACL断裂对上述参数的影响,结果以中位数(最小值~最大值)表示。结果:ACL断裂侧和未伤侧相比:(1)等速向心时,股四头肌平均力矩显著下降[61.2(20.0~100.1) N· m vs.84.0(32.3~127.7) N· m,P<0.001];(2)等速离心时,股四头肌平均力矩显著下降[55.3(31.3~114.1) N· m vs.71.7(24.5~149.7) N· m,P=0.04],腘绳肌平均力矩亦显著下降[55.3(3.1~119.2) N· m vs.80.3(17.2~127.4) N· m,P=0.002];(3)Hc∶Qc、He∶Qc和Qe∶Qc均显著增大(P<0.05)。结论:60°/s等速开链模式膝关节30°时H∶Q比值是评定ACL断裂患者大腿肌肉功能的新方法,ACL 断裂侧的股四头肌力矩显著降低, Hc∶Qc、He∶Qc和Qe∶Qc显著增加。%Objective:To evaluate the change in hamstring ( H ):quadriceps ( Q ) ratio following anterior cruciate ligament ( ACL) rupture during isokinetic knee extension and flexion at 30 degrees of flexion which is important for knee dynamic function .Methods:A study was performed in 25 male com-plete unilateral ACL ruptures .Isokinetic concentric and eccentric

  2. Efeito do intervalo de recuperação entre séries de extensões isocinéticas de joelho em homens jovens destreinados Effect of recovery interval between sets of isokinetic knee extensions among untrained young men

    Directory of Open Access Journals (Sweden)

    R Celes

    2009-08-01

    Full Text Available OBJETIVO: Avaliar o efeito de dois diferentes Intervalos de Recuperação (IR entre séries de extensões isocinéticas de joelho no Pico de Torque (PT e no Trabalho Total (TT em jovens destreinados. MÉTODOS: Dezoito homens (24,22±2,58 anos; 80,42±11,41 kg realizaram três séries de 10 extensões isocinéticas com o joelho direito a 60° e 180°/s. O IR entre as séries foram de 1 e 2 minutos, contrabalanceados entre os dois dias de teste, separados por, no mínimo, 48 horas. A taxa de trabalho-recuperação foi de 1:3 e 1:6 para 60°/s e 1:6 e 1:12 para 180°/s. Os voluntários não participavam de programas de treinamento resistido há pelo menos 6 meses. A análise estatística foi a ANOVA de medidas repetidas 2 x 3 [IR (1 e 2 minutos x série (1ª, 2ª e 3ª]. O nível de significância foi aOBJECTIVE: To assess the effect of two recovery intervals (RIs between sets of isokinetic knee extension exercises on peak torque (PT and total work (TW, among untrained young men. METHODS: Eighteen men (24.22±2.58 years; 80.42±11.41 kg performed three sets of ten isokinetic extensions of the right knee, at 60° and 180°/s. The RIs between the sets were one and two minutes long, spread over two test days separated by a minimum of 48 hours. The work-to-recovery ratio was 1:3 and 1:6 for 60°/s, and 1:6 and 1:12 for 180°/s. The subjects had not participated in any resistance training programs within the last six months. The statistical analysis consisted of 2 x 3 repeated-measures ANOVA [RI (one or two minutes x set (1st, 2nd or 3rd]. The significance level was a<0.05. RESULTS: Neither one minute nor two minutes RIs maintained the PT and TW throughout the three sets (p<0.05. However, at 60°/s, two minutes RIs enabled better PT and TW in the second and third sets than one minute RIs (p<0.05. At 180°/s, two minutes RIs were only better (p<0.05 than one minute RIs for TW in the third set. CONCLUSION: This study indicated that, during an isokinetic

  3. Low-intensity eccentric contractions attenuate muscle damage induced by subsequent maximal eccentric exercise of the knee extensors in the elderly.

    Science.gov (United States)

    Chen, Trevor C; Tseng, Wei-Chin; Huang, Guan-Ling; Chen, Hsin-Lian; Tseng, Kou-Wei; Nosaka, Kazunori

    2013-04-01

    This study investigated whether low-intensity eccentric contractions of the knee extensors would attenuate the magnitude of muscle damage induced by maximal eccentric exercise of the same muscle performed 7 days later using elderly individuals. Healthy older men (66.4 ± 4.6 years) were assigned to control or experimental (Exp) group (n = 13 per group). The control group performed six sets of ten maximal eccentric contractions (MaxECC) of the knee extensors of non-dominant leg. The Exp group performed six sets of ten low-intensity eccentric contractions of the knee extensors on a leg extension machine by lowering a weight of 10 % maximal voluntary isometric knee extension strength (10 %ECC) 7 days prior to MaxECC. Changes in maximal voluntary isokinetic concentric torque (MVC-CON), angle at peak torque, range of motion (ROM), upper thigh circumference, muscle soreness, plasma creatine kinase activity and myoglobin (Mb) concentration and B-mode ultrasound echo-intensity before and for 5 days after MaxECC were compared between groups by a mixed factor ANOVA. No significant changes in any variables were observed following 10 %ECC. Following MaxECC, all variables changed significantly, and changes in all variables except for angle at peak torque were significantly different between groups. MVC-CON and ROM decreased smaller and recovered faster (P eccentric contractions was effective for attenuating muscle damage induced by subsequent MaxECC of the knee extensors for elderly individuals.

  4. Unilateral eccentric exercise of the knee flexors affects muscle activation during gait.

    Science.gov (United States)

    Dover, Geoffrey C; Legge, Laura; St-Onge, Nancy

    2012-05-01

    Uni-lateral muscle soreness is common yet the effects on gait or electromyographic (EMG) activity are unknown. The purpose of our study was to induce delayed onset muscle soreness (DOMS) in the knee flexor group and measure the resultant change in EMG activity and knee motion during gait. Nine healthy subjects participated in the study. Measures of function, evoked tenderness of the biceps femoris, as well as knee angle, and EMG activity during gait were assessed prior and 48 h after an eccentric exercise protocol. DOMS was induced unilaterally in the knee flexors using an isokinetic dynamometer and subjects exercised until they could not generate 50% of their maximal voluntary isometric contraction (MVIC). There was a significant decrease in biceps femoris activity after DOMS during the last phase of gait. Moreover, there was a day × phase interaction for gastrocnemius activity with the last two phases displaying an increase in activity. There was no significant change in knee angle during gait. The decrease in biceps femoris activity as well as the increase in gastrocnemius activity could be evidence of a protective mechanism designed to decrease activity of the sore muscle while increasing the activity of a synergistic muscle. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Isokinetic eccentric resistance training prevents loss in mechanical muscle function after running

    DEFF Research Database (Denmark)

    Oliveira, Anderson S. C.; Caputo, Fabrizio; Aagaard, Per

    2013-01-01

    The aim of the study was to verify whether 8 weeks of resistance training employing maximal isokinetic eccentric (IERT) knee extensor actions would reduce the acute force loss observed after high-intensity treadmill running exercise. It was hypothesized that specific IERT would induce protective...... effects against muscle fatigue and ultrastructural damages, preventing or reducing the loss in mechanical muscle function after running. Subjects were tested before and after IERT protocol for maximal isometric, concentric and eccentric isokinetic knee extensor strength (60° and 180° s(-1)). In a second...... session, subjects performed treadmill running (~35 min) and the previously mentioned measurements were repeated immediately after running. Subsequently, subjects were randomized to training (n = 12) consisting of 24 sessions of maximal IERT knee extensors actions at 180° s(-1), or served as controls (n...

  6. Isokinetic muscle strength and running long jump performance in young jumpers

    Directory of Open Access Journals (Sweden)

    YIANNIS KOUTSIORAS; ATHANASIOS TSIOKANOS; DIMITRIOS TSAOPOULOS; PANAGIOTIS TSIMEAS

    2009-01-01

    Full Text Available The aim of this study was two-fold. Firstly we wanted to quantify the relationship of isokinetic muscle strength (IMS and long jump performance (LJP in young jumpers, and secondly to compare males and females in IMS. Our measurements in 7 males and 7 females showed that the LJP was correlated with the normalized peak joint moment of the concentric knee extensions and the concentric ankle plantar flexions. A low correlation was observed between the LJP and the eccentric knee extensions. The t-test showed significant gender differences in joint peak moment of concentric knee extensions and in normalized peak joint moment of concentric plantar flexions and eccentric plantar flexions at120 deg/sec. Although, our findings suggest that IMS is a major contributor to LJP, it is suggested that training intervention should not be based exclusively on isokinetic tests because of the differences in musculoskeletal function between the two movements.

  7. Influence of Isometric Exercise Training on Quadriceps Muscle Architecture and Strength in Obese Subjects with Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Waleed S Mahmoud

    2017-03-01

    Full Text Available Obese individuals have reduced quadriceps muscle strength relative to body mass that may increase the rate of progression of knee osteoarthritis (OA. The purpose of this study was to evaluate the effects of isometric exercise training on quadriceps muscle architecture and strength in obese subjects with knee osteoarthritis. Methods: Fortyfour obese male subjects aged 40–65 years diagnosed with knee osteoarthritis were randomly assigned into group A (n=32 and group B (n=12. Group A subjects performed a 12-week isometric exercise program. Group B subjects did not participate in any exercise program and maintained their ordinary activities for the same period. Both groups received the same conventional physical therapy program including hot packs and therapeutic ultrasonic. Muscle thickness, pennation angles and fascicle length of the vastus lateralis (VL muscle of the affected knee were measured at rest by B-mode ultrasonography. Maximal voluntary isometric knee extension torque (MVIC of the affected knee was measured using an isokinetic dynamometer. Knee pain and function were evaluated using visual analogue pain scale (VAS and Western Ontario and McMaster Universities Arthritis Index (WOMAC. All variables were evaluated before and the end of the intervention period for both groups. Results: at the end of the program, group A subjects showed significant improvements compared with group B subjects regarding MVIC and muscle architecture parameters (p<0.05. Also, there was significant improvement in post-test VAS and WOMAC scores in group A subjects compared to group B subjects (p<0.05. Conclusion: A 12-week quadriceps isometric training program improves knee pain and quadriceps muscle strength and architecture in obese subjects with knee OA. These results indicate that isometric training should be regarded as a proper exercise intervention for obese patients with knee OA.

  8. [Reliability and validity of the analysis of hand grip and pinch force in isometric and isokinetic conditions].

    Science.gov (United States)

    Benaglia, P G; Franchignoni, F; Ferriero, G; Zebellin, G; Sartorio, F

    1999-01-01

    Strength measurement of the hand grip is at the core of most protocols of functional assessment of the upper limb and in rehabilitation plays a major role in the analysis of treatment efficacy and patients' occupational ability. The aims of this study were to: a) verify the repeatability of strength measurements made during performance of the hand grip and three types of pinch, carried out under isometric and isokinetic conditions; b) compare maximal isometric strength with the corresponding isokinetic value for each of the manoeuvres studied; c) investigate the correlations between the strength expressed in the different manoeuvres, under both isometric and isokinetic conditions. We studied 14 voluntary subjects over three sessions conducted at 48-hr intervals, employing a computerized isokinetic dynamometer Lido WorkSet equipped with device N(o) 21 for the study of pinch (lateral pinch, pulp pinch, chuck pinch) and device N(o) 52 for the grip study. Isometric contractions resulted stronger than isokinetic ones, and the hand grip was found to be the manoeuvre able to produce most strength. The repeatability of each strength measurement test over the three days was high (Intraclass Correlation Coefficients: 0.89-0.93). Correlations between the isometric and isokinetic performance for each of the manoeuvres examined were always high (Pearson's r coefficients: 0.89-0.95) as were those between the different manoeuvres, whether performed in isometric or isokinetic modality (r: 0.60-0.94).

  9. Arthroscopically assisted combined anterior and posterior cruciate ligament reconstruction with autologous hamstring grafts-isokinetic assessment with control group.

    Directory of Open Access Journals (Sweden)

    Tomasz Piontek

    Full Text Available OBJECTIVE: The aim of the study was to: 1 evaluate the differences in pre-post operative knee functioning, mechanical stability, isokinetic knee muscle strength in simultaneous arthroscopic patients after having undergone an anterior cruciate ligament (ACL and the posterior cruciate ligament (PCL with hamstring tendons reconstruction, 2 compare the results of ACL/PCL patients with the control group. DESIGN: Controlled Laboratory Study. MATERIALS AND METHODS: Results of 11 ACL/PCL patients had been matched with 22 uninjured control participants (CP. Prior to surgery, and minimum 2 years after it, functional assessment (Lysholm and IKDC 2000, mechanical knee joint stability evaluation (Lachman and "drawer" test and isokinetic tests (bilateral knee muscle examination had been performed. Different rehabilitation exercises had been used: isometric, passive exercises, exercises increasing the range of motion and proprioception, strength exercises and specific functional exercises. RESULTS: After arthroscopy no significant differences had been found between the injured and uninjured leg in all isokinetic parameters in ACL/PCL patients. However, ACL/PCL patients had still shown significantly lower values of strength in relative isokinetic knee flexors (p = 0.0065 and extensors (p = 0.0171 compared to the CP. There were no differences between groups regarding absolute isokinetic strength and flexors/extensors ratio. There was statistically significant progress in IKDC 2000 (p = 0.0044 and Lysholm (p = 0.0044 scales prior to (44 and 60 points respectively and after the reconstruction (61 for IKDC 2000 and 94 points for Lysholm. CONCLUSIONS: Although harvesting tendons of semitendinosus and/or gracilis from the healthy extremity diminishes muscle strength of knee flexors in comparison to the CP, flexor strength had improved. Statistically significant improvement of the knee extensor function may indicate that the recreation of joint mechanical stability is

  10. Comparison of nutritional intake, body composition, bone mineral density, and isokinetic strength in collegiate female dancers.

    Science.gov (United States)

    Lim, Se-Na; Chai, Joo-Hee; Song, Jong Kook; Seo, Myong-Won; Kim, Hyun-Bae

    2015-12-01

    This study compared nutritional intake, body composition, bone mineral density, and isokinetic strength by dance type in collegiate female dancers. The study subjects included Korean dancers (n=12), ballet dancers (n=13), contemporary dancers (n=8), and controls (n=12). Nutritional intake was estimated using the Computer Aided Nutritional Analysis Program. Body composition and bone mineral density were measured using dual-energy X-ray absorptiometry. Isokinetic knee joint strength was measured by Cybex 770-NORM. All statistical analyses were performed by SAS 9.2. Means and standard deviations were calculated using descriptive statistics. One-way analysis of variance was applied to evaluate nutritional intake, body composition, bone mineral density, and isokinetic strength differences. Duncan multiple range test was used for post hoc testing. A level of significance was set at Pcontemporary and ballet dancers had lower body fat percentages than controls (Pdance type and more scientific methods of dance training are needed.

  11. Assessment of isokinetic muscle function in Korea male volleyball athletes

    Science.gov (United States)

    Kim, Chang-Gyun; Jeoung, Bog Ja

    2016-01-01

    Volleyball players performed numerous repetitions of spike actions, which uses and requires strong and explosive force, and control of the muscles of the shoulder, lower back, and legs. Muscle imbalance is one of the main causes of sport injuries. The purpose of this study was to assess isokinetic muscle functions in male volleyball players. We thus aim to accurately evaluate their muscle functions, and identify the best training strategy to achieve optimal muscle strength balance in future training programs. The participants in this study consisted of 14 male volleyball players. Muscle strength was measured using the isokinetic dynamometer. Muscle strength was evaluated in terms of peak torque and average power, calculated from five repeated measurements at an angular speed of 60°/sec. Three players who were left attackers showed shoulder imbalance, four players showed trunk joint imbalance, nine players had knee joint of extension/flexion imbalance and four players showed left/right imbalance. The results showed that the number of volleyball players with differences between the strength of the bilateral knee muscles, and between the strength of the hamstrings and quadriceps muscles was higher than the number of players with differences between the strength of the shoulder internal and external rotation muscles, and higher than the number of players with differences between the strength of the lower back extension and flexion muscles. PMID:27807521

  12. Isokinetic exercise: A review of the literature

    Science.gov (United States)

    Olree, H. D.; Corbin, B.; Smith, C.

    1978-01-01

    Isokinetic muscle training has all the advantages of isometrics and isotonics while minimizing their deficiencies. By holding the speed of movement constant throughout the full range of motion, isokinetic training devices respond with increased resistance rather than acceleration when the power output of the muscle is increased. Isokinetic training is superior to isometric and isotonic training with respect to increases in strength, specificity of training, desirable changes in motor performance tasks, lack of muscle soreness, and decreases in relative body fat.

  13. Scaling lower-limb isokinetic strength for biological maturation and body size in adolescent basketball players.

    Science.gov (United States)

    Carvalho, Humberto Moreira; Coelho-e-Silva, Manuel; Valente-dos-Santos, João; Gonçalves, Rui Soles; Philippaerts, Renaat; Malina, Robert

    2012-08-01

    The relationships between knee joint isokinetic strength, biological maturity status and body size were examined in 14-16-year-old basketball players, considering proportional allometric modeling. Biological maturity status was assessed with maturity offset protocol. Stature, body mass, sitting height, and estimated thigh volume were measured by anthropometry. Maximal moments of force of concentric and eccentric muscular actions for the knee extensors and flexors were assessed by isokinetic dynamometry at 60° s(-1). Regression analysis revealed a linear relation between maximal moments of force of the knee extensors in both muscular actions and knee flexors in concentric actions were moderately high (0.55 ≤ r ≤ 0.64). As for knee flexors in eccentric actions, a squared term of maturity indicator was significant indicating that the relationship with maturity offset tended to plateau approximately 2 years after PHV. Incorporating maturity indicator term with body size term (body mass or thigh volume) in the allometric models revealed that the size exponents for both body mass and thigh volume were reduced compared with simple allometric modeling. The results indicate a significant inter-individual variation in lower-limb isokinetic strength performance at 60° s(-1) in concentric and eccentric muscular actions in late adolescent basketball players. The variability in performance is related to inter-individual variation in estimated time before or after peak height velocity, as well as differences in body size. Proportional allometric models indicate that the influence of estimated time from age at peak height velocity on isokinetic strength performance is mostly mediated by corresponding changes in overall body mass.

  14. Isokinetic Evaluation of Quadriceps Strength in Open and Closed Kinetic Chains in Patients with Anterior Cruciate Ligament Reconstruction

    Directory of Open Access Journals (Sweden)

    Ali Ashraf-Jamshidi

    2014-06-01

    Full Text Available Background: Strength of knee extension and squat were compared between anterior cruciate ligament reconstructed (ACLR patients and healthy subjects. Materials and Methods: Twenty ACLR and twenty control subjects were participated in this non-exprimental study. Isokinetic peak strength of knee extension and squat in involved and uninvolved side of the ACLR patient and control group were measured. Results: Concentric and eccentric knee extension strength of the involved leg was decreased but squat strength showed no difference. Conclusion: In spite of return to sport activity and normal squat strength weakness of knee extensor muscles in the involved side of the ACLR patient was existed.

  15. Chronic Knee Injuries Impair the Voluntary Activation of Quadriceps Femoris%陈旧性膝关节运动损伤者股四头肌随意动员能力下降

    Institute of Scientific and Technical Information of China (English)

    徐刚; 黄力平; 周石; 王昭君; 李猛; 敖铭; 王聪; 赵美苓; 梁军

    2012-01-01

    目的:观察陈旧性膝关节运动损伤股四头肌随意动员能力的变化.方法:60名天津体育学院学生,自愿参加测试,根据其是否有陈旧性膝关节运动损伤分为2组,损伤组(有训练史)30人,对照组(无训练史)30人.应用股四头肌随意动员能力评定系统测定分析股四头肌最大随意等长肌力(MVC)、随意动员能力(MA)和力量上升速率(RFD).结果:对照组两侧股四头肌MVC、MA和RFD无显著差异(P>0.05),损伤组两侧股四头肌MVC无显著性差异(P>0.05).对照组右侧股四头肌MVC、RFD值显著低于损伤组未损伤侧(P<0.05,P< 0.01),损伤组膝关节损伤侧MA、RFD值显著低于未损伤侧(P< 0.05,P< 0.01).结论:即使陈旧性膝关节运动损伤者股四头肌肌肉力量已恢复到未损伤侧水平,其随意动员能力和力量上升速率依然较低,膝关节神经肌肉控制仍较差,这可能是影响陈旧性膝关节运动损伤功能状态的主要因素之一.股四头肌随意动员能力评价系统可检测这一变化.%Objective To determine whether voluntary activation of quadriceps femoris persons with chronic knee injuries is impaired. Methods Thirty participants with knee injuries and thirty healthy participants voluntarily participated in the study. Muscle strength in maximum voluntary contraction (MVC) .muscle activation (MA),and the rate of force development (RFD) in isometric knee extension were assessed for both legs using a custom-built dynamometer. Independent-Samples T test was used to compare the mean values between the two groups or/and both legs. Results No significant differences were found in the measured variables between the two legs in the healthy control group. There was no significant difference in the MVC between legs in the injury group(P>0.05). The MVC and RFD of the right leg in the control group were lower than the uninjured left side in the injury group (P<0.05,P< 0.01). The MA and RFD of the injured side in

  16. The Total Work Measured During a High Intensity Isokinetic Fatigue Test Is Associated With Anaerobic Work Capacity

    Science.gov (United States)

    Bosquet, Laurent; Gouadec, Kenan; Berryman, Nicolas; Duclos, Cyril; Gremeaux, Vincent; Croisier, Jean Louis

    2016-01-01

    The purpose of the study was to determine whether total work measured during a high intensity isokinetic fatigue test (TWFAT) could be considered as a valid measure of anaerobic work capacity (AWC), such as determined by total work measured during a Wingate Anaerobic Test (TWWAnT). Twenty well-trained cyclists performed 2 randomly ordered sessions involving a high intensity isokinetic fatigue test consisting in 30 reciprocal maximal concentric contractions of knee flexors and extensors at 180°·s-1, and a Wingate Anaerobic Test. We found that TWFAT of knee extensors was largely lower than TWWAnT (4151 ± 691 vs 22313 ± 2901 J, respectively, p knee flexors (2151 ± 540 J) was largely lower than TWWAnT (p knee flexors and knee extensors into a single measure (6302 ± 818 J) did not changed neither improved these observations. We still found a large difference with TWWAnT (p knee extensors could be considered as a valid measure of AWC, since both measure were highly associated. However, the mean difference between both measures and their 95% LoA were too large to warrant interchangeability. Key points Total work performed during a high intensity isokinetic fatigue test can be considered as a valid measure of anaerobic work capacity (as determined by total work performance during a 30-s Wingate anaerobic test). The 95% limits of agreement are two large to allow a direct comparison between both measures. In other words, it is not possible to estimate the magnitude of performance improvement during a 30-s Wingate anaerobic test from that observed during a high intensity isokinetic fatigue test. In addition to provide sport scientists and coaches with measures of peak torque and ratios between agonists and antagonists muscles in a perspective of injury prevention, isokinetic dynamometry can also be used in the physiological assessment of athletes. However, some precautions should be taken in the interpretation of data. PMID:26957935

  17. Hamstrings to quadriceps peak torque ratios diverge between sexes with increasing isokinetic angular velocity.

    Science.gov (United States)

    Hewett, Timothy E; Myer, Gregory D; Zazulak, Bohdanna T

    2008-09-01

    Our purpose was to determine if females demonstrate decreased hamstrings to quadriceps peak torque (H/Q) ratios compared to males and if H/Q ratios increase with increased isokinetic velocity in both sexes. Maturation disproportionately increases hamstrings peak torque at high velocity in males, but not females. Therefore, we hypothesised that mature females would demonstrate decreased H/Q ratios compared to males and the difference in H/Q ratio between sexes would increase as isokinetic velocity increased. Studies that analysed the H/Q ratio with gravity corrected isokinetic strength testing reported between 1967 and 2004 were included in our review and analysis. Keywords were hamstrings/quadriceps, isokinetics, peak torque and gravity corrected. Medline and Smart databases were searched combined with cross-checked bibliographic reference lists of the publications to determine studies to be included. Twenty-two studies were included with a total of 1568 subjects (1145 male, 423 female). Males demonstrated a significant correlation between H/Q ratio and isokinetic velocity (R=0.634, pratio at the lowest angular velocity (47.8+/-2.2% at 30 degrees /s) compared to the highest velocity (81.4+/-1.1% at 360 degrees /s, pratio and isokinetic velocity (R=0.065, p=0.77) or a change in relative hamstrings strength as the speed increased (49.5+/-8.8% at 30 degrees /s; 51.0+/-5.7% at 360 degrees /s, p=0.84). Gender differences in isokinetic H/Q ratios were not observed at slower angular velocities. However, at high knee flexion/extension angular velocities, approaching those that occur during sports activities, significant gender differences were observed in the H/Q ratio. Females, unlike males, do not increase hamstrings to quadriceps torque ratios at velocities that approach those of functional activities.

  18. 不同级别竞技健美操运动员髋、膝和踝关节等速肌力特征研究%Isokinetic Test and Characteristics of Hip,Knee and Ankle Joint Muscle Strength of Aerobics Gymnastics with Different Levels

    Institute of Scientific and Technical Information of China (English)

    岳建军

    2014-01-01

    The purpose of this study is to research the hip ,knee ,ankle flexion muscle group of national team training base of competitive aerobics in China by using BIODEX isokinetic testing instrument .We came to an overall conclusion that compared with a national level athletes ,the international athletes have better hip joint and knee joint muscle’s strength endurance ,explo-sive force and power control and the relative weight of peak torque has no difference ;Ankle joint flexor muscle force control ,extensor explosive force and power control is better .Vertical jump height and peak torque with hip hop number percent leg have high correlation with knee joint time and acceleration time ,percentage of fatigue ,the number of maximum work ,especial under the high speed situation and low relevance with ankle joint ;The indicators have certain relevance between adjacent joints .World-class athletes hip and knee flexion extend strength ra-tio is bigger than the national athletes ,there is no difference for ankle ;among them ,the inter-national athletes knee flexion extend strength ratio is biggest under high speed .%运用BIODEX等速测试仪对我国竞技健美操国家队训练基地男运动员髋、膝、踝关节屈伸肌群及其相关素质进行测试与分析。研究认为,竞技健美操国际级运动员与国家一级运动员相比,髋关节与膝关节肌肉的力量耐力更好,爆发力与力量控制能力更强,而相对体重峰力矩没有差别;踝关节屈肌力量控制能力更好,伸肌爆发力与力量控制能力更好。纵跳高度与髋膝关节峰力矩时间、加速时间有较高相关性,30 s分腿跳次数与髋膝关节肌肉疲劳百分数和最大功次数有较高相关性,其中,高速度情况下呈现非常显著相关性,与踝关节各项指标相关性较低;相邻关节各项指标有一定的相关性。国际级运动员髋关节与膝关节屈伸肌力比国家一级运动员要大,而踝关节没

  19. Relation between isokinetic muscle strength and functional capacity in recreational athletes with chondromalacia patellae

    Science.gov (United States)

    Yildiz, Y; Aydin, T; Sekir, U; Cetin, C; Ors, F; Alp, K

    2003-01-01

    Objectives: To investigate the effects of isokinetic exercise on pain and functional test scores of recreational athletes with chondromalacia patellae (CMP) and to examine the correlation between isokinetic parameters and functional tests or pain score. Methods: The functional ability of 30 recreational athletes with unilateral CMP was evaluated using six different tests. Pain scores were assessed during daily activities before and after the treatment protocol. Isokinetic exercise sessions were carried out at angular velocities of 60°/s (25–90° range of flexion) and 180°/s (full range). These sessions were repeated three times a week for six weeks. Results: Quadriceps and hamstring peak torque, total work, and endurance ratios had improved significantly after the treatment, as did the functional parameters and pain scores. There was a poor correlation between the extensor endurance ratio and one leg standing test. A moderate correlation between the visual analogue scale and the extensor endurance ratio or flexion endurance ratio was also found. Conclusions: The isokinetic exercise programme used in this study had a positive effect on muscle strength, pain score, and functional ability of knees with CMP. The improvement in the functional capacity did not correlate with the isokinetic parameters. PMID:14665581

  20. Muscular performance characterization in athletes: a new perspective on isokinetic variables

    Directory of Open Access Journals (Sweden)

    Giovanna M. Amaral

    2014-12-01

    Full Text Available Background: Isokinetic dynamometry allows the measurement of several variables related to muscular performance, many of which are seldom used, while others are redundantly applied to the characterization of muscle function. Objectives: The present study aimed to establish the particular features of muscle function that are captured by the variables currently included in isokinetic assessment and to determine which variables best represent these features in order to achieve a more objective interpretation of muscular performance. Method: This study included 235 male athletes. They performed isokinetic tests of concentric knee flexion and extension of the dominant leg at a velocity of 60º/s. An exploratory factor analysis was performed. Results: The findings demonstrated that isokinetic variables can characterize more than muscle torque production and pointed to the presence of 5 factors that enabled the characterization of muscular performance according to 5 different domains or constructs. Conclusions: The constructs can be described by torque generation capacity; variation of the torque generation capacity along repetitions; movement deceleration capacity; mechanical/physiological factors of torque generation; and acceleration capacity (torque development. Fewer than eight out of sixteen variables are enough to characterize these five constructs. Our results suggest that these variables and these 5 domains may lead to a more systematic and optimized interpretation of isokinetic assessments.

  1. Leg strength improvement in elderly fallers and non fallers after eigth week of isokinetic strengthening

    Directory of Open Access Journals (Sweden)

    SEMALTIANOU ELENI

    2012-01-01

    Full Text Available The purpose of the present study was to investigate the effects of an eight week strengthening program in an isokinetic dynamometer, in the knee joint muscles of healthy elderly people, with and with out a history of falls. In the study participated 59 elderly men and women all in good health aged 60 years and over. The elderly were assessed in five concentric, two eccentric speeds (60°, 90°, 120°, 180°, 240° and 60°, 120°/sec respectively and in four angular positions (75°, 60°, 45°, 30° of knee flexion, 0° = full extension in an Cybex Norm® isokinetic dynamometer. The experimental group of the study followed a strengthening program for quadriceps andhamstring muscles in the isokinetic dynamometer for eight weeks, in five concentric speeds. The results of the study indicated statistically significant differences (p _.05 in strength and power between initial and final assessment in the experimental group. The results indicated also statistically significant differences (p<0.05 in strength and power between fallers and non - fallers of the experimental group in the initial assessment. These differences were diminished after the intervention period with fallers achieving statistically significant improvement (p<0.05. The results of the study provide evidence that an eight week isokinetic strengthening program of lower extremities in elderly people is very efficient in fall prevention.

  2. A study of isokinetic strength and laxity with and without anterior cruciate ligament injury

    Science.gov (United States)

    Kim, Kewwan; Jeon, Kyoungkyu; Mullineaux, David R.; Cho, Eunok

    2016-01-01

    [Purpose] The purpose of this study was to provide useful information for future treatments and to organize rehabilitation programs for anterior cruciate ligament injury by assessing isokinetic muscle strength and laxity of knee joints in athletes with anterior cruciate ligament injuries. [Subjects and Methods] Thirty-one high school athletes with anterior cruciate ligament injuries participated in this study. Isokinetic muscle strength at 60°/sec and anterior cruciate ligament laxity for non-involved and involved sides, classified on the basis of the severity of anterior cruciate ligament injury, were assessed. [Results] A comparison of isokinetic muscle strength measured from the non-involved and involved sides showed a significant difference in the maximum strength and knee flexor muscle strength. For laxity, a significant difference was observed in the anterior drawer test results obtained with a force of 88 N. [Conclusion] In conclusion, this study has shown that the assessment of isokinetic muscle strength and ligament laxity from athletes with anterior cruciate ligament injury should be utilized to provide baseline data for prevention and prediction of injury. PMID:28174432

  3. Experimental knee pain reduces muscle strength

    DEFF Research Database (Denmark)

    Henriksen, Marius; Rosager, Sara; Aaboe, Jens

    2011-01-01

    Pain is the principal symptom in knee pathologies and reduced muscle strength is a common observation among knee patients. However, the relationship between knee joint pain and muscle strength remains to be clarified. This study aimed at investigating the changes in knee muscle strength following...... experimental knee pain in healthy volunteers, and if these changes were associated with the pain intensities. In a crossover study, 18 healthy subjects were tested on 2 different days. Using an isokinetic dynamometer, maximal muscle strength in knee extension and flexion was measured at angular velocities 0....... Knee pain reduced the muscle strength by 5 to 15% compared to the control conditions (P muscle strength was positively correlated to the pain intensity. Experimental knee pain significantly reduced knee extension...

  4. Acute effects of two different stretching techniques on isokinetic strength and power

    OpenAIRE

    Ayala, F.; De Ste Croix, M; Sainz de Baranda, P.; Santonja, F.

    2015-01-01

    Objectives: To examine and compare the acute effects of short duration static and dynamic lower-limb stretching routines on the knee flexor and extensor peak torque and mean power during maximal concentric and eccentric muscle actions. Method: Forty-nine active adults completed the following intervention protocols on separate days: non-stretching, static stretching and dynamic stretching. After the stretching or control intervention, concentric and eccentric isokinetic peak torque and mean...

  5. Isokinetic strength of knee flexors and extensors of adolescent soccer players and its changes based on movement speed and age [Izokinetická síla flexorů a extenzorů kolena u adolescentních fotbalistů a její změny s rychlostí pohybu a s věkem

    Directory of Open Access Journals (Sweden)

    Rudolf Psotta

    2011-06-01

    Full Text Available BACKGROUND: During childhood and adolescence there is growth in muscle strength. The dynamics of change in muscle strength and its causes have not yet been fully clarified and may differ within individuals and specific groups. The knowledge of current isokinetic strength levels among athletes of varying ages and disciplines represents important information from the point of view of sport performance, as well as health prevention. OBJECTIVE: The aim of this study is to determine within a group of highly trained adolescent soccer players (n = 45; age = 17 ± 1.2 years; body height 178.4 ± 5.3 cm, body weight 68.5 ± 7.6 kg the isokinetic strength of knee flexors and extensors and to judge whether it is significantly influenced by age and movement speed. METHODS: A group of players was further divided according to age into 3 subgroups – U16 (n = 16; U17 (n = 14; U18 (n = 15. Unilateral strength was measured by the isokinetic dynamometer ISOMED 2000 (D. & R. Ferstl GmbH, Hemau, Germany at angular speeds of 60° • s-1, 180° • s-1 and 360° • s-1. The parameter evaluated was the isokinetic peak torque (PT; Nm. RESULTS: The ANOVA results demonstrate that there was a significant decrease in the PT within the entire group of players with an increase in speed during both flexion and extension (dominant extremity: p < 0.001 resp. p < 0.019; non-dominant extremity: p < 0.001; resp. p < 0.001. The difference in PT among the age categories was not significant for both flexors and extensors at the speed of 60° ∙ s-1 (p = 0.005; resp. p = 0.036 and the speed of 180° ∙ s-1 (p = 0.036; resp. p = 0.033. However, significant differences in PT among individual categories were confirmed only in some cases and, by contrast, an insignificant decrease was marked with nondominant leg extensors. CONCLUSIONS: The results of this study indicated the state of the strength readiness of the highly trained soccer players in the junior category and the potential

  6. 24周综合运动对45至59岁中年人群膝关节等速肌力干预效果的研究%Intervention outcomes of 24-week comprehensive exercise on knee isokinetic muscle strength in 45-59-year-old middle-aged population

    Institute of Scientific and Technical Information of China (English)

    高雪峰; 徐勇灵; 张晓文; 陈守超

    2015-01-01

    目的 探讨24周综合运动干预方案对中年健身人群膝关节肌群力量素质的影响.方法 选取年龄45至49岁中年男性21人、女性34人进行运动干预并进行等速肌力测量膝关节肌群,指标包括屈膝峰值力矩(FPT)、伸膝峰值力矩(EPT)、屈膝相对峰值力矩(FPT/BW)、屈膝相对峰值力矩(EPT/BW)、屈伸力矩比(F/E)、屈膝总功(FTW)、伸膝总功(ETW)、屈膝平均功率(FAP)、伸膝平均功率(EAP).结果 男性受试者在60°/s速度运动干预16周、24周后较运动干预前FPT(屈)分别增加14.18%、11.52%,FPT/BW(屈)分别增加16.39%、15.57%,EPT/BW(伸)分别增加0.45%、6.28%,F/E、FTW(屈)、ETP(伸)等指标呈现出明显增加.在180°/s速度下上述各指标增加幅度更为明显.女性受试者在60°/s速度运动干预16周、24周后较运动干预前FPT(屈)分别增加29.48%、27.66%,FPT/BW(屈)分别增加29.76%、29.76%,在180./s速度下除EPT/BW(伸)、ETP(伸)无明显变化外,上述各指标呈现出更为显著的增加.结论 24周综合运动干预对中年健身人群膝关节肌群力量素质有明显改善,本方案对中年人群膝关节肌群的锻炼有显著促进作用.%Objective To investigate the effects of the intervention protocol of 24-week comprehensive exercise on knee isokinetic muscle strength in middle-aged population.Methods Twentyone males and 34 females aged 45-49 years were included in the study and underwent exercise intervention and isokinetic muscle strength measurement to determine indicators of the knee muscle group,which included flexion peak torque (FPT),extension peak torque (EPT),FPT/BW,EPT/BW,Flexor/Extensor (F/ E),flexion total work (FTW),extensor total work (ETW),flexion average power (FAP),and extensor average power (EAP).Results The FPT (flexor),FPT/BW (flexor) and EPT/ BW (flexor) in male subjects were increased 14.18% vs.11.52%,16.39% vs.15.57%,and 0.45% vs.6.28% after received 60

  7. A methodologic approach for normalizing angular work and velocity during isotonic and isokinetic eccentric training.

    Science.gov (United States)

    Guilhem, Gaël; Cornu, Christophe; Guével, Arnaud

    2012-01-01

    Resistance exercise training commonly is performed against a constant external load (isotonic) or at a constant velocity (isokinetic). Researchers comparing the effectiveness of isotonic and isokinetic resistance-training protocols need to equalize the mechanical stimulus (work and velocity) applied. To examine whether the standardization protocol could be adjusted and applied to an eccentric training program. Controlled laboratory study. Controlled research laboratory. Twenty-one sport science male students (age = 20.6 ± 1.5 years, height = 178.0 ± 4.0 cm, mass = 74.5 ± 9.1 kg). Participants performed 9 weeks of isotonic (n = 11) or isokinetic (n = 10) eccentric training of knee extensors that was designed so they would perform the same amount of angular work at the same mean angular velocity. Angular work and angular velocity. The isotonic and isokinetic groups performed the same total amount of work (-185.2 ± 6.5 kJ and -184.4 ± 8.6 kJ, respectively) at the same angular velocity (21 ± 1°/s and 22°/s, respectively) with the same number of repetitions (8.0 and 8.0, respectively). Bland-Altman analysis showed that work (bias = 2.4%) and angular velocity (bias = 0.2%) were equalized over 9 weeks between the modes of training. The procedure developed allows angular work and velocity to be standardized over 9 weeks of isotonic and isokinetic eccentric training of the knee extensors. This method could be useful in future studies in which researchers compare neuromuscular adaptations induced by each type of training mode with respect to rehabilitating patients after musculoskeletal injury.

  8. 不同速度下膝关节等速肌力和自然步速下步态的时空参数比较%Comparison of isokinetic knee muscle strength under different angular velocity and temporal-distance gait parameter

    Institute of Scientific and Technical Information of China (English)

    纪之光; 庄洁; 黄亮

    2014-01-01

    BACKGROUND:The current studies concerning the effect of obesity on children are limited to metabolic physiology, and there is little evidence available on skeletal muscle and motor ability. OBJECTIVE:To compare isokinetic knee muscle strength between obese children and normal children, and analyze the causes of physical performance decline in obese children. METHODS:A total of 56 children were recruited in this study, including 28 obese children and 28 normal children. The isokinetic muscle strength was tested by CON-TREX. The gaits were tested by VICON. The statistical analysis of al the differences between obese children and normal children were measured using SPSS 19.0 software. RESULTS AND CONCLUSION:At the same gait speed, obese children had higher absolute peak torque and average power than normal children (P0.05) except extensor group at 60(°)/s was significantly lower than normal children. At the same gait speed, the torque and power of extensor group were significantly higher than that of flexor group in the two groups (P  目的:比较肥胖儿童与正常儿童膝关节的等速肌力,从肌力方面分析肥胖儿童运动能力下降的原因。  方法:招募56名儿童,其中28名肥胖儿童,28名正常儿童。采用CON-TREX等速测试仪测量下肢肌力,采用VICON系统采集运动数据,采用SPSS 19.0统计软件对所有实验数据进行统计学处理。  结果与结论:在同一速度下,肥胖儿童的膝关节伸屈绝对峰力矩和平均功率大于正常儿童(P0.05)。在同一速度下,两组儿童的伸肌群力矩和功率均大于屈肌群(P<0.05),同时肥胖组儿童在较高速度[120(°)/s]下伸屈肌群绝对峰力矩和绝对平均功率与相对峰力矩和相对平均功率差异均有显著性意义(P<0.05)。两组儿童均表现屈肌在较高速度下力矩大,伸肌在较低速度下力矩大。正常儿童的步频步速快于肥胖儿童,单步时间和步

  9. Learning effect of isokinetic measurements in healthy subjects, and reliability and comparability of Biodex and Lido dynamometers

    DEFF Research Database (Denmark)

    Lund, Hans; Søndergaard, K; Zachariassen, T

    2005-01-01

    The aim of this study was to examine the learning effect during a set of isokinetic measurements, to evaluate the reliability of the Biodex System 3 PRO dynamometer, and to compare the Biodex System 3 PRO and the Lido Active dynamometers on both extension and flexion over the elbow and the knee...... extension (P = 0.18) and elbow extension (P = 0.63). However, elbow flexion showed a 14.8% (95% CI: 11.2-18.4%; P = 0.0001) higher peak torque on Biodex. In conclusion, no learning effect was observed and the Biodex proved to be a highly reliable isokinetic dynamometer. A difference was observed when...

  10. Voluntary muscle activation improves with power training and is associated with changes in gait speed in mobility-limited older adults - A randomized controlled trial.

    Science.gov (United States)

    Hvid, Lars G; Strotmeyer, Elsa S; Skjødt, Mathias; Magnussen, Line V; Andersen, Marianne; Caserotti, Paolo

    2016-07-01

    Incomplete voluntary muscle activation may contribute to impaired muscle mechanical function and physical function in older adults. Exercise interventions have been shown to increase voluntary muscle activation, although the evidence is sparse for mobility-limited older adults, particularly in association with physical function. This study examined the effects of 12weeks of power training on outcomes of voluntary muscle activation and gait speed in mobility-limited older adults from the Healthy Ageing Network of Competence (HANC) study. We included 37 older men and women with a usual gait speed of analysis: n=16 in the training group (TG: 12weeks of progressive high-load power training, 2 sessions per week; age: 82.3±1.3years, 56% women) and n=21 in the control group (CG: no interventions; age: 81.6±1.1years, 67% women). Knee extensor muscle thickness (ultrasonography), strength (isokinetic dynamometry), voluntary activation (interpolated twitch technique), and gait speed (2-min maximal walking test) were assessed at baseline and post-intervention. At baseline, TG and CG were comparable for all measures. Post-intervention, significant between-group changes (TG vs. CG; pgait speed (+0.12m/s), whereas the between-group change in muscle thickness was non-significant (+0.08cm). Improvements in voluntary muscle activation were associated with improvements in gait speed in TG (r=0.67, ppower training, and is associated with improved maximal gait speed. Incomplete voluntary muscle activation should be considered one of the key mechanisms influencing muscle mechanical function and gait speed in older adults.

  11. Effect of isokinetic cycling versus weight training on maximal power output and endurance performance in cycling.

    Science.gov (United States)

    Koninckx, Erwin; Van Leemputte, Marc; Hespel, Peter

    2010-07-01

    The aim of this study was to compare the effects of a weight training program for the leg extensors with isokinetic cycling training (80 rpm) on maximal power output and endurance performance. Both strength training interventions were incorporated twice a week in a similar endurance training program of 12 weeks. Eighteen trained male cyclists (VO(2peak) 60 +/- 1 ml kg(-1) min(-1)) were grouped into the weight training (WT n = 9) or the isokinetic training group (IT n = 9) matched for training background and sprint power (P (max)), assessed from five maximal sprints (5 s) on an isokinetic bicycle ergometer at cadences between 40 and 120 rpm. Crank torque was measured (1 kHz) to determine the torque distribution during pedaling. Endurance performance was evaluated by measuring power, heart rate and lactate during a graded exercise test to exhaustion and a 30-min performance test. All tests were performed on subjects' individual race bicycle. Knee extension torque was evaluated isometrically at 115 degrees knee angle and dynamically at 200 degrees s(-1) using an isokinetic dynamometer. P (max) at 40 rpm increased in both the groups (~15%; P < 0.05). At 120 rpm, no improvement of P (max) was found in the IT training group, which was possibly related to an observed change in crank torque at high cadences (P < 0.05). Both groups improved their power output in the 30-min performance test (P < 0.05). Isometric knee extension torque increased only in WT (P < 0.05). In conclusion, at low cadences, P (max) improved in both training groups. However, in the IT training group, a disturbed pedaling technique compromises an improvement of P (max) at high cadences.

  12. Isokinetic profile of subjects with the ruptured anterior cruciated ligament

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    Drapšin Miodrag

    2016-01-01

    Full Text Available Background/Aim. All changes in the knee that appear after anterior cruciate ligament (ACL lesion lead to difficulties in walking, running, jumping especially during sudden changes of the line of movement. This significantly impairs quality of life of these subjects and leads to decrease in physical activity. Knee injuries make 5% of all most severe acute sport injuries. The aim of the study was to determine strength of the thigh muscles in persons with unilateral rupture of the ACL and to evaluate potential bilateral differences between healthy and injured leg. Methods. This study involved 114 male athletes of different sport specialities with the clinical diagnosis of ACL rupture. Each subject had unilateral ACL rupture and the other leg was actually the control for this research. An isokinetic device was used to evaluate the muscle strength of thigh muscles. Testing was performed for two testing speeds, 60º/s and 180º/s. Results. Data analysis showed a statistically significant difference (p < 0.01 between the ACL and the healthy leg in the following parameters: peak torque for thigh extensors (Ptrq_E, angle to peak torque during extension (Ang_E, power of extension (Pow_E and work during extension (Work_E. Analysing hamstrings to quadriceps (H/Q ratio we found the unilateral disbalance of thigh muscle strength in ACL leg. Conclusion. A high level of validity makes isokinetic dynamometry the method for evaluation of thigh muscles strength and leaves this field of research open for new studies in order to improve both diagnostic and rehabilitation of patients with the insufficient ACL.

  13. Isokinetic Strength Profile of Elite Female Handball Players

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    Xaverova Zuzana

    2015-12-01

    Full Text Available 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.

  14. Isokinetic Strength Profile of Elite Female Handball Players.

    Science.gov (United States)

    Xaverova, Zuzana; Dirnberger, Johannes; Lehnert, Michal; Belka, Jan; Wagner, Herbert; Orechovska, Karolina

    2015-12-22

    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.

  15. Isokinetic assessment of the flexor-extensor balance of the knee in athletes with total rupture of the anterior cruciate ligament Avaliação isocinética do equilíbrio flexo-extensor do joelho nos atletas com ruptura total do ligamento cruzado anterior

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    Antonio Sérgio A. P. Terreri

    1999-04-01

    Full Text Available The purpose of this study was to assess the flexor-extensor group of muscles of the knee in young athletes diagnosed with a total rupture of the anterior cruciate ligament (ACL. Eighteen knees of 18 athletes (14 men and 4 women with an average age of 21.6 years (range 16-32 years were assessed with a Cybex 6000 model isokinetic apparatus. The average interval between occurrence of the injury and assessment was 10.2 months (range 2 - 48 months. There was an associated meniscal injury in eight of the knees. Athletes with any other kind of associated injury, limitation, or blockage of the movement of the joint, significant pain during the exam, or interval between injury and exam of less than two months were excluded from the study. The parameters studied were the peak torque-velocity and flexor-extensor relationships at the constant angular velocities of 60°/sec and 240°/sec. Previous warming-up was done by means of an ergometric bicycle and adaptation with 3 submaximal repetitions. The contra-lateral side, which presented no injury, was used as control. Peak torque (PT at the constant velocity of 60°/sec was greater than that at 240°/sec for knees with and without injuries. However, there was no significant difference between the injured and uninjured sides at 60°/sec or at 240°/sec. The average value for the flexor-extensor relationship at 60°/sec on the injured was 60% (( 6, compared to 57% (( 10 on the contra-lateral side. At 240°/sec, the average value was 75% ((10 on the injured side, and 65% ((12 on the contra-lateral side. In conclusion, despite the complete rupture of the ACL of one knee, the average values for the flexor-extensor relationship were similar on the injured and uninjured sides at the velocity of 60°/sec. As the velocity increased, an increase in the values for the flexor-extensor relationship of the knee also occurred, indicating a tendency of the performance of the flexor muscle group to approach that of the

  16. EFFICACY OF ISOKINETIC STRENGTH TRAINING AND BALANCE EXERCISES ON LOWER LIMB MUSCLES IN SUBJECTS WITH STROKE

    Directory of Open Access Journals (Sweden)

    Dr.P.Keerthi Chandra Sekhar

    2013-06-01

    Full Text Available Background:To evaluate the efficacy of isokinetic strength training and balance exercises on lower limb musclesamong the subjects suffering with stroke.Materials and Methods:40 subjects who are suffering from strokewere divided into two groups, Experimental group received Isokinetic strength training and balance exercises(n=20 and Control group received conventional physiotherapy, results were measured withIsokinetic deviceand Berg balance scale for peak torque of knee extensors on paretic leg and balance respectively.Results:obtained results were analyzed with the use ofPaired T-test, which has been carried out to observe the treat-ment impact between the groups before and after the treatment. After a 6 week treatment period, thesub-jects in the Group I (strength training and balance exercise compared with the subjects in the Group II (con-ventional physiotherapy had shown a statistically significant improvement with the outcome measuresat 0.05level.Conclusion:Isokinetic strength training and balance exercise was found much effective in improving strengthof quadriceps lower limb and balance in subjects with stroke.

  17. Effect of isokinetic training on muscle strength and postural balance in children with Down's syndrome.

    Science.gov (United States)

    Eid, Mohamed A; Aly, Sobhy M; Huneif, Mohamed A; Ismail, Dina K

    2017-06-01

    Children with Down's syndrome (DS) often have greater postural sway and delay in motor development. Muscle weakness and hypotonia, particularly of the lower extremities, are theorized to impair their overall physical health and ability to perform daily activities. Therefore, the aim of this study was to investigate the effects of isokinetic training on muscle strength and postural balance in children with DS. Thirty-one children with DS ranging in age from 9 to 12 years were assigned randomly into two groups. The control group received the conventional physical therapy, whereas the study group received the same therapy as the control group in addition to the isokinetic training 3 days a week for 12 weeks. Measurement of stability indices using the Biodex Stability System as well as peak torque of knee flexors and extensors of both sides using the isokinetic dynamometer was performed before and after 12 weeks of the treatment program. Each group showed significant improvements in postural balance and peak torque of knee flexors and extensors (Ptraining program induced greater improvements in muscle strength and postural balance in children with DS.

  18. Early changes in muscle strength after total knee arthroplasty. A 6-month follow-up of 30 knees

    DEFF Research Database (Denmark)

    Lorentzen, J S; Petersen, M M; Brot, C

    1999-01-01

    to surgery, and after 3 and 6 months, isokinetic and isometric muscle strength in both legs were measured, using a Cybex 6000 dynamometer. Isokinetic tests showed a bilateral, significant, and progressive increase (30-53%) in flexor muscle strength most pronounced in the operated legs. Isokinetic extensor...... to the preoperative level. No significant change in isometric strength was observed in the contralateral legs. The knee pain during the muscle strength measurements decreased significantly from the preoperative level, which may indicate that the substantial pain relief within 3 months after a TKA is an important...... factor for evaluation of muscle strength....

  19. Análise da resposta da freqüência cardíaca durante a realização de exercício isocinético excêntrico de grupamento extensor de joelho Analysis of heart rate response during eccentric isokinetic exercise of knee extensor muscle group

    Directory of Open Access Journals (Sweden)

    CA Malfatti

    2006-01-01

    Full Text Available Objetivo: Investigar a magnitude da resposta da freqüência cardíaca durante o exercício isocinético excêntrico do grupamento extensor do joelho, em diferentes velocidades angulares. Materiais e Métodos: Dez voluntários jovens, sadios e ativos foram submetidos a contração excêntrica máxima do grupo extensor do joelho dominante. Foi utilizado um dinamômetro isocinético, nas velocidades de 30º/s, 60º/s e 120º/s, ordenadas aleatoriamente. A FC foi obtida batimento a batimento, na derivação eletrocardiográfica MC5 modificada, durante 60s pré-exercício, durante o tempo de contração, sendo cinco repetições para cada velocidade, e por 120s após o esforço. Foram calculadas: FC média dos 60s pré-exercício, FC pico atingida ao final do esforço, e variação da FC (DFC, além dos valores do pico de torque. Também foram comparados valores da FC média dos 6 minutos pré-exercício com os 6 minutos de recuperação. Os resultados foram comparados pelo teste de Friedman com post hoc de Dunn. O nível de significância estabelecido foi de 5%. Resultados: Não foram observadas diferenças estatisticamente significantes entre os valores medianos da FC de repouso (68bpm para 30º/s e 60º/s, 70bpm para 120º/s, FC pico (107bpm para 30º/s, 103 em 60º/s e 100bpm em 120º/s e DFC (37bpm para 30º/s, 35bpmem 60º/s e 27bpm para 120ºs, além do pico de torque (209,5N/m para 30º/s, 217,2N/m em 60º/s e 210,6N/m para 120º/s. A mediana dos valores de FC anteriores ao esforço foi semelhante aos de recuperação (67bpm. Conclusão:A magnitude de resposta da FC foi semelhante, durante atividade muscular excêntrica, indicando uma mesma sobrecarga cardíaca, independente da velocidade angular realizada.Objective: To investigate heart rate response magnitudes during eccentric isokinetic exercise of the knee extensor muscles, at different angular velocities. Method: Ten healthy and active young volunteers underwent maximum eccentric

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

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    Paweł Korman

    2015-01-01

    Full Text Available 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.

  1. Test-retest reliability of lower limb isokinetic endurance in COPD: a comparison of angular velocities

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    Ribeiro F

    2015-06-01

    Full Text Available Fernanda Ribeiro,* Pierre-Alexis Lépine,* Corine Garceau-Bolduc, Valérie Coats, Étienne Allard, François Maltais, Didier Saey Centre de recherche de l’Institut Universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada *These authors contributed equally to this workBackground: The purpose of this study was to determine and compare the test-retest reliability of quadriceps isokinetic endurance testing at two knee angular velocities in patients with chronic obstructive pulmonary disease (COPD. Methods: After one familiarization session, 14 patients with moderate to severe COPD (mean age 65±4 years; forced expiratory volume in 1 second (FEV1 55%±18% predicted performed two quadriceps isokinetic endurance tests on two separate occasions within a 5–7-day interval. Quadriceps isokinetic endurance tests consisted of 30 maximal knee extensions at angular velocities of 90° and 180° per second, performed in random order. Test-retest reliability was assessed for peak torque, muscle endurance, work slope, work fatigue index, and changes in FEV1 for dyspnea and leg fatigue from rest to the end of the test. The intraclass correlation coefficient, minimal detectable change, and limits of agreement were calculated. Results: High test-retest reliability was identified for peak torque and muscle total work at both velocities. Work fatigue index was considered reliable at 90° per second but not at 180° per second. A lower reliability was identified for dyspnea and leg fatigue scores at both angular velocities. Conclusion: Despite a limited sample size, our findings su pport the use of a 30-maximal repetition isokinetic muscle testing procedure at angular velocities of 90° and 180° per second in patients with moderate to severe COPD. Endurance measurement (total isokinetic work at 90° per second was highly reliable, with a minimal detectable change at the 95% confidence level of 10%. Peak torque and fatigue index

  2. Rehabilitative effectiveness of isokinetic training on chondromalacia patellae at early-middle stage%等速训练对早中期髌骨软骨病的康复疗效研究

    Institute of Scientific and Technical Information of China (English)

    徐卫华; 赵彦; 王鸿; 王家祥; 孙强

    2016-01-01

    目的::在超短波和温针治疗的基础上,观察等速训练对早中期髌骨软骨病患者进行康复的效果。方法:将58例早中期髌骨软骨病单膝自愿患者随机分成等速组30例和常规组28例。2组均采用超短波、温针进行治疗;在此基础上,等速组用等速测力仪器进行康复训练,常规组进行常规的运动疗法康复;检测比较2组患者治疗前后大腿围度和角速度为60°/s 时等速肌力测试峰力矩等指标,同时进行 Lysholm 膝关节评分和治疗后临床疗效比较。结果:治疗8周后,2组患膝屈伸肌 PT、伸肌 PT 患/健侧比值及患侧 PT 屈/伸比均较治疗前有明显改善(P <0.01),同时等速组在患膝伸肌 PT 和伸肌 PT 患/健侧比值上较常规组提高更显著(P <0.05)。2组患膝大腿腿围和 Lysholm 膝关节功能评分均较治疗前明显提高(P <0.01),等速组更高于常规组(P <0.05)。治疗后,等速组总有效率明显高于常规组(P <0.05)。结论:等速训练在早中期髌骨软骨病的康复中疗效显著。%Objective:On the basis of remedy by ultrashort wave and acupuncture with warmed needle,to observe the curative effect of isokinetic training on chondromalacia patellae (CP)at early-middle stage.Methods:Fifty-eight voluntary sole knee patients with CP at early-middle stage were randomly divided into isokinetic group (n=30)and control group (n=28).Both two groups were treated with ultrashort wave and acupuncture with warmed needle. The isokinetic group was given rehabilitation training with isokinetic dynamometer,and control group was given conventional kinesiatrics.The indexes including thigh circumference,peak torque which were measured at 60°/sec with isokinetic dynamometer before and after the treatment were detected.Simultaneously,the knee Lysholm scores and the curative effectiveness after the treatment were compared.Results:After 8-week treatment,PT of extensor and flexor,the peak torque ratios for

  3. Surface electromyographic amplitude-to-work ratios during isokinetic and isotonic muscle actions.

    Science.gov (United States)

    Purkayastha, Sushmita; Cramer, Joel T; Trowbridge, Cynthia A; Fincher, A Louise; Marek, Sarah M

    2006-01-01

    Isokinetic and isotonic resistance training exercises are commonly used to increase strength during musculoskeletal rehabilitation programs. Our study was designed to examine the efficacy of isokinetic and isotonic muscle actions using surface electromyographic (EMG) amplitude-to-work ratios (EMG/WK) and to extend previous findings to include a range of isokinetic velocities and isotonic loads. To examine work (WK), surface EMG amplitude, and EMG/WK during concentric-only maximal isokinetic muscle actions at 60, 120, 180, 240, and 300 degrees /s and isotonic muscle actions at 10%, 20%, 30%, 40%, and 50% of the maximal voluntary isometric contraction (MVIC) torque during leg extension exercises. A randomized, counterbalanced, cross-sectional, repeated-measures design. A university-based human muscle physiology research laboratory. Ten women (mean age = 22.0 +/- 2.6 years) and 10 men (mean age = 20.8 +/- 1.7 years) who were apparently healthy and recreationally active. Using the dominant leg, each participant performed 5 maximal voluntary concentric isokinetic leg extension exercises at randomly ordered angular velocities of 60, 120, 180, 240, and 300 degrees /s and 5 concentric isotonic leg extension exercises at randomly ordered loads of 10%, 20%, 30%, 40%, and 50% of the isometric MVIC. Work was recorded by a Biodex System 3 dynamometer, and surface EMG was recorded from the superficial quadriceps femoris muscles (vastus lateralis, rectus femoris, and vastus medialis) during the testing and was normalized to the MVIC. The EMG/WK ratios were calculated as the quotient of EMG amplitude (muVrms) and WK (J) during the concentric phase of each exercise. Isotonic EMG/WK remained unchanged ( P > .05) from 10% to 50% MVIC, but isokinetic EMG/WK increased ( P Isotonic EMG/WK was greater ( P .05) between 20% MVIC versus 240 degrees /s or 10% MVIC versus 300 degrees /s. An 18% decrease in active range of motion was seen for the isotonic muscle actions, from 10% to 50% MVIC

  4. The effects of kinesio tape on isokinetic muscular function of horse racing jockeys.

    Science.gov (United States)

    Kim, Hyeyoung; Lee, Byounghee

    2013-10-01

    [Purpose] The purpose of this study was to conduct a scientific analysis of the effectiveness of Kinesio taping at preventing injury and improving horse racing jockey' performance, by studying the effects on isokinetic muscular function of Kinesio taping applied to the knee joint muscle. [Subjects] Eight horse racing jockeys were selected for this study. [Methods] Measurement of isokinetic muscular function of both flexor and extensor muscles was performed at the angular velocities of 60°/sec and 180°/sec using a Biodex system 3, before and after application of Kinesio taping to the rectus femoris, vastus medialis, vastus lateralis, and hamstring. [Result] At the angular velocities of 60°/sec and 180°/sec, significant differences were observed in both flexor and extensor peak torque, average power, and total work of the knee joint after application of Kinesio taping. [Conclusion] The application of Kinesio taping has a positive effect on the function of both knee flexors and extensors, and also kinetic ability. Therefore, its use would lead to a significant increase in the muscle function of horse racing jockeys.

  5. Assessment of the Relationship between Physical Activity Levels and Isokinetic Muscle Performance

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    Ahmet Miçooğulları

    2016-04-01

    Full Text Available Objective: To evaluate the association between physical activity levels and isokinetic muscle strength of knee. Materials and Methods: Thirty amateur athletes and 30 healthy volunters (aged between 20-24 were included in the study. Participants were divided into two groups as amateur athletes (group 1 and healthy controls (group 2. Physical activity levels of the participants were assessed by International Physical Activity Questionnaire (IPAQ. Dominant knee flexion and extension muscle strength of the participants were measured with an isokinetic dynamometer at 60°/s and 180°/s angular velocities. Results: There were no statistically significant difference between the groups in age, sex, weight, height, body mass index and, smoking status (p>0.05. There was a statistically significant difference in IPA scores between the groups (p0.05. Group 1 was divided into subgroups according to IPA scores. In patients with high activity level, peak torque values at the angular velocities of 60°/s and 180°/s for knee muscles were significiantly higher (p<0.05. Conclusion: Further studies that evaluating of the many factors that determining and affecting muscle strength are with larger groups will be beneficia

  6. Co-activation of sprinter and distance runner muscles in isokinetic exercise.

    Science.gov (United States)

    Osternig, L R; Hamill, J; Lander, J E; Robertson, R

    1986-08-01

    The purpose of this study was to investigate the extent of co-activation of quadriceps and hamstring musculature in sprinters and distance runners. Nine female intercollegiate track athletes performed maximal knee extensions and flexions on a modified orthotron isokinetic dynamometer at two speeds (100 degrees and 400 degrees X s-1). Simultaneous recordings of torque, joint position, and agonist/antagonist electromyographic activity from the quadriceps and hamstrings were computer-processed. The results revealed the hamstrings to be considerably more active during knee extension than the quadriceps during flexion. The integrated electromyographic activity of co-contracting hamstrings and quadriceps, throughout the joint range, averaged 33 and 6%, respectively, of the same muscle group during its agonist phase. Hamstring co-activation increased sharply during the last 25% of knee extension, generating 58% of the integrated electromyographic agonist activity. Co-activation of the sprinters' hamstrings was four times that of distance runners (57/14%), however, the faster speed of movement (400 degrees X s-1) increased hamstring coactivation of distance runners more acutely than sprinters in the final phase of extension. The data suggest that the hamstrings are used to a much greater extent than quadriceps for limb deceleration and that the distraction of antagonist muscle tension should be considered when analyzing agonist isokinetic torques. Furthermore, the relatively high co-activation of the hamstrings, particularly during the last 25% of extension, may induce hamstring soreness or strain in vulnerable subjects.

  7. Voluntary Slavery

    Directory of Open Access Journals (Sweden)

    Danny Frederick

    2014-06-01

    Full Text Available The permissibility of actions depends upon facts about the flourishing and separateness of persons. Persons differ from other creatures in having the task of discovering for themselves, by conjecture and refutation, what sort of life will fulfil them. Compulsory slavery impermissibly prevents some persons from pursuing this task. However, many people may conjecture that they are natural slaves. Some of these conjectures may turn out to be correct. In consequence, voluntary slavery, in which one person welcomes the duty to fulfil all the commands of another, is permissible. Life-long voluntary slavery contracts are impermissible because of human fallibility; but fixed-term slavery contracts should be legally enforceable. Each person has the temporarily alienable moral right to direct her own life.

  8. Voluntary Slavery

    Directory of Open Access Journals (Sweden)

    Danny Frederick

    2014-06-01

    Full Text Available The permissibility of actions depends upon facts about the flourishing and separateness of persons. Persons differ from other creatures in having the task of discovering for themselves, by conjecture and refutation, what sort of life will fulfil them. Compulsory slavery impermissibly prevents some persons from pursuing this task. However, many people may conjecture that they are natural slaves. Some of these conjectures may turn out to be correct. In consequence, voluntary slavery, in which one person welcomes the duty to fulfil all the commands of another, is permissible. Life-long voluntary slavery contracts are impermissible because of human fallibility; but fixed-term slavery contracts should be legally enforceable. Each person has the temporarily alienable moral right to direct her own life.

  9. Isokinetic eccentric resistance training prevents loss in mechanical muscle function after running.

    Science.gov (United States)

    Oliveira, Anderson Souza; Caputo, Fabrizio; Aagaard, Per; Corvino, Rogério Bulhões; Gonçalves, Mauro; Denadai, Benedito Sergio

    2013-09-01

    The aim of the study was to verify whether 8 weeks of resistance training employing maximal isokinetic eccentric (IERT) knee extensor actions would reduce the acute force loss observed after high-intensity treadmill running exercise. It was hypothesized that specific IERT would induce protective effects against muscle fatigue and ultrastructural damages, preventing or reducing the loss in mechanical muscle function after running. Subjects were tested before and after IERT protocol for maximal isometric, concentric and eccentric isokinetic knee extensor strength (60° and 180° s(-1)). In a second session, subjects performed treadmill running (~35 min) and the previously mentioned measurements were repeated immediately after running. Subsequently, subjects were randomized to training (n = 12) consisting of 24 sessions of maximal IERT knee extensors actions at 180° s(-1), or served as controls (n = 8). The effects of acute running-induced fatigue and training on isokinetic and isometric peak torque, and rate of force development (RFD) were investigated. Before IERT, running-induced eccentric torque loss at 180° s(-1) was -8 %, and RFD loss was -11 %. Longitudinal IERT led to reduced or absent acute running-induced losses in maximal IERT torque at 180° s(-1) (+2 %), being significantly reduced compared to before IERT (p 0.05). In conclusion, IERT yields a reduced strength loss after high-intensity running workouts, which may suggest a protective effect against fatigue and/or morphological damages. However, IERT may not avoid reductions in explosive muscle actions. In turn, this may allow more intense training sessions to be performed, facilitating the adaptive response to running training.

  10. Knee Muscles Power Evolution in Patients with Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Ileana Monica BORDA

    2012-09-01

    Full Text Available Purpose: To measure changes in muscle power from before to 6 months after total knee arthroplasty and to compare outcomes with those from a control group of healthy adults. Material and Methods: 26 patients who underwent a total knee replacement were compared with 12 healthy age-matched adults in a prospective cohort study. Patients’ assessment was performed preoperatively, as well as at 1, 2 and 6 months postoperatively, by the isokinetic method. Healthy adults were assessed once by the same method. Isokinetic evaluation of knee extensor and flexor muscles was performed using a Gimnex Iso 2 dynamometer. After a warm-up protocol, measurements were done at angular velocities of 90 and 180°/sec. Results: Compared to healthy adults, patients performed significantly worse at all evaluation times, for both extensors and flexors of the knee, except for the 6-month evaluation at 180°/sec. One month postoperatively losses from preoperative levels were registered in patients, but without statistically significance, except for extension at 180°/sec. At 6 months postoperatively patients surpassed the preoperative levels, with statistical significance at 180°/sec. Conclusions: Power is an important parameter to follow after TKA, in parallel with peak torque. Increasing muscle power should be one of the central issues to address during postoperative rehabilitation.

  11. A feasibility study of the effect of intra-articular corticosteroid injection on isokinetic muscle strength in children with juvenile idiopathic arthritis.

    Science.gov (United States)

    McKay, Damien; Ostring, Genevieve; Broderick, Carolyn; Chaitow, Jeffrey; Singh-Grewal, Davinder

    2013-05-01

    This study assessed the magnitude of changes in isokinetic muscle strength in children with juvenile idiopathic arthritis (JIA) before and after treatment with intra-articular corticosteroid injection and assessed the feasibility of a larger study of the same effect. Isokinetic dynamometry was used to measure peak knee extension and flexion torque in 12 children before and after treatment for unilateral knee arthritis. Extensor and flexor strength was reduced on the affected side before treatment (-0.56 Nm/kg, p = .004 and -0.24 Nm/kg, p = .02 respectively). Increases in extensor strength were observed at two weeks (p = .01) and twelve weeks postinjection (p = .03). Improvements at 6 weeks approached but did not reach statistical significance (p = .17). Improvements in flexor strength were not observed until 12 weeks postinjection (p = .03). Despite significant improvements in extensor strength, low peak knee extensor torque continued to be observed at 12 weeks (p = .01). Knee extensor and flexor strength is reduced in children with JIA with active arthritis and improves following intra-articular corticosteroid injection. Significant improvements in knee extensor and flexor strength were seen postinjection; however deficits in extensor strength were still evident at three months. Isokinetic dynamometry was safe and well tolerated in our sample of children with JIA with active arthritis.

  12. Electromyographic analysis of upper limb muscles during standardized isotonic and isokinetic robotic exercise of spastic elbow in patients with stroke.

    Science.gov (United States)

    Sin, Minki; Kim, Won-Seok; Park, Daegeun; Min, Yu-Sun; Kim, Woo Jin; Cho, Kyujin; Paik, Nam-Jong

    2014-02-01

    Although it has been reported that strengthening exercise in stroke patients is beneficial for their motor recovery, there is little evidence about which exercise method is the better option. The purpose of this study was to compare isotonic and isokinetic exercise by surface electromyography (EMG) analysis using standardized methods. Nine stroke patients performed three sets of isotonic elbow extensions at 30% of their maximal voluntary isometric torque followed by three sets of maximal isokinetic elbow extensions with standardization of mean angular velocity and the total amount of work for each matched set in two strengthening modes. All exercises were done by using 1-DoF planner robot to regulate exact resistive torque and speed. Surface electromyographic activity of eight muscles in the hemiplegic shoulder and elbow was recorded. Normalized root mean square (RMS) values and co-contraction index (CCI) were used for the analysis. The isokinetic mode was shown to activate the agonists of elbow extension more efficiently than the isotonic mode (normalized RMS for pooled triceps: 96.0±17.0 (2nd), 87.8±14.4 (3rd) in isokinetic, 80.9±11.0 (2nd), 81.6±12.4 (3rd) in isotonic contraction, F[1,8]=11.168; P=0.010) without increasing the co-contraction of muscle pairs, implicating spasticity or synergy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Isokinetic Strength Changes Following Long-Duration Spaceflight on the ISS.

    Science.gov (United States)

    English, Kirk L; Lee, Stuart M C; Loehr, James A; Ploutz-Snyder, Robert J; Ploutz-Snyder, Lori L

    2015-12-01

    Long-duration spaceflight results in a loss of muscle strength that poses both operational and medical risks, particularly during emergency egress, upon return to Earth, and during future extraterrestrial exploration. Isokinetic testing of the knee, ankle, and trunk quantifies movement-specific strength changes following spaceflight and offers insight into the effectiveness of in-flight exercise countermeasures. We retrospectively evaluated changes in isokinetic strength for 37 ISS crewmembers (Expeditions 1-25) following 163 ± 38 d (mean ± SD) of spaceflight. Gender, in-flight resistance exercise hardware, and preflight strength were examined as potential modifiers of spaceflight-induced strength changes. Mean isokinetic strength declined 8-17% following spaceflight. One month after return to Earth, strength had improved, but small deficits of 1-9% persisted. Spaceflight-induced strength losses were not different between men and women. Mean strength losses were as much as 7% less in crewmembers who flew after the Advanced Resistive Exercise Device (ARED) replaced the interim Resistive Exercise Device (iRED) as the primary in-flight resistance exercise hardware, although these differences were not statistically significant. Absolute and relative preflight strength were moderately correlated (r = -0.47 and -0.54, respectively) with postflight strength changes. In-flight resistance exercise did not prevent decreased isokinetic strength after long-duration spaceflight. However, continued utilization of ARED, a more robust resistance exercise device providing higher loads than iRED, may result in greater benefits as exercise prescriptions are optimized. With reconditioning upon return to Earth, strength is largely recovered within 30 d.

  14. Knee function and knee muscle strength in middle-aged patients with degenerative meniscal tears eligible for arthroscopic partial meniscectomy

    DEFF Research Database (Denmark)

    Stensrud, Silje; Risberg, May Arna; Roos, Ewa M.

    2014-01-01

    BACKGROUND: Functional limitations exist postmeniscectomy, but preoperative data are scarce. PURPOSE: To examine knee function, knee muscle strength and performance in middle-aged patients with degenerative meniscal tears, eligible for arthroscopic partial meniscectomy. STUDY DESIGN: Cross......-sectional study. METHODS: Eighty-two participants with MRI verified degenerative meniscal tear (35% women, mean age 49 years) answered the Knee injury and Osteoarthritis Outcome Score (KOOS) and were tested for isokinetic knee muscle strength and lower extremity performance (one-leg hop for distance, 6 m timed...

  15. Knee Bursitis

    Science.gov (United States)

    Knee bursitis Overview By Mayo Clinic Staff Knee bursitis is inflammation of a small fluid-filled sac (bursa) situated ... in your knee can become inflamed, but knee bursitis most commonly occurs over the kneecap or on ...

  16. Knee Replacement

    Science.gov (United States)

    Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to ... Your doctor may recommend it if you have knee pain and medicine and other treatments are not ...

  17. Neuromuscular adaptations to isoload versus isokinetic eccentric resistance training.

    Science.gov (United States)

    Guilhem, Gaël; Cornu, Christophe; Maffiuletti, Nicola A; Guével, Arnaud

    2013-02-01

    The purpose of this study was to compare neuromuscular adaptations induced by work-matched isoload (IL) versus isokinetic (IK) eccentric resistance training. A total of 31 healthy subjects completed a 9-wk IL (n = 11) or IK (n = 10) training program for the knee extensors or did not train (control group; n = 10). The IL and IK programs consisted of 20 training sessions, which entailed three to five sets of eight repetitions in the respective modalities. The amount of work and the mean angular velocity were strictly matched between IL and IK conditions. Neuromuscular tests were performed before and after training and consisted of the assessment of quadriceps muscle strength, muscle architecture (vastus lateralis), EMG activity, and antagonist coactivation. IL, but not IK, eccentric resistance training enhanced eccentric strength at short muscle length (+20%), high-velocity eccentric strength (+15%), muscle thickness (+10%), and fascicle angle measured at rest (+11%; P eccentric movements (i.e., at short muscle lengths), which results in greater torque and angular velocities compared with IK actions, is the main determinant of strength and neuromuscular adaptations to eccentric training. These findings have important consequences for the optimization of IL and IK eccentric exercise for resistance training and rehabilitation purposes.

  18. Comparison of Three Methods of Assessing Muscle Strength and Imbalance Ratios of the Knee

    OpenAIRE

    Moss, Crayton L.; Wright, P. Thomas

    1993-01-01

    Three strength measurement methods for determining muscle strength and imbalance ratios of the knee were compared in 41 (23 female, 18 male) NCAA Division I track and field athletes. Peak quadriceps extensions and hamstring flexions were measured isotonically, isometrically, and isokinetically. Isokinetic measurements were performed on a Cybex II at 60°/s. Isometric extension and flexion measurements were performed using the Nicholas Manual Muscle Tester (Lafayette Instruments; Lafayette, Ind...

  19. Avaliação muscular isocinética da articulação do joelho em atletas das seleções brasileiras infanto e juvenil de voleibol masculino Evaluación muscular isocinetica de la articulación de la rodilla en atletas de las selecciones brasileras infanto y juveniles de voleibol masculino Isokinetic muscle evaluation of the knee joint in athletes of the Under-19 and Under-21 Male Brazilian National Volleyball Team

    Directory of Open Access Journals (Sweden)

    Natalia Franco N. Bittencourt

    2005-12-01

    . El estudio presente puede servir así, como base para las comparaciones de estudios futuros que evalúen la función muscular isocinética en atletas del voleibol.The vertical jump is a basic volleyball practice that demands a high ability to generate strength and work in the muscles involved, mainly in the quadriceps muscle. Due to such demand, muscle imbalances between extensor and flexor muscles may be present, causing an overloading on the muscle-tendinous structures of the knee joint. Thus, the establishment of normal parameters for the muscle function related to that joint in volleyball athletes is necessary. Therefore, the purpose of this study was to assess through isokinetic dynamometry the peak torque, work peak, agonist/antagonist ratio, and fatigue index of the flexor and extensor of the knee among both volleyball athlete population. The isokinetic flexion and extension tests of the knees were performed in the concentric-concentric seat mode at 60 and 300º/sec. velocity in thirty-six athletes (20 under 19-under 21, and 16 under 21. The data allowed to set the parameters for the muscle function of the knee joint among athletes of the 2003 Under 19-Under 21 and Under 21 Brazilian National Team Selection of Male Volleyball. Athletes presented peak torque and work peak values normalized by the body mass to the upper quadriceps to the mean normal values for the athletes and non-athletes populations. Compared to other categories, the under 21 athletes presented significantly higher values for the agonist/antagonist ratio, and peak work ratio of the knee flexors at 60º/sec. velocity. Furthermore, the agonist/antagonist ratio was lower than the reference value expected for both categories, thus characterizing predominance in the extensor musculature over the flexor musculature. The fatigue index was close to what would be expected for the majority of athletes. The present study may be useful as comparison basis for future studies aiming evaluate the isokinetic

  20. Role of flexors in knee stability.

    Science.gov (United States)

    Chen, C Y; Jiang, C C; Jan, M H; Lai, J S

    1995-05-01

    The muscle strength of knee extensors is commonly used as an indicator of a patient's functional recovery following reconstruction of the anterior cruciate ligament (ACL). The knee flexors are dynamic stabilizers that prevent tibial anterior displacement and may reinforce the function of the ACL. The purpose of this study was to examine the relationship of knee flexor performance assessed by isokinetic dynamometer and clinical evaluations including KT-1000 stability tests, shuttle run tests, thigh and calf circumference and range of motion of the knee joint. Ten patients who received ACL reconstruction over a 3- to 5-year period were included in this study, as were 15 normal controls who were tested for comparison. There was no significant difference in the time taken for the shuttle run test between normal controls and patients who underwent ACL, but there was a positive correlation between the shuttle run test and laxity of the knee joint. The knee laxity of ACL patients was significantly greater than that of the normal controls under passive anterior force. However, no significant difference was seen in the stability test under active contraction of the knee extensors. In addition, a positive correlation was seen between the KT-1000 knee ligament arthrometry test results and both torque acceleration energy and the average power of the flexors. These results suggest that physical therapy for patients following ACL reconstruction should emphasize the explosiveness of knee flexors to help strengthen the dynamic stability of the knee joint and motor performance.

  1. Rapid knee-extensions to increase quadriceps muscle activity in patients with total knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Rasmus Skov; Wilquin, Lousia; Jakobsen, Thomas Linding

    2017-01-01

    BACKGROUND: Inhibition of the quadriceps muscle and reduced knee-extension strength is common shortly following total knee arthroplasty (weeks to months), due to reduced voluntary activation of the quadriceps muscle. In healthy subjects, strength training with heavy loads is known to increase...... agonist muscle activity, especially if the exercise is conducted using rapid muscle contractions. PURPOSE: The purpose of this study was to examine if patients with total knee arthroplasty could perform rapid knee-extensions using a 10 RM load four to eight weeks after surgery, and the degree to which...... rapid knee-extensions were associated with greater voluntary quadriceps muscle activity during an experimental strength training session, compared to that elicited using slow knee-extensions. STUDY DESIGN: A randomized cross-over study. METHODS: Twenty-four patients (age 66.5) 4-8 weeks post total knee...

  2. Effect of antagonist muscle fatigue on knee extension torque.

    Science.gov (United States)

    Beltman, J G M; Sargeant, A J; Ball, D; Maganaris, C N; de Haan, A

    2003-09-01

    The effect of hamstring fatigue on knee extension torque was examined at different knee angles for seven male subjects. Before and after a dynamic flexion fatigue protocol (180 degrees s(-1), until dynamic torque had declined by 50%), maximal voluntary contraction extension torque was measured at four knee flexion angles (90 degrees, 70 degrees, 50 degrees and 30 degrees ). Maximal torque generating capacity and voluntary activation of the quadriceps muscle were determined using electrical stimulation. Average rectified EMG of the biceps femoris was determined. Mean dynamic flexion torque declined by 48+/-11%. Extensor maximal voluntary contraction torque, maximal torque generating capacity, voluntary activation and average rectified EMG at the four knee angles were unaffected by the hamstring fatigue protocol. Only at 50 degrees knee angle was voluntary activation significantly lower (15.7%) after fatigue ( P<0.05). In addition, average rectified EMG before fatigue was not significantly influenced by knee angle. It was concluded that a fatigued hamstring muscle did not increase the maximal voluntary contraction extension torque and knee angle did not change coactivation. Three possible mechanisms may explain the results: a potential difference in recruited fibre populations in antagonist activity compared with the fibres which were fatigued in the protocol, a smaller loss in isometric torque generating capacity of the hamstring muscle than was expected from the dynamic measurements and/or a reduction in voluntary activation.

  3. Electrical stimulation and isokinetic training: effects on strength and neuromuscular properties of healthy young adults Estimulação elétrica e treinamento isocinético: efeitos na força e propriedades neuromusculares de adultos jovens sadios

    Directory of Open Access Journals (Sweden)

    MA Avila

    2008-12-01

    Full Text Available OBJECTIVE: To assess the effects of neuromuscular electrical stimulation (NMES associated with an isokinetic training program in healthy young men and women. METHODS: Twenty participants (ten men, ten women; 21±1.5 years underwent an isokinetic training program for knee extensors of both sides (three sets of ten concentric repetitions at 30°/s twice a week for four weeks. One limb underwent only the isokinetic strength training (Ex while the other underwent the same training but with NMES associated with each contraction (Ex+NMES. The current used for NMES was the Russian current (frequency of 2,500Hz, 50 bursts/s and pulse duration of 200µs. Isometric and isokinetic concentric extensor torque at 30°/s were evaluated. RESULTS: The groups increased their peak torque in both test procedures, with no difference between Ex and Ex+NMES. The angle of peak torque increased for the Ex limb, thus showing a change in the tension-length relationship of the muscle group tested, which did not occur for the Ex+NMES limb. There was also a decrease in acceleration time in both limbs, without any effects from NMES on this variable. CONCLUSIONS: These results showed that the association between NMES and isokinetic concentric voluntary strength training did not improve the strength gains and neuromuscular properties of voluntary strength training itself for healthy young participants of both genders.OBJETIVO: Verificar os efeitos da estimulação elétrica neuromuscular (EENM associada a um programa de treinamento isocinético em homens e mulheres jovens e sadios. MÉTODOS: Vinte indivíduos (dez homens, dez mulheres, 21±1,5 anos submeteram-se a um programa de treinamento isocinético de ambos os seus extensores de joelho (três séries de dez repetições concêntricas a 30°/s duas vezes por semana por quatro semanas. Um membro foi submetido apenas ao treinamento de força isocinético (Ex enquanto o outro foi submetido ao mesmo treinamento, mas com EENM

  4. RAPID KNEE-EXTENSIONS TO INCREASE QUADRICEPS MUSCLE ACTIVITY IN PATIENTS WITH TOTAL KNEE ARTHROPLASTY

    DEFF Research Database (Denmark)

    Husted, Rasmus Skov; Wilquin, Lousia; Jakobsen, Thomas Linding

    2017-01-01

    BACKGROUND: Inhibition of the quadriceps muscle and reduced knee-extension strength is common shortly following total knee arthroplasty (weeks to months), due to reduced voluntary activation of the quadriceps muscle. In healthy subjects, strength training with heavy loads is known to increase ago...

  5. Knee Problems

    Science.gov (United States)

    ... BMI Calculator myhealthfinder Immunization Schedules Nutrient Shortfall Questionnaire Knee ProblemsPain, swelling, stiffness and "water" on the knee are common symptoms. Follow this chart for more ...

  6. Voluntary Environmental Governance Arrangements

    NARCIS (Netherlands)

    van der Heijden, J.

    2012-01-01

    Voluntary environmental governance arrangements have focal attention in studies on environmental policy, regulation and governance. The four major debates in the contemporary literature on voluntary environmental governance arrangements are studied. The literature falls short of sufficiently

  7. Voluntary Environmental Governance Arrangements

    NARCIS (Netherlands)

    van der Heijden, J.

    2012-01-01

    Voluntary environmental governance arrangements have focal attention in studies on environmental policy, regulation and governance. The four major debates in the contemporary literature on voluntary environmental governance arrangements are studied. The literature falls short of sufficiently specify

  8. Voluntary Service System (VSS)

    Data.gov (United States)

    Department of Veterans Affairs — Voluntary Service System (VSS) is a national-level application which replaced the site-based Voluntary Timekeeping System (VTK). VTK was used for many years at the...

  9. Short-term effects of kinesio tape on joint position sense, isokinetic measurements, and clinical parameters in patellofemoral pain syndrome.

    Science.gov (United States)

    Kurt, Emine Eda; Büyükturan, Öznur; Erdem, Hatice Rana; Tuncay, Figen; Sezgin, Hicabi

    2016-07-01

    [Purpose] To evaluate the short-term effects of kinesio tape on joint position sense, isokinetic measurements, kinesiophobia, symptoms, and functional limitations in patients with patellofemoral pain syndrome. [Subjects and Methods] A total of 90 patients (112 knees) with patellofemoral pain syndrome were randomized into a kinesio tape group (n=45) or placebo kinesio tape group (n=45). Baseline isokinetic quadriceps muscle tests and measurements of joint position sense were performed in both groups. Pain was measured with a Visual Analog Scale, kinesiophobia with the Tampa kinesiophobia scale, and symptoms and functional limitations with the Kujala pain scale. Measurements were repeated 2 days after kinesio tape application. [Results] No differences were found between baseline isokinetic muscle measurements and those taken 2 days after application. However, significant improvements were observed in the kinesio tape group, with regard to joint position sense, pain, kinesiophobia, symptoms, and functional limitations after treatment. Examination of the differences between pre- and post-treatment values in both groups revealed that the kinesio tape group demonstrated greater improvements compared to the placebo kinesio tape group. [Conclusion] Although short-term kinesio tape application did not increase hamstring muscle strength, it may have improved joint position sense, pain, kinesiophobia, symptoms, and daily limitations.

  10. [Chronic chondromalacia of the patella: comparison of morphological (magnetic resonance) and functional findings (isokinetic parameters) after rehabilitation].

    Science.gov (United States)

    Felicetti, G; Avanza, F; Fiori, M; Brignoli, E; Rovescala, R

    1996-01-01

    The knee is a common site for injuries of the cartilage, capsule and ligament, which calls for the use of noninvasive techniques to assess injury severity properly and to plan adequate rehabilitation. Our study was aimed at comparing MR with isokinetic findings. To this purpose, 40 patients were examined; they were all affected with chondromalacia patellae, grades I-III, previously diagnosed at arthroscopy. Namely, 8 patients had grade I and 32 grades II and III chondromalacia. After MR and isokinetic exams, all patients were submitted to a standardized rehabilitation program. Our results indicate a marked decrease in quadriceps strength, especially in the most severe cases; in less severe cases, recovery was complete at 6 months, while the deficit remained in grades II and III injuries. MR yield was not relevant in 4 of 8 cases, while isokinetic findings were negative in one case. Both methods were positive in the most severe cases. At 6 months, both functional and MR findings were normal in grade I injuries, while some alterations remained in the others.

  11. Short-term effects of kinesio tape on joint position sense, isokinetic measurements, and clinical parameters in patellofemoral pain syndrome

    Science.gov (United States)

    Kurt, Emine Eda; Büyükturan, Öznur; Erdem, Hatice Rana; Tuncay, Figen; Sezgin, Hicabi

    2016-01-01

    [Purpose] To evaluate the short-term effects of kinesio tape on joint position sense, isokinetic measurements, kinesiophobia, symptoms, and functional limitations in patients with patellofemoral pain syndrome. [Subjects and Methods] A total of 90 patients (112 knees) with patellofemoral pain syndrome were randomized into a kinesio tape group (n=45) or placebo kinesio tape group (n=45). Baseline isokinetic quadriceps muscle tests and measurements of joint position sense were performed in both groups. Pain was measured with a Visual Analog Scale, kinesiophobia with the Tampa kinesiophobia scale, and symptoms and functional limitations with the Kujala pain scale. Measurements were repeated 2 days after kinesio tape application. [Results] No differences were found between baseline isokinetic muscle measurements and those taken 2 days after application. However, significant improvements were observed in the kinesio tape group, with regard to joint position sense, pain, kinesiophobia, symptoms, and functional limitations after treatment. Examination of the differences between pre- and post-treatment values in both groups revealed that the kinesio tape group demonstrated greater improvements compared to the placebo kinesio tape group. [Conclusion] Although short-term kinesio tape application did not increase hamstring muscle strength, it may have improved joint position sense, pain, kinesiophobia, symptoms, and daily limitations. PMID:27512259

  12. Acute effects of static and dynamic stretching on hamstring eccentric isokinetic strength and unilateral hamstring to quadriceps strength ratios.

    Science.gov (United States)

    Ayala, Francisco; De Ste Croix, Mark; Sainz De Baranda, Pilar; Santonja, Fernando

    2013-01-01

    The main purposes of this study were to investigate the acute effects of static and dynamic lower limb stretching routines: (a) on peak torque, total external work and joint angle at peak torque of the hamstrings during maximal eccentric isokinetic leg flexion; (b) on unilateral hamstring to quadriceps (H/Q) strength ratios; as well as (c) to determine whether static and dynamic routines elicit similar responses. A total of 49 active adults completed the following intervention protocols in a randomised order on separate days: (a) non-stretching (control condition), (b) static stretching, and (c) dynamic stretching. After the stretching or control intervention, eccentric isokinetic peak torque, the angle of peak torque and total external work were assessed with participants prone at 1.04 and 3.14 rad · s(-1). Unilateral strength ratios of the knee were also recorded. Measures were compared via a fully-within-groups factorial analysis of variance (ANOVA). There were no main effects for eccentric isokinetic peak torque, angle of peak torque, total external work and unilateral H/Q strength ratios. The results suggest that dynamic and static stretching has no influence on eccentric strength profile and unilateral H/Q strength ratios and hence both forms of stretching do not reduce these two primary risk factors for muscle injury.

  13. Relative appendicular skeletal muscle mass is associated with isokinetic muscle strength and balance in healthy collegiate men.

    Science.gov (United States)

    Kim, Sung-Eun; Hong, Ju; Cha, Jun-Youl; Park, Jung-Min; Eun, Denny; Yoo, Jaehyun; Jee, Yong-Seok

    2016-11-01

    There are few studies on the relationship between skeletal muscle mass and balance in the young ages. We investigated the relationship between appendicular skeletal muscle mass, isokinetic muscle strength of lower extremity, and balance among healthy young men using relative skeletal muscle index. Thirty men were grouped according to relative appendicular skeletal muscle mass index: higher skeletal muscle group (n = 15) and lower skeletal muscle group (n = 15). Static and dynamic balance abilities were measured using the following: a test where participants stood on one leg with eyes closed, a modified Clinical Test of Sensory Interaction on Balance (mCTSIB) with eyes open and eyes closed, a stability test, and limits of stability test. The muscle strength of lower extremities was measured with an isokinetic analyser in hip, knee, and ankle joints. Participants with higher appendicular skeletal muscle mass were significantly more stable in maintaining dynamic balance than those with lower appendicular skeletal muscle mass. Moreover, appendicular skeletal muscle mass index was positively correlated with dynamic balance ability. Participants with higher appendicular skeletal muscle mass had stronger strength in the lower extremity, and there were significant differences in the isokinetic torque ratios between groups. From these results, it can be inferred that higher appendicular skeletal muscle mass relates to muscle strength and the alteration in the peak torque ratio of the lower extremity, contributing to the maintenance of balance.

  14. Knee Bursitis

    Science.gov (United States)

    ... make a diagnosis of knee bursitis during a physical exam. Your doctor will inspect your knee by: Comparing the condition of both knees, particularly if only one is painful Gently pressing on different areas of your knee to detect warmth, swelling and the source of pain Carefully moving ...

  15. The Effects of Multiple-Joint Isokinetic Resistance Training on Maximal Isokinetic and Dynamic Muscle Strength and Local Muscular Endurance.

    Science.gov (United States)

    Ratamess, Nicholas A; Beller, Noah A; Gonzalez, Adam M; Spatz, Gregory E; Hoffman, Jay R; Ross, Ryan E; Faigenbaum, Avery D; Kang, Jie

    2016-03-01

    The transfer of training effects of multiple-joint isokinetic resistance training to dynamic exercise performance remain poorly understood. Thus, the purpose of the present study was to investigate the magnitude of isokinetic and dynamic one repetition-maximum (1RM) strength and local muscular endurance increases after 6 weeks of multiple-joint isokinetic resistance training. Seventeen women were randomly assigned to either an isokinetic resistance training group (IRT) or a non-exercising control group (CTL). The IRT group underwent 6 weeks of training (2 days per week) consisting of 5 sets of 6-10 repetitions at 75-85% of subjects' peak strength for the isokinetic chest press and seated row exercises at an average linear velocity of 0.15 m s(-1) [3-sec concentric (CON) and 3-sec eccentric (ECC) phases]. Peak CON and ECC force during the chest press and row, 1RM bench press and bent-over row, and maximum number of modified push-ups were assessed pre and post training. A 2 x 2 analysis of variance with repeated measures and Tukey's post hoc tests were used for data analysis. The results showed that 1RM bench press (from 38.6 ± 6.7 to 43.0 ± 5.9 kg), 1RM bent-over row (from 40.4 ± 7.7 to 45.5 ± 7.5 kg), and the maximal number of modified push-ups (from 39.5 ± 13.6 to 55.3 ± 13.1 repetitions) increased significantly only in the IRT group. Peak isokinetic CON and ECC force in the chest press and row significantly increased in the IRT group. No differences were shown in the CTL group for any measure. These data indicate 6 weeks of multiple-joint isokinetic resistance training increases dynamic muscle strength and local muscular endurance performance in addition to specific isokinetic strength gains in women. Key pointsMultiple-joint isokinetic resistance training increases dynamic maximal muscular strength, local muscular endurance, and maximal isokinetic strength in women.Multiple-joint isokinetic resistance training increased 1RM strength in the bench press (by

  16. No reserve in isokinetic cycling power at intolerance during ramp incremental exercise in endurance-trained men.

    Science.gov (United States)

    Ferguson, Carrie; Wylde, Lindsey A; Benson, Alan P; Cannon, Daniel T; Rossiter, Harry B

    2016-01-01

    During whole body exercise in health, maximal oxygen uptake (V̇o2max) is typically attained at or immediately before the limit of tolerance (LoT). At the V̇o2max and LoT of incremental exercise, a fundamental, but unresolved, question is whether maximal evocable power can be increased above the task requirement, i.e., whether there is a "power reserve" at the LoT. Using an instantaneous switch from cadence-independent (hyperbolic) to isokinetic cycle ergometry, we determined maximal evocable power at the limit of ramp-incremental exercise. We hypothesized that in endurance-trained men at LoT, maximal (4 s) isokinetic power would not differ from the power required by the task. Baseline isokinetic power at 80 rpm (Piso; measured at the pedals) and summed integrated EMG from five leg muscles (ΣiEMG) were measured in 12 endurance-trained men (V̇o2max = 4.2 ± 1.0 l/min). Participants then completed a ramp incremental exercise test (20-25 W/min), with instantaneous measurement of Piso and ΣiEMG at the LoT. Piso decreased from 788 ± 103 W at baseline to 391 ± 72 W at LoT, which was not different from the required ramp-incremental flywheel power (352 ± 58 W; P > 0.05). At LoT, the relative reduction in Piso was greater than the relative reduction in the isokinetic ΣiEMG (50 ± 9 vs. 63 ± 10% of baseline; P power is not different from the power required by the task and is consequent to both central and peripheral limitations in evocable power. The absence of a power reserve suggests both the perceptual and physiological limits of maximum voluntary power production are not widely dissociated at LoT in this population.

  17. A prospective study on knee proprioception after meniscal allograft transplantation.

    Science.gov (United States)

    Thijs, Y; Witvrouw, E; Evens, B; Coorevits, P; Almqvist, F; Verdonk, R

    2007-06-01

    The meniscus plays an important role in the proprioceptive ability of the knee joint. The aim of this prospective study was to assess the short-term influence of a meniscus replacement on the proprioception of the knee. Fourteen patients who had undergone a fresh meniscal allograft transplantation between May 2001 and June 2003 were tested pre-operatively and 6 months post-operatively. Disability regarding pain, stiffness and functionality of the affected knee during daily activities was measured by the Western Ontario and McMaster Universities Arthritis (WOMAC) scale. The knee joint position sense was assessed using the Biodex System 3 isokinetic dynamometer. The results of the WOMAC scale showed no significant differences concerning pain, stiffness or knee function between the pre- and post-operative condition of the knee. Assessment of the knee joint position sense at a reference point of 70 degrees of knee flexion revealed a significant improvement of the proprioception of the operated knee at 6 months after surgery compared with the pre-operative condition. The results of this study suggest that although no significant improvement of pain and functionality of the operated knee occurred at this short-term follow-up period, a meniscal allograft transplantation seems to have a significant positive effect on the joint position sense of the previously meniscectomised knee.

  18. Effect of creatine supplementation during rapid body mass reduction on metabolism and isokinetic muscle performance capacity.

    Science.gov (United States)

    Oöpik, V; Pääsuke, M; Timpmann, S; Medijainen, L; Ereline, J; Smirnova, T

    1998-06-01

    Well-trained subjects (n = 6) were studied before and after losing a mean 3.0%-4.3% of body mass to determine whether muscle performance could be maintained or even enhanced by dietary creatine supplementation. During a 5-day period of loss of mass the subjects were randomly assigned to a creatine or placebo supplemented diet. All the subjects were measured before and after loss of mass on both supplements for isokinetic peak torque (PT) and work at peak torque (W(PT)) of knee extensors, also for intermittent high intensity working capacity of the same muscle group. The latter test consisted of submaximal isokinetic knee extensions at an angular velocity of 1.57 rad x s(-1) for 45 s at the rate of 30 contractions each min (submaximal work, Ws max) followed by 15-s maximal effort (maximal work, Wmax). Total duration of the test was 3 min. Haematocrit was measured and haemoglobin, ammonia, lactate, glucose and urea concentrations were analysed in blood samples obtained at rest and after cessation of muscle performance tests. The results indicated that creatine supplementation in comparison with placebo treatment during rapid body mass reduction may help to maintain muscle PT and W(PT)1 at high angular velocities, not influencing Wmax and the rate of fatigue development during Wmax, but affecting adversely Ws max. Within the limitations of the present study the reasons for the partially detrimental effect of creatine administration remain obscure, but it is suggested that impaired creatine uptake in muscle during body mass loss as well as creatine induced changes in muscle glucose and glycogen metabolism may be involved.

  19. Measurement variability and sincerity of effort: clinical utility of isokinetic strength coefficient of variation scores.

    Science.gov (United States)

    Birmingham, T B; Kramer, J F; Speechley, M; Chesworth, B M; MacDermid, J

    1998-06-01

    Although the use of measures of strength variability as a means of judging sincerity of effort is becoming common practice, the accuracy of doing so has been questioned. Coefficient of variation (CV) cut-off points, indicating the upper limit of variability for repeated maximal efforts, are routinely used to identify workers providing submaximal efforts during various strength tests. However, the stability of the CV itself has not been considered when comparing an individual's observed CV score to these cut-off points. The purpose of the present study was to examine the day-to-day variability of the CV calculated from maximal isokinetic knee extension efforts, and to describe how this measurement error affects the accuracy of the CV as a distinguishing criterion between maximal and submaximal efforts. Thirty-one healthy males (mean age 25 +/- 4.5 years) completed three maximal and three submaximal isokinetic knee extension efforts on two separate occasions. Although submaximal CVs were significantly greater than maximal CVs (15.6 versus 3.7%; p < 0.01), there was considerable overlap between submaximal and maximal CV frequency distributions. More importantly, an individual observed CV could vary +/- 3.1% as a result of day-to-day variation or measurement error. This range in possible CV scores should be considered when comparing an individual's score to proposed cut-off points. Since individual CVs vary considerably from day-to-day, and since precise cut-off values distinguishing between maximal and submaximal conditions cannot be identified, CV scores must be interpreted cautiously, and the potential errors in relying extensively on this approach to identifying insincere efforts should be recognised.

  20. Resistance training improves isokinetic strength and metabolic syndrome-related phenotypes in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Oliveira PFA

    2015-08-01

    Full Text Available Pedro Ferreira Alves Oliveira,1 André Bonadias Gadelha,2 Rafael Gauche,2 Flávio Macedo Lahud Paiva,2 Martim Bottaro,2 Lauro C Vianna,2 Ricardo Moreno Lima2 1Department of Physical Education, Instituto Federal de Brasília, 2College of Physical Education, University of Brasília, Brasília, DF, Brazil Purpose: To examine the effects of resistance training (RT on metabolic syndrome-related phenotypes in postmenopausal women. Patients and methods: Twenty-two postmenopausal women (65.0±4.2 years underwent 12 weeks of whole body progressive training with intensity prescribed based on rating of perceived exertion. Dominant knee extension strength was assessed using an isokinetic dynamometer before and after the intervention. Moreover, all volunteers had blood samples collected for lipid profile, glycemic control, and C-reactive protein analyses. Waist circumference and arterial blood pressure were also measured at baseline and after the training period. Student’s t-tests for paired samples and repeated measures ANOVA were used to compare dependent variables, and statistical significance was set at P<0.05. Results: Isokinetic muscle strength significantly increased (P<0.01 with training. It was observed that waist circumference as well as total and low-density lipoprotein cholesterol levels significantly decreased with training (P<0.01. Total cholesterol/high-density lipoprotein cholesterol ratio, an important marker of cardiovascular disease incidence, was also significantly reduced (from 3.91±0.91 to 3.60±0.74; P<0.01 after the program. Blood glucose, basal insulin, and homeostatic model assessment of insulin resistance were also significantly reduced (P<0.01. No significant alterations were observed for resting blood pressure, triglycerides, or C-reactive protein. Conclusion: Based on the observed results, it can be concluded that a 12-week progressive RT program, besides increasing isokinetic muscle strength, induces beneficial alterations

  1. Effects of Static and Dynamic Stretching on the Isokinetic Peak Torques and Electromyographic Activities of the Antagonist Muscles.

    Science.gov (United States)

    Serefoglu, Abdullah; Sekir, Ufuk; Gür, Hakan; Akova, Bedrettin

    2017-03-01

    The aim of this study was to investigate if static and dynamic stretching exercises of the knee muscles (quadriceps and hamstring muscles) have any effects on concentric and eccentric isokinetic peak torques and electromyographic amplitudes (EMG) of the antagonist muscles. Twenty healthy male athletes (age between 18-30 years) voluntarily participated in this study. All of the subjects visited the laboratory to complete the following intervention in a randomized order on 5 separate days; (a) non-stretching (control), (b) static stretching of the quadriceps muscles, (c) static stretching of the hamstring muscles, (d) dynamic stretching of the quadriceps muscles, and (e) dynamic stretching of the hamstring muscles. Static stretching exercises either for the quadriceps or the hamstring muscles were carried out at the standing and sitting positions. Subjects performed four successive repetitions of each stretching exercises for 30 seconds in both stretching positions. Similar to static stretching exercises two different stretching modes were designed for dynamic stretching exercises. Concentric and eccentric isokinetic peak torque for the non-stretched antagonist quadriceps or hamstring muscles at angular velocities of 60°/sec and 240°/sec and their concurrent electromyographic (EMG) activities were measured before and immediately after the intervention. Isokinetic peak torques of the non-stretched agonist hamstring and quadriceps muscles did not represent any significant (p > 0.05) differences following static and dynamic stretching of the antagonist quadriceps and hamstring muscles, respectively. Similarly, the EMG activities of the agonist muscles exhibited no significant alterations (p > 0.05) following both stretching exercises of the antagonist muscles. According to the results of the present study it is possible to state that antagonist stretching exercises either in the static or dynamic modes do not affect the isokinetic peak torques and the EMG activities

  2. [Isokinetic assessment of ankles in patients with rheumatoid arthritis].

    Science.gov (United States)

    Oliveira, Silvia Cristina Gutierrez; Oliveira, Leda Magalhaes; Jones, Anamaria; Natour, Jamil

    2015-01-01

    The foot and ankle in rheumatoid arthritis undergo highly destructive synovitis with loss of muscle strength. To evaluate the muscle strength of ankles in patients with rheumatoid arthritis based on isokinetic dynamometry parameters. Thirty patients with a diagnosis of rheumatoid arthritis involving the ankle(s) and 30 healthy subjects (control group) matched for age, gender, race, body mass index and lower limb dominance were studied. Dorsiflexion, plantarflexion, inversion and eversion were evaluated in all subjects on an isokinetic Cybex Norm dynamometer. The variables were compared between the rheumatoid arthritis and control groups and between the right and left ankles, and the dorsiflexor/plantar flexor and invertor/evertor muscle strength ratio was determined. Patients with rheumatoid arthritis performed statistically worse in the isokinetic dynamometry test for all ankle movements. The muscle strength ratio between dorsiflexors and plantar flexors was different in the two groups. No significant differences were observed in the invertor and evertor ratios. In the two groups the plantar flexor musculature was statistically stronger than dorsiflexors. We conclude that patients with rheumatoid arthritis perform worse in isokinetic dynamometry regarding all ankle movements than control subjects, with similar isokinetic test results being observed for the right and left side in both groups, with few exceptions. Isokinetic evaluation posed no additional risk such as important pain or inflammatory activity to patients with rheumatoid arthritis. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

  3. The Study of Isokinetic Concentration of Flexion and Extension Muscle Groups of Knee joints in North Lion player%北狮运动员膝关节屈伸肌群等速向心收缩生物力学特性的研究

    Institute of Scientific and Technical Information of China (English)

    雷志军; 杨小波; 宋乐军; 凡婷; 陈伊琳; 郑澜

    2012-01-01

    Objective: In order to reveal the characteristics of knee joint' s muscle contraction in lion dancing player and provide experimental basis for Scientific training, we explored nine lion dancing players' bilateral knee joint in Hunan Normal University by isokinetie machine. Method: The isokinetie explortion was carried out in lion dancing player' S knee joint' s flexion and extension muscle groups in Hunan Normal university with BIODEX SYSTEM 3. The explortion index are peak torque, peak torque to body weight, flexion and extension peak torque ratio, average power and work fatigue. Result: I } the peak torque and relative peak torque of the lion dancing player' s bilateral knee flexion and extension muscles increase with the explortion speed; 2 } there was no signifi- cant difference in average power and in working fatigue between lion head and lion -tail' s knee joints. 3 } there was no significant difference in the same muscle' s strength of lion head or lion tailed between left and right knee joints . Conclusion : Lion athletes knee muscle peak torque changes in the rate of increase with the reduction of ve- locity in testing, Changes of average power increases with velocity up to a certain speed and then decrease. Key words: Lion Dance; Knee Joint; Isokinetie Muscle Strength; Coneeutrie Contraction.%目的:通过对湖南师范大学9名北狮运动员双侧膝关节屈伸肌群进行等速测试,为揭示该项运动膝关节肌群收缩的生物力学特性提供实验依据。方法:采用BIODEX SYSTEM3等速测试系统对湖南师范大学北狮运动员膝关节屈伸肌群进行等速测试,测试指标为峰力矩、相对峰力矩、屈伸肌峰力矩比、平均功率及做功疲劳度。结果:1)北狮运动员双侧膝关节屈伸肌峰力矩和相对峰力矩随测试速度的增加呈递减趋势;2)狮头狮尾屈伸肌群峰力矩比值和做功疲劳度无显著性差异;3)狮头狮尾左右膝关节

  4. The effects of a prophylactic knee brace and two neoprene knee sleeves on the performance of healthy athletes: a crossover randomized controlled trial.

    Science.gov (United States)

    Mortaza, Niyousha; Ebrahimi, Ismail; Jamshidi, Ali Ashraf; Abdollah, Vahid; Kamali, Mohammad; Abas, Wan Abu Bakar Wan; Osman, Noor Azuan Abu

    2012-01-01

    Knee injury is one of the major problems in sports medicine, and the use of prophylactic knee braces is an attempt to reduce the occurrence and/or severity of injuries to the knee joint ligament(s) without inhibiting knee mobility. The aim of the present study was to examine the effect of one recently designed prophylactic knee brace and two neoprene knee sleeves upon performance of healthy athletes. Thirty-one healthy male athletes (age = 21.2 ± 1.5) volunteered as participants to examine the effect of prophylactic knee brace/sleeves on performance using isokinetic and functional tests. All subjects were tested in four conditions in a random order: 1. nonbraced (control) 2. using a neoprene knee sleeve 3. using a knee sleeve with four bilateral metal supports and 4. using a prophylactic knee brace. The study design was a crossover, randomized, controlled trial. Subjects completed single leg vertical jump, cross-over hop, and the isokinetic knee flexion and extension (at 60, 180, 300°/sec). Data were collected from the above tests and analyzed for jump height, cross-over hop distance, peak torque to body weight ratio and average power, respectively. Comparisons of these variables in the four testing conditions revealed no statistically significant difference (p>0.05). The selected prophylactic brace/sleeves did not significantly inhibit athletic performance which might verify that their structure and design have caused no complication in the normal function of the knee joint. Moreover, it could be speculated that, if the brace or the sleeves had any limiting effect, our young healthy athletic subjects were well able to generate a mean peak torque large enough to overcome this possible restriction. Further studies are suggested to investigate the long term effect of these prophylactic knee brace and sleeves as well as their possible effect on the adjacent joints to the knee.

  5. The effects of a prophylactic knee brace and two neoprene knee sleeves on the performance of healthy athletes: a crossover randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Niyousha Mortaza

    Full Text Available Knee injury is one of the major problems in sports medicine, and the use of prophylactic knee braces is an attempt to reduce the occurrence and/or severity of injuries to the knee joint ligament(s without inhibiting knee mobility. The aim of the present study was to examine the effect of one recently designed prophylactic knee brace and two neoprene knee sleeves upon performance of healthy athletes. Thirty-one healthy male athletes (age = 21.2 ± 1.5 volunteered as participants to examine the effect of prophylactic knee brace/sleeves on performance using isokinetic and functional tests. All subjects were tested in four conditions in a random order: 1. nonbraced (control 2. using a neoprene knee sleeve 3. using a knee sleeve with four bilateral metal supports and 4. using a prophylactic knee brace. The study design was a crossover, randomized, controlled trial. Subjects completed single leg vertical jump, cross-over hop, and the isokinetic knee flexion and extension (at 60, 180, 300°/sec. Data were collected from the above tests and analyzed for jump height, cross-over hop distance, peak torque to body weight ratio and average power, respectively. Comparisons of these variables in the four testing conditions revealed no statistically significant difference (p>0.05. The selected prophylactic brace/sleeves did not significantly inhibit athletic performance which might verify that their structure and design have caused no complication in the normal function of the knee joint. Moreover, it could be speculated that, if the brace or the sleeves had any limiting effect, our young healthy athletic subjects were well able to generate a mean peak torque large enough to overcome this possible restriction. Further studies are suggested to investigate the long term effect of these prophylactic knee brace and sleeves as well as their possible effect on the adjacent joints to the knee.

  6. The influence of exercises under isokinetic conditions on heart rate in males aged between 40 and 51.

    Science.gov (United States)

    Czamara, Andrzej; Krzemińska, Aleksandra; Szuba, Lukasz

    2011-01-01

    The aim of the study was to estimate changes in heart rate (HR) values in response to the exercise under isokinetic conditions, with defined protocol using three different angular velocities and 2 minute break. The subjects were divided into two groups. The first group contained 18 males aged between 40 and 50, and the second group contained 20 males who were 20-30 years old. The heart rate was monitored before, during and after the strength moment measurement under isokinetic conditions of extensors and flexors of knee joint. The strength moment was measured with an angular velocity of 180 °/s, 120°/s and 60 °/s. The number of repetitions of extension and flexion of the knee joint was 10 for the angular velocity of 180 °/s, 8 for the angular velocity of 120 °/s and 5 for the angular velocity of 60 °/s. The break between each series of repetitions took 2 minutes. The peak torques for extensors and flexors of both lower extremities were measured. The peak torque and heart rate values increased with a decrease in the preset angular velocity and were lower in the second group. The results were within the norm accepted for submaximal heart rate index in both age groups.

  7. Knee Injuries

    Science.gov (United States)

    ... bursitis . Symptoms of bursitis in the knee include warmth, tenderness, swelling, and pain on the front of ... injury without the aid of a television screen. Physical Therapy Depending on the type of knee injury ...

  8. Do Psychosocial Factors Predict Muscle Strength, Pain, or Physical Performance in Patients With Knee Osteoarthritis?

    Science.gov (United States)

    Baert, Isabel A C; Meeus, Mira; Mahmoudian, Armaghan; Luyten, Frank P; Nijs, Jo; Verschueren, Sabine M P

    2017-09-01

    The aim of this study was to examine the relationship of psychosocial factors, namely, pain catastrophizing, kinesiophobia, and maladaptive coping strategies, with muscle strength, pain, and physical performance in patients with knee osteoarthritis (OA)-related symptoms. A total of 109 women (64 with knee OA-related symptoms) with a mean age of 65.4 years (49-81 years) were recruited for this study. Psychosocial factors were quantified by the Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia, and Pain Coping Inventory. Clinical features were assessed using isometric and isokinetic knee muscle strength measurements, visual analog scale, Western Ontario and McMaster Universities Osteoarthritis Index, and functional tests. Associations were examined using correlation and regression analysis. In knee OA patients, pain catastrophizing, kinesiophobia, and coping strategy explained a significant proportion of the variability in isometric knee extension and flexion strength (6.3%-9.2%), accounting for more overall variability than some demographic and medical status variables combined. Psychosocial factors were not significant independent predictors of isokinetic strength, knee pain, or physical performance. In understanding clinical features related to knee OA, such as muscle weakness, pain catastrophizing, kinesiophobia, and coping strategy might offer something additional beyond what might be explained by traditional factors, underscoring the importance of a biopsychosocial approach in knee OA management. Further research on individual patient characteristics that mediate the effects of psychosocial factors is, however, required in order to create opportunities for more targeted, personalized treatment for knee OA.

  9. Knee extensor strength is associated with pressure pain thresholds in adults with fibromyalgia.

    Directory of Open Access Journals (Sweden)

    W Michael Hooten

    Full Text Available OBJECTIVE: Individuals with fibromyalgia (FM have lower muscle strength and lower pressure pain thresholds (PPT. The primary aim of this study was to determine the associations between muscle strength and PPT in adults with FM to test the hypothesis that greater measures of muscle strength would be associated with greater values of PPT. Secondary aims included determining the effects of pain severity and the peak uptake of oxygen (VO2 on the associations between muscle strength and PPT. METHODS: Knee extensor and flexor strength (N = 69 was measured in the dominant leg using a dynamometer, and PPT was assessed using an electronic algometer. Pain severity was determined using the Multidimensional Pain Inventory, and peak VO2 uptake was quantified using an electronically braked cycle ergometer. RESULTS: Univariable linear regression analysis demonstrated a significant association between PPT (dependent variable and isometric knee extensor (P<.001, isokinetic (60°/s knee extensor (P = .002, and isokinetic (60°/s knee flexor strength (P = .043. In a multiple variable linear regression analysis adjusted for age, sex, pain severity, body mass index and peak VO2 uptake, a significant association was found between PPT and isometric knee extensor strength (P = .008. In a similar multiple variable analysis, a significant association was found between PPT and isokinetic knee extensor strength (P = .044. CONCLUSION: Greater measures of isometric and isokinetic knee extensor strength were significantly associated with greater values of PPT in both univariable and multiple variable linear regression models. TRIAL REGISTRATION: ClinicalTrials.gov NCT01253395.

  10. Knee-Extension Training with a Single-Joint Hybrid Assistive Limb during the Early Postoperative Period after Total Knee Arthroplasty in a Patient with Osteoarthritis

    Science.gov (United States)

    Sugaya, Hisashi; Kubota, Shigeki; Onishi, Mio; Kanamori, Akihiro; Sankai, Yoshiyuki; Yamazaki, Masashi

    2016-01-01

    The knee range of motion is an important outcome of total knee arthroplasty (TKA). According to previous studies, the knee range of motion temporarily decreases for approximately 1 month after TKA due to postoperative pain and quadriceps dysfunction following surgical invasion into the knee extensor mechanism. We describe our experience with a knee-extension training program based on a single-joint hybrid assistive limb (HAL-SJ, Cyberdyne Inc., Tsukuba, Japan) during the acute recovery phase after TKA. HAL-SJ is a wearable robot suit that facilitates the voluntary control of knee joint motion. A 76-year-old man underwent HAL-SJ-based knee-extension training, which enabled him to perform knee function training during the acute phase after TKA without causing increased pain. Thus, he regained the ability to fully extend his knee postoperatively. HAL-SJ-based knee-extension training can be used as a novel post-TKA rehabilitation modality.

  11. Analysis of isokinetic muscle function and postural control in individuals with intermittent claudication

    Directory of Open Access Journals (Sweden)

    Morgan Lanzarin

    2016-02-01

    Full Text Available BACKGROUND: Intermittent claudication (IC is a debilitating condition that mostly affects elderly people. IC is manifested by a decrease in ambulatory function. Individuals with IC present with motor and sensory nerve dysfunction in the lower extremities, which may lead to deficits in balance. OBJECTIVE: This study aimed to measure postural control and isokinetic muscle function in individuals with intermittent claudication. METHOD: The study included 32 participants of both genders, 16 IC participants (mean age: 64 years, SD=6 and 16 healthy controls (mean age: 67 years, SD=5, which were allocated into two groups: intermittent claudication group (ICG and control group (CG. Postural control was assessed using the displacement and velocity of the center of pressure (COP during the sensory organization test (SOT and the motor control test (MCT. Muscle function of the flexor and extensor muscles of the knee and ankle was measured by an isokinetic dynamometer. Independent t tests were used to calculate the between-group differences. RESULTS: The ICG presented greater displacement (p =0.027 and speed (p =0.033 of the COP in the anteroposterior direction (COPap during the MCT, as well as longer latency (p =0.004. There were no between-group differences during the SOT. The ICG showed decreased muscle strength and power in the plantar flexors compared to the CG. CONCLUSION: Subjects with IC have lower values of strength and muscle power of plantiflexores, as well as changes in postural control in dynamic conditions. These individuals may be more vulnerable to falls than healthy subjects.

  12. Comparative evaluation of ambulation patterns and isokinetic muscle strength for the application of rehabilitation exercise in patients with patellofemoral pain syndrome.

    Science.gov (United States)

    Kim, Soonyoung

    2016-12-01

    [Purpose] The aim of this study was to evaluate the differences in the ambulation patterns and knee joint performance between people with and without patellofemoral pain. The present study also aimed to utilize these results as a basis for the development of pain-alleviating and performance-improving treatment programs. [Subjects and Methods] Subjects consisted of 32 adult females diagnosed with patellofemoral pain syndrome and 25 adult females without patellofemoral pain (controls). Contact ratio patterns during ambulation and isokinetic muscle strength around the knee joint were measured in both groups and then compared. [Results] Ambulation patterns, specifically the contact ratios of the left forefoot and right forefoot, differed significantly between patients with patellofemoral pain syndrome and controls. An isokinetic muscle strength test demonstrated that left and right knee extensor and flexor torques also significantly differed between these two groups. [Conclusion] Basic analysis based on ambulation patterns and muscle strength can be used to indicate functional recovery from patellofemoral pain syndrome and provide insight into improving the rehabilitation of patients.

  13. The Effects of Multiple-Joint Isokinetic Resistance Training on Maximal Isokinetic and Dynamic Muscle Strength and Local Muscular Endurance

    Directory of Open Access Journals (Sweden)

    Nicholas A. Ratamess, Noah A. Beller, Adam M. Gonzalez, Gregory E. Spatz, Jay R. Hoffman, Ryan E. Ross, Avery D. Faigenbaum, Jie Kang

    2016-03-01

    Full Text Available The transfer of training effects of multiple-joint isokinetic resistance training to dynamic exercise performance remain poorly understood. Thus, the purpose of the present study was to investigate the magnitude of isokinetic and dynamic one repetition-maximum (1RM strength and local muscular endurance increases after 6 weeks of multiple-joint isokinetic resistance training. Seventeen women were randomly assigned to either an isokinetic resistance training group (IRT or a non-exercising control group (CTL. The IRT group underwent 6 weeks of training (2 days per week consisting of 5 sets of 6-10 repetitions at 75-85% of subjects’ peak strength for the isokinetic chest press and seated row exercises at an average linear velocity of 0.15 m s-1 [3-sec concentric (CON and 3-sec eccentric (ECC phases]. Peak CON and ECC force during the chest press and row, 1RM bench press and bent-over row, and maximum number of modified push-ups were assessed pre and post training. A 2 x 2 analysis of variance with repeated measures and Tukey’s post hoc tests were used for data analysis. The results showed that 1RM bench press (from 38.6 ± 6.7 to 43.0 ± 5.9 kg, 1RM bent-over row (from 40.4 ± 7.7 to 45.5 ± 7.5 kg, and the maximal number of modified push-ups (from 39.5 ± 13.6 to 55.3 ± 13.1 repetitions increased significantly only in the IRT group. Peak isokinetic CON and ECC force in the chest press and row significantly increased in the IRT group. No differences were shown in the CTL group for any measure. These data indicate 6 weeks of multiple-joint isokinetic resistance training increases dynamic muscle strength and local muscular endurance performance in addition to specific isokinetic strength gains in women.

  14. Effect of 8 weeks of pre-season training on body composition, physical fitness, anaerobic capacity, and isokinetic muscle strength in male and female collegiate taekwondo athletes.

    Science.gov (United States)

    Seo, Myong-Won; Jung, Hyun-Chul; Song, Jong-Kook; Kim, Hyun-Bae

    2015-04-01

    The purpose of the study was to determine the effect of 8 weeks pre-season training on body composition, physical fitness, anaerobic capacity, and isokinetic strength in collegiate taekwondo athletes. Thirty-four collegiate athletes (male: 22, female: 12) participated. Body composition, bone mineral density, physical fitness, anaerobic capacity, and isokinetic muscle strength were tested. After statistical analysis was performed the results indicated that there were significant decreases in body weight, percent body fat, and fat tissue after 8 weeks of pre-season training. Bone mineral density increased significantly only in males. There were significant improvements in the 50 m shuttle run and 20 m multistage endurance run in both males and females. The sit & reach test and standing long jump were not significantly changed after 8 weeks. Relative peak power and anaerobic capacity were significantly improved in males. Significant increases in angular velocity were observed for knee extension at both % BW 60°/sec and 180°/sec in both males and females. A significant increase in angular velocity was seen for right knee flexion at % BW 60°/sec for males, but it decreased at % BW 180°/sec for both males and females. In conclusion, this study suggests that 8 weeks of pre-season training has a positive effect on body composition, physical fitness, anaerobic capacity, isokinetic muscular strength, and endurance. Nevertheless, an exercise approach with the goal of increasing lean tissue, and improving power in knee flexors and flexibility of athletes, should be included in the training program.

  15. Análise da associação entre a dinamometria isocinética da articulação do joelho e o salto horizontal unipodal, hop test, em atletas de voleibol Análisis de la asociación entre la dinamometria isocinética de la articulación de la rodilla y el salto horizontal unipodal, hop test, en los atletas de voleibol Analysis on the association between isokinetic dynamometry of the knee's articulation and one-leg horizontal jump, hop test, in volleyball athletes

    Directory of Open Access Journals (Sweden)

    Rogério Leão D'Alessandro

    2005-10-01

    ético en las velocidades de 60º/s y 300º/s y en el hop test a distancia. RESULTADOS: Fué observada solamente una correlación baja entre el déficit de pico de cambio (r = 0,441 y de trabajo (r = 0,610 a 60º/s con el déficit de la distancia saltada entre MMII. Fué observada una baja associação entre la performance muscular y la distancia saltada en el hop test excepto en el miembro inferior directo de mujeres. CONCLUSIÓN: Este estudio mostró que el hop test no puede ser usado para substituir la dinamometría isocinética en la evaluación de la función muscular.The isokinetic dynamometer has been widely used to assess the muscle performance. Due to its high cost, the use of such device in clinical practice becomes unfeasible. The one-leg hop is a test to evaluate the strength and reliance on lower limbs that may be used in routine clinical trials at low cost, being no time-consuming. The present study aimed to assess whether there is any association between the hop test and the muscular function data provided by the knee evaluations at the isokinetic dynamometer in professional athletes. MATERIAL AND METHODS: Thirty volleyball players (8 women and 22 men were evaluated by means of isokinetic dynamometer at speeds of 60º/s and 300º/s, and through the hop test at distance. RESULTS: It was observed a low correlation between the deficit of the peak torque (r = 0,441 and the work (r = 0,610 at 60º/s, with a deficit for hopped distance between lower limbs. Moreover, it was found a low correlation between the muscle performance and the distance reached during the hop test, except for women in the right lower limb. CONCLUSION: The current study has shown that the hop test cannot be used to replace isokinetic dynamometric tests for functional tests.

  16. Gender Differences in Isokinetic Strength after 60 and 90 d Bed Rest

    Science.gov (United States)

    English, K. L.; Ploutz-Snyder, R. J.; Cromwell, R. L.; Ploutz-Snyder, L. L.

    2010-01-01

    Recent reports suggest that changes in muscle strength following disuse may differ between males and females. PURPOSE: To examine potential gender differences in strength changes following 60 and 90 d of experimental bed rest. METHODS: Isokinetic extensor and flexor strength of the knee (60deg and 180deg/s, concentric only), ankle (30deg/s, concentric and eccentric), and trunk (60deg/s, concentric only) were measured following 60 d (males: n=4, 34.5+/-9.6 y; females: n=4, 35.5+/-8.2 y) and 90 d (males: n=10, 31.4+/-4.8 y; females: n=5, 37.6+/-9.9 y) of 6-degree head-down-tilt bed rest (BR; N=23). Subjects were fed a controlled diet (55%/15%/ 30%, CHO/PRO/FAT) that maintained body weight within 3% of the weight recorded on Day 3 of bed rest. After a familiarization session, testing was conducted 6 d before BR and 2 d after BR completion. Peak torque and total work were calculated for the tests performed. To allow us to combine data from both 60- and 90-d subjects, we used a mixed-model statistical analysis in which time and gender were fixed effects and bed rest duration was a random effect. Log-transformations of strength measures were utilized when necessary in order to meet statistical assumptions. RESULTS: Main effects were seen for both time and gender (p<0.05), showing decreased strength in response to bed rest for both males and females, and males stronger than females for most strength measures. Only one interaction effect was observed: females exhibited a greater loss of trunk extensor peak torque at 60 d versus pre-BR, relative to males (p=0.004). CONCLUSION: Sixty and 90 d of BR induced significant losses in isokinetic muscle strength of the locomotor and postural muscles of the knee, ankle, and trunk. Although males were stronger than females for most of the strength measures that we examined, only changes in trunk extensor peak torque were greater for females than males at day 60 of bed rest

  17. Multiarticular isokinetic high-load eccentric training induces large increases in eccentric and concentric strength and jumping performance.

    Science.gov (United States)

    Papadopoulos, Christos; Theodosiou, Konstantinos; Bogdanis, Gregory C; Gkantiraga, Evangelia; Gissis, Ioannis; Sambanis, Michalis; Souglis, Athanasios; Sotiropoulos, Aristomenis

    2014-09-01

    This study investigated the effects of short-term eccentric exercise training using a custom-made isokinetic leg press device, on concentric and eccentric strength and explosiveness as well as jumping performance. Nineteen healthy males were divided into an eccentric (ECC, n = 10) and a control group (CG, n = 9). The ECC group trained twice per week for 8 weeks using an isokinetic hydraulic leg press machine against progressively increasing resistance ranging from 70 to 90% of maximal eccentric force. Jumping performance and maximal force generating capacity were measured before and after eccentric training. In the ECC group, drop jump (DJ) height and maximal power were increased by 13.6 ± 3.2% (p knee, and hip joint angles were also reduced by 33.9 ± 1.1%, 31.1 ± 1.0%, and 32.4 ± 1.6% (all p eccentric and concentric leg press force was increased by 64.9 ± 5.5% (p eccentric force, explosiveness, and DJ performance were markedly increased after only 16 training sessions, possibly because of the high eccentric load attained during the bilateral eccentric leg press exercise performed on this custom-made device.

  18. Haptic control of a pneumatic muscle actuator to provide resistance for simulated isokinetic exercise; part II: control development and testing.

    Science.gov (United States)

    Hall, Kara L; Phillips, Chandler A; Reynolds, David B; Mohler, Stanley R; Rogers, Dana B; Neidhard-Doll, Amy T

    2015-01-01

    Pneumatic muscle actuators (PMAs) have a high power to weight ratio and possess unique characteristics which make them ideal actuators for applications involving human interaction. PMAs are difficult to control due to nonlinear dynamics, presenting challenges in system implementation. Despite these challenges, PMAs have great potential as a source of resistance for strength training and rehabilitation. The objective of this work was to control a PMA for use in isokinetic exercise, potentially benefiting anyone in need of optimal strength training through a joint's range of motion. The controller, based on an inverse three-element phenomenological model and adaptive nonlinear control, allows the system to operate as a type of haptic device. A human quadriceps dynamic simulator was developed (as described in Part I of this work) so that control effectiveness and accommodation could be tested prior to human implementation. Tracking error results indicate that the control system is effective at producing PMA displacement and resistance necessary for a scaled, simulated neuromuscular actuator to maintain low-velocity isokinetic movement during simulated concentric and eccentric knee extension.

  19. Comparison of whole-body vibration exercise and plyometric exercise to improve isokinetic muscular strength, jumping performance and balance of female volleyball players

    Science.gov (United States)

    Kim, Yong-Youn; Park, Si-Eun

    2016-01-01

    [Purpose] The purpose of this study was to assess the effect of whole-body vibration exercise and plyometric exercise on female volleyball players. [Subjects and Methods] Subjects were randomly allocated to two exercise groups (whole-body vibration exercise group and plyometric exercise group). The exercise was conducted three times each week for 8 weeks. Isokinetic muscular strength, jumping performance, and balance were measured before starting the exercise and after finishing the 8 weeks of exercise. [Results] Measurements of isokinetic muscular strength revealed that the whole-body vibration exercise group showed significant increase after the exercise. However, the plyometric exercise group had no significant increase in lumbar flexion, extension, and knee flexion. Measurements of vertical jumping revealed that, the whole-body vibration exercise group had no significant increase after the exercise. However, the plyometric exercise group showed significant increase. Measurements of balance revealed that, the whole-body vibration exercise group showed significant increase. However, the plyometric exercise group showed no significant increase. [Conclusion] Although both whole-body vibration and plyometric exercises are effective intervention methods, the two methods have different effects on the improvement of isokinetic muscular strength, jumping performance, and balance of female volleyball players. PMID:27942136

  20. Work and power of the knee flexor and extensor muscles in patients with osteoarthritis and after total knee arthroplasty.

    Science.gov (United States)

    Bastiani, Denise; Ritzel, Cintia Helena; Bortoluzzi, Silvia Manfrin; Vaz, Marco Aurelio

    2012-01-01

    The inflammatory manifestations of knee osteoarthritis (OA) lead to muscle inhibition and hypotrophy, resulting in a reduction in total muscle work and muscle power. Total knee arthroplasty (TKA) is the most adequate surgery for the treatment of advanced OA. However, its effects on muscle functional behavior have not been well understood. To compare the total work and power of the knee flexor and extensor muscles in patients with OA (20) and in patients post-TKA (12) at two angular velocities (60º/sec and 240º/sec). An isokinetic Biodex dynamometer was used to assess muscle power and total work during isokinetic contractions. Two-way ANOVA for repeated measures was used to compare total muscle work and muscle power between the groups (SPSS software, version 13.0; significance level, P 0.05). In addition, no difference was observed in the muscle power of the knee extensors and flexors (P > 0.05). Total work and power were similar in the OA and TKA groups, suggesting that TKA did not improve functional capacity, which was similar in both groups.

  1. Effect of 12 Weeks of Accelerated Rehabilitation Exercise on Muscle Function of Patients with ACL Reconstruction of the Knee Joint.

    Science.gov (United States)

    Lee, Joong-Chul; Kim, Ji Youn; Park, Gi Duck

    2013-12-01

    [Purpose] To examine changes in the knee joint's isokinetic muscle functions following systematic and gradual rehabilitation exercises lasting for 12 weeks for male and female patients who underwent anterior cruciate ligament (ACL) reconstruction. Differences in muscle functions between the uninvolved side (US) and the involved side (IS) before surgery, differences in muscle functions between US and IS after rehabilitation exercises lasting for 12 weeks, and changes in muscle functions on US and IS between before and after surgery were analyzed to examine the effects of accelerated rehabilitation exercises after ACL reconstruction. [Subjects] The study subjects were 10 patients, five females and five males, who underwent ACL reconstruction performed by the same surgeon. [Methods] As a measuring tool, a Biodex Multi-joint system 3pro (USA), which is an isokinetic measuring device, was used to examine the flexion and extension forces of the knee joint. During isokinetic muscle strength evaluation, the ROM of US was set to be the same as that of IS for consistency of measurement. [Results] At 60°/s, the isokinetic muscle functions of the females did not show any significant change between before and after surgery in any of the variables on both US and IS. At 60°/s, the isokinetic muscle functions of the males did not show any significant change between before and after surgery in the peak torque, average power, and entire work done on US. In extension, peak torque on IS did not show any significant change.

  2. A Ground-Based Comparison of the Muscle Atrophy Research and Exercise System (MARES) and a Standard Isokinetic Dynamometer

    Science.gov (United States)

    Hackney, K. J.; English, K. L.; Redd, E.; DeWitt, J. K.; Ploutz-Snyder, R.; Ploutz-Snyder, L. L.

    2010-01-01

    PURPOSE: 1) To compare the test-to-test reliability of Muscle Atrophy Research and Exercise System (MARES) with a standard laboratory isokinetic dynamometer (ISOK DYN) and; 2) to determine if measures of peak torque and total work differ between devices. METHODS: Ten subjects (6M, 4F) completed two trials on both MARES and an ISOK DYN in a counterbalanced order. Peak torque values at 60 deg & 180 deg / s were obtained from five maximal repetitions of knee extension (KE) and knee flexion (KF). Total work at 180 deg / s was determined from the area under the torque vs. displacement curve during twenty maximal repetitions of KE and KF. Reliability of measures within devices was interpreted from the intraclass correlation coefficient (ICC) and compared between devices using the ratio of the within-device standard deviations. Indicators of agreement for the two devices were evaluated from: 1) a calculation of concordance (rho) and; 2) the correlation between the mean of measures versus the delta difference between measures (m u vs delta). RESULTS: For all outcome measures ICCs were high for both the ISOK DYN (0.95-0.99) and MARES (0.90-0.99). However, ratios of the within-device standard deviation were 1.3 to 4.3 times higher on MARES. On average, a wide range (3.3 to 1054 Nm) of differences existed between the values obtained. Only KE peak torque measured at 60 deg & 180 deg / s showed similarities between devices (rho = 0.91 & 0.87; Pearson's r for m u vs delta = -0.22 & -0.37, respectively). CONCLUSION: Although MARES was designed for use in microgravity it was quite reliable during ground-based testing. However, MARES was consistently more variable than an ISOK DYN. Future longitudinal studies evaluating a change in isokinetic peak torque or total work should be limited within one device.

  3. A ground-based comparison of the Muscle Atrophy Research and Exercise System (MARES) and a commercially available isokinetic dynamometer

    Science.gov (United States)

    English, Kirk L.; Hackney, Kyle J.; De Witt, John K.; Ploutz-Snyder, Robert J.; Goetchius, Elizabeth L.; Ploutz-Snyder, Lori L.

    2013-11-01

    IntroductionInternational Space Station (ISS) crewmembers perform muscle strength and endurance testing pre- and postflight to assess the physiologic adaptations associated with long-duration exposure to microgravity. However, a reliable and standardized method to document strength changes in-flight has not been established. To address this issue, a proprietary dynamometer, the Muscle Atrophy Research and Exercise System (MARES) has been developed and flown aboard the ISS. The aims of this ground-based investigation were to: (1) evaluate the test-retest reliability of MARES and (2) determine its agreement with a commercially available isokinetic dynamometer previously used for pre- and postflight medical testing. MethodsSix males (179.5±4.7 cm; 82.0±8.7 kg; 31.3±4.0 yr) and four females (163.2±7.3 cm; 63.2±1.9 kg; 32.3±6.8 yr) completed two testing sessions on a HUMAC NORM isokinetic dynamometer (NORM) and two sessions on MARES using a randomized, counterbalanced, cross-over design. Peak torque values at 60° and 180° s-1 were calculated from five maximal repetitions of knee extension (KE) and knee flexion (KF) for each session. Total work at 180° s-1 was determined from the area under the torque versus displacement curve during 20 maximal repetitions of KE and KF. ResultsIntraclass correlation coefficients were relatively high for both devices (0.90-0.99). Only one dependent measure, KE peak torque at 60° s-1 exhibited good concordance between devices (ρ=0.92) and a small average difference (0.9±17.3 N m). ConclusionMARES demonstrated acceptable test-retest reliability and thus should serve as a good tool to monitor in-flight strength changes. However, due to poor agreement with NORM, it is not advisable to compare absolute values obtained on these devices.

  4. Effects of Static and Dynamic Stretching on the Isokinetic Peak Torques and Electromyographic Activities of the Antagonist Muscles

    Science.gov (United States)

    Serefoglu, Abdullah; Sekir, Ufuk; Gür, Hakan; Akova, Bedrettin

    2017-01-01

    The aim of this study was to investigate if static and dynamic stretching exercises of the knee muscles (quadriceps and hamstring muscles) have any effects on concentric and eccentric isokinetic peak torques and electromyographic amplitudes (EMG) of the antagonist muscles. Twenty healthy male athletes (age between 18-30 years) voluntarily participated in this study. All of the subjects visited the laboratory to complete the following intervention in a randomized order on 5 separate days; (a) non-stretching (control), (b) static stretching of the quadriceps muscles, (c) static stretching of the hamstring muscles, (d) dynamic stretching of the quadriceps muscles, and (e) dynamic stretching of the hamstring muscles. Static stretching exercises either for the quadriceps or the hamstring muscles were carried out at the standing and sitting positions. Subjects performed four successive repetitions of each stretching exercises for 30 seconds in both stretching positions. Similar to static stretching exercises two different stretching modes were designed for dynamic stretching exercises. Concentric and eccentric isokinetic peak torque for the non-stretched antagonist quadriceps or hamstring muscles at angular velocities of 60°/sec and 240°/sec and their concurrent electromyographic (EMG) activities were measured before and immediately after the intervention. Isokinetic peak torques of the non-stretched agonist hamstring and quadriceps muscles did not represent any significant (p > 0.05) differences following static and dynamic stretching of the antagonist quadriceps and hamstring muscles, respectively. Similarly, the EMG activities of the agonist muscles exhibited no significant alterations (p > 0.05) following both stretching exercises of the antagonist muscles. According to the results of the present study it is possible to state that antagonist stretching exercises either in the static or dynamic modes do not affect the isokinetic peak torques and the EMG activities

  5. Impairment of voluntary control of finger motion following stroke: role of inappropriate muscle coactivation.

    Science.gov (United States)

    Kamper, D G; Rymer, W Z

    2001-05-01

    Subjects with chronic hemiplegia following stroke attempted to perform voluntary isometric, isokinetic, and free contractions of the extensor muscles of the metacarpophalangeal (MCP) joints. We recorded torque, metacarpophalangeal joint angle and velocity, and electromyographic (EMG) activity of the extrinsic extensors and flexors and the first dorsal interosseous (FDI). We found that voluntary MCP joint extension in hemiparetic subjects was greatly impaired in comparison with control subjects: only two of the 11 stroke subjects were able to generate even 0.21 N-m of isometric extension torque, only two could produce positive finger extension with no load, and none could develop an isokinetic concentric extension. Deficits seemed to result from a combination of coactivation of the finger flexor and extensor muscles and decreased voluntary excitation of the extensors, as normalized flexor and FDI EMG activity were greater for stroke than for control subjects (P < 0.001), but normalized extensor activity was reduced (P < 0.001). Copyright 2001 John Wiley & Sons, Inc.

  6. Rethinking voluntary euthanasia.

    Science.gov (United States)

    Stoyles, Byron J; Costreie, Sorin

    2013-12-01

    Our goal in this article is to explicate the way, and the extent to which, euthanasia can be voluntary from both the perspective of the patient and the perspective of the health care providers involved in the patient's care. More significantly, we aim to challenge the way in which those engaged in ongoing philosophical debates regarding the morality of euthanasia draw distinctions between voluntary, involuntary, and nonvoluntary euthanasia on the grounds that drawing the distinctions in the traditional manner (1) fails to reflect what is important from the patient's perspective and (2) fails to reflect the significance of health care providers' interests, including their autonomy and integrity.

  7. Effect of generalized joint hypermobility on knee function and muscle activation in children and adults

    DEFF Research Database (Denmark)

    Jensen, Bente Rona; Olesen, Annesofie T.; Pedersen, Mogens Theisen

    2013-01-01

    were evaluated in 39 children and 36 adults during isometric knee extension and flexion. Subjects performed isometric maximum contractions, submaximal contractions at 25% maximum voluntary contraction (MVC), and explosive contractions. Results: Agonist activation was reduced, and coactivation ratio...

  8. Low-intensity eccentric contractions of the knee extensors and flexors protect against muscle damage.

    Science.gov (United States)

    Lin, Min-Ju; Chen, Trevor Chung-Ching; Chen, Hsin-Lian; Wu, Bo-Han; Nosaka, Kazunori

    2015-10-01

    This study investigated the magnitude and duration of the protective effect of low-intensity eccentric contractions (LowEC) against damage induced by maximal eccentric contractions (MaxEC) of the knee flexors (KF) and extensors (KE). Young men were assigned to 8 experimental groups and 2 control groups (n = 13/group); the experimental groups performed LowEC of KF or KE 2 days (2d), 1 week (1wk), 2 weeks (2wk), or 3 weeks (3wk) before MaxEC, while the control groups performed MaxEC of KF or KE without LowEC. The 2d, 1wk, 2wk, and 3wk groups performed 30 LowEC of KF or 60 LowEC of KE with a load of 10% of maximal voluntary isometric contraction strength on a resistance-training machine, and all groups performed 30 MaxEC of KF or 60 MaxEC of KE on an isokinetic dynamometer. Several muscle damage markers were measured from before to 2 days after exercise (LowEC) or from before to 5 days after exercise (MaxEC). No significant changes in any variables were evident after LowEC. The changes in all variables after MaxEC were smaller (P < 0.05) for the 2d and 1wk groups (e.g., peak creatine kinase activity: 1002 ± 501 IU/L; peak muscle soreness: 13 ± 5 mm) than for the control group (peak creatine kinase activity: 3005 ± 983 IU/L; peak muscle soreness 28 ± 6 mm) for both KE and KF. There were no significant differences between the 2d and 1wk groups or among the 2wk, 3wk, and control groups. These results show that LowEC provided 30%-66% protection against damage induced by MaxEC of KF and KE, and the protective effect lasted 1 week.

  9. Assessment of isokinetic muscle function in Korea male volleyball athletes

    OpenAIRE

    Kim, Chang-Gyun; Jeoung, Bog Ja

    2016-01-01

    Volleyball players performed numerous repetitions of spike actions, which uses and requires strong and explosive force, and control of the muscles of the shoulder, lower back, and legs. Muscle imbalance is one of the main causes of sport injuries. The purpose of this study was to assess isokinetic muscle functions in male volleyball players. We thus aim to accurately evaluate their muscle functions, and identify the best training strategy to achieve optimal muscle strength balance in future t...

  10. Muscle strength, physical performance and physical activity as predictors of future knee replacement

    DEFF Research Database (Denmark)

    Skou, Søren T; Wise, Barton L; Lewis, Cora E;

    2016-01-01

    OBJECTIVE: To investigate associations between lower levels of muscle strength, physical performance and physical activity and the risk of knee replacement (KR) in older adults with frequent knee pain. METHOD: Participants from the Multicenter Osteoarthritis Study (MOST) with knee pain on most...... of the past 30 days at baseline were included (n=1,257; mean (SD) age of 62.2 (8.2)). We examined the association between 1) baseline peak isokinetic knee extensor strength, (60°/sec, maximum out of 4 trials), 2) best time to stand in timed chair stand (2 trials of 5 repetitions), and 3) baseline Physical......% CI) 0.99 (0.99 to 1.00)), but not when adjusting for Kellgren-Lawrence grade (p = 0.97). CONCLUSION: Lower levels of chair stand performance and self-reported physical activity are not associated with an increased risk of KR within 7 years, while the independent effect of knee extensor strength...

  11. Knee Replacement

    Science.gov (United States)

    ... need knee replacement surgery usually have problems walking, climbing stairs, and getting in and out of chairs. Some ... a total living space on one floor since climbing stairs can be difficult. Install safety bars or a ...

  12. Knee Arthroscopy

    Science.gov (United States)

    ... experience any of the following: • Fever • Chills • Persistent warmth or redness around the knee • Persistent or increased ... you should be able to return to most physical activities a er 6 to 8 weeks, or ...

  13. Runner's Knee

    Science.gov (United States)

    ... Over the summer he bought a pair of running shoes and took up jogging. He started with ... bending the knee — when walking, kneeling, squatting, or running, for example. Walking or running downhill or even ...

  14. Voluntary Public Unemployment Insurance

    DEFF Research Database (Denmark)

    O. Parsons, Donald; Tranæs, Torben; Bie Lilleør, Helene

    Denmark has drawn much attention for its active labor market policies, but is almost unique in offering a voluntary public unemployment insurance program requiring a significant premium payment. A safety net program – a less generous, means-tested social assistance plan – completes the system...

  15. Knee Injuries and Disorders

    Science.gov (United States)

    Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty ...

  16. The spinal reflex cannot be perceptually separated from voluntary movements.

    Science.gov (United States)

    Ghosh, Arko; Haggard, Patrick

    2014-01-01

    Both voluntary and involuntary movements activate sensors in the muscles, skin, tendon and joints. As limb movement can result from a mixture of spinal reflexes and voluntary motor commands, the cortical centres underlying conscious proprioception might either aggregate or separate the sensory inputs generated by voluntary movements from those generated by involuntary movements such as spinal reflexes. We addressed whether healthy volunteers could perceive the contribution of a spinal reflex during movements that combined both reflexive and voluntary contributions. Volunteers reported the reflexive contribution in leg movements that were partly driven by the knee-jerk reflex induced by a patellar tendon tap and partly by voluntary motor control. In one condition, participants were instructed to kick back in response to a tendon tap. The results were compared to reflexes in a resting baseline condition without voluntary movement. In a further condition, participants were instructed to kick forwards after a tap. Volunteers reported the perceived reflex contribution by repositioning the leg to the perceived maximum displacement to which the reflex moved the leg after each tendon tap. In the resting baseline condition, the reflex was accurately perceived. We found a near-unity slope of linear regressions of perceived on actual reflexive displacement. Both the slope value and the quality of regression fit in individual volunteers were significantly reduced when volunteers were instructed to generate voluntary backward kicks as soon as they detected the tap. In the kick forward condition, kinematic analysis showed continuity of reflex and voluntary movements, but the reflex contribution could be estimated from electromyography (EMG) recording on each trial. Again, participants' judgements of reflexes showed a poor relation to reflex EMG, in contrast to the baseline condition. In sum, we show that reflexes can be accurately perceived from afferent information. However

  17. Recovery kinetics of knee flexor and extensor strength after a football match.

    Science.gov (United States)

    Draganidis, Dimitrios; Chatzinikolaou, Athanasios; Avloniti, Alexandra; Barbero-Álvarez, José C; Mohr, Magni; Malliou, Paraskevi; Gourgoulis, Vassilios; Deli, Chariklia K; Douroudos, Ioannis I; Margonis, Konstantinos; Gioftsidou, Asimenia; Flouris, Andreas D; Fouris, Andreas D; Jamurtas, Athanasios Z; Koutedakis, Yiannis; Fatouros, Ioannis G

    2015-01-01

    We examined the temporal changes of isokinetic strength performance of knee flexor (KF) and extensor (KE) strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices) or an experimental group (N = 20, participated also in a football match). Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12 h, 36 h and 60 h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant) were measured on an isokinetic dynamometer at baseline and at 12 h, 36 h and 60 h after the match. Functional (KFecc/KEcon) and conventional (KFcon/KEcon) ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60 h after the match in the control group. In the experimental group: a) isometric strength of knee extensors and knee flexors declined (Pfootball-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players' physical conditioning level.

  18. Recovery Kinetics of Knee Flexor and Extensor Strength after a Football Match

    Science.gov (United States)

    Draganidis, Dimitrios; Chatzinikolaou, Athanasios; Avloniti, Alexandra; Barbero-Álvarez, José C.; Mohr, Magni; Malliou, Paraskevi; Gourgoulis, Vassilios; Deli, Chariklia K.; Douroudos, Ioannis I.; Margonis, Konstantinos; Gioftsidou, Asimenia; Fouris, Andreas D.; Jamurtas, Athanasios Z.; Koutedakis, Yiannis; Fatouros, Ioannis G.

    2015-01-01

    We examined the temporal changes of isokinetic strength performance of knee flexor (KF) and extensor (KE) strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices) or an experimental group (N = 20, participated also in a football match). Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12h, 36h and 60h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant) were measured on an isokinetic dynamometer at baseline and at 12h, 36h and 60h after the match. Functional (KFecc/KEcon) and conventional (KFcon/KEcon) ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60h after the match in the control group. In the experimental group: a) isometric strength of knee extensors and knee flexors declined (Pfootball-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players' physical conditioning level. PMID:26043222

  19. Isokinetic and isometric strength-endurance after 6 hours of immersion and 6 degrees head-down tilt in men

    Science.gov (United States)

    Shaffer-Bailey, M.; Greenleaf, J. E.; Hutchinson, T. M.

    1996-01-01

    PURPOSE: To determine weight (water) loss levels for onset of muscular strength and endurance changes during deconditioning. METHODS: Seven men (27-40 yr) performed maximal shoulder-, knee-, and ankle-joint isometric (0 degree.s(-1) load) and isokinetic (60 degrees, 120 degrees, 180 degrees.s(-1) velocity) exercise tests during ambulatory control (AC), after 6 h of 6 degrees head-down tilt (HDT; dry-bulb temp. = 23.2 +/- SD 0.6 degrees C, relative humidity = 31.1+/- 11.1%) and after 6 h of 80 degrees foot-down head-out water immersion (WI; water temp. = 35.0 +/- SD 0.1 degree C) treatments. RESULTS: Weight (water) loss after HDT (1.10 +/- SE 0.14 kg, 1.4 +/- 0.2% body wt) and WI (1.54+/- 0.19 kg, 2.0 +/- 0.2% body wt) were not different, but urinary excretion with WI (1,354 +/- 142 ml.6 h(-1)) was 28% greater (p knee at 180 degrees.s(-1) for 30 s) was not different between AC and the WI or HDT treatments. Shoulder-, knee-, and ankle-joint strength was unchanged except for three knee-joint peak torques: AC torque (120 degrees.s(-1), 285 +/- 20 Nm) decreased to 268 +/- 21 Nm (delta = -6%, p torques (180 degrees.s(-1), 260 +/- 19 Nm) decreased to 236 +/- 15 Nm (delta = -9%, p joint strength and endurance decrements is more than 2% body weight (water) loss, while significant reduction in knee-joint muscular strength-endurance occurred only at moderate (120 degrees.s(-1) and lighter (180 degrees.s(-1)) loads with body weight loss of 1.4-2.0% following WI or HDT, respectively. These weight (water) losses and knee-joint strength decrements are somewhat less than the mean weight loss of 2.6% and knee-joint strength decrements of 6-20% of American astronauts after Skylab flights to 84 d.

  20. Differential Effect of Taekwondo Training on Knee Muscle Strength and Reactive and Static Balance Control in Children with Developmental Coordination Disorder: A Randomized Controlled Trial

    Science.gov (United States)

    Fong, Shirley S. M.; Chung, Joanne W. Y.; Chow, Lina P. Y.; Ma, Ada W. W.; Tsang, William W. N.

    2013-01-01

    This randomized controlled trial aimed to investigate the effect of short-term intensive TKD training on the isokinetic knee muscle strength and reactive and static balance control of children with developmental coordination disorder (DCD). Among the 44 children with DCD (mean age: 7.6 plus or minus 1.3 years) recruited, 21 were randomly assigned…

  1. Differential Effect of Taekwondo Training on Knee Muscle Strength and Reactive and Static Balance Control in Children with Developmental Coordination Disorder: A Randomized Controlled Trial

    Science.gov (United States)

    Fong, Shirley S. M.; Chung, Joanne W. Y.; Chow, Lina P. Y.; Ma, Ada W. W.; Tsang, William W. N.

    2013-01-01

    This randomized controlled trial aimed to investigate the effect of short-term intensive TKD training on the isokinetic knee muscle strength and reactive and static balance control of children with developmental coordination disorder (DCD). Among the 44 children with DCD (mean age: 7.6 plus or minus 1.3 years) recruited, 21 were randomly assigned…

  2. EFFICACY OF KINESIO-TAPING VERSUS PHONOPHORESIS ON KNEE OSTEOARTHRITIS: AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Magda Gaid Sedhom

    2016-08-01

    Full Text Available Background: Osteoarthritis (OA is the most common type of joint disease. Pain is the most common symptom of knee osteoarthritis. Also it characterized by sign, symptoms of inflammation, pain, stiffness and loss of mobility. This study was conducted to explore the efficacy of kinesio taping (KT versus Aescin, Diethylamine Salicylate gel phonophoresis (PH on pain level, range of motion (ROM, and proprioceptive accuracy on mild to moderate knee OA patients. Methods: Forty females with knee OA from Outpatient Clinic of Physical Therapy Faculty participated in the study with mean age (49±5.82 years. They were randomly assigned into 2 equal groups. Group I: received Aescin, Diethylamine Salicylate gel PH with pulsed ultrasound therapy and group II received KT. All patients received hot packs and selected exercise program for four weeks; three sessions per week. Visual analogue scale was used in assessment of pain level. Electronic digital goniometer was used in assessment of knee flexion ROM. Iso-kinetic daynamometer was used in assessment of knee proprioceptive accuracy. Results: There was a significant relieving of pain perception, increasing of knee flexion ROM and improving proprioceptive accuracy in knee joint post-study in both groups. But application of Aescin, Diethylamine Salicylate gel PH had significant relieve of knee pain than KT. Conclusion: Using of Aescin, Diethylamine Salicylate gel PH is more effective than KT application in reliving knee pain in knee osteoarthritic patients.

  3. Speed, not magnitude, of knee extensor torque production is associated with self-reported knee function early after anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Hsieh, Chao-Jung; Indelicato, Peter A; Moser, Michael W; Vandenborne, Krista; Chmielewski, Terese L

    2015-11-01

    To examine the magnitude and speed of knee extensor torque production at the initiation of advanced anterior cruciate ligament (ACL) reconstruction rehabilitation and the associations with self-reported knee function. Twenty-eight subjects who were 12 weeks post-ACL reconstruction and 28 age- and sex-matched physically active controls participated in this study. Knee extensor torque was assessed bilaterally with an isokinetic dynamometer at 60°/s. The variables of interest were peak torque, average rate of torque development, time to peak torque and quadriceps symmetry index. Knee function was assessed with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). Peak torque and average rate of torque development were lower on the surgical side compared to the non-surgical side and controls. Quadriceps symmetry index was lower in subjects with ACL reconstruction compared to controls. On the surgical side, average rate of torque development was positively correlated with IKDC-SKF score (r = 0.379) while time to peak torque was negatively correlated with IKDC-SKF score (r = -0.407). At the initiation of advanced ACL reconstruction rehabilitation, the surgical side displayed deficits in peak torque and average rate of torque development. A higher rate of torque development and shorter time to peak torque were associated with better self-reported knee function. The results suggest that the rate of torque development should be addressed during advanced ACL reconstruction rehabilitation and faster knee extensor torque generation may lead to better knee function. III.

  4. Myocellular enzyme leakage, polymorphonuclear neutrophil activation and delayed onset muscle soreness induced by isokinetic eccentric exercise.

    Science.gov (United States)

    Croisier, J L; Camus, G; Deby-Dupont, G; Bertrand, F; Lhermerout, C; Crielaard, J M; Juchmès-Ferir, A; Deby, C; Albert, A; Lamy, M

    1996-01-01

    To address the question of whether delayed onset muscular soreness (DOMS) following intense eccentric muscle contraction could be due to increased production of the arachidonic acid derived product prostaglandin E2 (PGE2). 10 healthy male subjects were submitted to eccentric and concentric isokinetic exercises on a Kin Trex device at 60 degrees/s angular velocity. Exercise consisted of 8 stages of 5 maximal contractions of the knee extensor and flexor muscle groups of both legs separated by 1 min rest phases. There was an interval of at least 30 days between eccentric and concentric testing, and the order of the two exercise sessions was randomly assigned. The subjective presence and intensity of DOMS was evaluated using a visual analogue scale, immediately, following 24 h and 48 h after each test. Five blood samples were drawn from an antecubital vein: at rest before exercise, immediately after, after 30 min recovery, 24 h and 48 h after the tests. The magnitude of the acute inflammatory response to exercise was assessed by measuring plasma levels of polymorphonuclear elastase ([EL]), myeloperoxidase ([MPO]) and PGE2 ([PGE2]). Using two way analysis of variance, it appeared that only eccentric exercise significantly increased [EL] and DOMS, especially of the hamstring muscles. Furthermore, a significant decrease in eccentric peak torque of this muscle group only was observed on day 2 after eccentric work (- 21%; P < 0.002). Serum activity of creatine kinase and serum concentration of myoglobin increased significantly 24 and 48 h after both exercise tests. However, these variables reached significantly higher values following eccentric contractions 48 h after exercise. Mean [PGE2] in the two exercise modes remained unchanged over time and were practically equal at each time point. On the basis of these findings, we conclude that the magnitude of polymorphonuclear (PMN) activation, muscle damage, and DOMS are greater after eccentric than after concentric muscle

  5. Effects of Series Elasticity on the Human Knee Extension Torque-Angle Relationship in Vivo

    Science.gov (United States)

    Kubo, Keitaro; Ohgo, Kazuya; Takeishi, Ryuichi; Yoshinaga, Kazunari; Tsunoda, Naoya; Kanehisa, Hiroaki; Fukunaga, Tetsuo

    2006-01-01

    The purpose of this study was to investigate the effects of series elasticity on the torque-angle relationship of the knee extensors in vivo. Forty-two men volunteered to take part in the present study. The participants performed maximal voluntary isometric contractions at eight knee-joint angles (40, 50, 60, 70, 80, 90, 100, 110[degree]). The…

  6. Knee extensor and flexor muscle power explains stair ascension time in patients with unilateral late-stage knee osteoarthritis: a cross-sectional study.

    Science.gov (United States)

    Valtonen, Anu M; Pöyhönen, Tapani; Manninen, Mikko; Heinonen, Ari; Sipilä, Sarianna

    2015-02-01

    To determine the extent of asymmetrical deficits in knee extensor and flexor muscles, and to examine whether asymmetrical muscle deficits are associated with mobility limitations in persons with late-stage knee osteoarthritis (OA). Cross-sectional. Research laboratory. A clinical sample (N=56; age range, 50-75y) of eligible persons with late-stage knee OA awaiting knee replacement. Not applicable. Knee extensor and flexor power and torque assessed isokinetically; thigh muscle cross-sectional area (CSA) assessed by computed tomography; mobility limitation assessed by walking speed and stair ascension time; and pain assessed with the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. The asymmetrical deficits in knee extensor and flexor power and torque were between 18% and 29% (Pmuscle CSA, the asymmetrical deficit was 4% (Ppower deficits and weaker knee extensor and flexor power on the contralateral side were associated with slower stair ascension times. Moreover, weaker knee extensor and flexor power on the ipsilateral side were associated with slower stair ascension times. Greater knee pain in the OA joint was independently associated with slower stair ascending time in both models. The knee extensor and flexor muscle power of both the ipsilateral and contralateral sides and the pain in the OA knee were independently associated with stair ascension times. These results highlight the importance of assessing muscle power on both sides and knee pain in the prevention of mobility limitations in patients with knee OA. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  7. The effect of beta-alanine supplementation on isokinetic force and cycling performance in highly trained cyclists.

    Science.gov (United States)

    Howe, Samuel T; Bellinger, Phillip M; Driller, Matthew W; Shing, Cecilia M; Fell, James W

    2013-12-01

    Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this randomized double-blind placebo-controlled study was to examine the effects of beta-alanine supplementation on aspects of muscular performance in highly trained cyclists. Sixteen highly trained cyclists (mean ± SD; age = 24 ± 7 yr; mass = 70 ± 7 kg; VO2max = 67 ± 4 ml · kg(-1) · min(-1)) supplemented with either beta-alanine (n = 8, 65 mg · kg - 1BM) or a placebo (n = 8; dextrose monohydrate) over 4 weeks. Pre- and postsupplementation cyclists performed a 4-minute maximal cycling test to measure average power and 30 reciprocal maximal isokinetic knee contractions at a fixed angular velocity of 180° · sec(-1) to measure average power/repetition, total work done (TWD), and fatigue index (%). Blood pH, lactate (La-) and bicarbonate (HCO3-) concentrations were measured pre- and postisokinetic testing at baseline and following the supplementation period. Beta-alanine supplementation was 44% likely to increase average power output during the 4-minute cycling time trial when compared with the placebo, although this was not statistically significant (p = .25). Isokinetic average power/repetition was significantly increased post beta-alanine supplementation compared with placebo (beta-alanine: 6.8 ± 9.9 W, placebo: -4.3 ± 9.5 W, p = .04, 85% likely benefit), while fatigue index was significantly reduced (p = .03, 95% likely benefit). TWD was 89% likely to be improved following beta-alanine supplementation; however, this was not statistically significant (p = .09). There were no significant differences in blood pH, lactate, and HCO3- between groups (p > .05). Four weeks of beta-alanine supplementation resulted in worthwhile changes in time-trial performance and short-duration muscular force production in highly trained cyclists.

  8. Piroxicam fails to reduce myocellular enzyme leakage and delayed onset muscle soreness induced by isokinetic eccentric exercise

    Directory of Open Access Journals (Sweden)

    J-L. Croisier

    1996-01-01

    Full Text Available To test the hypothesis that delayed onset muscular soreness (DOMS following intense eccentric muscle contraction could be due to increased production of prostaglandin E2 (PGE2, ten healthy male subjects were studied. Using a double-blind randomized crossover design, each subject performed two isokinetic tests separated by a period of at least 6 weeks: once with placebo, and once with piroxicam (Feldene®. They were given one capsule containing either placebo or piroxicam (20 mg per day for 6 days with initial doses given starting 3 days prior to isokinetic testing. Exercise consisted of eight stages of five maximal contractions of the knee extensor and flexor muscle groups of both legs separated by 1 min rest phases, on a Kin Trex device at 60°/s angular velocity. The subjective presence and intensity of DOMS were evaluated using a visual analogue scale immediately after, and 24 and 48 h after each test. The mean plasma concentration of PGE2 measured at rest and after exercise was significantly lower in the group treated with piroxicam (p < 0.05. However, statistical analysis (two-way ANOVA test revealed that exercise did not cause any significant change of mean plasma PGE2 over time in either of the two groups. Eccentric work was followed by severe muscle pain in extensor and flexor muscle groups. Maximal soreness was noted 48 h postexercise. Serum creatine kinase activity and the serum concentration of myoglobin increased significantly, and reached peak values 48 h after exercise in both experimental conditions (p < 0.001. By paired t-test, it appeared that there were no significant differences in the serum levels of these two markers of muscle damage between the two groups at any time point. We conclude that: (1 oral administration of piroxicam fails to reduce muscle damage and DOMS caused by strenuous eccentric exercise; and (2 the hypothetical role of increased PGE2 production in eccentric exercise-induced muscle damage, DOMS, and reduced

  9. Piroxicam fails to reduce myocellular enzyme leakage and delayed onset muscle soreness induced by isokinetic eccentric exercise

    Science.gov (United States)

    Croisier, J-L.; Monfils, T.; Deby-Dupon, G.; Fafchamps, M.; Venneman, I.; Crielaard, J-M.; Juchmès-Ferir, A.; Lhermerout, C.; Lamy, M.; Deby, C.

    1996-01-01

    To test the hypothesis that delayed onset muscular soreness (DOMS) following intense eccentric muscle contraction could be due to increased production of prostaglandin E2 (PGE2), ten healthy male subjects were studied. Using a double-blind randomized crossover design, each subject performed two isokinetic tests separated by a period of at least 6 weeks: once with placebo, and once with piroxicam (Feldene®). They were given one capsule containing either placebo or piroxicam (20 mg) per day for 6 days with initial doses given starting 3 days prior to isokinetic testing. Exercise consisted of eight stages of five maximal contractions of the knee extensor and flexor muscle groups of both legs separated by 1 min rest phases, on a Kin Trex device at 60°/s angular velocity. The subjective presence and intensity of DOMS were evaluated using a visual analogue scale immediately after, and 24 and 48 h after each test. The mean plasma concentration of PGE2 measured at rest and after exercise was significantly lower in the group treated with piroxicam (p < 0.05). However, statistical analysis (two-way ANOVA test) revealed that exercise did not cause any significant change of mean plasma PGE2 over time in either of the two groups. Eccentric work was followed by severe muscle pain in extensor and flexor muscle groups. Maximal soreness was noted 48 h postexercise. Serum creatine kinase activity and the serum concentration of myoglobin increased significantly, and reached peak values 48 h after exercise in both experimental conditions (p < 0.001). By paired t-test, it appeared that there were no significant differences in the serum levels of these two markers of muscle damage between the two groups at any time point. We conclude that: (1) oral administration of piroxicam fails to reduce muscle damage and DOMS caused by strenuous eccentric exercise; and (2) the hypothetical role of increased PGE2 production in eccentric exercise-induced muscle damage, DOMS, and reduced isokinetic

  10. Neuromuscular performance of maximal voluntary explosive concentric contractions is influenced by angular acceleration.

    Science.gov (United States)

    Hahn, D; Bakenecker, P; Zinke, F

    2016-12-28

    Torque production during maximal voluntary explosive contractions is considered to be a functionally more relevant neuromuscular measure than steady-state torque, but little is known about accelerated concentric contractions. This study investigated torque, muscle activity, and fascicle behavior during isometric and fast concentric contractions of quadriceps femoris. Ten participants performed maximal voluntary explosive isometric, isovelocity, and additional concentric knee extensions at angular accelerations ranging from 700 to 4000° s(-2) that resulted in an angular velocity of 300° s(-1) at 40° knee flexion. Concentric torque at 40° knee flexion was corrected for inertia, and the corresponding isometric torque was matched to the time when the target knee angle of 40° was reached during concentric contractions. Electromyography of quadriceps femoris and hamstrings and ultrasound of vastus lateralis were measured to determine muscle activity, fascicle length, and fascicle velocity (FV). The faster the acceleration, the more torque was produced during concentric contractions at 40° knee flexion, which was accompanied by a reduction in FV. In comparison with isometric conditions, concentric quadriceps muscle activity was increased and torque during accelerations ≥3000° s(-2) equaled the time-matched isometric torque. Our results provide novel evidence that acceleration influences torque production during maximal voluntary explosive concentric contractions. This is suggested to be due to series elasticity and reduced force depression.

  11. Antagonist muscle moment is increased in ACL deficient subjects during maximal dynamic knee extension

    DEFF Research Database (Denmark)

    Alkjær, Tine; Simonsen, Erik B; Magnusson, S Peter

    2012-01-01

    INTRODUCTION: Coactivation of the hamstring muscles during dynamic knee extension may compensate for increased knee joint laxity in anterior cruciate ligament (ACL) deficient subjects. This study examined if antagonist muscle coactivation during maximal dynamic knee extension was elevated...... in subjects with anterior cruciate ligament (ACL) deficiency compared to age-matched healthy controls. METHODS: Electromyography (EMG) and net knee joint moments were recorded during maximal concentric quadriceps and eccentric hamstring contractions, performed in an isokinetic dynamometer (ROM: 90......-10°, angular speed: 30°/s). Hamstring antagonist EMG recorded during concentric quadriceps contraction was converted into antagonist moment based on the EMG-moment relationship observed during eccentric agonist contractions. RESULTS: The magnitude of antagonist hamstring EMG was 65.5% higher in ACL deficient...

  12. Effect of Exercise Therapy Compared with Arthroscopic Surgery on Knee Muscle Strength and Functional Performance in Middle-Aged Patients with Degenerative Meniscus Tears

    DEFF Research Database (Denmark)

    Stensrud, Silje; Risberg, May Arna; Roos, Ewa M.

    2015-01-01

    OBJECTIVE: The aim of this study was to compare the effect of a 12-wk exercise therapy program and arthroscopic partial meniscectomy on knee strength and functional performance in middle-aged patients with degenerative meniscus tears. DESIGN: A total of 82 patients (mean age, 49 yrs; 35% women......) with a symptomatic, unilateral, magnetic resonance imaging-verified degenerative meniscus tear and no or mild radiographic osteoarthritis were randomly assigned to a supervised neuromuscular and strength exercise program or arthroscopic partial meniscectomy. Outcomes assessed 3 mos after intervention initiation were...... isokinetic knee muscle strength, lower extremity performance, and self-reported global rating of change. RESULTS: Mean difference in isokinetic knee extension peak torque between the two groups was 16% (95% confidence interval, 7.1-24.0) (P

  13. Intrinsic muscle strength and voluntary activation of both lower limbs and functional performance after stroke.

    Science.gov (United States)

    Horstman, Astrid M; Beltman, Marijke J; Gerrits, Karin H; Koppe, Peter; Janssen, Thomas W; Elich, Peter; de Haan, Arnold

    2008-07-01

    The objective of this study was to assess the nature of muscle weakness in both legs after stroke compared with able-bodied control individuals and to examine whether there is a relationship between the degree of muscle weakness and coactivation of knee extensors and flexors as well as voluntary activation capacity of knee extensors of both paretic and non-paretic legs and indices of functional performance. Maximal voluntary isometric torques of knee extensors (MVCe) and flexors (MVCf) were determined in 14 patients (bilaterally) and 12 able-bodied controls. Simultaneous measurements were made of torque and surface EMG from agonist and antagonist muscles. Coactivation was calculated. Supramaximal triplets were evoked with electrical stimulation to estimate maximal torque capacity and degree of voluntary activation of knee extensors. MVCs, activation and coactivation parameters were correlated to scores of seven functional performance tests. MVCe, MVCf and voluntary activation were lower in paretic lower limb (PL) compared with both non-paretic lower limb (NL) and control. Besides, all these parameters of NL were also lower than control. Electrically evoked torque capacity of knee extensors of PL was about 60% of both NL and control, which were not significantly different from each other. Strong significant correlations between strength, as well as voluntary activation, and functional performance were found. Coactivation did not correlate well with functional performance. Thus, whereas for NL activation failure can explain weakness, for PL both activation failure and reduced intrinsic torque capacity are responsible for the severe weakness. Activation capacity and muscle strength correlated strongly to functional performance, while coactivation did not.

  14. Isokinetic profile of subjects with the ruptured anterior cruciated ligament

    OpenAIRE

    Drapšin Miodrag; Lukač Damir; Rašović Predrag; Drid Patrik; Klašnja Aleksandar; Lalić Ivica

    2016-01-01

    Background/Aim. All changes in the knee that appear after anterior cruciate ligament (ACL) lesion lead to difficulties in walking, running, jumping especially during sudden changes of the line of movement. This significantly impairs quality of life of these subjects and leads to decrease in physical activity. Knee injuries make 5% of all most severe acute sport injuries. The aim of the study was to determine strength of the thigh muscles in persons with uni...

  15. Water on the Knee

    Science.gov (United States)

    ... your knee joint. Some people call this condition "water on the knee." A swollen knee may be ... Choose low-impact exercise. Certain activities, such as water aerobics and swimming, don't place continuous weight- ...

  16. Knee pain (image)

    Science.gov (United States)

    ... front of the knee can be due to bursitis, arthritis, or softening of the patella cartilage as ... knee. Overall knee pain can be due to bursitis, arthritis, tears in the ligaments, osteoarthritis of the ...

  17. Knee microfracture surgery

    Science.gov (United States)

    Cartilage regeneration - knee ... Three types of anesthesia may be used for knee arthroscopy surgery: Medicine to relax you, and shots of painkillers to numb the knee Spinal (regional) anesthesia General anesthesia (you will be ...

  18. Preventing Knee Injuries

    Science.gov (United States)

    ... Our Newsletter Donate Blog Skip breadcrumb navigation Preventing Knee Injuries Knee injuries in children and adolescent athletes ... this PDF Share this page: WHAT ARE COMMON KNEE INJURIES? Pain Syndromes One of the most common ...

  19. Unilateral eccentric resistance training: A direct comparison between isokinetic and dynamic constant external resistance modalities.

    Science.gov (United States)

    Coratella, Giuseppe; Milanese, Chiara; Schena, Federico

    2015-01-01

    Aim of the study was to compare the effects of unilateral eccentric-only training using constant velocity vs. constant external load. Forty-seven participants were randomized in isokinetic (IK), dynamic constant external resistance (DCER) unilateral eccentric training or control groups. Knee extension 1RM and isometric, eccentric and concentric knee extensors peak torque, as well as changes in vastus lateralis fascicle pennation angle, fascicle length, muscle thickness, and quadriceps fat-free mass were measured. Both IK and DCER training consisted in 5 × 8 eccentric-only repetitions, 2d/w, for 6 weeks. IK and DCER training sessions were matched for total volume. After training, both IK and DCER similarly increased 1RM (respectively, +4.4 kg, CI95% 1.8-7.0 and +5.5 kg, CI95% 3.3-7.9), isometric (respectively, +34.5 N/m, CI95% 23.0-45.9 and +15.8, CI95% 5.4-26.2) and concentric peak torque (respectively, +17.0 N/m, CI95% 6.6 to +27.4 and 12.2 CI95% 2.8-21.7). IK increased eccentric peak torque significantly more than DCER (respectively, +84.2 N/m, CI95% 66.3-102.1 and +38.2 N/m, CI95% 21.9-54.4). Both IK and DCER similarly increased fascicle length (respectively, +14.7 mm, CI95% 5.4-24.0 and +14.4 mm, CI95% 5.4-23.3) and muscle thickness (respectively, +3.3 mm, CI95% 1.5-5.1, and +4.1 mm, CI95% 2.5-5.7). Matching the training volume resulted in similar adaptations comparing eccentric-only IK or DCER resistance training. Both in rehabilitation and in training practice, the use of easily available gym devices can be a good substitute for expensive and often unavailable IK devices.

  20. Measurement of fatigue in knee flexor and extensor muscles.

    Directory of Open Access Journals (Sweden)

    Kawabata Y

    2000-04-01

    Full Text Available In order to examine fatigue of the knee flexor and extensor muscles and to investigate the characteristics of muscular fatigue in different sports, a Cybex machine was used to measure muscle fatigue and recovery during isokinetic knee flexion and extension. Eighteen baseball players, 12 soccer players and 13 marathon runners were studied. Each subject was tested in the sitting position and made to perform 50 consecutive right knee bends and stretches at maximum strength. This was done 3 times with an interval of 10 min between each series. The peak torque to body weight ratio and the fatigue rate were determined in each case. In all subjects, the peak torque to body weight ratio was higher for extensors than flexors. Over the 3 trials, the fatigue rate of extensors showed little change, while that of flexors had a tendency to increase. In each subject, knee extensors showed a high fatigue rate but a quick recovery, while knee flexors showed a low fatigue rate but a slow recovery. As the marathon runners had the smallest fatigue rates for both flexors and extensors, we concluded that marathon runners had more stamina than baseball players and soccer players.

  1. Algorithms and novel applications based on the isokinetic ensemble. I. Biophysical and path integral molecular dynamics

    Science.gov (United States)

    Minary, Peter; Martyna, Glenn J.; Tuckerman, Mark E.

    2003-02-01

    In this paper (Paper I) and a companion paper (Paper II), novel new algorithms and applications of the isokinetic ensemble as generated by Gauss' principle of least constraint, pioneered for use with molecular dynamics 20 years ago, are presented for biophysical, path integral, and Car-Parrinello based ab initio molecular dynamics. In Paper I, a new "extended system" version of the isokinetic equations of motion that overcomes the ergodicity problems inherent in the standard approach, is developed using a new theory of non-Hamiltonian phase space analysis [M. E. Tuckerman et al., Europhys. Lett. 45, 149 (1999); J. Chem. Phys. 115, 1678 (2001)]. Reversible multiple time step integrations schemes for the isokinetic methods, first presented by Zhang [J. Chem. Phys. 106, 6102 (1997)] are reviewed. Next, holonomic constraints are incorporated into the isokinetic methodology for use in fast efficient biomolecular simulation studies. Model and realistic examples are presented in order to evaluate, critically, the performance of the new isokinetic molecular dynamic schemes. Comparisons are made to the, now standard, canonical dynamics method, Nosé-Hoover chain dynamics [G. J. Martyna et al., J. Chem. Phys. 97, 2635 (1992)]. The new isokinetic techniques are found to yield more efficient sampling than the Nosé-Hoover chain method in both path integral molecular dynamics and biophysical molecular dynamics calculations. In Paper II, the use of isokinetic methods in Car-Parrinello based ab initio molecular dynamics calculations is presented.

  2. Differential effect of Taekwondo training on knee muscle strength and reactive and static balance control in children with developmental coordination disorder: a randomized controlled trial.

    Science.gov (United States)

    Fong, Shirley S M; Chung, Joanne W Y; Chow, Lina P Y; Ma, Ada W W; Tsang, William W N

    2013-05-01

    This randomized controlled trial aimed to investigate the effect of short-term intensive TKD training on the isokinetic knee muscle strength and reactive and static balance control of children with developmental coordination disorder (DCD). Among the 44 children with DCD (mean age: 7.6 ± 1.3 years) recruited, 21 were randomly assigned to undergo daily TKD training for 1h over three consecutive months, with the remaining 23 children being assigned to the DCD control group. Eighteen typically developing children (mean age: 7.2 ± 1.0 years) received no training as normal controls. Knee extensor and flexor muscle strength and reactive and static balance control were assessed using an isokinetic machine (with low, moderate and high movement velocities), a motor control test (MCT) and a unilateral stance test (UST), respectively. A repeated measures MANCOVA revealed a significant group through time interaction effect in isokinetic outcomes at 180°/s and in the UST outcome. Post hoc analysis demonstrated that DCD-TKD children's isokinetic knee muscle strength, specifically at 180°/s, was as high as that of the normal control children (p>0.0083) after TKD training. Moreover, UST body sway velocity was slower in the DCD-TKD group than in the DCD control group (p0.05) after TKD training. However, no such improvement in balance was observed in the MCT (p>0.025). The results show that children with DCD who undergo a 3-month program of intensive TKD training experience improvements in isokinetic knee muscle strength at 180°/s and static single-leg standing balance control, but do not benefit from improved reactive balance control.

  3. Voluntary Simplicity: A Lifestyle Option.

    Science.gov (United States)

    Pestle, Ruth E.

    This guide provides practical ideas for incorporating the concept of voluntary simplicity into home economics classes. Discussed in the first chapter are the need to study voluntary simplicity, its potential contributions to home economics, and techniques and a questionnaire for measuring student attitudes toward the concept. The remaining…

  4. Operant Variability and Voluntary Action

    Science.gov (United States)

    Neuringer, Allen; Jensen, Greg

    2010-01-01

    A behavior-based theory identified 2 characteristics of voluntary acts. The first, extensively explored in operant-conditioning experiments, is that voluntary responses produce the reinforcers that control them. This bidirectional relationship--in which reinforcer depends on response and response on reinforcer--demonstrates the functional nature…

  5. Toward voluntary parenthood.

    Science.gov (United States)

    Scarr, S

    2000-06-01

    David Lykken's proposal to license married parents for child rearing, and to deny the same opportunity to single and inept parents, springs from his deep concern for millions of youngsters cruelly subjected to abusive and neglectful rearing circumstances. Children from such inadequate homes grow up to have high rates of school failure, criminality, and drug addiction. The problem is clear, but Lykken's remedies of mandated marriage and parental licensure are unacceptable in U.S. society, where our reproductive rights are fortunately protected by our Constitution. As a devoted proponent of reproductive rights, I propose a legally and morally acceptable proposal to the same end. Increasing women's effective control of reproduction and moving toward entirely voluntary parenthood will accomplish the same goals without compromising our civil liberties.

  6. Comparison of acute responses to isotonic or isokinetic eccentric muscle action: differential outcomes in skeletal muscle damage and implications for rehabilitation.

    Science.gov (United States)

    Alemany, J A; Delgado-Díaz, D C; Mathews, H; Davis, J M; Kostek, M C

    2014-01-01

    Both isotonic and isokinetic eccentric muscle contractions are commonly used in muscle research laboratories to induce muscle damage, yet, the muscle damage outcomes between these 2 modes of eccentric contraction have not been compared. The purpose of this study was to compare modes of contraction for differences in muscle damage. 16 men were placed in the isotonic (IT: 110% of maximal isometric torque) or the isokinetic (IK: 120°/s) group, with each group performing 200 eccentric muscle actions of the knee extensors. Isometric peak torque, perceived soreness and CK activity were measured immediately pre and post exercise, and 48-h post exercise. Mean total work (~1700 J) and peak torque per set (~265 Nm) decreased over the 200 repetitions (ptorque (-13%), creatine kinase activity (+200%) and self-perceived muscular soreness (+4 unit change). Significant group×time interactions (ptorque was 22% lower, and creatine kinase and self-perceived muscular soreness were 330% and 3 unit difference higher in the IT as compared to the IK groups, 48-h post exercise. When equating for total work, skeletal muscle damage markers are higher during IT vs. IK modes. This reflects differences inherent in contraction type and suggests that this should be taken into account during physical rehabilitation.

  7. Comparison of different passive knee extension torque-angle assessments.

    Science.gov (United States)

    Freitas, Sandro R; Vaz, João R; Bruno, Paula M; Valamatos, Maria J; Mil-Homens, Pedro

    2013-11-01

    Previous studies have used isokinetic dynamometry to assess joint torques and angles during passive extension of the knee, often without reporting upon methodological errors and reliability outcomes. In addition, the reliability of the techniques used to measure passive knee extension torque-angle and the extent to which reliability may be affected by the position of the subjects is also unclear. Therefore, we conducted an analysis of the intra- and inter-session reliability of two methods of assessing passive knee extension: (A) a 2D kinematic analysis coupled to a custom-made device that enabled the direct measurement of resistance to stretch and (B) an isokinetic dynamometer used in two testing positions (with the non-tested thigh either flexed at 45° or in the neutral position). The intra-class correlation coefficients (ICCs) of torque, the slope of the torque-angle curve, and the parameters of the mathematical model that were fit to the torque-angle data for the above conditions were measured in sixteen healthy male subjects (age: 21.4 ± 2.1 yr; BMI: 22.6 ± 3.3 kg m(-2); tibial length: 37.4 ± 3.4 cm). The results found were: (1) methods A and B led to distinctly different torque-angle responses; (2) passive torque-angle relationship and stretch tolerance were influenced by the position of the non-tested thigh; and (3) ICCs obtained for torque were higher than for the slope and for the mathematical parameters that were fit to the torque-angle curve. In conclusion, the measurement method that is used and the positioning of subjects can influence the passive knee extension torque-angle outcome.

  8. MYOELECTRIC ALTERATIONS AFTER VOLUNTARY INDUCED HIGH - AND LOW - FREQUENCY FATIGUE

    Directory of Open Access Journals (Sweden)

    Vojko Strojnik

    2008-06-01

    Full Text Available The aim of the study was to find whether voluntary induced high- and low-frequency peripheral fatigue exhibit specific alteration in surface EMG signal (SEMG during evoked and maximum voluntary contractions. Ten male students of physical education performed 60 s long stretch-shortening cycle (SSC exercise with maximal intensity and 30 s long concentric (CON exercise with maximal intensity. To verify voluntary induced peripheral fatigue, knee torques during low- (T20 and high-frequency electrical stimulation (T100 of relaxed vastus lateralis muscle (VL were obtained. Contractile properties of the VL were measured with passive twitch and maximal voluntary knee extension test (MVC. Changes in M-waves and SEMG during MVC test were used to evaluate the differences in myoelectrical signals. T100/T20 ratio decreased by 10.9 ± 8.4 % (p < 0.01 after the SSC exercise and increased by 35.9 ± 17.5 % (p < 0.001 after the CON exercise. Significant SEMG changes were observed only after the CON exercise where peak to peak time of the M-waves increased by 9.2 ± 13.3 % (p < 0.06, SEMG amplitude during MVC increased by 32.9 ± 21.6 % (p < 0.001 and SEMG power spectrum median frequency decreased by 11.0 ± 10.5 % (p < 0.05. It is concluded that high frequency fatigue wasn't reflected in SEMG, however the SEMG changes after the CON seemed to reflect metabolic changes due to acidosis

  9. Fatigue-related firing of muscle nociceptors reduces voluntary activation of ipsilateral but not contralateral lower limb muscles.

    Science.gov (United States)

    Kennedy, David S; Fitzpatrick, Siobhan C; Gandevia, Simon C; Taylor, Janet L

    2015-02-15

    During fatiguing upper limb exercise, maintained firing of group III/IV muscle afferents can limit voluntary drive to muscles within the same limb. It is not known if this effect occurs in the lower limb. We investigated the effects of group III/IV muscle afferent firing from fatigued ipsilateral and contralateral extensor muscles and ipsilateral flexor muscles of the knee on voluntary activation of the knee extensors. In three experiments, we examined voluntary activation of the knee extensors by measuring changes in superimposed twitches evoked by femoral nerve stimulation. Subjects attended on 2 days for each experiment. On one day a sphygmomanometer cuff occluded blood flow of the fatigued muscles to maintain firing of group III/IV muscle afferents. After a 2-min extensor contraction (experiment 1; n = 9), mean voluntary activation was lower with than without maintained ischemia (47 ± 19% vs. 87 ± 8%, respectively; P contraction (MVC) (experiment 2; n = 8), mean voluntary activation was also lower with than without ischemia (59 ± 21% vs. 79 ± 9%; P muscle afferents reduces voluntary activation of the fatigued muscle and nonfatigued antagonist muscles in the same leg. However, group III/IV muscle afferents from the fatigued left leg had no effect on the unfatigued right leg. This suggests that any "crossover" of central fatigue in the lower limbs is not mediated by group III/IV muscle afferents.

  10. Knee flexion with quadriceps cocontraction: A new therapeutic exercise for the early stage of ACL rehabilitation.

    Science.gov (United States)

    Biscarini, Andrea; Contemori, Samuele; Busti, Daniele; Botti, Fabio M; Pettorossi, Vito E

    2016-12-08

    Quadriceps strengthening exercises designed for the early phase of anterior cruciate ligament (ACL) rehabilitation should limit the anterior tibial translation developed by quadriceps contraction near full knee extension, in order to avoid excessive strain on the healing tissue. We hypothesize that knee-flexion exercises with simultaneous voluntary contraction of quadriceps (voluntary quadriceps cocontraction) can yield considerable levels of quadriceps activation while preventing the tibia from translating forward relative to the femur. Electromyographic activity in quadriceps and hamstring muscles was measured in 20 healthy males during isometric knee-flexion exercises executed near full knee extension with maximal voluntary effort of quadriceps cocontraction and external resistance (R) ranging from 0% to 60% of the 1-repetition maximum (1RM). Biomechanical modeling was applied to derive the shear (anterior/posterior) tibiofemoral force developed in each exercise condition. Isometric knee-flexion exercises with small external resistance (R=10% 1RM) and maximal voluntary effort of quadriceps cocontraction yielded a net posterior (ACL-unloading) tibial pull (P=0.005) and levels of activation of 32%, 50%, and 45% of maximum voluntary isometric contraction, for the rectus femoris, vastus medialis, and vastus lateralis, respectively. This exercise might potentially rank as one of the most appropriate quadriceps strengthening interventions in the early phase of ACL rehabilitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio.

    Science.gov (United States)

    Flansbjer, Ulla-Britt; Lexell, Jan

    2010-06-01

    To assess the reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio. A test-retest reliability study. Thirty men and women (mean age 63 (standard deviation 6.4) years) with verified late effects of polio. Knee extensor and flexor muscle strength in both lower limbs were measured twice 7 days apart using a Biodex dynamometer (isokinetic concentric contractions at 60 degrees /sec and isometric contractions with knee flexion angle 90 degrees) and a Leg Extension/Curl Rehab exercise machine with pneumatic resistance (HUR) (isotonic contractions). Reliability was assessed with the intraclass correlation coefficient (ICC1,1), the mean difference between the test sessions (d) together with the 95% confidence intervals for d, the standard error of measurement (SEM and SEM%), the smallest real difference (SRD and SRD%) and Bland-Altman graphs. Test-retest agreements were high, (ICC1,1 0.93-0.99) and measurement errors generally small. The SEM% was 4-14% and the SRD% 11-39%, with the highest values for the isokinetic measurements. Knee muscle strength can be measured reliably and can be used to detect real changes after an intervention for a group of persons with late effects of polio, whereas the values may be too high for single individuals or to detect smaller short-term changes over time for a group of individuals.

  12. Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

    National Research Council Canada - National Science Library

    Luna, Natália Mariana Silva; Alonso, Angelica Castilho; Brech, Guilherme Carlos; Mochizuki, Luis; Nakano, Eduardo Yoshio; Greve, Júlia Maria D'Andrea

    2012-01-01

    OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes. METHODS...

  13. Analyzing voluntary medical incident reports.

    Science.gov (United States)

    Gong, Yang; Richardson, James; Zhijian, Luan; Alafaireet, Patricia; Yoo, Illhoi

    2008-11-06

    Voluntary medical incident reports lacking consistency and accuracy impede the ultimate use of the reports for patient safety research. To improve this, two coders examined harm score usage in a voluntary medical incident reporting system where the harm scores were selected from a predefined list by different reporters. The two coders inter-rater agreement percent was 82%. The major categories and reviewed harm score jointly demonstrate that this process is critical and necessary in preparing the voluntary reports for further content and semantics analysis.

  14. Modelling the maximum voluntary joint torque/angular velocity relationship in human movement.

    Science.gov (United States)

    Yeadon, Maurice R; King, Mark A; Wilson, Cassie

    2006-01-01

    The force exerted by a muscle is a function of the activation level and the maximum (tetanic) muscle force. In "maximum" voluntary knee extensions muscle activation is lower for eccentric muscle velocities than for concentric velocities. The aim of this study was to model this "differential activation" in order to calculate the maximum voluntary knee extensor torque as a function of knee angular velocity. Torque data were collected on two subjects during maximal eccentric-concentric knee extensions using an isovelocity dynamometer with crank angular velocities ranging from 50 to 450 degrees s(-1). The theoretical tetanic torque/angular velocity relationship was modelled using a four parameter function comprising two rectangular hyperbolas while the activation/angular velocity relationship was modelled using a three parameter function that rose from submaximal activation for eccentric velocities to full activation for high concentric velocities. The product of these two functions gave a seven parameter function which was fitted to the joint torque/angular velocity data, giving unbiased root mean square differences of 1.9% and 3.3% of the maximum torques achieved. Differential activation accounts for the non-hyperbolic behaviour of the torque/angular velocity data for low concentric velocities. The maximum voluntary knee extensor torque that can be exerted may be modelled accurately as the product of functions defining the maximum torque and the maximum voluntary activation level. Failure to include differential activation considerations when modelling maximal movements will lead to errors in the estimation of joint torque in the eccentric phase and low velocity concentric phase.

  15. Differences in twitch potentiation between voluntary and stimulated quadriceps contractions of equal intensity.

    Science.gov (United States)

    Jubeau, M; Gondin, J; Martin, A; Van Hoecke, J; Maffiuletti, N A

    2010-02-01

    This study compared the extent of twitch and M-wave potentiation (POT) between voluntary and stimulated quadriceps contractions performed at the same intensity. Sixteen healthy men completed 10-s isometric knee extensions at 40% of the maximal voluntary contraction torque under electrical stimulation and voluntary conditions. Single stimuli were delivered to the femoral nerve to evoke twitches before (PRE) and from 3 to 600 s after the end of each conditioning contraction. Changes in twitch contractile properties and M-wave characteristics were compared between the conditions. The extent of twitch peak torque POT was smaller for the stimulated (122+/-20% of PRE) than for the voluntary condition (133+/-20% of PRE). The magnitude of POT for the maximal rate of twitch torque development was also smaller for the stimulated trial. Rectus femoris M-wave amplitude was potentiated by the voluntary but not by the stimulated contraction. It was concluded that stimulated contractions resulted in smaller twitch and M-wave POT than voluntary contractions, despite equivalent torque output and duration. The spatially and temporally fixed recruitment of motor units with electrical stimulation and therefore the lower number of activated motor units compared with voluntary actions of equal intensity could explain the present findings.

  16. Understanding the effect of speed of exertion on isokinetic strength using a multiaxial dynamometer.

    Science.gov (United States)

    Nimbarte, Ashish D; Aghazadeh, Fereydoun; Bogolu, Sai Chaitanya R; Rajulu, Sudhakar L

    2009-01-01

    In this study a multiaxial isokinetic dynamometer was used to measure strength during various upper-body isokinetic exertions. Ten male participants performed 7 different upper-body isokinetic exertions. In addition, to evaluate the effect of speed on strength, each participant performed sitting pull exertions at the speed of 0.026, 0.130, and 0.260 m/s. Average isokinetic strength increased from 236.6 +/- 39.1 to 291.8 +/- 65.8 N with the initial increase in speed from 0.026 to 0.130 m/s. The average isokinetic strength decreased to 276.7 +/- 87.2 N with a further increase in speed to 0.260 m/s. The curve between isokinetic strength and speed followed a bell-shaped curve (fitted with the Gaussian function, R(2) = .9). The results of this study could be useful in deciding on the work pace of various manual material handling tasks requiring maximal and/or near maximal exertions.

  17. The Notion of Voluntary Unemployment.

    Science.gov (United States)

    Standing, Guy

    1981-01-01

    Considers the distinction between voluntary and involuntary unemployment by analyzing six behavioral characteristics attributed to groups of workers suspected of indulging in the former, and the labor market mechanisms supposedly encouraging them. (Author/CT)

  18. The relationship between isokinetic quadriceps strength test and hop tests for distance and one-legged vertical jump test following anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Petschnig, R; Baron, R; Albrecht, M

    1998-07-01

    Isokinetic measurements and functional tests are often used to assess function following knee ligament reconstruction using the opposite limb as a control. However, the question of whether the uninvolved leg may serve as a reference on functional tests has not been adequately answered. In particular, the one-legged rebound vertical jump has not been used to assess functional levels following surgery of the cruciate ligament. The purposes of this study were: 1) to determine whether the uninvolved leg is within normal range of an age- and weight-matched group, 2) to determine differences between the involved and uninvolved leg in patients after anterior cruciate ligament reconstruction, 3) to examine the relationship between knee extensor strength and four functional performance tests, and 4) to determine if the one-legged rebound vertical jump yields more information in the assessment of knee function than the other functional tests with respect to two time-frames. Fifty healthy subjects (group A, mean age = 28.1 years) and 55 anterior cruciate ligament patients (groups B and C) participated in dynamometric measurement, one-legged and two-legged vertical jump, and the single- and the triple-hop test. Mean time for testing was 13 weeks following surgery for group B (N = 30, mean age = 27.8 years) and 54 weeks following surgery for group C (N = 25, mean age = 29.9 years). Pearson product moment correlation coefficients between peak torque and single and triple hop were r = .45, r = .48, r = .51, and r = .55 for groups B and C, respectively. Pearson product moment correlation coefficients between peak torque and the height of the vertical jump was r = .51 for group C. Results for group A revealed limb symmetry indices of 95% or more on all functional performance and isokinetic tests. In group B, all patients showed a limb symmetry index of less than 85% on all tests. In group C, the index for the vertical jump was the only functional test that fell below the level of

  19. Effects of underwater treadmill walking training on the peak torque of the knee in hemiplegic patients.

    Science.gov (United States)

    Lee, Dong-Geol; Jeong, Seong-Kwan; Kim, Young-Dong

    2015-09-01

    [Purpose] This study investigated the effects of underwater treadmill walking training on the peak torque of the knee in hemiplegic patients. [Subjects and Methods] Thirty-two subjects, who were randomly allocated to an experimental group (n=16) and a control group (n=16), performed underwater treadmill walking training and overground treadmill walking training, respectively, for 30 minutes/session, 3 sessions/week, for 6 weeks. An isokinetic dynamometer was used to assess the peak torque. [Results] The subjects in the experimental group showed an increase in the peak knee extension torque compared to the control group. [Conclusion] The results suggested that underwater treadmill walking training has a greater effect on peak knee extension torque at velocities of 60°/sec and 120°/sec than overground treadmill walking training.

  20. Hip Strength Deficits in People With Symptomatic Knee Osteoarthritis: A Systematic Review With Meta-analysis.

    Science.gov (United States)

    Deasy, Margaret; Leahy, Edmund; Semciw, Adam Ivan

    2016-08-01

    Study Design Systematic review with meta-analysis. Background A complete understanding of impairments associated with knee osteoarthritis would optimize exercise interventions for people with knee osteoarthritis. Our current understanding of hip strength deficits in this population is based on studies with conflicting findings and small samples. There is a need to systematically review and pool current evidence. Objectives To determine whether hip strength deficits exist in people with symptomatic knee osteoarthritis. Methods Electronic databases (MEDLINE, CINAHL, Embase, the Cochrane Library, and PsycINFO) were searched through February 2016. Studies comparing hip strength in people diagnosed with symptomatic knee osteoarthritis to healthy control participants were included in the review. A meta-analysis with random effects was applied to relevant data from included studies and a modified Grading of Recommendations Assessment, Development and Evaluation approach was used to evaluate the quality of evidence for each pooled analysis. Results Five studies were included in the review. Meta-analysis revealed moderate-quality evidence of weaker isometric and isokinetic hip abduction strength in people with knee osteoarthritis (moderate difference: 7% to 24% weaker) and very low-quality evidence of no difference in isometric hip adduction strength. There was very low- to moderate-quality evidence of weaker isokinetic hip strength in the remaining planes of motion (moderate to large differences: 14% to 55% weaker). Conclusion Significant hip strength deficits exist in people with knee osteoarthritis. Hip strength assessment should be considered in clinical practice and may assist with directing targeted management strategies. Level of Evidence Symptom prevalence, level 1a-. J Orthop Sports PhysTher 2016;46(8):629-639. Epub3 Jul 2016. doi:10.2519/jospt.2016.6618.

  1. Knee joint angle affects EMG-force relationship in the vastus intermedius muscle.

    Science.gov (United States)

    Saito, Akira; Akima, Hiroshi

    2013-12-01

    It is not understood how the knee joint angle affects the relationship between electromyography (EMG) and force of four individual quadriceps femoris (QF) muscles. The purpose of this study was to examine the effect of the knee joint angle on the EMG-force relationship of the four individual QF muscles, particularly the vastus intermedius (VI), during isometric knee extensions. Eleven healthy men performed 20-100% of maximal voluntary contraction (MVC) at knee joint angles of 90°, 120° and 150°. Surface EMG of the four QF synergists was recorded and normalized by the root mean square during MVC. The normalized EMG of the four QF synergists at a knee joint angle of 150° was significantly lower than that at 90° and 120° (P knee joint angle of 150°. Furthermore, the neuromuscular activation of the VI was the most sensitive to change in muscle length among the four QF synergistic muscles.

  2. Comparing Voluntary and Mandatory Gameplay

    Directory of Open Access Journals (Sweden)

    Esther Kuindersma

    2016-09-01

    Full Text Available Gameplay is commonly considered to be a voluntary activity. Game designers generally believe that voluntary gameplay is essentially different from mandatory gameplay. Such a belief may be a challenge for serious games, as instruction is usually mandatory. The article describes the outcomes of two experiments on the impact of voluntariness on the learning effect and enjoyment of a serious game. In the first experiment freedom of choosing to play a serious game was studied, with participants who had volunteered to participate. The results suggested that, contrary to the opinion of many game designers, being required to play a serious game does not automatically take the fun out of the game. The second experiment had voluntary participants and mandatory participants, who had to participate as part of a homework assignment. The outcomes show that mandatory participants enjoyed the game as much as the voluntary participants, even if they had to play the game for a minimum required time. These studies indicate that mandatory gameplay does not reduce enjoyment and learning effect.

  3. Voluntary organisation and adult education

    Directory of Open Access Journals (Sweden)

    Konrad Elsdon

    1998-12-01

    Full Text Available The author starts by offering a definition of voluntary organisations. He then discusses their importance and role, focusing on the issue of adult education wi­ thin these organisations. He also wells upon learning and change of voluntary organisation members, making use of the results of a study he conducted together with his collaborators. One of their fin­dings has been that voluntary organisati­ons, due to their organisational targets li­ke painting, singing or caring for people in need, lead their members to learning, i.e. essentially content learning. Moreo­ver, voluntary organisations offer a fair number of opportunities for social lear­ning and change. ln spite of the fact that the respondents were mostly not aware of the outcomes of their learning and change, careful listeners conducting the interview made them understand the im­portance of the learning they had gone through. The author concludes by poin­ ting out that formal education of adults can get its inspiration in learning in voluntary organisations. On the other hand, such learning would benefit greatly from findings and methods of formal education of adults.

  4. Muscle Damage following Maximal Eccentric Knee Extensions in Males and Females.

    Directory of Open Access Journals (Sweden)

    K M Hicks

    Full Text Available To investigate whether there is a sex difference in exercise induced muscle damage.Vastus Lateralis and patella tendon properties were measured in males and females using ultrasonography. During maximal voluntary eccentric knee extensions (12 reps x 6 sets, Vastus Lateralis fascicle lengthening and maximal voluntary eccentric knee extensions torque were recorded every 10° of knee joint angle (20-90°. Isometric torque, Creatine Kinase and muscle soreness were measured pre, post, 48, 96 and 168 hours post damage as markers of exercise induced muscle damage.Patella tendon stiffness and Vastus Lateralis fascicle lengthening were significantly higher in males compared to females (p0.05. Creatine Kinase levels post exercise induced muscle damage were higher in males compared to females (p<0.05, and remained higher when maximal voluntary eccentric knee extension torque, relative to estimated quadriceps anatomical cross sectional area, was taken as a covariate (p<0.05.Based on isometric torque loss, there is no sex difference in exercise induced muscle damage. The higher Creatine Kinase in males could not be explained by differences in maximal voluntary eccentric knee extension torque, Vastus Lateralis fascicle lengthening and patella tendon stiffness. Further research is required to understand the significant sex differences in Creatine Kinase levels following exercise induced muscle damage.

  5. Analysis of Interrelationships among Voluntary and Prosthetic Leg Joint Parameters Using Cyclograms

    Directory of Open Access Journals (Sweden)

    Nur Azah Hamzaid

    2017-04-01

    Full Text Available The walking mechanism of a prosthetic leg user is a tightly coordinated movement of several joints and limb segments. The interaction among the voluntary and mechanical joints and segments requires particular biomechanical insight. This study aims to analyze the inter-relationship between amputees' voluntary and mechanical coupled leg joints variables using cyclograms. From this analysis, the critical gait parameters in each gait phase were determined and analyzed if they contribute to a better powered prosthetic knee control design. To develop the cyclogram model, 20 healthy able-bodied subjects and 25 prosthesis and orthosis users (10 transtibial amputees, 5 transfemoral amputees, and 10 different pathological profiles of orthosis users walked at their comfortable speed in a 3D motion analysis lab setting. The gait parameters (i.e., angle, moment and power for the ankle, knee and hip joints were coupled to form 36 cyclograms relationship. The model was validated by quantifying the gait disparities of all the pathological walking by analyzing each cyclograms pairs using feed-forward neural network with backpropagation. Subsequently, the cyclogram pairs that contributed to the highest gait disparity of each gait phase were manipulated by replacing it with normal values and re-analyzed. The manipulated cyclograms relationship that showed highest improvement in terms of gait disparity calculation suggested that they are the most dominant parameters in powered-knee control. In case of transfemoral amputee walking, it was identified using this approach that at each gait sub-phase, the knee variables most responsible for closest to normal walking were: knee power during loading response and mid-stance, knee moment and knee angle during terminal stance phase, knee angle and knee power during pre-swing, knee angle at initial swing, and knee power at terminal swing. No variable was dominant during mid-swing phase implying natural pendulum effect of the

  6. Microprocessor prosthetic knees.

    Science.gov (United States)

    Berry, Dale

    2006-02-01

    This article traces the development of microprocessor prosthetic knees from early research in the 1970s to the present. Read about how microprocessor knees work, functional options, patient selection, and the future of this prosthetic.

  7. Prosthetic Knee Systems

    Science.gov (United States)

    ... Facebook Google Bookmarks Technorati Yahoo MyWeb Prosthetic Knee Systems Translated into plain language by Helen Osborne of ... Consulting Original article by Bill Dupes Prosthetic knee systems are among the most complex of all components. ...

  8. Partial knee replacement - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  9. Knee braces - unloading

    Science.gov (United States)

    ... most people talk about the arthritis in their knees, they are referring to a type of arthritis ... is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions ...

  10. Knee arthroscopy - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100117.htm Knee arthroscopy - series—Normal anatomy To use the sharing ... to slide 5 out of 5 Overview The knee is a complex joint made up of the ...

  11. Knee joint replacement - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series—Normal anatomy To use the ... to slide 4 out of 4 Overview The knee is a complex joint. It contains the distal ...

  12. Effect of low-level laser therapy on muscle adaptation to knee extensor eccentric training.

    Science.gov (United States)

    Baroni, Bruno Manfredini; Rodrigues, Rodrigo; Freire, Bruno Bolla; Franke, Rodrigo de Azevedo; Geremia, Jeam Marcel; Vaz, Marco Aurélio

    2015-03-01

    Eccentric training has been popularized for physical conditioning and prevention/rehabilitation of musculoskeletal disorders, especially due to the expressive responses in terms of muscular strength gain. In view of evidence that low-level laser therapy (LLLT) is able to increase exercise performance and accelerate post-exercise recovery, the aim of this study was to verify the effect of LLLT on hypertrophy and strengthening of knee extensor muscles submitted to eccentric training. Thirty healthy male subjects were randomized into three groups: Control Group (CG), Training Group (TG) and Training + LLLT Group (TLG). CG received no intervention, while TG and TLG were engaged on an 8-week knee extensor isokinetic eccentric training program. Only subjects from TLG were treated with LLLT (wavelength = 810 nm; power output = 200 mW; total dosage = 240 J) before each training session. Knee extensor muscle thickness and peak torque were assessed through ultrasonography and isokinetic dynamometry, respectively. CG presented no changes in any variable throughout the study, while eccentric training led to significant increases in muscle thickness and peak torque in TG and TLG. Subjects from TLG reached significantly higher percent changes compared to subjects from TG for sum of muscles' thicknesses (15.4 vs. 9.4%), isometric peak torque (20.5 vs. 13.7%), and eccentric peak torque (32.2 vs. 20.0%). LLLT applied before eccentric training sessions seems to improve the hypertrophic response and muscular strength gain in healthy subjects.

  13. Strength, balance, and the modifying effects of obesity and knee pain: results from the Observational Arthritis Study in Seniors (oasis).

    Science.gov (United States)

    Jadelis, K; Miller, M E; Ettinger, W H; Messier, S P

    2001-07-01

    To examine the relationship between muscular strength and dynamic balance in a sample of older adults with knee pain and to determine the role that obesity and severity of knee pain play in the ability to maintain balance. Cross-sectional study designed to examine the association between strength and balance in a cohort of older adults with chronic knee pain. A university health and exercise science center. A cohort of 480 adults age 65 and older with knee pain. Force platform dynamic balance measure of the center of pressure excursion during a forward and subsequent backward lean. Isokinetic strength measures of concentric and eccentric knee flexion and extension and concentric ankle plantar flexion and dorsiflexion. Body mass index (BMI) and a knee pain scale were used to measure obesity and knee pain, respectively. A regression model was developed to investigate the relationship between dynamic balance and muscular strength while controlling for gender, BMI, radiographic severity, knee pain, and foot length. Knee strength alone explained 18.4% of the variability in dynamic balance. The addition of knee pain, BMI, radiographic severity, gender, and foot length explained an additional 6.7%. When the knee-ankle interaction, ankle strength, and knee strength--pain interaction variables were added to the regression model, 28.9% of the variability in dynamic balance was explained. Strength appears to play a significant role in maintaining balance in an older, osteoarthritic population. We found that mean knee strength accounted for approximately 19% of the variability in dynamic balance. Hence, greater knee strength was associated with better dynamic balance. The best dynamic balance performances occurred in participants that had a combination of strong knees and strong ankles. However, knee osteoarthritic patients with weak knee strength could still maintain high levels of dynamic balance by having strong ankle strength. Moreover, we have shown that obesity is

  14. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty

    DEFF Research Database (Denmark)

    Holm, Bente; Kristensen, Morten T; Bencke, Jesper;

    2010-01-01

    To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA).......To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA)....

  15. Total knee arthroplasty

    DEFF Research Database (Denmark)

    Schrøder, Henrik M.; Petersen, Michael M.

    2016-01-01

    Total knee arthroplasty (TKA) is a successful treatment of the osteoarthritic knee, which has increased dramatically over the last 30 years. The indication is a painful osteoarthritic knee with relevant radiographic findings and failure of conservative measures like painkillers and exercise. Trea...

  16. The effect of fatigue on knee position sense is not dependent upon the muscle group fatigued.

    Science.gov (United States)

    Ribeiro, Fernando; Venâncio, João; Quintas, Pedro; Oliveira, José

    2011-08-01

    Muscle fatigue could have a greater impact on position sense when antagonists of the movement are fatigued. Hence, this study aimed to compare the effects of antagonist and agonist exercise-induced muscle fatigue on knee joint position sense. This within-subjects repeated-measures study included 40 subjects. Knee position sense and muscle strength were measured before and after two exercise protocols consisting of 30 consecutive maximal concentric/eccentric contractions of the knee extensors or flexors on the isokinetic dynamometer at an angular velocity of 180°/s (3.14 rad/s). Both exercise protocols increased the absolute angular error (F(1.78) = 39.89, P knee extensors protocol from 2.0 ± 1.3° to 3.5 ± 2.0°, knee flexors protocol from 2.1 ± 1.2° to 3.7 ± 2.2°), and no differences were detected between protocols (F(1.78) = 0.034, P = 0.855). No changes were observed in the relative angular error. Muscle fatigue affects knee position sense, and the deleterious effect is not different depending upon the muscle group fatigued. Copyright © 2011 Wiley Periodicals, Inc.

  17. Correlation between Quadriceps Endurance and Adduction Moment in Medial Knee Osteoarthritis.

    Directory of Open Access Journals (Sweden)

    Soon-Hyuck Lee

    Full Text Available It is not clear whether the strength or endurance of thigh muscles (quadriceps and hamstring is positively or negatively correlated with the adduction moment of osteoarthritic knees. This study therefore assessed the relationships between the strength and endurance of the quadriceps and hamstring muscles and adduction moment in osteoarthritic knees and evaluated predictors of the adduction moment. The study cohort comprised 35 patients with unilateral medial osteoarthritis and varus deformity who were candidates for open wedge osteotomy. The maximal torque (60°/sec and total work (180°/sec of the quadriceps and hamstring muscles and knee adduction moment were evaluated using an isokinetic testing device and gait analysis system. The total work of the quadriceps (r = 0.429, P = 0.037 and hamstring (r = 0.426, P = 0.045 muscles at 180°/sec each correlated with knee adduction moment. Preoperative varus deformity was positively correlated with adduction moment (r = 0.421, P = 0.041. Multiple linear regression analysis showed that quadriceps endurance at 180°/sec was the only factor independently associated with adduction moment (β = 0.790, P = 0.032. The adduction moment of osteoarthritic knees correlated with the endurance, but not the strength, of the quadriceps muscle. However, knee adduction moment did not correlate with the strength or endurance of the hamstring muscle.

  18. Combined application of neuromuscular electrical stimulation and voluntary muscular contractions.

    Science.gov (United States)

    Paillard, Thierry

    2008-01-01

    Electromyostimulation (EMS) and voluntary muscle contraction (VC) constitute different modes of muscle activation and induce different acute physiological effects on the neuromuscular system. Long-term application of each mode of muscle activation can produce different muscle adaptations. It seems theoretically possible to completely or partially cumulate the muscle adaptations induced by each mode of muscle activation applied separately. This work consisted of examining the literature concerning the muscle adaptations induced by long-term application of the combined technique (CT) [i.e. EMS is combined with VC - non-simultaneously] compared with VC and/or EMS alone in healthy subjects and/or athletes and in post-operative knee-injured subjects. In general, CT induced greater muscular adaptations than VC whether in sports training or rehabilitation. This efficiency would be due to the fact that CT can facilitate cumulative effects of training completely or partially induced by VC and EMS practiced alone. CT also provides a greater improvement of the performance of complex dynamic movements than VC. However, EMS cannot improve coordination between different agonistic and antagonistic muscles and thus does not facilitate learning the specific coordination of complex movements. Hence, EMS should be combined with specific sport training to generate neuromuscular adaptations, but also allow the adjustment of motor control during a voluntary movement. Likewise, in a therapeutic context, CT was particularly efficient to accelerate recovery of muscle contractility during a rehabilitation programme. Strength loss and atrophy inherent in a traumatism and/or a surgical operation would be more efficiently compensated with CT than with VC. Furthermore, CT also restored more functional abilities than VC. Finally, in a rehabilitation context, EMS is complementary to voluntary exercise because in the early phase of rehabilitation it elicits a strength increase, which is necessary

  19. The effect of knee joint angle on torque control.

    Science.gov (United States)

    Sosnoff, Jacob J; Voudrie, Stefani J; Ebersole, Kyle T

    2010-01-01

    The purpose of the author's investigation was to examine the effect of knee joint angle on torque control of the quadriceps muscle group. In all, 12 healthy adults produced maximal voluntary contractions and submaximal torque (15, 30, and 45% MVC [maximal voluntary contraction]) at leg flexion angles of 15 degrees , 30 degrees , 60 degrees , and 90 degrees below the horizontal plane. As expected, MVC values changed with respect to joint angle with maximum torque output being greatest at 60 degrees and least at 15 degrees . During the submaximal tasks, participants appropriately scaled their torque output to the required targets. Absolute variability (i.e., standard deviation) of torque output was greatest at 60 degrees and 90 degrees knee flexion. However, relative variability as indexed by coefficient of variation (CV) decreased as joint angle increased, with the greatest CV occurring at 15 degrees . These results are congruent with the hypothesis that joint angle influences the control of torque.

  20. Traumatic knee extension deficit (the locked knee)

    DEFF Research Database (Denmark)

    Helmark, I C; Neergaard, K; Krogsgaard, M R

    2007-01-01

    In the present study we investigated the validity of magnetic resonance imaging (MRI) and arthroscopy in knees with acute, traumatic extension deficit (the "locked knee"), and evaluated whether arthroscopy of knees with no mechanical pathology could be avoided by MRI evaluation. The study consisted...... of 50 patients who had an acute, traumatic extension deficit of the knee. All patients were submitted to MRI prior to arthroscopy. Following MRI and surgery, standardized forms were filled out, attempting to objectify the findings. The orthopaedic surgeon was not aware of the MRI result prior to surgery......, the following results were calculated for the overall appearance of a lesion able to cause locking: Positive predictive value = 0.85, negative predictive value = 0.77, sensitivity = 0.95, specificity = 0.53. Two knees were erroneously evaluated with no mechanical locking at MRI (one bucket-handle lesion and one...

  1. Knee Arthrodesis after failure of Knee Arthroplasty

    DEFF Research Database (Denmark)

    Gottfriedsen, Tinne B; Morville Schrøder, Henrik; Odgaard, Anders

    2016-01-01

    BACKGROUND: Arthrodesis is considered a salvage procedure after failure of a knee arthroplasty. Data on the use of this procedure are limited. The purpose of this study was to identify the incidence, causes, surgical techniques, and outcomes of arthrodesis after failed knee arthroplasty...... in a nationwide population. METHODS: Data were extracted from the Danish Civil Registration System, the Danish National Patient Register, and the Danish Knee Arthroplasty Register. A total of 92,785 primary knee arthroplasties performed in Denmark from 1997 to 2013 were identified by linking the data using....... Differences in cumulative incidence were compared with the Gray test. RESULTS: A total of 164 of the 165 arthrodeses were performed for causes related to failed knee arthroplasty. The 15-year cumulative incidence of arthrodesis was 0.26% (95% confidence interval, 0.21% to 0.31%). The 5-year cumulative...

  2. Voluntary euthanasia: a utilitarian perspective.

    Science.gov (United States)

    Singer, Peter

    2003-10-01

    Belgium legalised voluntary euthanasia in 2002, thus ending the long isolation of the Netherlands as the only country in which doctors could openly give lethal injections to patients who have requested help in dying. Meanwhile in Oregon, in the United States, doctors may prescribe drugs for terminally ill patients, who can use them to end their life--if they are able to swallow and digest them. But despite President Bush's oft-repeated statements that his philosophy is to 'trust individuals to make the right decisions' and his opposition to 'distant bureaucracies', his administration is doing its best to prevent Oregonians acting in accordance with a law that its voters have twice ratified. The situation regarding voluntary euthanasia around the world is therefore very much in flux. This essay reviews ethical arguments regarding voluntary euthanasia and physician-assisted suicide from a utilitarian perspective. I shall begin by asking why it is normally wrong to kill an innocent person, and whether these reasons apply to aiding a person who, when rational and competent, asks to be killed or given the means to commit suicide. Then I shall consider more specific utilitarian arguments for and against permitting voluntary euthanasia.

  3. Social Cohesion and Voluntary Associations

    Science.gov (United States)

    Heuser, Brian L.

    2005-01-01

    Voluntary organizations exert great influence over how social norms and ethical codes are guided into action. As such, they have a significant impact on societal levels of social cohesion. Although social capital involves generalized trust becoming manifest as spontaneous sociability, social cohesion is determined by how that sociability is…

  4. Voluntary Incentive Early Retirement Programs.

    Science.gov (United States)

    Research Dialogues, 1988

    1988-01-01

    Arrangements in educational institutions for voluntary early retirement programs are discussed. Retirement at any age can be a profound and stressful lifetime change; and it can also represent a welcome transition into newly satisfying and rewarding opportunities. The focus is on: mandatory retirement (exceptions and the new meaning of "early");…

  5. Voluntary disclosure: Evidence from UK

    NARCIS (Netherlands)

    N.S. Zourarakis (Nicolaos)

    2009-01-01

    textabstractThis paper investigates the voluntary disclosure of Intellectual Capital (IC) of British firms and provides some evidence on an unexplored area of the literature; that of the association of Corporate Governance (CG) with IC disclosure. Inconsistent with expectations, the results show tha

  6. Knee joint proprioception in ballet dancers and non-dancers.

    Science.gov (United States)

    Dieling, Simone; van der Esch, Martin; Janssen, Thomas W J

    2014-01-01

    The aim of this study was to evaluate the influence of upper-leg muscle fatigue on knee joint proprioception in 13 ballet dancers and 13 non-dancer controls. Proprioception acuity, expressed as position and motion sense, was measured with an isokinetic dynamometer. The position and motion sense assessments were prior to and immediately after an isokinetic upper-leg muscle fatigue protocol. Participants wore blindfolds for both tasks to eliminate vision, an inflated air splint on their lower leg to neutralize cutaneous sensation, and headphones with white noise during the motion sense task to eliminate auditory cues. Results showed no significant differences in position and motion sense between dancers and controls in the non-fatigued state. In the fatigued state no significant differences were found in position sense between dancers and controls, while controls increased significantly in motion sense error (p = 0.030) and ballet dancers showed no change in motion sense. It is concluded that position sense and motion sense acuity are not affected by muscle fatigue in dancers, but motion sense is affected by muscle fatigue in non-dancers.

  7. Voluntary sterilization in Serbia: Unmet need?

    OpenAIRE

    Rašević Mirjana M.

    2002-01-01

    Is voluntary sterilization as a birth control method accepted in Serbia? This is certainly a question that is being imposed for research, regardless of the fact that voluntary sterilization is neither accessible nor promoted. Most importantly because there is no understanding in the social nor political sphere for legalization of voluntary sterilization as a form of birth control, apart from the clear necessity for this, first, step. They are: the recognition that voluntary sterilization is a...

  8. Knee joint strength ratios and effects of hip position in rugby players.

    Science.gov (United States)

    Deighan, Martine A; Serpell, Benjamin G; Bitcon, Mark J; De Ste Croix, Mark

    2012-07-01

    Measures of knee joint function, although useful in predicting injury, can be misleading because hip position in traditional seated isokinetic tests is dissimilar to when injuries occur. This study aimed to determine the differences between seated and supine peak torques and strength ratios and examine the interaction of position with joint velocity. This was a cross-sectional, repeated measures study. Isokinetic knee extensor and flexor concentric and eccentric peak torque was measured seated and supine (10° hip flexion) at 1.04 and 3.14 rad·s(-1) in 11 Rugby players. Repeated measures analysis of variance and paired t-tests were used to analyze peak torques and strength ratios. Bonferroni post hoc, limits of agreement, and Pearson's correlation were applied. Seated peak torque was typically greater than that for supine for muscle actions and velocities. The values ranged from 109 ± 18 N·m (mean ± σ) for supine hamstring concentric peak torque at 1.04 rad·s(-1) to 330 ± 71 for seated quadriceps eccentric peak torque at 1.04 rad·s(-1). There was a significant position × muscle action interaction; eccentric peak torque was reduced more than concentric in the supine position. Knee joint strength ratios ranged from 0.47 ± 0.06 to 0.86 ± 0.23, with a significant difference in means between supine and seated positions for functional ratio at 3.14 rad·s(-1) observed; for seated it was 0.86 ± 0.23; and for supine, it was 0.68 ± 0.15 (p torques and knee joint strength ratios. Therefore, the hip angle should be nearer 10° when measuring knee joint function because this is more ecologically valid. Using similar protocols, sports practitioners can screen for injury and affect training to minimize injury.

  9. 22 CFR 513.210 - Voluntary exclusion.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Voluntary exclusion. 513.210 Section 513.210... GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (GRANTS) Effect of Action § 513.210 Voluntary exclusion. Persons who accept voluntary exclusions under § 513.315 are excluded in accordance with the terms of...

  10. A practical strategy for sEMG-based knee joint moment estimation during gait and its validation in individuals with cerebral palsy.

    Science.gov (United States)

    Kwon, Suncheol; Park, Hyung-Soon; Stanley, Christopher J; Kim, Jung; Kim, Jonghyun; Damiano, Diane L

    2012-05-01

    Individuals with cerebral palsy have neurological deficits that may interfere with motor function and lead to abnormal walking patterns. It is important to know the joint moment generated by the patient's muscles during walking in order to assist the suboptimal gait patterns. In this paper, we describe a practical strategy for estimating the internal moment of a knee joint from surface electromyography (sEMG) and knee joint angle measurements. This strategy requires only isokinetic knee flexion and extension tests to obtain a relationship between the sEMG and the knee internal moment, and it does not necessitate comprehensive laboratory calibration, which typically requires a 3-D motion capture system and ground reaction force plates. Four estimation models were considered based on different assumptions about the functions of the relevant muscles during the isokinetic tests and the stance phase of walking. The performance of the four models was evaluated by comparing the estimated moments with the gold standard internal moment calculated from inverse dynamics. The results indicate that an optimal estimation model can be chosen based on the degree of cocontraction. The estimation error of the chosen model is acceptable (normalized root-mean-squared error: 0.15-0.29, R: 0.71-0.93) compared to previous studies (Doorenbosch and Harlaar, 2003; Doorenbosch and Harlaar, 2004; Doorenbosch, Joosten, and Harlaar, 2005), and this strategy provides a simple and effective solution for estimating knee joint moment from sEMG.

  11. Core stability, knee muscle strength, and anterior translation are correlated with postural stability in anterior cruciate ligament-reconstructed patients.

    Science.gov (United States)

    Cinar-Medeni, Ozge; Baltaci, Gul; Bayramlar, Kezban; Yanmis, Ibrahim

    2015-04-01

    The purpose of this study was to investigate the relationship of postural stability and lower extremity performance with core stability, knee laxity, and muscle strength in patients with anterior cruciate ligament reconstruction. Twenty-eight anterior cruciate ligament-reconstructed subjects were included in the study. Anterior knee laxity tests, isokinetic knee muscle strength tests, and core stability tests were performed. Single-limb postural stability was assessed in both eyes-open and eyes-closed positions on a static surface and an eyes-open condition on a foam surface. A single-legged hop test was performed to assess lower extremity performance. To detect differences between the operated and healthy leg, a Mann-Whitney U test was performed, and a correlation analysis was performed using the Spearman correlation coefficient. Knee muscle strength and laxity were different between the operated and healthy legs (P stability scores correlated with core stability tests (P core stability, decreased knee muscle strength, and increased knee laxity correlated with single-limb postural stability. Better hop performance was demonstrated with better knee flexor and extensor muscle strength and was independent from core stability.

  12. RAPID HAMSTRINGS/QUADRICEPS STRENGTH CAPACITY IN PROFESSIONAL SOCCER PLAYERS WITH DIFFERENT CONVENTIONAL ISOKINETIC MUSCLE STRENGTH RATIOS

    Directory of Open Access Journals (Sweden)

    Camila C. Greco

    2012-09-01

    Full Text Available Muscle strength imbalance can be an important factor in hamstrings muscle strain. A hamstrings/quadriceps (H/Q strength ratio based on concentric peak torque values (Hcon:Qcon has traditionally been used to describe the potential for knee-joint destabilization. Because certain standard actions in soccer are explosive, the analysis of the H/Q strength ratio based on the rate of torque development (Hrtd:Qrtd might also be useful in the evaluation of joint stability. The objective of this study was to compare the Hrtd:Qrtd between professional soccer players with heterogeneous values of Hcon:Qcon. Thirty-nine professional soccer players took part in the following procedures on different days: 1 Familiarization session with the isokinetic dynamometer, and 2 Two maximal isometric actions and five maximal concentric actions at 60°·s-1 for hamstrings (H and quadriceps (Q. Participants were ranked according to their Hcon:Qcon ratio. The median third was excluded to form a high torque group (HTG, and a low torque group (LTG. Peak isometric (H and concentric (H and Q torques and rate of torque development (H were significantly greater in the HTG group. Similarly, Hcon:Qcon (0.68 ± 0.02 vs. 0.52 ± 0.03 and Hrtd:Qrtd (0.54 ± 0.12 vs. 0.43 ± 0.16 were significantly greater in the HTG group than in the LTG group. There was no significant correlation between Hcon:Qcon and Hrtd:Qrtd. It can be concluded that Hcon:Qcon and Hrtd:Qrtd are determined, but not fully defined, by shared putative physiological mechanisms. Thus, the physiologic and clinical significance of Hcon:Qcon and Hrtd:Qrtd to an athlete's individual evaluation might be different

  13. International Voluntary Renewable Energy Markets (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Heeter, J.

    2012-06-01

    This presentation provides an overview of international voluntary renewable energy markets, with a focus on the United States and Europe. The voluntary renewable energy market is the market in which consumers and institutions purchase renewable energy to match their electricity needs on a voluntary basis. In 2010, the U.S. voluntary market was estimated at 35 terawatt-hours (TWh) compared to 300 TWh in the European market, though key differences exist. On a customer basis, Australia has historically had the largest number of customers, pricing for voluntary certificates remains low, at less than $1 megawatt-hour, though prices depend on technology.

  14. A comparison of muscle stiffness and musculoarticular stiffness of the knee joint in young athletic males and females.

    Science.gov (United States)

    Wang, Dan; De Vito, Giuseppe; Ditroilo, Massimiliano; Fong, Daniel T P; Delahunt, Eamonn

    2015-06-01

    The objective of this study was to investigate the gender-specific differences in peak torque (PT), muscle stiffness (MS) and musculoarticular stiffness (MAS) of the knee joints in a young active population. Twenty-two male and twenty-two female recreational athletes participated. PT of the knee joint extensor musculature was assessed on an isokinetic dynamometer, MS of the vastus lateralis (VL) muscle was measured in both relaxed and contracted conditions, and knee joint MAS was quantified using the free oscillation technique. Significant gender differences were observed for all dependent variables. Females demonstrated less normalized PT (mean difference (MD)=0.4Nm/kg, p=0.005, η(2)=0.17), relaxed MS (MD=94.2N/m, pknee joint injury incidence and prevalence in females when compared to males.

  15. Isokinetic strength of the trunk Xexor muscles after surgical repair for incisional hernia

    NARCIS (Netherlands)

    D. den Hartog (Dennis); H.H. Eker (Hasan); W.E. Tuinebreijer (Wim); G.J. Kleinrensink (Gert Jan); H.J. Stam (Henk); J.F. Lange (Johan)

    2010-01-01

    textabstractPurpose The repair of incisional hernias can be accomplished by open or laparoscopic techniques. The Biodex® dynamometer measures muscle strength during isokinetic movement. The objectives of this study are to compare the strength of the trunk Xexors between patients who underwent repair

  16. Establishing isokinetic flow for a plasma torch exhaust gas diagnostic for a plasma hearth furnace

    Energy Technology Data Exchange (ETDEWEB)

    Pollack, B.R.

    1996-05-01

    Real time monitoring of toxic metallic effluents in confined gas streams can be accomplished through use of Microwave Induced Plasmas to perform atomic emission spectroscopy, For this diagnostic to be viable it is necessary that it sample from the flowstream of interest in an isokinetic manner. A method of isokinetic sampling was established for this device for use in the exhaust system of a plasma hearth vitrification furnace. The flow and entrained particulate environment were simulated in the laboratory setting using a variable flow duct of the same dimensions (8-inch diameter, schedule 40) as that in the field and was loaded with similar particulate (less than 10 {mu}m in diameter) of lake bed soil typically used in the vitrification process. The flow from the furnace was assumed to be straight flow. To reproduce this effect a flow straightener was installed in the device. An isokinetic sampling train was designed to include the plasma torch, with microwave power input operating at 2.45 GHz, to match local freestream velocities between 800 and 2400 ft/sec. The isokinetic sampling system worked as planned and the plasma torch had no difficulty operating at the required flowrates. Simulation of the particulate suspension was also successful. Steady particle feeds were maintained over long periods of time and the plasma diagnostic responded as expected.

  17. Isokinetic strength effects of FIFA'a "The 11+" injury prevention training programme

    DEFF Research Database (Denmark)

    Brito, João; Figueiredo, Pedro; Fernandes, Luís;

    2010-01-01

    times a week for 10 weeks. Isokinetic measurements were performed on the hamstrings and quadriceps muscles on both lower extremities at concentric 60 and 180°/s and eccentric 30°/s. The peak torque (PT) as well as conventional and dynamic control ratios (DCR) were calculated. Hamstrings PT in the non...

  18. Establishing isokinetic flow for a plasma torch exhaust gas diagnostic for a plasma hearth furnace

    Energy Technology Data Exchange (ETDEWEB)

    Pollack, Brian R. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    1996-05-01

    Real time monitoring of toxic metallic effluents in confined gas streams can be accomplished through use of Microwave Induced Plasmas to perform atomic emission spectroscopy, For this diagnostic to be viable it is necessary that it sample from the flowstream of interest in an isokinetic manner. A method of isokinetic sampling was established for this device for use in the exhaust system of a plasma hearth vitrification furnace. The flow and entrained particulate environment were simulated in the laboratory setting using a variable flow duct of the same dimensions (8-inch diameter, schedule 40) as that in the field and was loaded with similar particulate (less than 10 μm in diameter) of lake bed soil typically used in the vitrification process. The flow from the furnace was assumed to be straight flow. To reproduce this effect a flow straightener was installed in the device. An isokinetic sampling train was designed to include the plasma torch, with microwave power input operating at 2.45 GHz, to match local freestream velocities between 800 and 2400 ft/sec. The isokinetic sampling system worked as planned and the plasma torch had no difficulty operating at the required flowrates. Simulation of the particulate suspension was also successful. Steady particle feeds were maintained over long periods of time and the plasma diagnostic responded as expected.

  19. An Analysis of Isotonic and Isokinetic Strength-Training Methods and Techniques.

    Science.gov (United States)

    Metcalfe, Randall E.

    This annotated bibliography documents traditional isotonic strength training and nontraditional isotonic strength training (isokinetics) to aid the athletic coach in deciding which type and scheme of training will best develop strength. A glossary of terms is provided. Appendices include muscle action charts and tables, body position charts, a…

  20. Isokinetic Leg Flexion and Extension Strength of Elite Adolescent Female Track and Field Athletes.

    Science.gov (United States)

    Housh, Terry J.; And Others

    1984-01-01

    Adolescent female track-and-field athletes were measured to compare isokinetic strength of leg flexion and extension movements. Throwers, jumpers, middle-distance runners, and sprinters participated in the study. Throwers were found to be stronger in absolute strength, but there were no significant differences in relative strength. Results are…

  1. Use of isokinetic muscle strength as a measure of severity of rheumatoid arthritis

    DEFF Research Database (Denmark)

    Schiøttz-Christensen, Berit; Lyngberg, K; Keiding, N

    2001-01-01

    The aim of this study was to study the association between isokinetic muscle strength (IMS) and other clinical indicators of disability and disease activity in patients with rheumatoid arthritis (RA). A cohort of 36 RA patients was followed over a 1-year period with five measurements of disease a...

  2. Oxygenation and EMG in the proximal and distal vastus lateralis during submaximal isometric knee extension

    DEFF Research Database (Denmark)

    Crenshaw, Albert G.; Bronee, Lars; Krag, Ida

    2010-01-01

    /or (2) fatigue development. Nine males performed 2-min sustained isometric knee extensions at 15% and 30% maximum voluntary contraction during which oxygenation and EMG were recorded simultaneously from proximal and distal locations of the vastus lateralis muscle. Near infrared spectroscopy variables...

  3. RAPID KNEE-EXTENSIONS TO INCREASE QUADRICEPS MUSCLE ACTIVITY IN PATIENTS WITH TOTAL KNEE ARTHROPLASTY: A RANDOMIZED CROSS-OVER STUDY

    Science.gov (United States)

    Wilquin, Lousia; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders; Bandholm, Thomas

    2017-01-01

    Background Inhibition of the quadriceps muscle and reduced knee-extension strength is common shortly following total knee arthroplasty (weeks to months), due to reduced voluntary activation of the quadriceps muscle. In healthy subjects, strength training with heavy loads is known to increase agonist muscle activity, especially if the exercise is conducted using rapid muscle contractions. Purpose The purpose of this study was to examine if patients with total knee arthroplasty could perform rapid knee-extensions using a 10 RM load four to eight weeks after surgery, and the degree to which rapid knee-extensions were associated with greater voluntary quadriceps muscle activity during an experimental strength training session, compared to that elicited using slow knee-extensions. Study Design A randomized cross-over study. Methods Twenty-four patients (age 66.5) 4-8 weeks post total knee arthroplasty randomly performed one set of five rapid, and one set of five slow knee-extensions with the operated leg, using a load of their 10 repetition maximum, while surface electromyography recordings were obtained from the vastus medialis and lateralis of the quadriceps muscle. Results Data from 23 of the 24 included patients were analyzed. Muscle activity was significantly higher during rapid knee-extensions (120.2% [10th-90th percentile: 98.3-149.1]) compared to slow knee-extensions (106.0% [88.8-140.8]) for the vastus lateralis (pknee-extensions were performed at a median angular velocity of 19.7 degrees/sec (13.7-24.4) and 51.4 degrees/sec (28.9-63.1), respectively Conclusion Four to eight weeks after their total knee arthroplasty, the patients in the present study were able to conduct rapid knee-extensions according to the experimental protocol with an approximately doubled angular velocity compared to slow knee-extensions. This was associated with increased muscle activity in the vastus lateralis when compared to slow knee-extensions, but not in the vastus medialis. Whether

  4. Measuring postural control during mini-squat posture in men with early knee osteoarthritis.

    Science.gov (United States)

    Petrella, M; Gramani-Say, K; Serrão, P R M S; Lessi, G C; Barela, J A; Carvalho, R P; Mattiello, S M

    2017-02-06

    Studies have suggested a compromised postural control in individuals with knee osteoarthritis (OA) evidenced by larger and faster displacement of center of pressure (COP). However, quantification of postural control in the mini-squat posture performed by patients with early knee OA and its relation to muscle strength and self-reported symptoms have not been investigated. The main aim of this cross-sectional, observational, controlled study was to determine whether postural control in the mini-squat posture differs between individuals with early knee OA and a control group (CG) and verify the relation among knee extensor torque (KET) and self-reported physical function, stiffness and pain. Twenty four individuals with knee OA grades I and II (OAG) (mean age: 52.35±5.00) and twenty subjects without knee injuries (CG) (mean age: 51.40±8.07) participated in this study. Participants were assessed in postural control through a force plate (Bertec Mod. USA), which provided information about the anterior-posterior (AP) and medial-lateral (ML) COP displacement during the mini-squat, in isometric, concentric and eccentric knee extensor torque (KET) (90°/s) through an isokinetic dynamometer (BiodexMulti-Joint System3, Biodex Medical Incorporation, New York, NY, USA), and in self-reported symptoms through the WOMAC questionnaire. The main outcomes measured were the AP and ML COP amplitude and velocity of displacement; isometric, concentric, and eccentric KET and self-reported physical function, stiffness and pain. No significant differences were found between groups for postural control (p>0.05). Significant lower eccentric KET (p=0.01) and higher scores for the WOMAC subscales of pain (p=postural instability and the need to include quadriceps muscle strengthening, especially by eccentric contractions. The relationship between the self-reported symptoms and a lower and slower COP displacement suggest that the postural control strategy during tasks with a semi-flexed knee

  5. Angle- and gender-specific quadriceps femoris muscle recruitment and knee extensor torque.

    Science.gov (United States)

    Pincivero, Danny M; Salfetnikov, Yuliya; Campy, Robert M; Coelho, Alan J

    2004-11-01

    The objectives were to examine knee angle-, and gender-specific knee extensor torque output and quadriceps femoris (QF) muscle recruitment during maximal effort, voluntary contractions. Fourteen young adult men and 15 young adult women performed three isometric maximal voluntary contractions (MVC), in a random order, with the knee at 0 degrees (terminal extension), 10 degrees, 30 degrees, 50 degrees, 70 degrees, and 90 degrees flexion. Knee extensor peak torque (PT), and average torque (AT) were expressed in absolute (N m), relative (N m kg(-1)) and allometric-modeled (N m kg(-n)) units. Vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF) muscle EMG signals were full-wave rectified and integrated over the middle 3 s of each contraction, averaged over the three trials at each knee angle, and normalized to the activity recorded at 0 degrees. Muscle recruitment efficiency was calculated as the ratio of the normalized EMG of each muscle to the allometric-modeled average torque (normalized to the values at 0 degrees flexion), and expressed as a percent. Men generated significantly greater knee extensor PT and AT than women in absolute, relative and allometric-modeled units. Absolute and relative PT and AT were significantly highest at 70 degrees, while allometric-modeled values were observed to increase significantly across knee joint angles 10-90 degrees. VM EMG was significantly greater than the VL and RF muscles across all angles, and followed a similar pattern to absolute knee extensor torque. Recruitment efficiency improved across knee joint angles 10-90 degrees and was highest for the VL muscle. VM recruitment efficiency improved more than the VL and RF muscles across 70-90 degrees flexion. The findings demonstrate angle-, and gender-specific responses of knee extensor torque to maximal-effort contractions, while superficial QF muscle recruitment was most efficient at 90 degrees, and less dependent on gender.

  6. Imaging of knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Theodore T. [Department of Radiology, North Shore University Hospital, 825 Northern Blvd., Great Neck, NY 11021 (United States)]. E-mail: TMiller@NSHS.edu

    2005-05-01

    Knee replacement surgery, either with unicompartmental or total systems, is common. The purpose of this manuscript is to review the appearance of normal knee arthroplasty and the appearances of complications such as infection, polyethylene wear, aseptic loosening and particle-induced osteolysis, patellofemoral abnormalities, axial instability, and periprosthetic and component fracture. Knowledge of the potential complications and their imaging appearances will help the radiologist in the diagnostic evaluation of the patient with a painful knee arthroplasty.

  7. Estimation of Electrically-Evoked Knee Torque from Mechanomyography Using Support Vector Regression.

    Science.gov (United States)

    Ibitoye, Morufu Olusola; Hamzaid, Nur Azah; Abdul Wahab, Ahmad Khairi; Hasnan, Nazirah; Olatunji, Sunday Olusanya; Davis, Glen M

    2016-07-19

    The difficulty of real-time muscle force or joint torque estimation during neuromuscular electrical stimulation (NMES) in physical therapy and exercise science has motivated recent research interest in torque estimation from other muscle characteristics. This study investigated the accuracy of a computational intelligence technique for estimating NMES-evoked knee extension torque based on the Mechanomyographic signals (MMG) of contracting muscles that were recorded from eight healthy males. Simulation of the knee torque was modelled via Support Vector Regression (SVR) due to its good generalization ability in related fields. Inputs to the proposed model were MMG amplitude characteristics, the level of electrical stimulation or contraction intensity, and knee angle. Gaussian kernel function, as well as its optimal parameters were identified with the best performance measure and were applied as the SVR kernel function to build an effective knee torque estimation model. To train and test the model, the data were partitioned into training (70%) and testing (30%) subsets, respectively. The SVR estimation accuracy, based on the coefficient of determination (R²) between the actual and the estimated torque values was up to 94% and 89% during the training and testing cases, with root mean square errors (RMSE) of 9.48 and 12.95, respectively. The knee torque estimations obtained using SVR modelling agreed well with the experimental data from an isokinetic dynamometer. These findings support the realization of a closed-loop NMES system for functional tasks using MMG as the feedback signal source and an SVR algorithm for joint torque estimation.

  8. Recovery kinetics of knee flexor and extensor strength after a football match.

    Directory of Open Access Journals (Sweden)

    Dimitrios Draganidis

    Full Text Available We examined the temporal changes of isokinetic strength performance of knee flexor (KF and extensor (KE strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices or an experimental group (N = 20, participated also in a football match. Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12 h, 36 h and 60 h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant were measured on an isokinetic dynamometer at baseline and at 12 h, 36 h and 60 h after the match. Functional (KFecc/KEcon and conventional (KFcon/KEcon ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60 h after the match in the control group. In the experimental group: a isometric strength of knee extensors and knee flexors declined (P<0.05 at 12 h (both limbs and 36 h (dominant limb only, b eccentric and concentric peak torque of knee extensors and flexors declined (P<0.05 in both limbs for 36 h at 60°/s and for 60 h at 180°/s with eccentric peak torque of knee flexors demonstrating a greater (P<0.05 reduction than concentric peak torque, c strength deterioration was greater (P<0.05 at 180°/s and in dominant limb, d the functional ratio was more sensitive to match-induced fatigue demonstrating a more prolonged decline. Discriminant and regression analysis revealed that strength deterioration and recovery may be related to the amount of eccentric actions performed during the match and athletes' football-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players

  9. Muscle Damage following Maximal Eccentric Knee Extensions in Males and Females.

    Science.gov (United States)

    Hicks, K M; Onambélé, G L; Winwood, K; Morse, C I

    2016-01-01

    To investigate whether there is a sex difference in exercise induced muscle damage. Vastus Lateralis and patella tendon properties were measured in males and females using ultrasonography. During maximal voluntary eccentric knee extensions (12 reps x 6 sets), Vastus Lateralis fascicle lengthening and maximal voluntary eccentric knee extensions torque were recorded every 10° of knee joint angle (20-90°). Isometric torque, Creatine Kinase and muscle soreness were measured pre, post, 48, 96 and 168 hours post damage as markers of exercise induced muscle damage. Patella tendon stiffness and Vastus Lateralis fascicle lengthening were significantly higher in males compared to females (pexercise induced muscle damage (p>0.05). Creatine Kinase levels post exercise induced muscle damage were higher in males compared to females (peccentric knee extension torque, relative to estimated quadriceps anatomical cross sectional area, was taken as a covariate (pexercise induced muscle damage. The higher Creatine Kinase in males could not be explained by differences in maximal voluntary eccentric knee extension torque, Vastus Lateralis fascicle lengthening and patella tendon stiffness. Further research is required to understand the significant sex differences in Creatine Kinase levels following exercise induced muscle damage.

  10. 中国女子曲棍球运动员膝关节伸、屈肌群等速力量测试研究%Isokinetic strength of hamstring and quadriceps muscles in Chinese women hockey players

    Institute of Scientific and Technical Information of China (English)

    付颖; 闫琪

    2011-01-01

    通过对19名国家女子曲棍球队队员膝关节伸屈肌群的等速力量测试,探讨我国优秀女曲队员的下肢力量特点,为科学训练提供依据.结果表明:我国优秀女子曲棍运动员下肢屈肌力量较强,屈肌和伸肌群力量之间的比率(H/Q)比较合理;仅快速运动时(300°/s)弱侧屈膝肌群力量相对较弱,需加强该侧屈肌快速力量训练.%The isokinetic strength of hamstring and quadriceps muscles of 19 elite Chinese women hockey players were determined using Cybex 6000 system.The results indicated that the ratio of H/Q in these players was reasonable;the isokinetic strength of left knee flexors was lower at 300°/sec,and this speed strength would be enhanced.

  11. The effects of agonist and antagonist muscle activation on the knee extension moment-angle relationship in adults and children.

    Science.gov (United States)

    O'Brien, Thomas D; Reeves, Neil D; Baltzopoulos, Vasilios; Jones, David A; Maganaris, Constantinos N

    2009-08-01

    The present study examined the effect of agonist activation and antagonist co-activation on the shape of the knee extension moment-angle relationship in adults and children. Isometric knee extension maximum voluntary contractions (MVCs) were performed at every 5 degrees of knee flexion between 55 degrees and 90 degrees (full extension = 0 degrees) by ten men, ten women, ten boys and ten girls. For each trial, the knee extensors' voluntary activation level was quantified using magnetic stimulation and the level of antagonist co-activation was quantified from their electromyographical activity. Peak MVC moment was greater for men (264 +/- 63 N m) than women (177 +/- 60 N m), and greater for adults than children (boys 78 +/- 17 N m, girls 91 +/- 28 N m) (p architecture, and the pattern of the moment arm-angle relationship may in combination occur so that as children develop and mature into adults the shape of the moment-angle relationship is not altered.

  12. EFFECT OF DIFFERENT LEVELS OF LOCALIZED MUSCLE FATIGUE ON KNEE POSITION SENSE

    Directory of Open Access Journals (Sweden)

    William S. Gear

    2011-12-01

    Full Text Available There is little information available regarding how proprioceptive abilities decline as the amount of exertion increases during exercise. The purpose of this study was to determine the role of different levels of fatigue on knee joint position sense. A repeated measures design was used to examine changes in active joint reposition sense (AJRS prior to and following three levels of fatigue. Eighteen participants performed knee extension and flexion isokinetic exercise until torque output was 90%, 70%, or 50% of the peak hamstring torque for three consecutive repetitions. Active joint reposition sense at 15, 30, or 45 degrees was tested following the isokinetic exercise session. Following testing of the first independent measure, participants were given a 20 minute rest period. Testing procedures were repeated for two more exercise sessions following the other levels of fatigue. Testing of each AJRS test angle was conducted on three separate days with 48 hours between test days. Significant main effect for fatigue was indicated (p = 0.001. Pairwise comparisons indicated a significant difference between the pre-test and following 90% of peak hamstring torque (p = 0.02 and between the pre-test and following 50% of peak hamstring torque (p = 0.02. Fatigue has long been theorized to be a contributing factor in decreased proprioceptive acuity, and therefore a contributing factor to joint injury. The findings of the present study indicate that fatigue may have an effect on proprioception following mild and maximum fatigue.

  13. Isokinetic performance capacity of trunk muscles. Part II: Coefficient of variation in isokinetic measurement in maximal effort and in submaximal effort.

    Science.gov (United States)

    Luoto, S; Hupli, M; Alaranta, H; Hurri, H

    1996-12-01

    It has been claimed that with the aid of isokinetic trunk strength measuring devices it is possible to distinguish true muscular weakness from submaximal effort in the test. This proposition is based on the presumption that in the isokinetic trunk strength test identical performances can only be reproduced by maximal effort. The purpose of this study was to investigate whether it is possible to distinguish maximal effort from submaximal with the aid of the coefficient of variation (CV) in an isokinetic trunk muscle strength test. The study group included 35 (21 male and 14 female) subjects of whom 12 were healthy, 10 had a mild low-back pain and 13 had a more severe chronic low-back pain. The subjects performed five consecutive bendings both with maximal (100%) and submaximal (50%) efforts at a speed of 90 degrees/second. In maximal effort only healthy subjects reached an average level of CV close to 10% both in extension and in flexion. In the chronic low-back pain group the average CV was close to 20%. The difference in CV was statistically significant (p < 0.05-0.02) between the healthy and the chronic low-back pain subjects. In the submaximal effort all health groups had a CV of approximately 20% or more and no significant differences were found. The group of slightly variable measurements (CV = 11-20%) was remarkably large in both the maximal and submaximal effort. The results suggest that an effort with a CV of 11-20% cannot be classified as definitely submaximal or maximal. When the CV is less than 10% the effort can be fairly certainly classified as maximal.

  14. 78 FR 49382 - Voluntary Education Programs

    Science.gov (United States)

    2013-08-14

    ... English, reading, writing, speaking, mathematics, and computer skills that are essential to successful job... education advisor: Education Services Specialist, Education Services Officer (ESO), Voluntary...

  15. Pneumatic osteoarthritis knee brace.

    Science.gov (United States)

    Stamenović, Dimitrije; Kojić, Milos; Stojanović, Boban; Hunter, David

    2009-04-01

    Knee osteoarthritis is a chronic disease that necessitates long term therapeutic intervention. Biomechanical studies have demonstrated an improvement in the external adduction moment with application of a valgus knee brace. Despite being both efficacious and safe, due to their rigid frame and bulkiness, current designs of knee braces create discomfort and difficulties to patients during prolonged periods of application. Here we propose a novel design of a light osteoarthritis knee brace, which is made of soft conforming materials. Our design relies on a pneumatic leverage system, which, when pressurized, reduces the excessive loads predominantly affecting the medial compartment of the knee and eventually reverses the malalignment. Using a finite-element analysis, we show that with a moderate level of applied pressure, this pneumatic brace can, in theory, counterbalance a greater fraction of external adduction moment than the currently existing braces.

  16. Musculoskeletal MR: knee

    Energy Technology Data Exchange (ETDEWEB)

    Staebler, A.; Glaser, C.; Reiser, M. [Dept. of Diagnostic Radiology, Klinikum Grosshadern, Ludwig-Maximilian Universitaet Muenchen (Germany)

    2000-02-01

    Magnetic resonance imaging is the most sensitive, specific, and accurate noninvasive method for diagnosing internal derangement of the knee. During the past 15 years knowledge of pathologic conditions of the knee had evolved significantly. Beyond the basic principles of imaging knee injuries great impact was made on the understanding of indirect or collateral findings, even in rare diseases. In this article the spectrum of disorders of the knee are reviewed and an overview of the current literature is given. This includes considerations about how to achieve a high-standard MR imaging study of the knee, and principles of imaging anterior cruciate ligament and meniscal tears. A focus is put on distinct diseases including intra-articular and intraosseous ganglion cysts, iliotibial band friction syndrome, transient osteoporosis, osteonecrosis, osteochondritis dissecans, and imaging of the articular cartilage. (orig.)

  17. Dynamics of Voluntary Cough Maneuvers

    Science.gov (United States)

    Naire, Shailesh

    2008-11-01

    Voluntary cough maneuvers are characterized by transient peak expiratory flows (PEF) exceeding the maximum expiratory flow-volume (MEFV) curve. In some cases, these flows can be well in excess of the MEFV, generally referred to as supramaximal flows. Understanding the flow-structure interaction involved in these maneuvers is the main goal of this work. We present a simple theoretical model for investigating the dynamics of voluntary cough and forced expiratory maneuvers. The core modeling idea is based on a 1-D model of high Reynolds number flow through flexible-walled tubes. The model incorporates key ingredients involved in these maneuvers: the expiratory effort generated by the abdominal and expiratory muscles, the glottis and the flexibility and compliance of the lung airways. Variations in these allow investigation of the expiratory flows generated by a variety of single cough maneuvers. The model successfully reproduces PEF which is shown to depend on the cough generation protocol, the glottis reopening time and the compliance of the airways. The particular highlight is in simulating supramaximal PEF for very compliant tubes. The flow-structure interaction mechanisms behind these are discussed. The wave speed theory of flow limitation is used to characterize the PEF. Existing hypotheses of the origin of PEF, from cough and forced expiration experiments, are also tested using this model.

  18. Respostas cardiovasculares durante avaliação muscular isocinética em claudicantes Cardiovascular responses during isokinetic muscle assessment in claudicant patients

    Directory of Open Access Journals (Sweden)

    Lucas Caseri Câmara

    2010-10-01

    Full Text Available FUNDAMENTO: A dinamometria isocinética tem tido crescente importância para avaliação da função muscular em indivíduos com claudicação intermitente. No entanto, ainda há escassez de informações sobre as respostas cardiovasculares desses doentes durante este tipo de avaliação. OBJETIVO: Avaliar e comparar as respostas cardiovasculares na avaliação da força e resistência muscular de dois exercícios comumente utilizados para de pacientes com CI (flexão plantar/dorsiflexão e flexão/extensão de joelhos. MÉTODOS: Dezessete claudicantes com doença estável há pelo menos 6 meses compuseram a amostra avaliada no dinamômetro isocinético. Frequência cardíaca, pressão arterial e duplo produto foram mensurados não invasivamente em repouso e no pico do esforço, em protocolos específicos para avaliação de força e resistência muscular. RESULTADOS: Com exceção da pressão arterial diastólica, a frequência cardíaca, pressão arterial sistólica e o duplo produto aumentaram durante o exercício em comparação ao repouso (p BACKGROUND: Isokinetic dynamometry is becoming increasingly important for the assessment of muscle function in individuals with intermittent claudication. However, there is still little information available about the cardiovascular responses of these patients during this type of assessment. OBJECTIVE: To assess and compare the cardiovascular responses recorded during the assessment of muscle strength and endurance for two exercises commonly used in patients with IC (plantar flexion/dorsiflexion and knee flexion/extension. METHODS: The sample consisted of 17 claudicant patients with stable disease for at least 6 months. During the isokinetic dynamometer testing, non-invasive measurements of heart rate, blood pressure and double product at rest and at peak exertion were obtained according to specific protocols established for muscle strength and endurance assessment. RESULTS: Except for diastolic blood

  19. Characteristics of flexed knee gait and functional outcome of a patient who underwent knee reconstruction with a hingeless prosthesis for bone tumor resection: a case report with gait analysis and comparison with healthy subjects.

    Science.gov (United States)

    Okita, Y; Tatematsu, N; Nagai, K; Nakayama, T; Nakamata, T; Okamoto, T; Toguchida, J; Ichihashi, N; Tsuboyama, T

    2013-12-01

    We report on a patient after knee reconstruction for osteosarcoma in the distal femur using a hingeless prosthesis K-MAX KNEE system K-5 who walked without ipsilateral knee extension in the latter half of the stance phase (flexed knee gait). We evaluated the patient using three-dimensional gait analysis and isokinetic knee strength measurement, and compared the patient with five healthy subjects. The Musculoskeletal Tumor Society (MSTS) score was also used for evaluation. The patient kept his operated knee flexed during mid stance. The maximal ankle plantarflexion internal moment was lower on the ipsilateral side than on the contralateral side, and lower than in the healthy subjects. The negative ankle power during the stance phase was generally stronger on the ipsilateral side than on the contralateral side, and also in the healthy subjects. Unusual contralateral hip flexion occurred after the initial contact, indicating increased joint load on the ipsilateral ankle and the contralateral hip. The ratios of the peak knee extension/flexion torque were 0.7 on the ipsilateral side, 1.9 on the contralateral side, and 1.7 in the healthy subjects. The MSTS score of the patient was 23/30 (76.6%). Flexed knee gait might account for the reduction of ipsilateral hip flexion and ankle plantarflexion moment during the late stance phase. These results suggest the importance of focusing more on the ipsilateral ankle joint and the contralateral hip joint to maintain the function of the entire limb joints of the patients with flexed knee gait.

  20. Muscular function and functional mobility of faller and non-faller elderly women with osteoarthritis of the knee

    OpenAIRE

    Alencar,M.A.; Arantes,P.M.M.; Dias,J.M.D.; Kirkwood, R.N.; L.S.M. Pereira; R.C. Dias

    2007-01-01

    Falls are a major concern in the elderly population with chronic joint disease. To compare muscular function and functional mobility among older women with knee osteoarthritis with and without a history of falls, 15 elderly women with a history of falls (74.20 ± 4.46 years) and 15 without a history of falls (71.73 ± 4.73 years) were studied. Muscular function, at the angular speed of 60, 120, and 180º/s, was evaluated using the Biodex Isokinetic Dynamometer. The sit-to-stand task was performe...

  1. 等速肌力训练对脑卒中偏瘫患者下肢功能恢复的影响%Effect of isokinetic exercise on lower limb function recovery of hemiplegic patients

    Institute of Scientific and Technical Information of China (English)

    杨华中; 吴莹莹; 周永生; 邓雯娇

    2015-01-01

    目的::观察等速肌力训练对偏瘫患者下肢功能恢复的影响。方法:将我院收治的40例偏瘫患者随机分为观察组和对照组各20例,对照组采用常规康复训练,包括运动治疗(神经促进疗法、平衡功能训练、等张肌力训练、桥式运动、重心转移训练、步态训练、协调与运动控制训练等)、作业治疗、传统康复疗法、物理因子治疗。观察组在常规康复训练的基础上增加偏瘫下肢屈、伸膝肌群等速肌力训练,测试及训练模式为普通等速向心/向心模式。治疗前后分别采用等速肌力测试训练仪的峰力矩值(PT)、Fugl-Meyer 运动功能评分、功能独立性评分、Berg 平衡功能评分及改良 Ashworth 肌痉挛分级(MAS)对患者下肢肌痉挛及功能情况进行分析。结果:治疗10周后,2组患者膝关节伸屈膝肌 PT、Fugl-Meyer 评分、Berg 评分及 FIM 评分均较治疗前明显提高,且观察组更高于对照组(P <0.05)。治疗前后 2组患者肌痉挛 MAS 评分组间及组内比较差异均无统计学意义。结论:等速肌力训练对偏瘫患者下肢功能恢复有明显改善作用。%Objective:To investigate the effect of isokinetic exercise on lower limb function recovery of hemiplegia patients.Methods:Forty hemiplegic patients in XiangYa BoAi Rehabilitation Hospital were randomly divided into experimental group and control group.All the cases accepted routine rehabilitation exercise,including therapeutic exercise (neuromuscular facilitation technique,balance exercise,isotonic exercise,bridge motion,transfer exercise, coordination and motor control training,etc),occupational therapy,traditional Chinese medicine rehabilitation ther-apy and physiatrics.The experimental group additionally accepted isokinetic exercise for knee flexion & extension muscles of the hemiplegic side.After therapy,their lower limb function was measured by isokinetic peak torque, Fugl-Meyer motor functional score

  2. Effects of the training status on the hormonal response and recovery from high-intensity isokinetic exercise: comparisons between endurance-trained athletes and sedentary subjects.

    Science.gov (United States)

    Minetto, M A; Paccotti, P; Borrione, P; Massazza, G; Ventura, M; Termine, A; Di Luigi, L; Pigozzi, F; Angeli, A

    2006-09-01

    Aims of the study were: to determine the differences in the mechanical, hormonal and lactate responses to a high-intensity isokinetic exercise in two groups of endurance-trained athletes (EA, n = 11) and sedentary subjects (SED, n = 11); to evaluate the relationships between the hormonal and lactate responses; to evaluate the effects of the training status on the pituitary responsiveness to the exercise. EA and SED completed, for each leg, 4 sets of 20 maximal concentric contractions of the knee extensor muscle groups at 180 degrees s-1 angular velocity. Blood and saliva for hormonal and lactate determinations were sampled before, immediately after the test and during the subsequent recovery of 2 hours. The exercise was completed by all subjects and elicited significant mechanical and biochemical responses both in EA and in SED subjects. No differences were found between the two groups both in the mechanical performances and in the increases of lactate and hormones of the pituitary-adrenal axis or in the comparison of the slopes of adrenocorticotropic hormone (ACTH), cortisol, and dehydroepiandrosterone recovery after the peak. The correlation analyses showed significant positive relationships between lactate peak values and percentages of change for ACTH (r2 = 0.16, P training status on the pituitary responsiveness to exercise was evident, as it was indirectly confirmed by no abnormalities in the rates of hormonal recovery after the exercise session.

  3. An analytical model of the knee for estimation of internal forces during exercise.

    Science.gov (United States)

    Zheng, N; Fleisig, G S; Escamilla, R F; Barrentine, S W

    1998-10-01

    An analytical model of the knee joint was developed to estimate the forces at the knee during exercise. Muscle forces were estimated based upon electromyographic activities during exercise and during maximum voluntary isometric contraction (MVIC), physiological cross-sectional area (PCSA), muscle fiber length at contraction and the maximum force produced by an unit PCSA under MVIC. Tibiofemoral compressive force and cruciate ligaments' tension were determined by using resultant force and torque at the knee, muscle forces, and orientations and moment arms of the muscles and ligaments. An optimization program was used to minimize the errors caused by the estimation of the muscle forces. The model was used in a ten-subject study of open kinetic chain exercise (seated knee extension) and closed kinetic chain exercises (leg press and squat). Results calculated with this model were compared to those from a previous study which did not consider muscle length and optimization. Peak tibiofemoral compressive forces were 3134 +/- 1040 N during squat, 3155 +/- 755 N during leg press and 3285 +/- 1927 N during knee extension. Peak posterior cruciate ligament tensions were 1868 +/- 878 N during squat, 1866 +/- 383 N during leg press and 959 +/- 300 N for seated knee extension. No significant anterior cruciate ligament (ACL) tension was found during leg press and squat. Peak ACL tension was 142 +/- 257 N during seated knee extension. It is demonstrated that the current model provided better estimation of knee forces during exercises, by preventing significant overestimates of tibiofemoral compressive forces and cruciate ligament tensions.

  4. The Change in Knee Angle during the Gait by Applying Elastic Tape to the Skin

    Science.gov (United States)

    Yamamoto, Hiroyuki

    2014-01-01

    [Purpose] The aim of this study was to verify how the application of elastic tape to the anterior surface of the thigh changes the knee angle pattern during gait. [Subjects] The subjects were 10 people who showed an abnormal knee angle change pattern during usual walking. They did not show the so-called double knee action. [Methods] Subjects were asked to walk as usual, and then to walk with elastic tape attached to the anterior surface of the thigh. The knee angle was measured during gait with an electronic goniometer. We graphed the temporal changes of the knee angle and compared them with the normal gait pattern. [Results] The knee angle gait pattern of six of the 10 subjects improved after application of the tape and became like a normal gait pattern. The changes in the knee angle resulted from a stimulus via the skin, rather than voluntary muscular adjustment, suggesting that the changes may have originated due to differences in reflexive tensile strength. [Conclusion] In normal speed gait, it is suggested that the knee angle was altered such that it exhibited a normal pattern by applying elastic tape to the anterior surface of the thigh. We suspect that application of the elastic tape may change the muscle tonus. PMID:25140100

  5. Older Adults without Radiographic Knee Osteoarthritis: Knee Alignment and Knee Range of Motion

    OpenAIRE

    Lissa Fahlman; Emmeline Sangeorzan; Nimisha Chheda; Daphne Lambright

    2014-01-01

    This study describes knee alignment and active knee range of motion (ROM) in a community-based group of 78-year old adults (n = 143) who did not have radiographic evidence of knee osteoarthritis in either knee (KL 0.001) than women with varus or...

  6. 75 FR 47504 - Voluntary Education Programs

    Science.gov (United States)

    2010-08-06

    ... America. TTT helps relieve teacher shortages, especially in math, science, special education, and other... of the Secretary 32 CFR Part 68 RIN 0790-AI50 Voluntary Education Programs AGENCY: Office of the... for the operation of voluntary education programs within DoD. Included are: Procedures for Service...

  7. Pedagogical Aspects of Voluntary School Work

    Science.gov (United States)

    Mária Jármai, Erzsébet; Palányi, Ildikó Zsupanekné

    2015-01-01

    The economic importance of voluntary work has been exceedingly appreciated in the last few decades. This is not surprising at all, because it is highly profitable according to the related estimated data. There are 115,9 million people doing voluntary work only in Europe, which means that they would create the world's 7th biggest economy with EUR…

  8. 14 CFR 234.7 - Voluntary reporting.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Voluntary reporting. 234.7 Section 234.7 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIRLINE SERVICE QUALITY PERFORMANCE REPORTS § 234.7 Voluntary reporting. (a) In addition to the...

  9. Changing Dynamics in the Voluntary Market (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Heeter, J.

    2014-12-01

    Voluntary green power markets are those in which consumers and institutions voluntarily purchase renewable energy to match their electricity needs. This presentation, presented at the Renewable Energy Markets Conference in December 2014, outlines the voluntary market in 2013, including community choice aggregation and community solar.

  10. 12 CFR 546.4 - Voluntary dissolution.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Voluntary dissolution. 546.4 Section 546.4... ASSOCIATIONS-MERGER, DISSOLUTION, REORGANIZATION, AND CONVERSION § 546.4 Voluntary dissolution. A Federal savings association's board of directors may propose a plan for dissolution of the association. The plan...

  11. Neuromuscular and muscle-tendon system adaptations to isotonic and isokinetic eccentric exercise.

    Science.gov (United States)

    Guilhem, G; Cornu, C; Guével, A

    2010-06-01

    To present the properties of an eccentric contraction and compare neuromuscular and muscle-tendon system adaptations induced by isotonic and isokinetic eccentric trainings. An eccentric muscle contraction is characterized by the production of muscle force associated to a lengthening of the muscle-tendon system. This muscle solicitation can cause micro lesions followed by a regeneration process of the muscle-tendon system. Eccentric exercise is commonly used in functional rehabilitation for its positive effect on collagen synthesis but also for resistance training to increase muscle strength and muscle mass in athletes. Indeed, eccentric training stimulates muscle hypertrophy, increases the fascicle pennation angle, fascicles length and neural activation, thus inducing greater strength gains than concentric or isometric training programs. Eccentric exercise is commonly performed either against a constant external load (isotonic) or at constant velocity (isokinetic), inducing different mechanical constraints. These different mechanical constraints could induce structural and neural adaptive strategies specific to each type of exercise. The literature tends to show that isotonic mode leads to a greater strength gain than isokinetic mode. This observation could be explained by a greater neuromuscular activation after IT training. However, the specific muscle adaptations induced by each mode remain difficult to determine due to the lack of standardized, comparative studies. 2010 Elsevier Masson SAS. All rights reserved.

  12. Effect of unilateral exercise on spinal and pelvic deformities, and isokinetic trunk muscle strength.

    Science.gov (United States)

    Jeon, Kyoungkyu; Kim, Soonyoung

    2016-03-01

    [Purpose] The purpose of this study was to collect basic data regarding the prevention of spinal and pelvic deformities by investigating the spinal shape and muscular function characteristics of imbalance reduction and functional improvement following asymmetric activities. [Subjects and Methods] The subjects were 14 archery athletes who mostly perform unilateral motion with spinal and pelvic pain, and 19 healthy subjects. All the participants were evaluated using spinal structure analysis and for 60°/sec isokinetic muscular strength of the trunk. [Results] Between the two groups, there were significant differences in the interaction effect of trunk inclination deformities, and flexor and extensor 60°/sec isokinetic muscular strength of the trunk. Also, the main effects of gender comparison showed significant differences in the trunk inclination deformities, pelvic rotation deformities, lordosis angles, and flexor and extensor 60 ˚/sec isokinetic muscular strengths of the trunk. [Conclusion] The basic data obtained in this study can be used to help develop a strategic exercise program for improving unilateral movement and malalignment of the spine and pelvis.

  13. Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

    Directory of Open Access Journals (Sweden)

    Natália Mariana Silva Luna

    2012-09-01

    Full Text Available OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes. METHODS: Seventy-five males with a mean age of 30.26 (±6.5 years were divided into three groups: a triathlete group (n=26, a long-distance runner group (n = 23, and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer. RESULTS: The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180º/s was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60º/s was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups. CONCLUSIONS: The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners.

  14. Proprioceptive accuracy in women with early and established knee osteoarthritis and its relation to functional ability, postural control, and muscle strength.

    Science.gov (United States)

    Baert, Isabel A C; Mahmoudian, Armaghan; Nieuwenhuys, Angela; Jonkers, Ilse; Staes, Filip; Luyten, Frank P; Truijen, Steven; Verschueren, Sabine M P

    2013-09-01

    The purpose of this study was to identify differences in knee proprioceptive accuracy between subjects with early knee osteoarthritis (OA), established knee OA, and healthy controls. Furthermore, the relation between proprioceptive accuracy on the one hand and functional ability, postural balance, and muscle strength on the other hand was also explored. New MRI-based classification criteria showing evidence of beginning joint degeneration have been used to identify subjects with early knee OA. A total of 45 women with knee OA (early OA, n = 21; established OA, n = 24) and 20 healthy female control subjects participated in the study. Proprioceptive accuracy was evaluated using the repositioning error of a knee joint position sense test using a three-dimensional motion analysis system. Subjective and objective functional ability was assessed by the knee injury and osteoarthritis outcome score, the timed "Up & Go" test, and the stair climbing test. The sensory organization test measured postural control. Muscle strength was measured by isokinetic dynamometry. Early OA subjects showed no significant differences in proprioceptive accuracy compared to healthy controls. In contrast, established OA subjects showed a higher repositioning error compared to early OA subjects (+29 %, P = 0.033) and healthy controls (+25 %, P = 0.068). Proprioceptive accuracy was not significantly associated with functional ability, postural balance, and muscle strength. Knee joint proprioceptive deficits were observed in established OA but not in early OA, suggesting that impaired proprioception is most likely a consequence of structural degeneration, rather than a risk factor in the pathogenesis of knee OA. Impaired proprioceptive accuracy was not associated with disease-related functionality in knee OA patients. Treatment strategies designed to address proprioceptive deficits may be not effective in prevention of knee OA progression and may have no impact on patients

  15. Kinesio Taping effects on knee extension force among soccer players

    Directory of Open Access Journals (Sweden)

    Maysa V. G. B. Serra

    2015-04-01

    Full Text Available Background : Kinesio Taping (KT is widely used, however the effects of KT on muscle activation and force are contradictory. Objective : To evaluate the effects of KT on knee extension force in soccer players. Method: This is a clinical trial study design. Thirty-four subjects performed two maximal isometric voluntary contractions of the lower limbs pre, immediately post, and 24 hours after tape application on the lower limbs. Both lower limbs were taped, using K-Tape and 3M Micropore tape randomly on the right and left thighs of the participants. Isometric knee extension force was measured for dominant side using a strain gauge. The following variables were assessed: peak force, time to peak force, rate of force development until peak force, time to peak rate of force development, and 200 ms pulse. Results : There were no statistically significant differences in the variables assessed between KT and Micropore conditions (F=0.645, p=0.666 or among testing sessions (pre, post, and 24h after (F=0.528, p=0.868, and there was no statistical significance (F=0.271, p=0.986 for interaction between tape conditions and testing session. Conclusion: KT did not affect the force-related measures assessed immediately and 24 hours after the KT application compared with Micropore application, during maximal isometric voluntary knee extension.

  16. Preoperative Strength Training for Elderly Patients Awaiting Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    D. M. van Leeuwen

    2014-01-01

    Full Text Available Objective. To investigate the feasibility and effects of additional preoperative high intensity strength training for patients awaiting total knee arthroplasty (TKA. Design. Clinical controlled trial. Patients. Twenty-two patients awaiting TKA. Methods. Patients were allocated to a standard training group or a group receiving standard training with additional progressive strength training for 6 weeks. Isometric knee extensor strength, voluntary activation, chair stand, 6-minute walk test (6MWT, and stair climbing were assessed before and after 6 weeks of training and 6 and 12 weeks after TKA. Results. For 3 of the 11 patients in the intensive strength group, training load had to be adjusted because of pain. For both groups combined, improvements in chair stand and 6MWT were observed before surgery, but intensive strength training was not more effective than standard training. Voluntary activation did not change before and after surgery, and postoperative recovery was not different between groups (P>0.05. Knee extensor strength of the affected leg before surgery was significantly associated with 6-minute walk (r=0.50 and the stair climb (r−=0.58, P<0.05. Conclusion. Intensive strength training was feasible for the majority of patients, but there were no indications that it is more effective than standard training to increase preoperative physical performance. This trial was registered with NTR2278.

  17. Between voluntary agreement and legislation

    DEFF Research Database (Denmark)

    Gwozdz, Wencke; Hedegaard, Liselotte; Reisch, Lucia

    2009-01-01

    Voluntary agreements and self-imposed standards are broadly applied to restrict the influence food advertising exerts on children’s food choices – yet their effects are unknown. The current project will therefore investigate whether and, if yes, how the Danish Code for Responsible Food Marketing...... Communication towards Children (hereafter: CODE) – with its dependence on a supportive institutional environment and acceptance of as well as dynamics between involved key stakeholders like consumers, political actors and firms – contributes to fighting the obesity pandemic.Thus, we explore within this article...... what information about the process of implementing the CODE as well as about the evolved dynamics between key stakeholders is already available. Here, the recently published report of the PolMark project sheds light on the dynamics between the key stakeholders in relation to the current Danish...

  18. The repeated bout effect of eccentric exercise is not associated with changes in voluntary activation.

    Science.gov (United States)

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Skikas, Laimutis; Duchateau, Jacques

    2010-04-01

    The aim of this study was to compare the possible changes in muscle activation level between a first and second bout of damaging eccentric exercise performed at 2 weeks interval (i.e. repeated bout effect). To that purpose, ten physically active males took part in this study. The eccentric exercise consisted of 10 sets of 12 maximal voluntary contractions (MVC) produced by the knee extensors during movements performed at a constant speed of 160 degrees s(-1). Changes in voluntary and electrically evoked torque in concentric and/or isometric conditions were assessed at the following time points: pre-exercise, and 2 min, 1 and 24 h after each eccentric exercise. At the same time points, voluntary activation was quantified by the superimposed electrical stimulation technique. Muscle soreness and plasma CK activity were measured within 48 h after the eccentric exercise. The results showed that the decrease in eccentric peak torque was linear throughout the exercise protocol. At the end of bouts 1 and 2, torque was significantly reduced by 27.7 +/- 9.1 and 23.4 +/- 11.2, respectively, with no difference between bouts (P > 0.05). At 24 h post-exercise, a lower reduction (P eccentric exercise appears to reduce muscle damage, but does not influence the level of voluntary activation.

  19. Measurement of voluntary activation based on transcranial magnetic stimulation over the motor cortex.

    Science.gov (United States)

    Todd, Gabrielle; Taylor, Janet L; Gandevia, Simon C

    2016-09-01

    This article reviews the use of transcranial magnetic stimulation (TMS) over the motor cortex to make estimates of the level of voluntary drive to muscles. The method, described in 2003 (Todd et al. J Physiol 551: 661-671, 2003), uses a TMS pulse to produce descending corticospinal volleys that synaptically activate motoneurons, resulting in a muscle twitch. Linear regression of the superimposed twitch amplitude and voluntary force (or torque) can generate an "estimated" resting twitch for muscles involved in a task. This procedure has most commonly been applied to elbow flexors but also to knee extensors and other muscle groups. Data from 44 papers using the method were tabulated. We identify and discuss five major technical challenges, and the frequency with which they are addressed. The technical challenges include inadvertent activation of the cortical representation of antagonist muscles, the role of antagonist torques at the studied joint, uncertainty about the effectiveness of the TMS pulse in activating the motoneuron pool, the linearity of the voluntary force (or torque) and superimposed twitch relationship, and variability in the TMS-evoked EMG and force/torque responses. The ideal situation in which the descending corticospinal volleys recruit all of the agonist motoneurons and none of the antagonist motoneurons is unlikely to ever occur, and hence results must be carefully examined to assess the authenticity of the voluntary activation estimates in the context of the experimental design. A partial compromise lies in the choice of stimulus intensity. We also identify aspects of the procedure that require further investigation.

  20. The efficacy of shock wave therapy in patients with knee osteoarthritis and popliteal cyamella

    Directory of Open Access Journals (Sweden)

    Tien-Wen Chen

    2014-07-01

    Full Text Available This randomized, controlled study was performed to compare the effects of extracorporeal shockwave therapy (ESWT and ultrasound on the rehabilitation of knee osteoarthritis with popliteal cyamella. One hundred and twenty patients with bilateral moderate knee osteoarthritis (Altman III and popliteal cyamella were selected and randomly assigned to four groups (GI–GIV. Patients in Groups I–III received isokinetic muscular strengthening exercises three times weekly for 8 weeks. Group II received pulse ultrasound treatment for popliteal cyamella three times weekly for 8 weeks, Group III received weekly shock wave therapy for popliteal cyamella for the first 6 weeks, and Group IV acted as controls. The therapeutic effects were evaluated by changes in the arthritic knees range of motion (ROM, visual analogue scale, Lequesne's index, and muscle peak torques after treatment and at follow-up 6 months later. Each treated group exhibited increased muscle peak torques and significantly reduced pain and disability after treatment and at follow-ups. However, only patients in Groups II and III showed significant improvements in ROM after treatment, and only participants in Group III showed immediate improvement in ROM after each treatment. Patients in Group III also showed the greatest increase in muscular strength and the greatest decrease in disability after treatment and at the follow-ups. ESWT is better than pulse ultrasound in rehabilitation of patients with knee osteoarthritis and popliteal cyamella results in more functional improvements.

  1. Prehabilitation before total knee arthroplasty increases strength and function in older adults with severe osteoarthritis.

    Science.gov (United States)

    Swank, Ann M; Kachelman, Joseph B; Bibeau, Wendy; Quesada, Peter M; Nyland, John; Malkani, Arthur; Topp, Robert V

    2011-02-01

    Preparing for the stress of total knee arthroplasty (TKA) surgery by exercise training (prehabilitation) may improve strength and function before surgery and, if effective, has the potential to contribute to postoperative recovery. Subjects with severe osteoarthritis (OA), pain intractable to medicine and scheduled for TKA were randomized into a usual care (UC) group (n = 36) or usual care and exercise (UC + EX) group (n = 35). The UC group maintained normal daily activities before their TKA. The UC + EX group performed a comprehensive prehabilitation program that included resistance training using bands, flexibility, and step training at least 3 times per week for 4-8 weeks before their TKA in addition to UC. Leg strength (isokinetic peak torque for knee extension and flexion) and ability to perform functional tasks (6-minute walk, 30 second sit-to-stand repetitions, and the time to ascend and descend 2 flights of stairs) were assessed before randomization at baseline (T1) and 1 week before the subject's TKA (T2). Repeated-measures analysis of variance indicated a significant group by time interaction (p torque for knee extension in the surgical knee. Prehabilitation increased leg strength and the ability to perform functional tasks for UC + EX when compared to UC before TKA. Short term (4-8 weeks) of prehabilitation was effective for increasing strength and function for individuals with severe OA. The program studied is easily transferred to a home environment, and clinicians working with this population should consider prehabilitation before TKA.

  2. Effects of trunk stability on isometric knee extension muscle strength measurement while sitting.

    Science.gov (United States)

    Hirano, Masahiro; Gomi, Masahiro; Katoh, Munenori

    2016-09-01

    [Purpose] This study aimed to investigate the effect of trunk stability on isometric knee extension muscle strength measurement while sitting by performing simultaneous measurements with a handheld dynamometer (HHD) and an isokinetic dynamometer (IKD) in the same seated condition. [Subjects and Methods] The subjects were 30 healthy volunteers. Isometric knee extension muscle strength was simultaneously measured with a HHD and an IKD by using an IKD-specific chair. The measurement was performed twice. Measurement instrument variables and the number of measurements were examined by using the analysis of variance and correlation tests. [Results] The measurement instrument variables and the number of measurements were not significantly different. The correlation coefficients between the HHD and IKD measurements were ≥0.96. [Conclusion] Isometric knee extension muscle strength measurement using the HHD in the sitting position resulted in a lower value than that using the IKD, presumably because of the effect of trunk stability on the measurement. In the same seated posture with trunk stability, no significant difference in measurement values was observed between the HHD and IKD. The present findings suggest that trunk stability while seated during isometric knee extension muscle strength measurement influenced the HHD measurement.

  3. Knee function after anterior cruciate ligament reconstruction with patellar or hamstring tendon: a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    SHI Dong-liang; YAO Zhen-jun

    2011-01-01

    Background There is currently no consensus regarding the best graft type for anterior cruciate ligament reconstruction.Therefore,the aim of this study was to investigate the effects of patellar and hamstring tendon grafts on long-term knee function after anterior cruciate ligament reconstruction.Methods This meta-analysis was conducted according to the methodological guidelines outlined by the Cochrane Collaboration.An electronic search of the literature was performed and all trials published between January 1966 and August 2011 comparing knee function after anterior cruciate ligament reconstruction using patellar tendon grafts with knee function after reconstruction with hamstring tendon grafts were pooled.Six studies were included in the final meta-analysis.Results Anterior cruciate ligament reconstruction using hamstring tendon grafts resulted in greater pain upon kneeling than reconstruction using pateliar tendon grafts (P=0.001).However,both grafts resulted in similar levels of anterior tibial translation,and similar results regarding isokinetic extension/flexion tests,Lysholm scores,and the stair-hop test (P >0.05).Conclusion Anterior cruciate ligament reconstruction using patellar or hamstring tendon grafts results in similar long-term knee function.

  4. EFFECT OF TREADMILL TRAINING ON QUADRICEPS AND HAMSTRING MUSCLES STRENGTH IN CHILDREN WITH KNEE HEAMARTHROSIS

    Directory of Open Access Journals (Sweden)

    Amira Mahmoud Abd-Elmonem,

    2014-08-01

    Full Text Available Background: Heamarthrosis is the most disabling complication of hemophilia causing pain, swelling, limited joint range, and weakness. Without appropriate treatment, chronic heamarthrosis remains a serious problem with permanent disability. The Purpose of this work was to study the effect of treadmill training on quadriceps and hamstring muscles strength in children with knee heamarthrosis. Material and methods: Thirty hemophilic male children with unilateral knee heamarthrosis, their ages ranged from 8 to 12 years. They were divided randomly into two groups in equal numbers, control (A and study (B, 15 patients each. Both groups received traditional treatment program for one hour 5 days / weak, in addition the study group received treadmill training for 15 minutes. Peak torque of quadriceps and hamstring muscles was measured by Biodex Isokinetic Dynamometer. Knee swelling was measured by tape measurement. Assessment was performed before and after three successive months of treatment. Results: The results revealed significant difference in all tested variables (p<0.05 after three months of treatment in both groups in favor to the study group. Conclusion: Treadmill training is beneficial in increasing muscle strength and reducing joint swelling in children with knee heamarthrosis.

  5. Muscle Damage following Maximal Eccentric Knee Extensions in Males and Females

    Science.gov (United States)

    2016-01-01

    Aim To investigate whether there is a sex difference in exercise induced muscle damage. Materials and Method Vastus Lateralis and patella tendon properties were measured in males and females using ultrasonography. During maximal voluntary eccentric knee extensions (12 reps x 6 sets), Vastus Lateralis fascicle lengthening and maximal voluntary eccentric knee extensions torque were recorded every 10° of knee joint angle (20–90°). Isometric torque, Creatine Kinase and muscle soreness were measured pre, post, 48, 96 and 168 hours post damage as markers of exercise induced muscle damage. Results Patella tendon stiffness and Vastus Lateralis fascicle lengthening were significantly higher in males compared to females (ptorque loss and muscle soreness post exercise induced muscle damage (p>0.05). Creatine Kinase levels post exercise induced muscle damage were higher in males compared to females (pknee extension torque, relative to estimated quadriceps anatomical cross sectional area, was taken as a covariate (ptorque loss, there is no sex difference in exercise induced muscle damage. The higher Creatine Kinase in males could not be explained by differences in maximal voluntary eccentric knee extension torque, Vastus Lateralis fascicle lengthening and patella tendon stiffness. Further research is required to understand the significant sex differences in Creatine Kinase levels following exercise induced muscle damage. PMID:26986066

  6. Knee MRI scan

    Science.gov (United States)

    MRI - knee ... radiologist see certain areas more clearly. During the MRI, the person who operates the machine will watch ... less anxious. Your provider may suggest an "open" MRI, in which the machine is not as close ...

  7. Runners knee (image)

    Science.gov (United States)

    ... forces on the knee, such as a misaligned patella. Chondromalacia is treated with rest or immobilization and nonsteroidal anti-inflammatory drugs for pain. Physical therapy, especially ... alignment of the patella that cannot be corrected with therapy.

  8. Osteotomy of the knee

    Science.gov (United States)

    Proximal tibial osteotomy; Lateral closing wedge osteotomy; High tibial osteotomy; Distal femoral osteotomy ... There are two types of surgery: Tibial osteotomy is surgery done on ... osteotomy is surgery done on the thigh bone above the knee ...

  9. Dashboard (in the) knee

    National Research Council Canada - National Science Library

    Patel, M S; Qureshi, A A; Green, T P

    2015-01-01

    We present the case of a 19-year-old individual presenting to an orthopaedic outpatient clinic several months following a dashboard knee injury during a road traffic accident with intermittent mechanical symptoms...

  10. Total Knee Replacement

    Science.gov (United States)

    ... walking, swimming, golf, driving, light hiking, biking, ballroom dancing, and other low-impact sports. With appropriate activity ... help prevent leg swelling and blood clots. Physical Therapy Most patients begin exercising their knee the day ...

  11. Partial knee replacement

    Science.gov (United States)

    ... al. American Academy of Orthopaedic Surgeons. Treatment of osteoarthritis of the knee (nonarthroplasty). J Am Acad ... Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, ...

  12. Prevalent knee pain and sport

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders

    1998-01-01

    STUDY OBJECTIVE: To estimate the prevalence of knee pain in active athletes and to investigate potential associations to type, amount and duration of sports participation. MEASUREMENTS: 339 athletes gave information about occupation, sports activity and different features of knee pain, based...... on a self-filled questionnaire. MAIN RESULTS: The prevalence of knee pain within the preceding 12 months, constant or recurrent knee pain, absence from sport and absence from work due to knee pain, was 54%, 34%, 19% and 4%, respectively. Knee pain was positively associated with years of jogging...... and with weekly hours of participation in competitive gymnastics but negatively with weekly hours of tennis. Constant or recurrent knee pain was positively associated with years of swimming. Absence from sport due to knee pain was positively associated with weekly hours of soccer participation. CONCLUSIONS: Knee...

  13. An EMG-driven musculoskeletal model to estimate muscle forces and knee joint moments in vivo.

    Science.gov (United States)

    Lloyd, David G; Besier, Thor F

    2003-06-01

    This paper examined if an electromyography (EMG) driven musculoskeletal model of the human knee could be used to predict knee moments, calculated using inverse dynamics, across a varied range of dynamic contractile conditions. Muscle-tendon lengths and moment arms of 13 muscles crossing the knee joint were determined from joint kinematics using a three-dimensional anatomical model of the lower limb. Muscle activation was determined using a second-order discrete non-linear model using rectified and low-pass filtered EMG as input. A modified Hill-type muscle model was used to calculate individual muscle forces using activation and muscle tendon lengths as inputs. The model was calibrated to six individuals by altering a set of physiologically based parameters using mathematical optimisation to match the net flexion/extension (FE) muscle moment with those measured by inverse dynamics. The model was calibrated for each subject using 5 different tasks, including passive and active FE in an isokinetic dynamometer, running, and cutting manoeuvres recorded using three-dimensional motion analysis. Once calibrated, the model was used to predict the FE moments, estimated via inverse dynamics, from over 200 isokinetic dynamometer, running and sidestepping tasks. The inverse dynamics joint moments were predicted with an average R(2) of 0.91 and mean residual error of approximately 12 Nm. A re-calibration of only the EMG-to-activation parameters revealed FE moments prediction across weeks of similar accuracy. Changing the muscle model to one that is more physiologically correct produced better predictions. The modelling method presented represents a good way to estimate in vivo muscle forces during movement tasks.

  14. The effect of knee joint angle on plantar flexor power in young and old men.

    Science.gov (United States)

    Dalton, Brian H; Allen, Matti D; Power, Geoffrey A; Vandervoort, Anthony A; Rice, Charles L

    2014-04-01

    Human adult aging is associated with a loss of strength, contractile velocity and hence, power. The principal plantar flexors, consisting of the bi-articular gastrocnemeii and the mono-articular soleus, appear to be affected differently by the aging process. However, the age-related effect of knee joint angle on the torque-angular velocity relationship and power production of this functionally important muscle group is unknown. The purpose was to determine whether flexing the knee, thereby reducing the gastrocnemius contribution to plantar flexion, would exacerbate the age-related decrements in plantar flexion power, or shift the torque-angular velocity relationship differently in older compared with young men. Neuromuscular properties were recorded from 10 young (~25 y) and 10 old (~78 y) men with the knee extended (170°) and flexed (90°), in a randomized order. Participants performed maximal voluntary isometric contractions (MVCs), followed by maximal velocity-dependent shortening contractions at pre-set loads, ranging from 15 to 75% MVC. The young men were ~20-25% stronger, ~12% faster and ~30% more powerful than the old for both knee angles (Ptorque was ~17% greater in the extended than flexed knee position, with no differences in voluntary activation (>95%). The young men produced 7-12% faster angular velocities in the extended knee position for loads ≤30% MVC, but no differences at higher loads; whereas there were no detectable differences in angular velocity between knee positions in the old across all relative loads. For both knee angles, young men produced peak power at 43.3±9.0% MVC, whereas the old men produced peak power at 54.8±7.9% MVC. These data indicate that the young, who have faster contracting muscles compared with the old, can rely more on velocity than torque for generating maximal power.

  15. Taking care of your new knee joint

    Science.gov (United States)

    Knee arthroplasty - precautions; Knee replacement - precautions ... After you have knee replacement surgery , you will need to be careful about how you move your knee, especially for the first few ...

  16. Distribution of joint isokinetic muscle strength in shot putters%铅球运动员主要关节等速肌力配布特征

    Institute of Scientific and Technical Information of China (English)

    娄彦涛

    2014-01-01

    背景:目前,国内外利用等速仪器针对铅球运动主要环节肌肉力量特征方面研究的文献较少。  目的:查找铅球运动员不同速度下各主要环节肌力配布特征和存在的不足。  方法:利用德国ISOMED2000等速肌力测试系统,对第十一届全运会男子铅球冠军膝关节、髋关节、腰背环节和肩关节进行慢速60(°)/s和快速180(°)/s等速测试。  结果与结论:①膝关节慢速左右侧屈伸肌比值为25.6%、39.4%,快速屈伸肌比值为28.5%、29.8%,屈肌群肌力较小。②髋关节在快、慢速时,右侧伸肌群分别为左侧的2.11和1.87倍,屈肌群为1.25和1.64倍,右髋非常显著性大于左髋。③腰背环节慢速屈伸肌比值为93.3%,快速测试屈伸肌比值为84.3%。④肩关节自然位屈伸,慢速屈伸肌力右肩分别为左肩的1.27和1.34倍,快速为左肩的1.40和1.92倍。⑤各环节根据人体模型相对质量按膝关节为基准膝、髋、躯干、肩为1∶2.38∶3.30∶0.70。结果表明:①膝关节屈伸肌群绝对肌力、快速屈肌群肌力均较弱,肌群配备不合理。②躯干肌力在右侧最大力量伸肌群、左右侧快速伸肌群非常薄弱,增加腰背肌力伸肌训练,特别是慢速和快速肌肉力量和伸展性训练。③右侧各环节伸肌群薄弱,加强右肩伸肌群的绝对肌肉力量。%BACKGROUND:At present, the detections of muscular strength of the main joints in shot putters by using isokinetic system are rarely reported. OBJECTIVE:To find out the characteristics of muscular strength of the main joints in shot putters under different speed, and explore the existing shortcomings. METHODS:Using German ISOMED2000 isokinetic test system, we detected the isokinetic muscular strength of knee joint, hip joint, waist-back segment, and shoulder joint of the men’s shot put champion in the 11th Games, at slow 60°/s and fast 180°/s. RESULTS AND

  17. Provocative mechanical tests of the peripheral nervous system affect the joint torque-angle during passive knee motion.

    Science.gov (United States)

    Andrade, R J; Freitas, S R; Vaz, J R; Bruno, P M; Pezarat-Correia, P

    2015-06-01

    This study aimed to determine the influence of the head, upper trunk, and foot position on the passive knee extension (PKE) torque-angle response. PKE tests were performed in 10 healthy subjects using an isokinetic dynamometer at 2°/s. Subjects lay in the supine position with their hips flexed to 90°. The knee angle, passive torque, surface electromyography (EMG) of the semitendinosus and quadriceps vastus medialis, and stretch discomfort were recorded in six body positions during PKE. The different maximal active positions of the cervical spine (neutral; flexion; extension), thoracic spine (neutral; flexion), and ankle (neutral; dorsiflexion) were passively combined for the tests. Visual analog scale scores and EMG were unaffected by body segment positioning. An effect of the ankle joint was verified on the peak torque and knee maximum angle when the ankle was in the dorsiflexion position (P Upper trunk positioning had an effect on the knee submaximal torque (P cervical and thoracic spines were flexed (P angle response since different positions of head, upper trunk, and foot induce dissimilar knee mechanical responses during passive extension.

  18. Influence of patellofemoral bracing on pain, knee extensor torque, and gait function in females with patellofemoral pain.

    Science.gov (United States)

    Powers, Christopher M; Doubleday, Kathryn L; Escudero, Carina

    2008-01-01

    Our purpose was to evaluate the effects of a patellofemoral brace on pain response, knee extensor torque production, and gait function in females with patellofemoral pain (PFP). Sixteen females between the ages of 14 and 46 with diagnosis of PFP participated. Knee extensor torque was measured by using a LIDO isokinetic dynamometer. Pain levels were documented by using the Visual Analog Pain Scale. Stride characteristics during the conditions of free walk, fast walk, ascend stairs, descend stairs, ascend ramp, and descend ramp were obtained with a stride analyzer unit. EMG activity of the vasti musculature was recorded by using indwelling, bipolar, wire electrodes. Knee joint motion was assessed by using a VICON motion analysis system. All testing was performed with and without the Bauerfeind Genutrain P3 patellofemoral brace. There were no significant differences in torque production, pain levels, and stride characteristics between braced and non-braced trials. In addition, there were no significant differences in mean vasti EMG between braced and non-braced trials. When averaged across all conditions, a small but statistically significant increase in knee flexion was found during the braced trials. Although the current study did not find significant improvements in the clinical measures evaluated, 8 of the 16 subjects did experience a decrease in knee pain. This finding suggests that certain patients with PFP may respond favorably to bracing, and criteria must be established to determine which patients would best benefit from such an intervention.

  19. AN ECONOMETRIC APPROACH ABOUT VOLUNTARY TURNOVER

    Directory of Open Access Journals (Sweden)

    ADALET EREN

    2013-06-01

    Full Text Available This study analyzes individual and organizational variables that affect voluntary turnover are determined in the special defence and security companies. A binomial logistic regression model is used to estimate voluntary turnover.  Binomial Logistic regression, reliability test (scale alfa, variance (ANOVA, Post-hoc/Tukey, correlation (Pearson and other basic statistical techniques  with SPSS 13 statistical packet program was used in the analyzes ofresearch data. The study finds that; situation of suppose working, number of child, number of death child, number of home’s moving, support of rent, total monthly income of household, last work’s region, number of prizes, affect voluntary turnover are determined.

  20. Progressive Resistance Exercise with Eccentric Loading for the Management of Knee Osteoarthritis.

    Science.gov (United States)

    Hernandez, Haniel J; McIntosh, Valerie; Leland, Azadeh; Harris-Love, Michael O

    2015-01-01

    The patient was a 58-year-old African-American male with radiographic evidence of bilateral knee osteoarthritis (OA). He participated in a standardized 12-week eccentric strengthening program within a Veterans Affairs (VA) medical center. The use of an eccentric training paradigm may prove to be beneficial for older adults with knee OA since eccentric muscle actions are involved in the energy absorption at the knee joint during gait and controlled movement during stair descent. Furthermore, in comparison to standard muscle actions, eccentric muscle actions result in higher torque generation and a lower rate of oxygen consumption at a given level of perceived exertion. Therefore, this mode of progressive resistance exercise may be ideal for older adults. The patient completed an eccentric strengthening regimen for the knee flexors and extensors twice per week without an exacerbation of knee pain. Muscle morphology measures of the rectus femoris were measured using diagnostic ultrasound. Isokinetic measures of muscle peak torque were obtained at 60°/s and 180°/s. Functional performance was assessed using a physical performance battery and stair-step performance was assessed from the linear displacement of the center of gravity trajectories obtained with a force plate. Visual analog scale pain ratings and self-reported global disease status were also documented. Post-exercise assessments revealed improvements in sonographic muscle size and tissue composition estimates, peak knee extensor torque (ranging from 60 to 253%), functional performance, and global disease status. The patient exhibited improvements in muscle morphology, muscle strength, functional performance, pain, and global disease status after 12 weeks of an eccentric strengthening regimen. The intervention and outcomes featured in this case were feasible to implement within a VA medical center and merit further investigation.

  1. Progressive Resistance Exercise with Eccentric Loading for the Management of Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Michael O Harris-Love

    2015-07-01

    Full Text Available Introduction: The patient was a 58-year-old African-American male with radiographic evidence of knee osteoarthritis. He participated in a standardized 12-week eccentric strengthening program within a VA medical center. Background: The use of an eccentric training paradigm may prove to be beneficial for older adults with knee osteoarthritis since eccentric muscle actions are involved in the energy absorption at the knee joint during gait and controlled movement during stair descent. Furthermore, in comparison to standard muscle actions, eccentric muscle actions result in higher torque generation and a lower rate of oxygen consumption at a given level of perceived exertion. Therefore, this mode of progressive resistance exercise may be ideal for older adults. Discussion: The patient completed an eccentric strengthening regimen for the knee flexors and extensors twice per week without an exacerbation of knee pain. Muscle morphology measures of the rectus femoris were measured using diagnostic ultrasound. Isokinetic measures of muscle peak torque were be obtained at 60°/s and 180°/s. Functional performance was assessed using a physical performance battery and stair step performance was assessed from the linear displacement of the center of gravity trajectories obtained with a force plate. Visual analogue scale pain ratings and self-reported global disease status were also documented. Post-exercise assessments revealed improvements in sonographic muscle size and tissue composition estimates, peak knee extensor torque (ranging from 60% to 253%, functional performance, and global disease status. Concluding Remarks: The patient exhibited improvements in muscle morphology, muscle strength, functional performance, pain, and global disease status after 12 weeks of an eccentric strengthening regimen. The intervention and outcomes featured in this case were feasible to implement within a VA medical center and merit further investigation.

  2. An examination of ankle, knee, and hip torque production in individuals with chronic ankle instability.

    Science.gov (United States)

    Gribble, Phillip A; Robinson, Richard H

    2009-03-01

    There is some debate in the literature as to whether strength deficits exist at the ankle in individuals with chronic ankle instability (CAI). Additionally, there is evidence to suggest that knee and hip performance is altered in those with CAI. Therefore, the purpose of this study was to determine whether CAI is associated with deficits in ankle, knee, and hip torque. Fifteen subjects with unilateral CAI and fifteen subjects with healthy ankles participated. Subjects reported to the laboratory for one session during which the torque production of ankle plantar flexion/dorsiflexion, knee flexion/extension, and hip flexion/extension were measured with an isokinetic device. Subjects performed 5 maximum-effort repetitions of a concentric/concentric protocol at 60 degrees .s for both extremities. Average peak torque (APT) values were calculated. The subjects with CAI demonstrated significantly less APT production for knee flexion (F1,28 = 5.40; p = 0.03) and extension (F1,28 = 5.34; p = 0.03). Subjects with CAI exhibited significantly less APT for ankle plantar flexion in the injured limb compared with their noninjured limb (F1,28 = 6.51; p = 0.02). No significant difference in ankle dorsiflexion or hip flexion/extension APT production existed between the 2 groups. Individuals with CAI, in addition to deficits in ankle plantar flexion torque, had deficits in knee flexor and extensor torque, suggesting that distal joint instability may lead to knee joint neuromuscular adaptations. There were no similar deficits at the hip. Future research should determine what implications this has for prevention and rehabilitation of lower-extremity injury. Clinicians may need to consider including rehabilitation efforts to address these deficits when rehabilitating patients with CAI.

  3. Does post-operative knee awareness differ between knees in bilateral simultaneous total knee arthroplasty?

    DEFF Research Database (Denmark)

    Nielsen, Katrine Abildgaard; Thomsen, Morten Grove; Latifi Yaghin, Roshan;

    2016-01-01

    PURPOSE: To evaluate the difference in post-operative knee awareness between knees in patients undergoing bilateral simultaneous total knee arthroplasty (TKA) and to assess factors predicting high or low knee awareness. METHODS: This study was conducted on 99 bilateral simultaneous TKAs performed...... at our institution from 2008 to 2012. All patients received one set of questionnaires [Forgotten Joint Score (FJS) and Oxford Knee Score (OKS)] for each knee. Based on the FJS, the patients' knees were divided into two groups: "best" and "worst" knees. The median of the absolute difference in FJS and OKS...... within each patient was calculated. Multivariate linear regression was performed to identify factors affecting FJS. RESULTS: The difference between knees was 1 point (CI 0-5) for the FJS and 1 point (CI 0-2) for the OKS. The FJS for females increased (decreasing awareness) with increasing age. Males had...

  4. A Study on the Differences of Quadriceps Femoris Activities by Knee Alignment during Isometric Contraction.

    Science.gov (United States)

    Park, Seol; Ko, Yu-Min; Jang, Gwon-Uk; Hwang, Yoon-Tae; Park, Ji-Won

    2014-11-01

    [Purpose] This study attempted to identify how genu varum or valgum affects the electromyographic activities of the vastus medialis, vastus lateralis, and rectus femoris during knee isometric contraction. [Subjects] Fifty-two healthy young adults were enrolled in this study. They were enrolled and classified into three groups by knee alignment conditions: the genu varum, genu valgum, and control groups. [Methods] The electromyographic activity ratio of the vastus medialis to the vastus lateralis and rectus femoris were calculated using the percentage of maximum voluntary contraction. The participants contracted their quadriceps during isometric contraction at 30 and 60° of knee flexion. [Results] The genu varum group had more activity in the vastus medialis than in the vastus lateralis and rectus femoris, whereas the genu valgum group had more activity in the vastus lateralis and rectus femoris than in the vastus medialis. There was a significant difference in the muscle activity ratio between the vastus medialis and vastus lateralis by angle of knee flexion degree only in the genu valgum. There were no significant differences in any of the three groups in terms of the muscle activity ratio of the vastus medialis to the rectus femoris by angle of knee flexion. [Conclusion] The quadriceps femoris was used for different strategies according to knee alignment during isometric contraction at 30 and 60°. This study suggests that rehabilitation training programs used to strengthen the quadriceps should consider the knee alignment conditions of the target subjects.

  5. Anticipatory signatures of voluntary memory suppression.

    Science.gov (United States)

    Hanslmayr, Simon; Leipold, Philipp; Pastötter, Bernhard; Bäuml, Karl-Heinz

    2009-03-04

    Voluntary memory suppression can keep unwanted memories from entering consciousness, inducing later forgetting of the information. In the present study, we searched for the existence of anticipatory processes, mediating such voluntary memory suppression. Using the think/no-think paradigm, subjects received a cue whether to prepare to think of a previously studied cue-target pair or whether to not let a previously studied cue-target pair enter consciousness. Examining event-related potentials, we identified two electrophysiological processes of voluntary memory suppression: (1) an early anticipatory process operating before the memory cue for a to-be-suppressed memory was provided, and (2) a later process operating after memory cue presentation. Both ERP effects were due to a decreased right frontal and left parietal positivity. They were positively related and predicted later forgetting. The results point to the existence of anticipatory processes, mediating voluntary memory suppression.

  6. Pedagogical Aspects of Voluntary School Work

    Directory of Open Access Journals (Sweden)

    Mária Jármai Erzsébet

    2015-03-01

    Full Text Available The economic importance of voluntary work has been exceedingly appreciated in the last few decades. This is not surprising at all, because it is highly profitable according to the related estimated data. There are 115,9 million people doing voluntary work only in Europe, which means that they would create the world's 7th biggest economy with EUR 282 billion value creation if they formed an individual state. The organizations know that voluntary work has several advantages apart from the economic benefits. It is profitable both for the society and for the individuals as well. Several researches have proven that voluntary work positively influences the development of the personality, because the key-competencies - such as: co-operation, empathy, solidarity, conflict handling, problem solving, etc. - expected in the labor market can be improved.

  7. Managing voluntary turnover through challenging assignments

    NARCIS (Netherlands)

    Preenen, P.T.Y.; Pater, I.E. de; Vianen, A.E.M. van; Keijzer, L.

    2011-01-01

    This study examines employees' challenging assignments as manageable means to reduce turnover intentions, job search behaviors, and voluntary turnover. Results indicate that challenging assignments are negatively related to turnover intentions and job search behaviors and that these relationships

  8. Corticospinal excitability in human voluntary movement

    NARCIS (Netherlands)

    Elswijk, G.A.F. van

    2008-01-01

    The research described in this thesis addressed the neurophysiologic changes in the human corticospinal system during preparation and execution of voluntary hand movements. The experiments involved transcranial magnetic stimulation (TMS) of the motor cortex combined with electromyography (EMG) and e

  9. Contemplated Suicide Among Voluntary and Involuntary Retirees

    Science.gov (United States)

    Peretti, Peter O.; Wilson, Cedric

    1978-01-01

    This study explored anomic and egoistic dimensions of contemplated suicide among voluntary and involuntary retired males. Results indicated a direct relationship between anomie and egoism on the one hand, and contemplation of suicide on the other. (Author)

  10. A Free Market Requires Voluntary Actions

    DEFF Research Database (Denmark)

    Sløk-Madsen, Stefan Kirkegaard

    are essential to the construct of consumer sovereignty. Understanding the degree of voluntary actions in a given commercial setting has implications for both business strategy and policy making. This paper thus aims to contribute to explain why restricted markets become crony capitalism.......This paper draws attention to the importance of the understanding of voluntary actions in the free market construct. Failing to understand the role of voluntary actions in the free market construct will often result in discussions of capitalism versus socialism focusing on asset ownership...... and not consumer sovereignty. I argue that asset ownership is less important than true consumer sovereignty, which again is the essential argument for why capitalism is the superior mode of resource allocation and social organization. The paper analyzes how our understanding of markets and voluntary actions...

  11. Contemplated Suicide Among Voluntary and Involuntary Retirees

    Science.gov (United States)

    Peretti, Peter O.; Wilson, Cedric

    1978-01-01

    This study explored anomic and egoistic dimensions of contemplated suicide among voluntary and involuntary retired males. Results indicated a direct relationship between anomie and egoism on the one hand, and contemplation of suicide on the other. (Author)

  12. How to quantify knee function after total knee arthroplasty?

    NARCIS (Netherlands)

    Boonstra, M.C.; Waal Malefijt, M.C. de; Verdonschot, N.J.J.

    2008-01-01

    Total knee arthroplasty (TKA) is being undertaken in a younger population than before and as a result the functional demands on the knee are likely to be increasing. As a consequence, it is important to define quantitative functional knee tests that can monitor any increase. A valuable functional

  13. Differences in onset timing between the vastus medialis and lateralis during concentric knee contraction in individuals with genu varum or valgum.

    Science.gov (United States)

    Park, Seol; Kong, Yong-Soo; Ko, Yu-Min; Jang, Gwon-Uk; Park, Ji-Won

    2015-04-01

    [Purpose] The purpose of this study was to investigate the difference in onset timing between the vastus medialis and lateralis among the different knee alignments, as well as the best isokinetic angular velocity for an isokinetic concentric contraction. [Subjects] Fifty-two adults (20 with genu varum, 12 genu valgum, and 20 controls) were enrolled in this study. Subjects with > 4 cm between the medial epicondyles of the knee were placed in the genu varum group, whereas subjects with > 4 cm between the medial malleolus of the ankle were placed in the genu valgum group. [Methods] Surface electromyography was used to measure the onset times of the vastus medialis and vastus lateralis during concentric contractions at 30, 60, and 90°/sec. [Results] The vastus lateralis showed more delayed firing than the vastus medialis in the genu varum group, whereas vastus medialis firing was delayed more than that of the vastus lateralis in the genu valgum group. No differences in onset timing were observed between the vastus medialis and lateralis according the different angular velocities during concentric contractions in all three groups. [Conclusion] Genu varum and valgum affect quadriceps firing. Therefore, selective rehabilitation training of the quadriceps femoris should be considered to prevent pain or knee malalignment deformities.

  14. Pull factors of Finland and voluntary work

    OpenAIRE

    Jurvakainen, Janika

    2016-01-01

    This thesis studies pull factors of Finland and voluntary work. The aim of this study is to understand the pull factors of Finland from the perspective of young travelers. Which pull factors attract to choose Finland as their destination? In addition, which pull factors attract young travelers to participate in international voluntary work? The commissioner of this thesis is Allianssi Youth Exchange. The thesis is research-based and includes a quantitative Webropol survey and some qualit...

  15. The effect of heating and cooling on time course of voluntary and electrically induced muscle force variation.

    Science.gov (United States)

    Brazaitis, Marius; Skurvydas, Albertas; Vadopalas, Kazys; Daniusevičiūtė, Laura; Senikienė, Zibuoklė

    2011-01-01

    The aim of this study was to investigate the effect of heating and cooling on time course of voluntary and electrically induced muscle force variation. Ten volunteers performed 50 maximal voluntary and electrically induced contractions of the knee extensors at an angle of 120 degrees under the control conditions and after passive lower body heating and cooling in the control, heating, and cooling experiments. Peak torque, torque variation, and half-relaxation time were assessed during the exercise. Passive lower body heating increased muscle and core temperatures, while cooling lowered muscle temperature, but did not affect core temperature. We observed significantly lower muscle fatigue during voluntary contraction compared with electrically induced contractions. Body heating (opposite to cooling) increased involuntarily induced muscle force, but caused greater electrically induced muscle fatigue. In the middle of the exercise, the coefficient of correlation for electrically induced muscle torque decreased significantly as compared with the beginning of the exercise, while during maximal voluntary contractions, this relation for torque remained significant until the end of the exercise. It was shown that time course of voluntary contraction was more stable than in electrically induced contractions.

  16. Shoulder isokinetic profile of male handball players of the Brazilian National Team

    Directory of Open Access Journals (Sweden)

    Marilia S. Andrade

    2013-12-01

    Full Text Available BACKGROUND: Data obtained on an isokinetic dynamometer are useful to characterize muscle status and have been reported in muscle imbalance studies in different types of sport. However, few studies have assessed elite handball players to establish reference values. OBJECTIVE: The purpose of this study was to compare, for the dominant (D and non-dominant (ND side, the isokinetic profile of shoulder rotator muscle strength between male handball players (H and asymptomatic non-athletes (NA. METHOD: Isokinetic concentric and eccentric strength tests for D upper limbs were performed by the H group (n=20 and the NA group (n=12. Internal and external rotator muscle peak torque in concentric action was assessed at 60°/s and 300°/s and in eccentric action at 300°/s. We also calculated conventional balance (the ratio of external rotator peak torque to internal rotator peak torque in concentric action and functional balance (the ratio of external rotator peak torque in eccentric action to internal rotator peak torque in concentric action. RESULTS: In the H group, dominant limbs were stronger in concentric action for external rotation at 60 and 300°/s. The conventional balance ratio for the D side was significantly lower at 60 and 300°/s for H compared to NA. The functional ratio for the D side was significantly lower at 300º/s for H compared to NA. CONCLUSIONS: Compared to asymptomatic non-athletes, handball players presented significant muscular imbalance resulting from daily sports practice, a known risk factor for shoulder injuries.

  17. Strength deficits of the shoulder complex during isokinetic testing in people with chronic stroke

    Directory of Open Access Journals (Sweden)

    Lucas R. Nascimento

    2014-07-01

    Full Text Available OBJECTIVES: To examine the strength deficits of the shoulder complex after stroke and to characterize the pattern of weakness according to type of movement and type of isokinetic parameter. METHOD: Twelve chronic stroke survivors and 12 age-matched healthy controls had their shoulder strength measured using a Biodex isokinetic dynamometer. Concentric measures of peak torque and work during shoulder movements were obtained in random order at speeds of 60°/s for both groups and sides. Type of movement was defined as scapulothoracic (protraction and retraction, glenohumeral (shoulder internal and external rotation or combined (shoulder flexion and extension. Type of isokinetic parameter was defined as maximum (peak torque or sustained (work. Strength deficits were calculated using the control group as reference. RESULTS: The average strength deficit for the paretic upper limb was 52% for peak torque and 56% for work. Decreases observed in the non-paretic shoulder were 21% and 22%, respectively. Strength deficit of the scapulothoracic muscles was similar to the glenohumeral muscles, with a mean difference of 6% (95% CI -5 to 17. Ability to sustain torque throughout a given range of motion was decreased as much as the peak torque, with a mean difference of 4% (95% CI -2 to 10. CONCLUSIONS: The findings suggest that people after stroke might benefit from strengthening exercises directed at the paretic scapulothoracic muscles in addition to exercises of arm elevation. Clinicians should also prescribe different exercises to improve the ability to generate force and the ability to sustain the torque during a specific range of motion.

  18. Knee Injuries in Downhill Skiers

    OpenAIRE

    Shea, Kevin G.; Archibald-Seiffer, Noah; Murdock, Elizabeth; Grimm, Nathan L.; Jacobs, John C.; Willick, Stuart; Van Houten, Heather

    2014-01-01

    Background: Knee injuries account for approximately one third of injuries in skiers. Researchers have proposed several mechanisms of knee injury in skiers. However, the frequencies of these mechanisms have varied in different studies. Purpose: To identify the most common knee injury mechanisms in recreational downhill skiers and to assess injury frequencies across several demographics. Study Design: Descriptive epidemiology study. Methods: Over 6 ski seasons, 541 patients with acute knee inju...

  19. 47 CFR 80.310 - Watch required by voluntary vessels.

    Science.gov (United States)

    2010-10-01

    ... Watches § 80.310 Watch required by voluntary vessels. Voluntary vessels not equipped with DSC must.... Voluntary vessels equipped with VHF-DSC equipment must maintain a watch on 2182 kHz and on either 156.525... used to communicate. Voluntary vessels equipped with MF-HF DSC equipment must have the radio turned...

  20. The Effect of Concentric Isokinetic Strength Training of the Quadriceps Femoris on Electromyography and Muscle Strength in the Trained and Untrained Limb.

    Science.gov (United States)

    Evetovich, Tammy K.; Housh, Terry J.; Housh, Dona J.; Johnson, Glen O.; Smith, Douglas B.; Ebersole, Kyle T.

    2001-01-01

    Examined the effects of unilateral concentric isokinetic leg extension training on peak torque and electromyographic (EMG) responses in trained and untrained limbs. Adult men participated in training and control groups. Overall, unilateral concentric isokinetic strength training induced strength increases in trained as well as untrained limbs.…

  1. Self-reported chair-rise ability relates to stair-climbing readiness of total knee arthroplasty patients: a pilot study.

    Science.gov (United States)

    Nyland, John; Frost, Karen; Quesada, Peter; Angeli, Claudia; Swank, Ann; Topp, Robert; Malkani, Art L

    2007-01-01

    Following total knee arthroplasty (TKA), physical therapists must evaluate patient readiness to safely begin stair-climbing. Physical therapists might find self-reported chair-rise ability useful in determining stair-climbing readiness of patients. We grouped 31 subjects who were at approximately 3.6 weeks post-TKA by chair-rise ability (group 1 = "Because of my knee, I can only rise from a chair if I use my hands and arms to assist," group 2 = "I have pain when rising from the seated position, but it does not affect my ability to rise from the seated position," and group 3 = "My knee does not affect my ability to rise from a chair"). Next, we determined time of stair-climbing ascent and descent, number of chair rises in 30 seconds, isokinetic quadriceps femoris and hamstring muscle group strength, and self-reported knee function survey scores. Groups 3 and 2 descended stairs more quickly than group 1; group 3 displayed greater involved and noninvolved knee extensor torque per body weight than group 1 or 2 and had superior self-reported knee function scores than group 1. Patient perception of chair-rise ability at approximately 3.6 weeks post-TKA is useful in helping physical therapists determine patient readiness to safely begin stair-climbing.

  2. VALIDITY OF TWO CLINICAL KNEE STRENGTH ASSESSMENTS COMPARED TO THE REFERENCE STANDARD

    Directory of Open Access Journals (Sweden)

    Philipp Weng

    2015-12-01

    Full Text Available Objectives: Patello femoral Pain (PFP is the most common lower limb condition encountered in clinical practice. It recently emerged as the third highest ranked topic out of 185 in the Chartered Society of Physiotherapy Musculoskeletal Research Priority Project. For a valid assessment of knee strength during rehabilitation, the isometric test using the isokinetic dynamometer (Cybex and the hand-held dynamometer (HHD is not well received with clinical practice. An alternative way is through functional hop tests which clinicians have used to assess their patients' lower extremity muscular strength. This study investigates the validity of knee strength assessments conducted with the HHD and the hoptest compared to the isokinetic dynamometer and also explores differences between genders of the three assessments. Design: Each assessment included one submaximal and three recorded maximal efforts of the dominant leg. Quadriceps muscle strength was displayed in normalized torques. Correlation coefficients and box-and-whisker plots was used to analyze the data. Setting: Movement analysis laboratory Participants: Sixteen males (age 23.5 ± 4.23 years, height 1.79 ± 0.08 m and body mass 76.21 ± 10.58 kg, BMI 23.82 ± 2.38 kg/m² and 16 females (age 25.38 ± 5.49 years, height 1.67 ± 0.08 m and body mass 71.99 ± 16.05 kg, BMI 25.83 ± 4.74 kg/m² between 18 and 40 years old without any musculoskeletal injuries participated. Main outcome measures: Knee moments normalized for bodyweight (Nm/kg for dynamometers and distance jumped for single legged hoptest. Results: The strongest significant correlation was found for the comparison between the HHD and Cybex (r=0.71, r²=0.504, p=0.001. Correlation between the HHD and hoptest (r=0.4, r²=0.19, p=0.013, and Cybex and hoptest (r=0.53, r²=0.295, p=0.001 were poor. Comparing genders, the normalized knee extension moment on the Cybex was 28.8% lower and with the HHD 22.3% lower for females. Conclusions: Single

  3. Effects of Kinesio Tape application to quadriceps muscles on isokinetic muscle strength, gait, and functional parameters in patients with stroke.

    Science.gov (United States)

    Ekiz, Timur; Aslan, Meryem Doğan; Özgirgin, Neşe

    2015-01-01

    The aim of this study was to evaluate the effects of Kinesio Tape (KT) application to quadriceps muscles on isokinetic muscle strength, gait, and functional parameters in patients with stroke. Twenty-four patients were allocated into KT and control groups. All patients participated in the same conventional rehabilitation program 5 times/wk for 4 wk. In addition, KT was applied to quadriceps muscles bilaterally to the patients in the KT group. Compared with baseline, peak torque levels increased significantly in both groups (all p 0.05). KT application to quadriceps muscles in addition to conventional exercises for 4 wk is effective on isokinetic but not functional parameters.

  4. Knee-extension-assist for knee-ankle-foot orthoses.

    Science.gov (United States)

    Spring, Alexander; Kofman, Jonathan; Lemaire, Edward

    2011-01-01

    Individuals with quadriceps muscle weakness often have difficulty generating the knee-extension moments required for common mobility tasks. A new device that provides a knee-extension moment was designed to help individuals perform sit-to-stand and stand-to-sit. The knee-extension-assist (KEA) was designed as a modular component to be incorporated into existing knee-ankle-foot-orthoses (KAFO). The KEA loads a set of springs as the knee flexes under bodyweight and returns the stored energy as an extension moment during knee extension. The springs can be locked in place at the end of flexion to prevent unwanted knee extension while seated. When the affected leg is unloaded, the device disengages, allowing free joint motion. A prototype KEA underwent mechanical testing and biomechanical evaluation on an able-bodied individual during sit-to-stand and stand-to-sit.

  5. Plyometric training improves voluntary activation and strength during isometric, concentric and eccentric contractions.

    Science.gov (United States)

    Behrens, Martin; Mau-Moeller, Anett; Mueller, Karoline; Heise, Sandra; Gube, Martin; Beuster, Nico; Herlyn, Philipp K E; Fischer, Dagmar-C; Bruhn, Sven

    2016-02-01

    This study investigated effects of plyometric training (6 weeks, 3 sessions/week) on maximum voluntary contraction (MVC) strength and neural activation of the knee extensors during isometric, concentric and eccentric contractions. Twenty-seven participants were randomly assigned to the intervention or control group. Maximum voluntary torques (MVT) during the different types of contraction were measured at 110° knee flexion (180°=full extension). The interpolated twitch technique was applied at the same knee joint angle during isometric, concentric and eccentric contractions to measure voluntary activation. In addition, normalized root mean square of the EMG signal at MVT was calculated. The twitch torque signal induced by electrical nerve stimulation at rest was used to evaluate training-related changes at the muscle level. In addition, jump height in countermovement jump was measured. After training, MVT increased by 20Nm (95% CI: 5-36Nm, P=0.012), 24Nm (95% CI: 9-40Nm, P=0.004) and 27Nm (95% CI: 7-48Nm, P=0.013) for isometric, concentric and eccentric MVCs compared to controls, respectively. The strength enhancements were associated with increases in voluntary activation during isometric, concentric and eccentric MVCs by 7.8% (95% CI: 1.8-13.9%, P=0.013), 7.0% (95% CI: 0.4-13.5%, P=0.039) and 8.6% (95% CI: 3.0-14.2%, P=0.005), respectively. Changes in the twitch torque signal of the resting muscle, induced by supramaximal electrical stimulation of the femoral nerve, were not observed, indicating no alterations at the muscle level, whereas jump height was increased. Given the fact that the training exercises consisted of eccentric muscle actions followed by concentric contractions, it is in particular relevant that the plyometric training increased MVC strength and neural activation of the quadriceps muscle regardless of the contraction mode. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  6. No Differences Between Alter G-Trainer And Active And Passive Recovery Strategies On Isokinetic Strength, Systemic Oxidative Stress And Perceived Muscle Soreness After Exercise-Induced Muscle Damage.

    Science.gov (United States)

    Cooke, Matthew B; Nix, Carrie; Greenwood, Lori; Greenwood, Mike

    2016-11-28

    The incidence of muscle injuries is prevalent in elite sport athletes as well as weekend warriors and strategies that safely and effectively hasten recovery are highly desirable. The purpose of this study was to examine the differences between three recovery methods after eliciting muscle damage in recreationally active men relative to maximal isokinetic contractions, perceived muscle soreness and psychological mood states. Twenty-five recreationally active men (22.15±3.53yrs, 75.75±11.91kg, 180.52±7.3cm) were randomly matched by VO2 peak (53.86±6.65ml·kg·min) and assigned to one of three recovery methods: Anti-gravity Treadmill (G-Trainer) (N = 8), Conventional Treadmill (N = 8) or Static Stretching (N = 9). Recovery methods were performed 30 minutes, 24, 48 and 72 hours following a 45 minute downhill run. Following eccentrically-biased running, no significant differences were noted in isokinetic knee flexion and extension peak torque, systemic markers of muscle damage, oxidative stress and lipid peroxidation such as serum creatine kinase (CK), superoxide dismutase (SOD), and malondialdehyde (MDA), respectively, and subjective ratings of perceived muscle soreness between recovery methods. The G-Trainer group did however display a higher mood state as indicated by the Profile of Mood State global scores at 24 hours post-exercise when compared to the conventional treadmill recovery group (p=0.035). The improved mood state following the use of the anti-gravity treadmill may provide clinical relevance to other populations.

  7. Efeitos de diferentes intervalos de recuperação no desempenho muscular isocinético em idosos Effects of different rest intervals on isokinetic muscle performance among older adults

    Directory of Open Access Journals (Sweden)

    C Ernesto

    2009-02-01

    Full Text Available OBJETIVO: Comparar os efeitos de diferentes intervalos de recuperação (IR entre séries de contração isocinética no desempenho muscular em idosos. MÉTODOS: Vinte idosos voluntários (66,9±3,9 anos, 76,1±13,4kg, 169±5,2cm foram submetidos a três sessões de exercício resistido isocinético unilateral da musculatura extensora do joelho com diferentes IR (1 minuto, 2 minutos, e 3 minutos na velocidade de 60°•s-1. Cada sessão consistia em três séries de 10 repetições durante as quais foram avaliados o pico de torque (PT, trabalho total (TT e índice de fadiga (IF. ANOVA fatorial para medidas repetidas, com a análise de Post hoc por Bonferroni, foi utilizada para identificar possíveis diferenças entre os IR. O nível de significância estatístico utilizado foi de p0,05. Apesar de ter sido observado menor desempenho muscular na 3ª série em todos os IR, maiores quedas no PT, TT e IF foram observadas quando adotado o IR de 1minuto (pOBJECTIVE: To compare the effects of different rest intervals (RI between sets of isokinetic contractions on muscle performance in older adults. METHODS: Twenty older participants (66.9±3.9 years; 76.1±13.4kg; 169±5.2cm underwent three sessions of unilateral isokinetic training for the knee extensor muscles, with different RI (1 minute, 2 minutes and 3 minutes at an angular velocity of 60°•s-1. Each session consisted of three sets of 10 repetitions, during which the peak torque (PT, total work (TW and fatigue index (FI were evaluated. Factorial ANOVA for repeated measurements, with Bonferroni post-hoc analysis, was used to identify possible differences between the RI. The statistical significance level was set at p0.05. Although muscle performance was lower during the third sets with all RI, the greatest decreases in PT, TW and FI occurred with the 1 minute RI (p<0.05. CONCLUSIONS: The results showed that the RI variable has an important influence on isokinetic muscle performance in older

  8. Alpine Skiing With total knee ArthroPlasty (ASWAP): effects on strength and cardiorespiratory fitness.

    Science.gov (United States)

    Pötzelsberger, B; Stöggl, T; Lindinger, S J; Dirnberger, J; Stadlmann, M; Buchecker, M; Hofstaedter, T; Gordon, K; Müller, E

    2015-08-01

    This study investigated the effect of a 12-week recreational skiing intervention on lower limb muscle strength and cardiorespiratory fitness in participants with unilateral total knee arthroplasty (TKA). Twenty-seven older adults (70 ± 5 years) were assigned to the intervention (n = 13) or control group (n = 14) after surgery (2.5 ± 1 years). Leg muscle strength was measured using an IsoMed 2000 dynamometer and cardiorespiratory fitness was determined by cycle ergometry before and after the intervention as well as after an 8-week retention period. The skiing intervention led to increased muscle strength in the operated leg during unilateral single joint isometric extension (maximal force: 11%; P torque development: 24%; P < 0.05) and during the unilateral multi-joint isokinetic single leg strength test (8%; P < 0.05). This resulted in a decreased asymmetry index in the isokinetic test (13% to 5%; P < 0.05). These adaptations remained unchanged toward the retention test. No effect was observed for cardiorespiratory fitness. The results demonstrate that muscle contraction forces required during recreational skiing in individuals with TKA seem adequate and effective to increase quadriceps and hamstrings muscle strength in the initially weaker operated leg and to reduce an augmented post-operative asymmetry index.

  9. Gas exchange kinetics following concentric-eccentric isokinetic arm and leg exercise.

    Science.gov (United States)

    Drescher, U; Mookerjee, S; Steegmanns, A; Knicker, A; Hoffmann, U

    2017-06-01

    To evaluate the effects of exercise velocity (60, 150, 240deg∙s(-1)) and muscle mass (arm vs leg) on changes in gas exchange and arterio-venous oxygen content difference (avDO2) following high-intensity concentric-eccentric isokinetic exercise. Fourteen subjects (26.9±3.1years) performed a 3×20-repetition isokinetic exercise protocol. Recovery beat-to-beat cardiac output (CO) and breath-by-breath gas exchange were recorded to determine post-exercise half-time (t1/2) for oxygen uptake (V˙O2pulm), carbon dioxide output (V˙CO2pulm), and ventilation (V˙E). Significant differences of the t1/2 values were identified between 60 and 150deg∙s(-1). Significant differences in the t1/2 values were observed between V˙O2pulm and V˙CO2pulm and between V˙CO2pulm and V˙E. The time to attain the first avDO2-peak showed significant differences between arm and leg exercise. The present study illustrates, that V˙O2pulm kinetics are distorted due to non-linear CO dynamics. Therefore, it has to be taken into account, that V˙O2pulm may not be a valuable surrogate for muscular oxygen uptake kinetics in the recovery phases. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Is the subscapularis normal after the open Latarjet procedure? An isokinetic and magnetic resonance imaging evaluation.

    Science.gov (United States)

    Caubère, Alexandre; Lami, Damien; Boileau, Pascal; Parratte, Sébastien; Ollivier, Matthieu; Argenson, Jean-Noël

    2017-10-01

    The Latarjet procedure is considered to be a violation of the subscapularis muscle. This study evaluated the postoperative status of the subscapularis through isokinetic and magnetic resonance imaging analysis after splitting. We hypothesized that compared with a healthy contralateral shoulder, there would be satisfactory recovery of subscapularis strength at the cost of some fatigability and some mild fatty infiltration. This was a case-control retrospective study of patients who underwent a Latarjet procedure between January 2013 and January 2015. A total of 20 patients were reviewed at 1 year postoperatively. With the patient seated, strength testing of both shoulders was done (concentric, eccentric, and fatigability) with a dynamometer. Trophicity and fatty infiltration were analyzed by magnetic resonance imaging. Strength of the internal rotators (IRs) and external rotators (ERs) of the injured shoulder was significantly lower compared with the healthy shoulder in concentric testing at 180°/s and 60°/s (13% for IR and 20% for E, P Latarjet procedure, isokinetic testing showed a combined strength deficit in both internal and external rotation with a conserved muscle balance. Although no significant subscapularis fatty infiltration or atrophy was noted, there was a significant deficit in endurance compared with the healthy shoulder. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  11. Isokinetic imbalance of hip muscles in soccer players with osteitis pubis.

    Science.gov (United States)

    Mohammad, Walaa Sayed; Abdelraouf, Osama Ragaa; Elhafez, Salam Mohamed; Abdel-Aziem, Amr Almaz; Nassif, Nagui Sobhi

    2014-01-01

    In this study, we compared the isokinetic torques of hip flexors/extensors and abductors/adductors in soccer players suffering from osteitis pubis (OP), with normal soccer players. Twenty soccer male athletes with OP and 20 normal soccer athletes were included in this study. Peak torque/body weight (PT/BW) was recorded from hip flexor/extensor and abductor/adductor muscles during isokinetic concentric contraction modes at angular velocity of 2.1 rad · s(-1), for both groups. The results showed a significant difference between the normal and OP groups for hip flexors (P muscles (P > 0.05). Regarding the hip adductor/abductor PT ratio, there was no significant difference between the normal and OP groups of athletes (P > 0.05). The OP group displayed increase in hip flexor strength that disturbed the hip flexor/extensor torque ratio of OP. Therefore, increasing the hip extensor strength should be part of rehabilitation programmes of patients with OP.

  12. Arthroscopic surgery for degenerative knee

    DEFF Research Database (Denmark)

    Thorlund, J B; Juhl, C B; Roos, E M;

    2015-01-01

    OBJECTIVE: To determine benefits and harms of arthroscopic knee surgery involving partial meniscectomy, debridement, or both for middle aged or older patients with knee pain and degenerative knee disease. DESIGN: Systematic review and meta-analysis. MAIN OUTCOME MEASURES: Pain and physical function....... RESULTS: The search identified nine trials assessing the benefits of knee arthroscopic surgery in middle aged and older patients with knee pain and degenerative knee disease. The main analysis, combining the primary endpoints of the individual trials from three to 24 months postoperatively, showed a small...... included symptomatic deep venous thrombosis (4.13 (95% confidence interval 1.78 to 9.60) events per 1000 procedures), pulmonary embolism, infection, and death. CONCLUSIONS: The small inconsequential benefit seen from interventions that include arthroscopy for the degenerative knee is limited in time...

  13. Alpine Skiing With total knee ArthroPlasty (ASWAP): muscular adaptations.

    Science.gov (United States)

    Rieder, F; Kösters, A; Wiesinger, H-P; Dorn, U; Hofstaedter, T; Fink, C; Seynnes, O R; Müller, E

    2015-08-01

    This study investigated the effectiveness of recreational skiing as an intervention to improve quadriceps muscle architecture, strength, and antagonistic co-activation in patients with unilateral total knee arthroplasty (TKA). Hence, patients with TKA were assigned to either an intervention group (IG) or control group (CG). The IG completed a 12-week guided skiing program whereas the CG was instructed not to change their daily routines for the same period and was not allowed to ski. Before, after the intervention/after an 8-week retention period m. rectus femoris (RF) cross-sectional area (CSA), m. vastus lateralis muscle thickness, fascicle length, and pennation angle were measured with ultrasonography, while isometric (90° knee angle) knee extension, flexion torque and m. biceps femoris co-activation were assessed on an isokinetic dynamometer in 26 patients. There were significant and stable increases in RF CSA for the operated (10%; P  0.05). There were no significant effects for other parameters (all P > 0.05). Overall, the skiing intervention was successful in increasing muscle mass in TKA older patients.

  14. Acute Effects of Kinesio Taping on Knee Extensor Peak Torque and Stretch Reflex in Healthy Adults

    Science.gov (United States)

    Yeung, Simon S.; Yeung, Ella W.

    2016-01-01

    Abstract Kinesio Tex tape (KT) is used to prevent and treat sports-related injuries and to enhance muscle performance. It has been proposed that the direction of taping may either facilitate or inhibit the muscle by having different effects on cutaneous receptors that modulate excitability of the motor neurons. This study had 2 goals. First, we wished to determine if KT application affects muscle performance and if the method of application facilitates or inhibits muscle performance. This was assessed by measuring isokinetic knee extension peak torque in the knee extensor. Second, we assessed neurological effects of taping on the excitability of the motor neurons by measuring the reflex latency and action potential by electromyography (EMG) in the patellar reflex. The study was a single-blind, placebo-controlled crossover trial with 28 healthy volunteers with no history of knee injuries. Participants received facilitative KT treatment, inhibitory KT treatment, or Hypafix taping of the knee extensor. There were significant differences in the peak torque between 3 treatments (F(2,54) = 4.873, P < 0.01). Post hoc analysis revealed that facilitative KT treatment resulted in higher knee extensor peak torque performance than inhibitory KT treatment (P = 0.036, effect size 0.26). There were, however, no significant differences in the reflex latency (F(2,54) = 2.84, P = 0.067) nor in the EMG values (F(2,54) = 0.18, P = 0.837) in the patellar reflex between the 3 taping applications. The findings suggest that the direction of KT application over the muscle has specific effects on muscle performance. Given the magnitude of effect is small, interpretation of clinical significance should be considered with caution. The underlying mechanism warrants further investigation. PMID:26825916

  15. Knee flexor strength recovery following hamstring tendon harvest for anterior cruciate ligament reconstruction: a systematic review

    Directory of Open Access Journals (Sweden)

    Clare Ardern

    2009-07-01

    Full Text Available The hamstring tendons are an increasingly popular graft choice for anterior cruciate ligament reconstruction due to preservation of quadriceps function and the absence of anterior knee pain post-operatively. Two commonly used hamstring grafts are a quadruple strand semitendinosus graft (4ST and a double strand semitendinosus-double strand gracilis graft (2ST-2G. It has been suggested that concurrent harvest of the semitendinsous and gracilis tendons may result in sub-optimal hamstring strength recovery as the gracilis may play a role in reinforcing the semitendinosus particularly in deep knee flexion angles. The objective of this systematic review was to synthesize the findings of available literature and determine whether semitendinosus and gracilis harvest lead to post-operative hamstring strength deficits when compared to semitendinosus harvest alone. Seven studies were identified which compared hamstring strength outcomes between the common hamstring graft types. The methodological quality of each paper was assessed, and where possible effect sizes were calculated to allow comparison of results across studies. No differences were reported between the groups in isokinetic hamstring strength. Deficits in hamstring strength were reported in the 2ST-2G groups when compared to the 4ST groups in isometric strength testing at knee flexion angles ≥70°, and in the standing knee flexion angle. Preliminary evidence exists to support the hypothesis that harvesting the semitendinosus tendon alone is preferable to harvesting in combination with the gracilis tendon for minimizing post-operative hamstring strength deficits at knee flexion angles greater than 70°. However, due to the paucity of research comparing strength outcomes between the common hamstring graft types, further investigation is warranted to fully elucidate the implications for graft harvest.

  16. Effects of Quadriceps Muscle Fatigue on Stiff-Knee Gait in Patients with Hemiparesis

    Science.gov (United States)

    Boudarham, Julien; Roche, Nicolas; Pradon, Didier; Delouf, Eric; Bensmail, Djamel; Zory, Raphael

    2014-01-01

    The relationship between neuromuscular fatigue and locomotion has never been investigated in hemiparetic patients despite the fact that, in the clinical context, patients report to be more spastic or stiffer after walking a long distance or after a rehabilitation session. The aim of this study was to evaluate the effects of quadriceps muscle fatigue on the biomechanical gait parameters of patients with a stiff-knee gait (SKG). Thirteen patients and eleven healthy controls performed one gait analysis before a protocol of isokinetic quadriceps fatigue and two after (immediately after and after 10 minutes of rest). Spatiotemporal parameters, sagittal knee and hip kinematics, rectus femoris (RF) and vastus lateralis (VL) kinematics and electromyographic (EMG) activity were analyzed. The results showed that quadriceps muscle weakness, produced by repetitive concentric contractions of the knee extensors, induced an improvement of spatiotemporal parameters for patients and healthy subjects. For the patient group, the increase in gait velocity and step length was associated with i) an increase of sagittal hip and knee flexion during the swing phase, ii) an increase of the maximal normalized length of the RF and VL and of the maximal VL lengthening velocity during the pre-swing and swing phases, and iii) a decrease in EMG activity of the RF muscle during the initial pre-swing phase and during the latter 2/3 of the initial swing phase. These results suggest that quadriceps fatigue did not alter the gait of patients with hemiparesis walking with a SKG and that neuromuscular fatigue may play the same functional role as an anti-spastic treatment such as botulinum toxin-A injection. Strength training of knee extensors, although commonly performed in rehabilitation, does not seem to be a priority to improve gait of these patients. PMID:24718087

  17. Acute Effects of Kinesio Taping on Knee Extensor Peak Torque and Stretch Reflex in Healthy Adults.

    Science.gov (United States)

    Yeung, Simon S; Yeung, Ella W

    2016-01-01

    Kinesio Tex tape (KT) is used to prevent and treat sports-related injuries and to enhance muscle performance. It has been proposed that the direction of taping may either facilitate or inhibit the muscle by having different effects on cutaneous receptors that modulate excitability of the motor neurons. This study had 2 goals. First, we wished to determine if KT application affects muscle performance and if the method of application facilitates or inhibits muscle performance. This was assessed by measuring isokinetic knee extension peak torque in the knee extensor. Second, we assessed neurological effects of taping on the excitability of the motor neurons by measuring the reflex latency and action potential by electromyography (EMG) in the patellar reflex. The study was a single-blind, placebo-controlled crossover trial with 28 healthy volunteers with no history of knee injuries. Participants received facilitative KT treatment, inhibitory KT treatment, or Hypafix taping of the knee extensor. There were significant differences in the peak torque between 3 treatments (F(2,54) = 4.873, P < 0.01). Post hoc analysis revealed that facilitative KT treatment resulted in higher knee extensor peak torque performance than inhibitory KT treatment (P = 0.036, effect size 0.26). There were, however, no significant differences in the reflex latency (F(2,54) = 2.84, P = 0.067) nor in the EMG values (F(2,54) = 0.18, P = 0.837) in the patellar reflex between the 3 taping applications. The findings suggest that the direction of KT application over the muscle has specific effects on muscle performance. Given the magnitude of effect is small, interpretation of clinical significance should be considered with caution. The underlying mechanism warrants further investigation.

  18. Effects of quadriceps muscle fatigue on stiff-knee gait in patients with hemiparesis.

    Directory of Open Access Journals (Sweden)

    Julien Boudarham

    Full Text Available The relationship between neuromuscular fatigue and locomotion has never been investigated in hemiparetic patients despite the fact that, in the clinical context, patients report to be more spastic or stiffer after walking a long distance or after a rehabilitation session. The aim of this study was to evaluate the effects of quadriceps muscle fatigue on the biomechanical gait parameters of patients with a stiff-knee gait (SKG. Thirteen patients and eleven healthy controls performed one gait analysis before a protocol of isokinetic quadriceps fatigue and two after (immediately after and after 10 minutes of rest. Spatiotemporal parameters, sagittal knee and hip kinematics, rectus femoris (RF and vastus lateralis (VL kinematics and electromyographic (EMG activity were analyzed. The results showed that quadriceps muscle weakness, produced by repetitive concentric contractions of the knee extensors, induced an improvement of spatiotemporal parameters for patients and healthy subjects. For the patient group, the increase in gait velocity and step length was associated with i an increase of sagittal hip and knee flexion during the swing phase, ii an increase of the maximal normalized length of the RF and VL and of the maximal VL lengthening velocity during the pre-swing and swing phases, and iii a decrease in EMG activity of the RF muscle during the initial pre-swing phase and during the latter 2/3 of the initial swing phase. These results suggest that quadriceps fatigue did not alter the gait of patients with hemiparesis walking with a SKG and that neuromuscular fatigue may play the same functional role as an anti-spastic treatment such as botulinum toxin-A injection. Strength training of knee extensors, although commonly performed in rehabilitation, does not seem to be a priority to improve gait of these patients.

  19. Effects of quadriceps muscle fatigue on stiff-knee gait in patients with hemiparesis.

    Science.gov (United States)

    Boudarham, Julien; Roche, Nicolas; Pradon, Didier; Delouf, Eric; Bensmail, Djamel; Zory, Raphael

    2014-01-01

    The relationship between neuromuscular fatigue and locomotion has never been investigated in hemiparetic patients despite the fact that, in the clinical context, patients report to be more spastic or stiffer after walking a long distance or after a rehabilitation session. The aim of this study was to evaluate the effects of quadriceps muscle fatigue on the biomechanical gait parameters of patients with a stiff-knee gait (SKG). Thirteen patients and eleven healthy controls performed one gait analysis before a protocol of isokinetic quadriceps fatigue and two after (immediately after and after 10 minutes of rest). Spatiotemporal parameters, sagittal knee and hip kinematics, rectus femoris (RF) and vastus lateralis (VL) kinematics and electromyographic (EMG) activity were analyzed. The results showed that quadriceps muscle weakness, produced by repetitive concentric contractions of the knee extensors, induced an improvement of spatiotemporal parameters for patients and healthy subjects. For the patient group, the increase in gait velocity and step length was associated with i) an increase of sagittal hip and knee flexion during the swing phase, ii) an increase of the maximal normalized length of the RF and VL and of the maximal VL lengthening velocity during the pre-swing and swing phases, and iii) a decrease in EMG activity of the RF muscle during the initial pre-swing phase and during the latter 2/3 of the initial swing phase. These results suggest that quadriceps fatigue did not alter the gait of patients with hemiparesis walking with a SKG and that neuromuscular fatigue may play the same functional role as an anti-spastic treatment such as botulinum toxin-A injection. Strength training of knee extensors, although commonly performed in rehabilitation, does not seem to be a priority to improve gait of these patients.

  20. Estimation of Electrically-Evoked Knee Torque from Mechanomyography Using Support Vector Regression

    Directory of Open Access Journals (Sweden)

    Morufu Olusola Ibitoye

    2016-07-01

    Full Text Available The difficulty of real-time muscle force or joint torque estimation during neuromuscular electrical stimulation (NMES in physical therapy and exercise science has motivated recent research interest in torque estimation from other muscle characteristics. This study investigated the accuracy of a computational intelligence technique for estimating NMES-evoked knee extension torque based on the Mechanomyographic signals (MMG of contracting muscles that were recorded from eight healthy males. Simulation of the knee torque was modelled via Support Vector Regression (SVR due to its good generalization ability in related fields. Inputs to the proposed model were MMG amplitude characteristics, the level of electrical stimulation or contraction intensity, and knee angle. Gaussian kernel function, as well as its optimal parameters were identified with the best performance measure and were applied as the SVR kernel function to build an effective knee torque estimation model. To train and test the model, the data were partitioned into training (70% and testing (30% subsets, respectively. The SVR estimation accuracy, based on the coefficient of determination (R2 between the actual and the estimated torque values was up to 94% and 89% during the training and testing cases, with root mean square errors (RMSE of 9.48 and 12.95, respectively. The knee torque estimations obtained using SVR modelling agreed well with the experimental data from an isokinetic dynamometer. These findings support the realization of a closed-loop NMES system for functional tasks using MMG as the feedback signal source and an SVR algorithm for joint torque estimation.

  1. Bilateral knee replacements for treatment of acute septic arthritis in both knees.

    Science.gov (United States)

    Ashraf, Muhammad Omer; Asumu, Theophilus

    2013-11-01

    A case report of bilateral acute septic arthritis of knees is presented, which was managed with staged total knee replacements for both knees. A literature review on septic arthritis treated with knee arthroplasty is also presented.

  2. Voluntary attention increases perceived spatial frequency.

    Science.gov (United States)

    Abrams, Jared; Barbot, Antoine; Carrasco, Marisa

    2010-08-01

    Voluntary covert attention selects relevant sensory information for prioritized processing. The behavioral and neural consequences of such selection have been extensively documented, but its phenomenology has received little empirical investigation. Involuntary attention increases perceived spatial frequency (Gobell & Carrasco, 2005), but involuntary attention can differ from voluntary attention in its effects on performance in tasks mediated by spatial resolution (Yeshurun, Montagna, & Carrasco, 2008). Therefore, we ask whether voluntary attention affects the subjective appearance of spatial frequency--a fundamental dimension of visual perception underlying spatial resolution. We used a demanding rapid serial visual presentation task to direct voluntary attention and measured perceived spatial frequency at the attended and unattended locations. Attention increased the perceived spatial frequency of suprathreshold stimuli and also improved performance on a concurrent orientation discrimination task. In the control experiment, we ruled out response bias as an alternative account by using a lengthened interstimulus interval, which allows observers to disengage attention from the cued location. In contrast to the main experiment, the observers showed neither increased perceived spatial frequency nor improved orientation discrimination at the attended location. Thus, this study establishes that voluntary attention increases perceived spatial frequency. This phenomenological consequence links behavioral and neurophysiological studies on the effects of attention.

  3. Anterior knee pain

    Science.gov (United States)

    ... Armstrong B. Rehabilitation of the knee following sports injury. Clin Sports Med. 2010;29:81-106. PMID: 19945588 www. ... by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic ... and Disorders Browse the Encyclopedia A.D.A. ...

  4. Unicompartmental knee arthroplasty

    NARCIS (Netherlands)

    Kort, Nanne Pieter

    2007-01-01

    This thesis concerns technical aspects of unicompartmental knee arthroplasty. Recent years have witnessed a resurgence of interest in unicompartmental arthroplasty, particularly with the introduction of the minimally invasive technique. In the light of the excellent long-term results of the total kn

  5. Knee injuries in football

    African Journals Online (AJOL)

    estimated 240 million (in 2000)1 to 265 million (in 2006)2 players ... injuries during a season, but due to variations in the definition of ... a risk for a major knee injury, with 20% of illegal activity-related ... Rob Collins is a lecturer in the Section Sports Medicine at the University of .... full return to football is between 6 and 9.

  6. A MULTI-STATION PROPRIOCEPTIVE EXERCISE PROGRAM IN PATIENTS WITH BILATERAL KNEE OSTEOARTHROSIS: FUNCTIONAL CAPACITY, PAIN AND SENSORIOMOTOR FUNCTION. A RANDOMIZED CONTROLLED TRIAL

    Directory of Open Access Journals (Sweden)

    Ufuk Sekir

    2005-12-01

    Full Text Available We investigated the effects of a multi-station proprioceptive exercise program on functional capacity, perceived knee pain, and sensoriomotor function. Twenty-two patients (aged 41-75 years with grade 2-3 bilateral knee osteoarthrosis were randomly assigned to two groups: treatment (TR; n = 12 and non-treatment (NONTR; n = 10. TR performed 11 different balance/coordination and proprioception exercises, twice a week for 6 weeks. Functional capacity and perceived knee pain during rest and physical activity was measured. Also knee position sense, kinaesthesia, postural control, isometric and isokinetic knee strength (at 60, 120 and 180°·s-1 measures were taken at baseline and after 6 weeks of training. There was no significant difference in any of the tested variables between TR and NONTR before the intervention period. In TR perceived knee pain during daily activities and functional tests was lessened following the exercise program (p < 0.05. Perceived knee pain was also lower in TR vs. NONTR after training (p < 0.05. The time for rising from a chair, stair climbing and descending improved in TR (p < 0.05 and these values were faster compared with NONTR after training (p < 0.05. Joint position sense (degrees for active and passive tests and for weight bearing tests improved in TR (p < 0.05 and the values were lower compared with NONTR after training (p < 0.05. Postural control ('eyes closed' also improved for single leg and tandem tests in TR (p < 0.01 and these values were higher compared with NONTR after training. The isometric quadriceps strength of TR improved (p < 0.05 but the values were not significantly different compared with NONTR after training. There was no change in isokinetic strength for TR and NONTR after the training period. The results suggest that using a multi-station proprioceptive exercise program it is possible to improve postural control, functional capacity and decrease perceived knee pain in patients with bilateral knee

  7. Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability

    Science.gov (United States)

    Gustafson, Jonathan A.; Gorman, Shannon; Fitzgerald, G. Kelley; Farrokhi, Shawn

    2017-01-01

    Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (pknee flexion excursions (pknee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted. PMID:26481256

  8. Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability.

    Science.gov (United States)

    Gustafson, Jonathan A; Gorman, Shannon; Fitzgerald, G Kelley; Farrokhi, Shawn

    2016-01-01

    Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (pknee flexion excursions (pknee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted.

  9. Custom Knee Device for Knee Contractures After Internal Femoral Lengthening.

    Science.gov (United States)

    Bhave, Anil; Shabtai, Lior; Ong, Peck-Hoon; Standard, Shawn C; Paley, Dror; Herzenberg, John E

    2015-07-01

    The development of knee flexion contractures is among the most common problems and complications associated with lengthening the femur with an internal device or external fixator. Conservative treatment strategies include physical therapy, serial casting, and low-load prolonged stretching with commercially available splinting systems. The authors developed an individually molded, low-cost custom knee device with polyester synthetic conformable casting material to treat knee flexion contractures. The goal of this study was to evaluate the results of treatment with a custom knee device and specialized physical therapy in patients who had knee flexion contracture during femoral lengthening with an intramedullary lengthening femoral nail. This retrospective study included 23 patients (27 limbs) who underwent femoral lengthening with an internal device for the treatment of limb length discrepancy. All patients had a knee flexion contracture raging from 10° to 90° during the lengthening process and were treated with a custom knee device and specialized physical therapy. The average flexion contracture before treatment was 36°. The mean amount of lengthening was 5.4 cm. After an average of 3.8 weeks of use of the custom knee device, only 2 of 27 limbs (7.5%) had not achieved complete resolution of the flexion contracture. The average final extension was 1.4°. Only 7 of 27 limbs (26%) required additional soft tissue release. The custom knee device is an inexpensive and effective method for treating knee flexion contracture after lengthening with an internal device.

  10. Component rotation and anterior knee pain after total knee arthroplasty.

    Science.gov (United States)

    Barrack, R L; Schrader, T; Bertot, A J; Wolfe, M W; Myers, L

    2001-11-01

    All patients undergoing cruciate-retaining primary total knee arthroplasty for degenerative osteoarthritis at one center were studied prospectively. Clinical and radiographic followup was obtained at a minimum 5 years in 102 knees in 73 patients. Patients were asked specifically about the presence of the pain in the anterior aspect of the knee in the vicinity of the patella and rated the severity of the pain on a visual analog scale. Significant anterior knee pain rating at least 3 of 10 on the visual analog scale was present in 16 knees (13 patients). Eleven patients with 14 symptomatic knees agreed to undergo computed tomography scanning to accurately determine the rotation of the tibial and femoral components. The epicondylar axis and tibial tubercle were used as references using a previously validated technique. A control group of 11 asymptomatic patients (14 knees), matched for age, gender, and length of followup also underwent computed tomography scanning. All patients in both groups had normal axial alignment. There was a highly significant difference in tibial component rotation between the two groups with the patients with anterior knee pain averaging 6.2 degrees internal rotation compared with 0.4 degrees external rotation in the control group. There also was a significant difference in combined component rotation with the patients with anterior knee pain averaging 4.7 degrees internal rotation compared with 2.6 degrees external rotation in the control group. There was no significant difference in the degree of radiographic patellar tilt or patellar subluxation between the two groups. Patients with combined component internal rotation were more than five times as likely to experience anterior knee pain after total knee arthroplasty compared with those with combined component external rotation. Component malrotation is a significant factor in the development of anterior knee pain after total knee arthroplasty.

  11. Research on Isokinetic Strength Training of Guangxi Female Sprinter%广西女子短跑运动员等速力量训练研究

    Institute of Scientific and Technical Information of China (English)

    黄志平

    2014-01-01

    目的:通过对广西女子4×100米接力队5名运动员下肢髋、膝、踝关节屈伸肌群进行肌力等速测试与训练,为女子短跑运动员的力量训练提供新的方法手段。方法:使用美国Biodex System 3 Pro多关节等速肌力测试与训练系统,采用低速(60°/s)×8次、中速(120°/s)×15次、高速(180°/s)×25次,三种角速度进行训练,每种速度练习2组,每周训练2次,共8周的训练。结果:(1)广西女子短跑运动员髋、膝、踝三关节屈伸肌群峰值力矩在训练前后都随角速度的提高而减小。(2)经8周等速肌力训练后,女子短跑运动员髋、膝、踝三关节屈伸肌力都有明显增大,髋关节屈伸肌群肌力训练前后峰值力矩比率都低于60%,踝关节屈伸肌群峰值力矩比率均低于30%。结论:使用多关节等速肌力测试与训练系统进行力量训练,可有效提高女子短跑运动员的肌肉力量,提高爆发力,训练后两侧同名屈伸肌群力量比率更合理,女子短跑运动员需针对性加强髋关节屈髋肌群和踝关节屈伸肌群力量训练。%Objective:through isokinetic testing and training for flexion and extension muscle group of hip , knee, ankle of five athletes of Guangxi female 4 ×100 meters relay, offering a new training method for strength of female sprinter .Methods:using the constant speed multiple -joints muscle strength testing and training system( Biodex System 3 Pro), training with 3 angular velocity ,that is, low speed (60 °/s) ×8 times, medium speed (120 °/s) ×15 times, high speed (180 °/s) ×25 times, practicing 2 set of each velocity, training twice a week, a total of eight weeks of training .Results:(1) the peaks moment value of flexion and extension muscle group of the hip , knee and ankle joints of Guangxi female sprinters decreases with the increase of angular velocity before and after training .( 2 ) after 8 weeks isokinetic

  12. From Voluntary Collective Action to Organized Collaboration?

    DEFF Research Database (Denmark)

    Hattke, Fabian; Blaschke, Steffen; Frost, Jetta

    2016-01-01

    internationalization. Based on our results, we suggest that, depending on the field of action, voluntary collective action and organized collaboration are substitutes with regard to performance. Our study contributes to the literature on collective action and to research on public organizations in pluralistic......Our study examines the relationship between voluntary collective action, organized collaboration, and the provision of public goods in pluralistic organizations. Using German higher education as a context, we investigate whether specialized central support structures contribute to performance...... in three fields of action: the training of young scientists, internationalization, and gender diversity. The findings indicate that organized collaboration may lead to improved performance in the training of young scientists and gender diversity. Conversely, voluntary collective action enhances...

  13. Voluntary reporting of greenhouse gases, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    The Voluntary Reporting Program for greenhouse gases is part of an attempt by the U.S. Government to develop innovative, low-cost, and nonregulatory approaches to limit emissions of greenhouse gases. It is one element in an array of such programs introduced in recent years as part of the effort being made by the United States to comply with its national commitment to stabilize emissions of greenhouse gases under the Framework Convention on Climate Change. The Voluntary Reporting Program, developed pursuant to Section 1605(b) of the Energy Policy Act of 1992, permits corporations, government agencies, households, and voluntary organizations to report to the Energy Information Administration (EIA) on actions taken that have reduced or avoided emissions of greenhouse gases.

  14. Knee injuries and Alpine skiing. Treatment and rehabilitation.

    Science.gov (United States)

    Paletta, G A; Warren, R F

    1994-06-01

    Alpine skiing is an increasingly popular recreational sport worldwide. While the overall injury rate has declined and the pattern of injury changed over the years, the incidence of knee injuries has not changed substantially and accounts for 20 to 30% of all alpine skiing injuries. Medial collateral ligament (MCL) injuries are the most common in skiing, accounting for 15 to 20% of all skiing injuries and 60% of knee injuries in skiers. Tears are commonly isolated, but may occur in association with other ligamentous injuries. Associated meniscal pathology is rare. Isolated MCL injuries are treated nonoperatively with a programme of initial immobilisation, early range-of-motion, and isometric quadriceps strengthening exercises. When full range of motion is achieved, a programme of progressive resistance exercises, isokinetic and closed chain exercises, and functional rehabilitation is instituted. Good results with return to skiing can be expected in most cases. Isolated lateral collateral ligament (LCL) injuries are rare in skiers. There is usually associated cruciate or arcuate ligament complex. Careful physical examination is essential to rule out associated ligament injuries and more complex instability patterns. In the rare case of isolated LCL injury, a similar approach to isolated MCL injury should be instituted. Anterior cruciate ligament (ACL) injuries have become increasingly common in skiers. This may reflect a true increase in the incidence or an improved awareness and ability to diagnose ACL injury. Physical examination and arthrometric analysis are important in assessing the integrity of the ACL. Radiographic and magnetic resonance imaging (MRI) evaluation may be helpful in assessing associated meniscal pathology. Treatment of the ACL-deficient knee is usually surgical. However, prior to reconstruction, a programme aimed at reducing effusion and regaining a full, pain-free range of motion is recommended. Surgical reconstruction is usually with the

  15. The effect of gender on force, muscle activity, and frontal plane knee alignment during maximum eccentric leg-press exercise.

    Science.gov (United States)

    Liebensteiner, Michael C; Platzer, Hans-Peter; Burtscher, Martin; Hanser, Friedrich; Raschner, Christian

    2012-03-01

    To investigate for gender differences during eccentric leg-press exercise. Tears of the anterior cruciate ligament (ACL) are considered to be related to eccentric tasks, altered neuromuscular control (e.g., reduced co-contraction of hamstrings), and increased knee abduction (valgus alignment). Based on these observations and the fact that ACL tears are more common in women, it was hypothesized that men and women differ significantly with regard to key parameters of force, knee stabilization, and muscle activity when exposed to maximum eccentric leg extension. Thirteen women and thirteen men were matched for age and physical activity. They performed maximum isokinetic eccentric leg-pressing against footplates of varied stability. The latter was done because earlier studies had shown that perturbational test conditions might be relevant in respect of ACL injuries. Key parameters of force, frontal plane knee stabilization, and muscle recruitment of significant muscles crossing the knee were recorded. The 'force stabilization deficit' (difference between maximum forces under normal and perturbed leg-pressing) did not differ significantly between genders. Likewise, parameters of muscle activity and frontal plane leg stabilization revealed no significant differences between men and women. This study is novel, in that gender differences in parameters of force, muscle activity, and leg kinematic were investigated during functional conditions of eccentric leg-pressing. No gender differences were observed in the measured parameters. However, the conclusion should be viewed with caution because the findings concurred with, but also contrasted, previous research in this field. Diagnostic study, Level III.

  16. Effects of knee joint angle on the fascicle behavior of the gastrocnemius muscle during eccentric plantar flexions.

    Science.gov (United States)

    Wakahara, Taku; Kanehisa, Hiroaki; Kawakami, Yasuo; Fukunaga, Tetsuo

    2009-10-01

    The present study aimed to clarify the effects of knee joint angle on the behavior of the medial gastrocnemius muscle (MG) fascicles during eccentric plantar flexions. Eight male subjects performed maximal eccentric plantar flexions at two knee positions [fully extended (K0) and 90 degrees flexed (K90)]. The eccentric actions were preceded by static plantar flexion at a 30 degrees plantar flexed position and then the ankle joint was forcibly dorsiflexed to 15 degrees of dorsiflexion with an isokinetic dynamometer at 30 degrees /s and 150 degrees /s. Tendon force was calculated by dividing the plantar flexion torque by the estimated moment arm of the Achilles tendon. The MG fascicle length was determined with ultrasonography. The tendon forces during eccentric plantar flexions were influenced by the knee joint angle, but not by the angular velocity. The MG fascicle lengths were elongated as the ankle was dorsiflexed in K0, but in K90 they were almost constant despite the identical range of ankle joint motion. These results suggested that MG fascicle behavior during eccentric actions was markedly affected by the knee joint angle. The difference in the fascicle behavior between K0 and K90 could be attributed to the non-linear force-length relations and/or to the slackness of tendinous tissues.

  17. BMD in elite female triathletes is related to isokinetic peak torque without any association to sex hormone concentrations

    DEFF Research Database (Denmark)

    Wulff Helge, E; Melin, Anna Katarina; Waaddegaard, M

    2012-01-01

    Female endurance athletes suffering from low energy availability and reproductive hormonal disorders are at risk of low BMD. Muscle forces acting on bone may have a reverse site-specific effect. Therefore we wanted to test how BMD in female elite triathletes was associated to isokinetic peak torque...

  18. Isokinetic muscle performance and salivary immune-endocrine responses in handball players by Fourier transform infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    P.C. Caetano Júnior

    2017-09-01

    Conclusions: The handball players had good muscle performance of the lower limbs in the isokinetic evaluation. The Fourier transform infrared spectroscopy analysis identified the main absorption bands of cortisol and salivary cortisol and immunoglobulin A, as well as playing positions that demand higher stress levels, through changes of bands related to salivary cortisol.

  19. Effects of Two Warm-up Programs on Balance and Isokinetic Strength in Male High School Soccer Players.

    Science.gov (United States)

    Ghareeb, Dana M; McLaine, Alice J; Wojcik, Janet R; Boyd, Joni M

    2017-02-01

    Ghareeb, DM, McLaine, AJ, Wojcik, JR, and Boyd, JM. Effects of two warm-up programs on balance and isokinetic strength in male high school soccer players. J Strength Cond Res 31(2): 372-379, 2017-One of the most common warm-up programs used to prevent injury in soccer, FIFA11+, integrates aerobic, strength, and balance. The purpose of this study was to compare FIFA11+ to a new warm-up program (NWP) on balance and isokinetic strength of the quadriceps and hamstrings at 60, 180, and 300°·s in male high school soccer players. Participants at one school (n = 17) performed the NWP before practice for 6 weeks during one soccer season, whereas participants at another school (n = 17) performed FIFA11+. There were no differences at baseline. At posttest, players in NWP significantly improved (p 1.3. No changes were seen in FIFA11+. Isokinetic strength peak torque increased at 60°·s in the quadriceps and hamstrings in dominant and nondominant legs in NWP (p soccer conditioning by improving balance and isokinetic strength.

  20. BMD in elite female triathletes is related to isokinetic peak torque without any association to sex hormone concentrations

    DEFF Research Database (Denmark)

    Helge, Eva Wulff; Melin, Anna; Waaddegaard, Mette

    2012-01-01

    Female endurance athletes suffering from low energy availability and reproductive hormonal disorders are at risk of low BMD. Muscle forces acting on bone may have a reverse site-specific effect. Therefore we wanted to test how BMD in female elite triathletes was associated to isokinetic peak torq...

  1. Hemochromatosis Patients as Voluntary Blood Donors

    Directory of Open Access Journals (Sweden)

    Tara E Power

    2004-01-01

    Full Text Available The present study was designed to investigate hemochromatosis patients' suitability as blood donors as well as their perceptions and experience with the current public donation system. Participants were gathered from a list of current hemochromatosis patients (n=120 and members of the Canadian Hemochromatosis Society (n=1000. Of the 1120 surveys mailed out to these groups, 801 surveys were returned completed. The sample respondents had a mean age of 57.44 years (SD=12.73; range 19 to 87 years, and 57% were men. It was found that 20% (160 of the respondents have donated blood since their diagnosis; however, only 12% of the respondents indicated that they use voluntary blood donation as a means of maintaining their iron levels. Forty per cent of the respondents indicated that they had been refused from voluntary donation. Despite the fact that in May 2001 the Canadian Blood Services, in collaboration with the Canadian Hemochromatosis Society, began a promotion campaign to encourage hemochromatosis patients to become voluntary blood donors, the present study found that 15% of the respondents reported having been refused from the voluntary blood donation service due to the diagnosis of hemochromatosis. With respect to quality of life, it was found that individuals who donate blood were generally healthier with respect to physical functioning and bodily pain, however, these findings may indicate that hemochromatosis patients who are healthier are better able to donate at public blood banks, rather than that voluntary blood donation has an effect on the donors' physical functioning over phlebotomy clinic users. These study findings suggest that although there may be other medical factors limiting individuals from donating, hemochromatosis patients are interested in being voluntary blood donors and this potential resource is currently under-used.

  2. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  3. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  4. Whole-body vibration does not influence knee joint neuromuscular function or proprioception.

    Science.gov (United States)

    Hannah, R; Minshull, C; Folland, J P

    2013-02-01

    This study examined the acute effects of whole-body vibration (WBV) on knee joint position sense and indices of neuromuscular function, specifically strength, electromechanical delay and the rate of force development. Electromyography and electrically evoked contractions were used to investigate neural and contractile responses to WBV. Fourteen healthy males completed two treatment conditions on separate occasions: (1) 5 × 1 min of unilateral isometric squat exercise on a synchronous vibrating platform [30 Hz, 4 mm peak-to-peak amplitude] (WBV) and (2) a control condition (CON) of the same exercise without WBV. Knee joint position sense (joint angle replication task) and quadriceps neuromuscular function were assessed pre-, immediately-post and 1 h post-exercise. During maximum voluntary knee extensions, the peak force (PF(V)), electromechanical delay (EMD(V)), rate of force development (RFD(V)) and EMG of the quadriceps were measured. Twitch contractions of the knee extensors were electrically evoked to assess EMD(E) and RFD(E). The results showed no influence of WBV on knee joint position, EMD(V), PF(V) and RFD(V) during the initial 50, 100 or 150 ms of contraction. Similarly, electrically evoked neuromuscular function and neural activation remained unchanged following the vibration exercise. A single session of unilateral WBV did not influence any indices of thigh muscle neuromuscular performance or knee joint proprioception.

  5. Isokinetic Muscle Strength Testing on Three Lower Ex-tremity Joints of Weightlifting Athletes%举重运动员下肢三关节等速肌力测试分析

    Institute of Scientific and Technical Information of China (English)

    黄志平; 刘敏; 尹彦

    2014-01-01

    [Objective]Testing the extension and flexion isokinetic torque of hip,knee and ankle was conducted in Guangxi weightlifters.The extension and flexion muscle strength and its ratio of peak extension and flexion muscle strength at different perspectives were studied in order to identify the weak muscles and to provide scientific basis for athletes'strength training.[Meth-ods]The American Biodex System 3 Pro joint isokinetic strength testing and training system was used to measure hip ,knee,ankle extension and flexion of muscle isokinetic peak torque in 16 Guangxi weightlifters under the speed of 60°/s、180°/s、240°/s.[Results](1 )The male weightlifters' hip,knee,ankle extension and flexion of muscle isokinetic peak torque are greater than the female weightlifters,and both male and female weightlifters'velocity decreases with the increase of speed(60~240°/s);The ex-tension and flexion muscle strength peak torque of male weightlifters'left hip peak torque at me-dium speed(180°/s)and higher speed(240°/s)is significantly lower than that of right hip.The extension and flexion muscle strength peak torque of male weightlifters'right knee at low(60°/s)speed is relatively lower than that of left knee.(2)When the speed changes from low (60°/s) to high speed(240°/s),the ratio of female weightlifters'right hip extension and flexion peak torque decreases significantly larger than the male weightlifters.The ratio of extension and flexion muscle strength peak torque varies greatly in both left and right knees at lower speed (60°/s)for male weightlifters,but at lower speed(60°/s)as well as higher speed(240°/s)for fe-male weightlifters.The ratio of weightlifters'ankle dorsiflexion and planter flexion strength is maximum at medium speed(180°/s),while it is minimum at high speed(240°/s)for the male weightlifters and at low speed(60°/s)for the female weightlifters.[Conclusion]The isokinetic muscle strength of Guangxi weightlifters is imbalance at both sides of hip,knee

  6. The institutional dynamics of voluntary organisations

    DEFF Research Database (Denmark)

    Aagaard, Peter

    this theoretical frame to analyse case studies of three voluntary organisations.  As a part of the analysis I describe four sets of institutional settings that can influence voluntary organisations ability to create institutional dynamic: institutionalization, moderation, self-organisation and loose-coupling....... organisations. I establish a theoretical frame of institutional dynamic, build primarily on J.G. March's theory on exploration and exploitation. I focus on two organisational arrangements drawn from the theory: The degree of strategic decision-making and the degree of diversity among the volunteers. I use...

  7. Nonoperative treatment of acute knee ligament injuries. A review with special reference to indications and methods.

    Science.gov (United States)

    Kannus, P; Järvinen, M

    1990-04-01

    Nonoperative treatment has received little attention in the numerous scientific reports on knee ligament injuries. Great controversy still exists concerning the proper treatment of a knee with a ruptured ligament, especially the anterior cruciate ligament. However, according to the studies of the authors and an extensive review of the literature the indications for conservative management can be established to be all grade I and II sprains (partial tears) of knee ligaments as well as an isolated grade III sprain (complete tear) of the posterior cruciate ligament. In addition, an isolated complete rupture of an anterior cruciate, or medial or lateral collateral ligament may be treated nonoperatively in an older sedentary person. Other injuries obviously call for an operative approach at the acute stage. Nonoperative therapy protocols must be based on the knowledge of the biological phenomenon occurring during connective tissue healing process. In the first phase of ligament healing the injured knee needs 2 to 3 weeks immobilisation for undisturbed fibroblast invasion and proliferation of collagen fibres. This is achieved by immobilising the knee in a rehabilitative knee brace locked in 40 to 45 degrees of flexion. Thereafter, a gradually increasing controlled mobilisation is allowed in the brace to avoid the deleterious effects of immobilisation to cartilage, bone, muscles, tendons and ligaments, and to enhance the orientation of collagen fibres to the stress lines of the healing ligament. After 4 to 8 weeks the goal for rehabilitation is rapid and full recovery to work and sports. A functional knee brace may be used at this phase to give extra protection before final strengthening of the injured ligament. During the mobilisation and muscle training of the therapy protocol various specific techniques can be used for strengthening of the hamstring and quadriceps muscles, including isometric, isotonic, isokinetic and eccentric exercises with or without resistive

  8. Does knee awareness differ between different knee arthroplasty prostheses?

    DEFF Research Database (Denmark)

    Thomsen, Morten G; Latifi, Roshan; Kallemose, Thomas

    2016-01-01

    BACKGROUND: Low knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations. To accommodate this manufacturers of TKAs have developed new prosthetic designs that potentially could give patients a more...... natural feeling knee during activities. The purpose af this study was to compare the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) of patients treated with a previous generation standard Cruciate Retaining (CR) TKA to the scores obtained by patients treated with a newer generation CR TKA...... and pre- and postoperative knee alignment. Patients were asked to complete the FJS and OKS questionnaires. Of the 316 patients completing the survey 64 standard CR TKAs to 35 new generation CR TKAs and 121 standard CR TKAs to 68 mobile bearing TKAs were matched. The FJS and OKS scores of the three TKA...

  9. Dental occlusion influences knee muscular performances in asymptomatic females.

    Science.gov (United States)

    Grosdent, Stéphanie; O'Thanh, Roseline; Domken, Olivier; Lamy, Marc; Croisier, Jean-Louis

    2014-02-01

    Some authors claim that occlusal appliances can enhance athletic performance. Therefore, this study investigated the influence of dental occlusion on knee muscle strength performance. Twelve healthy female subjects (mean age, 24.1 ± 3.1 years) without temporomandibular joint dysfunction participated in this study. Isokinetic quadriceps and hamstring strength were assessed in relation to 3 randomized jaw conditions: mouth closed in maximum intercuspidation without splint, mouth closed on a balanced splint which optimized contact over the dental arch, mouth closed on a piece of resin of 1 mm which created an imbalanced occlusion. Tests were performed at 60 and 240°·s in concentric and 30°·s in eccentric exertions. Concentric performances did not show any significant difference between the 3 jaw conditions (p > 0.05). In contrast, in the eccentric trials related to quadriceps performance, significant differences (p ≤ 0.05) were observed between the resin condition and the 2 other modalities (without splint or with a balanced splint). The imbalanced occlusion created by the resin component corresponded to an average decrease of 9% in eccentric peak torque. The eccentric hamstring peak torques also showed a significant difference (p ≤ 0.05) between measurements with splint and with resin (7% decrease when occlusion was imbalanced). In conclusion, among asymptomatic females, artificial imbalanced occlusion induces immediate and significant alteration of knee eccentric muscle performances. Therefore, occlusion examination should be undertaken on a regular and frequent basis for high-level athletes. Moreover, for athletes using mouthguards, muscular performance assessments should be planned with and without the dental protection.

  10. Cosmetic effect of knee joint in a knee disarticulation prosthesis

    OpenAIRE

    2015-01-01

    Despite numerous advantages, knee disarticulations (KDs) are rarely performed because of the anticipated KD prosthesis fitting problems that include the positioning of the knee joint distally from the KD socket. This results in lengthening of the thigh and subsequent shortening of the shank. The objective of this study was to assess the cosmetic effect of the knee joint in a KD prosthesis by determining the extent of the lengthening of the thigh and the shortening of the shank. This lengtheni...

  11. Evaluation of Knee Proprioception and Factors Related to Parkinson's Disease

    Science.gov (United States)

    Eltz, Giovana Duarte; Torman, Vanessa Bielefeldt Leotti

    2016-01-01

    Background. Changes in proprioception may contribute to postural instability in individuals with neurological disorders. Objectives. Evaluate proprioception in the lower limbs of patients with Parkinson's disease (PD) and the association between proprioception and cognitive ability, motor symptoms, postural instability, and disease severity. Methods. This is a cross-sectional, controlled study that evaluated proprioception in PD patients and healthy age- and sex-matched individuals. Kinetic postural proprioception of the knee was evaluated using an isokinetic dynamometer (Biodex® Multi-Joint System 4 Pro). Participants were evaluated using the Montreal Cognitive Assessment (MoCA), the Hoehn and Yahr rating scale and postural instability (pull test and stabilometric analysis), and motor function (UPDRS-III) tests. Results. A total of 40 individuals were enrolled in the study: 20 PD patients and 20 healthy controls (CG). The PD patients had higher angular errors on the proprioceptive ratings than the CG participants (p = 0.002). Oscillations of the center of pressure (p = 0.002) were higher in individuals with PD than in the controls. Proprioceptive errors in the PD patients were associated with the presence of tremors as the dominant symptom and more impaired motor performance. Conclusion. These findings show that individuals with PD have proprioceptive deficits, which are related to decreased cognitive ability and impaired motor symptoms. PMID:27672650

  12. Research on the Development of the Isokinetic Training Devices%等动训练器的开发研究

    Institute of Scientific and Technical Information of China (English)

    程桢; 王国凡

    2015-01-01

    研究运用机械传动原理,通过对变速自行车变速系统(档位)的改进和加入等动控制装置,使其实现“等动运动”;继而设计和制造出等动训练器。其工作原理:(1)将由传统训练器械的杠铃片产生的重量阻力替换为档位阻力,从而使训练者训练更加安全,也缩小了较多杠铃片所占的体积;(2)设计出的等动训练器可以灵活移动、安装,便于携带;(3)设计出的等动训练器可以通过移动固定点、安装变向滑轮、安装不同的手拉杆、套绳等,实现人体多部位的综合训练目的。%By using the principle of mechanical drive, based on the bicycle transmission system improvement and addition of Isokinetic control device, makes it realize“Isokinetic movement”and then design and manufacture Isokinetic training device. (1) It works mainly through repl-acing the traditional weight resistance produced by the barbell training apart-us forger resistance, so that the trainer more security and also narrowed more volume; (2) The Isokinetic training devices can move flexibly, installation, easy to carry; (3) Design of the Isokinetic training devices can move through a fixed point, install the turning pulley, install the different hand pull rod, rope etc, realize the human body parts comprehensive training objective.

  13. Contribution of mechanical unloading to trabecular bone loss following non-invasive knee injury in mice.

    Science.gov (United States)

    Anderson, Matthew J; Diko, Sindi; Baehr, Leslie M; Baar, Keith; Bodine, Sue C; Christiansen, Blaine A

    2016-10-01

    Development of osteoarthritis commonly involves degeneration of epiphyseal trabecular bone. In previous studies, we observed 30-44% loss of epiphyseal trabecular bone (BV/TV) from the distal femur within 1 week following non-invasive knee injury in mice. Mechanical unloading (disuse) may contribute to this bone loss; however, it is unclear to what extent the injured limb is unloaded following injury, and whether disuse can fully account for the observed magnitude of bone loss. In this study, we investigated the contribution of mechanical unloading to trabecular bone changes observed following non-invasive knee injury in mice (female C57BL/6N). We investigated changes in gait during treadmill walking, and changes in voluntary activity level using Open Field analysis at 4, 14, 28, and 42 days post-injury. We also quantified epiphyseal trabecular bone using μCT and weighed lower-limb muscles to quantify atrophy following knee injury in both ground control and hindlimb unloaded (HLU) mice. Gait analysis revealed a slightly altered stride pattern in the injured limb, with a decreased stance phase and increased swing phase. However, Open Field analysis revealed no differences in voluntary movement between injured and sham mice at any time point. Both knee injury and HLU resulted in comparable magnitudes of trabecular bone loss; however, HLU resulted in considerably more muscle loss than knee injury, suggesting another mechanism contributing to bone loss following injury. Altogether, these data suggest that mechanical unloading likely contributes to trabecular bone loss following non-invasive knee injury, but the magnitude of this bone loss cannot be fully explained by disuse. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1680-1687, 2016.

  14. Avaliação isocinética em atletas paraolímpicos Isokinetic evaluation in paralympic athletes

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Silva

    2002-06-01

    Full Text Available O equilíbrio dos parâmetros de força muscular nas articulações é de grande relevância, tanto no aspecto clínico como para o desempenho atlético. Informações sobre os valores desses parâmetros em atletas olímpicos e principalmente nos paraolímpicos são raras. Neste trabalho apresentamos os resultados da avaliação muscular isocinética (Cybex 6000 realizada na equipe brasileira que participou dos Jogos Paraolímpicos de Sidney 2000. Foram avaliados os músculos flexores e extensores dos joelhos de 11 jogadores de futebol (paralisia cerebral, idade 24,6 ± 4,8 anos; peso 67 ± 5,5kg; altura 177,7 ± 3,8cm e 12 de basquetebol (deficientes mentais, idade 24,7 ± 4,4 anos; peso 76,6 ± 13,4kg; altura 184,4 ± 10cm, e os músculos rotadores internos e rotadores externos de ombros de seis judocas (deficientes visuais, idade 29,8 ± 5,6 anos; peso 87 ± 21,6kg; altura 171,5 ± 6,9cm. Os jogadores de futebol apresentaram relação de equilíbrio muscular entre flexores e extensores de joelhos dentro dos parâmetros de normalidade apesar da fraqueza muscular imposta pela paralisia cerebral. Nos judocas o equilíbrio muscular entre rotadores externos e rotadores internos mostrou-se dentro dos limites de normalidade. A principal característica dos jogadores de basquetebol foi o valor de pico de torque próximo do esperado para indivíduos hígidos não atletas. Os valores numéricos estão apresentados no texto para serem usados como referência para profissionais da área.The balance between agonist and antagonist muscles in the joints is of great relevance to clinical practice and to sports performance. Information about these parameters amongst Olympic and especially Paralympic athletes is scarce. The purpose of this study was to present the results of the isokinetic evaluation (Cybex 6000 of the Brazilian team that participated in the Sydney Paralympic Games. The flexor and extensor muscles of the knee were evaluated in 11 soccer

  15. Knee Replacement: What you can Expect

    Science.gov (United States)

    ... improves function lessen with each additional surgery. Artificial knees can wear out Another risk of knee replacement ... replacement surgery to last about two hours. After knee replacement surgery After surgery, you're wheeled to ...

  16. Arthrography of the knee joint

    Energy Technology Data Exchange (ETDEWEB)

    Keyl, W.; Jaeger, M.

    1981-10-01

    The standardized examination technique and the clinical problems of the arthrographic mehtod applied on the knee joint is explained by the results obtained in 3000 examinations. Whereas the accuracy of the knee-joint arthrography provides a high degree in cases of meniscus lesions, computer tomography presents in chondral and capsular ligament lesions, and sonography in popliteal cysts better diagnostic information; but in any case arthroscopy gains more and more importance in knee-joint diagnostics.

  17. 77 FR 72941 - Voluntary Education Programs

    Science.gov (United States)

    2012-12-07

    ... decision will be made by the selected DoD contractor for the complete `third party review' process. Comment... seeks to enhance the educational opportunities to Service members who may have difficulty in completing... transitions to second careers in teaching. Voluntary education programs. Continuing, adult, or...

  18. Decentralized trade with bargaining and voluntary matching

    DEFF Research Database (Denmark)

    Tranæs, Torben; Sloth, Birgitte; Hendon, Ebbe

    1994-01-01

    Rubinstein and Wolinsky (1990) study a market with one seller, two buyers, and voluntary matching. Both the competitive outcomepc and the bilateral bargaining outcomepb are possible in subgame perfect equilibrium. We consider two variations. First, if there is a cost larger thanpc−pc to the seller...

  19. Social orienting: reflexive versus voluntary control.

    Science.gov (United States)

    Hill, Julia L; Patel, Saumil; Gu, Xue; Seyedali, Nassim S; Bachevalier, Jocelyne; Sereno, Anne B

    2010-09-24

    Many studies have shown that the direction of gaze of a face covertly facilitates the response to a target presented in the matching direction. In this study we seek to determine whether there exist separate reflexive and voluntary forms of such covert social orienting and how they interact with each other. We measured the effect of the predictive value of a gaze cue on manual choice reaction times. When the predictive value of the gaze cue was zero, a facilitatory cueing effect was still observed which peaked at a cue onset to target onset delay (CTD) of 150ms and largely diminished beyond a CTD of 500ms. When the gaze cue was 100% predictive of the future location of the target, at CTDs greater than 200, the predictive cue resulted in a significantly greater facilitation of response than occurred with a non-predictive cue. These results suggest that given enough time (about 200ms), the social cue is interpreted and a willful or voluntary spatially-specific social cueing effect occurs. In addition, we found that a predictive cue resulted in a significant slowing of the observer's responses up to a CTD of 200ms. These findings show that, similar to non-social spatial orienting, there appear to be two forms of social orienting including a reflexive component and voluntary component. We suggest a model of social orienting in which the voluntary social orienting system modulates tonic inhibition of the reflexive social orienting system. Published by Elsevier Ltd.

  20. Equality, self‐respect and voluntary separation

    NARCIS (Netherlands)

    M.S. Merry

    2012-01-01

    This paper argues that self‐respect constitutes an important value, and further, an important basis for equality. It also argues that under conditions of inequality‐producing segregation, voluntary separation in schooling may be more likely to provide the resources necessary for self‐respect. A prim

  1. School Ethical Climate and Teachers' Voluntary Absence

    Science.gov (United States)

    Shapira-Lishchinsky, Orly; Rosenblatt, Zehava

    2010-01-01

    Purpose: This paper aims to offer a theoretical framework for linking school ethical climate with teachers' voluntary absence. The paper attempts to explain this relationship using the concept of affective organizational commitment. Design/methodology/approach: Participants were 1,016 school teachers from 35 high schools in Israel. Data were…

  2. Voluntary Oral Administration of Losartan in Rats.

    Science.gov (United States)

    Diogo, Lucília N; Faustino, Inês V; Afonso, Ricardo A; Pereira, Sofia A; Monteiro, Emília C; Santos, Ana I

    2015-09-01

    Gavage is a widely performed technique for daily dosing in laboratory rodents. Although effective, gavage comprises a sequence of potentially stressful procedures for laboratory animals that may introduce bias into experimental results, especially when the drugs to be tested interfere with stress-dependent parameters. We aimed to test vehicles suitable for drug delivery by voluntary ingestion in rats. Specifically, Male Wistar rats (age, 2 to 3 mo) were used to test nut paste (NUT), peanut butter (PB), and sugar paste (SUG) as vehicles for long-term voluntary oral administration of losartan, an angiotensin II receptor blocker. Vehicles were administered for 28 d without drug to assess effects on the glucose level and serum lipid profile. Losartan was mixed with vehicles and either offered to the rats or administered by gavage (14 d) for subsequent quantification of losartan plasma levels by HPLC. After a 2-d acclimation period, all rats voluntarily ate the vehicles, either alone or mixed with losartan. NUT administration reduced blood glucose levels. The SUG group had higher concentrations of losartan than did the gavage group, without changes in lipid and glucose profiles. Our results showed that NUT, PB, and SUG all are viable for daily single-dose voluntary ingestion of losartan and that SUG was the best alternative overall. Drug bioavailability was not reduced after voluntary ingestion, suggesting that this method is highly effective for chronic oral administration of losartan to laboratory rodents.

  3. Staff's perceptions of voluntary assertiveness skills training.

    Science.gov (United States)

    McVanel, Sarah; Morris, Beth

    2010-01-01

    Clinicians' ability to be assertive when unsure or concerned about procedures, treatment modalities, or patients' symptoms is key in reducing risk and preventing sentinel events. In this article, the authors provide a framework for generic, voluntary assertiveness communication skills workshops that any educator can implement.

  4. Voluntary Organizations: Commitment, Leadership, and Organizational Effectiveness

    Science.gov (United States)

    Ekeland, Terry P.

    2004-01-01

    Voluntary organizations offer a unique opportunity to interpret participant relationships, leadership influences, and organizational effectiveness unencumbered by employment relationships. Regardless of organizational structure or purpose, all organizations are affected to some degree by their leadership and their membership. Based on the…

  5. Environmental Voluntary Agreements in the Dutch Context

    NARCIS (Netherlands)

    Bressers, Johannes T.A.; de Bruijn, Theo; Croci, Edoardo

    2005-01-01

    This paper describes and analyses the use of environmental voluntary agreements, or covenants, in Dutch environmental policy. Covenants have become a widely used policy instrument in the Netherlands. This trend reinforces the strong neo-corporatist traits of Dutch society with its tendency towards

  6. Voluntary Community Organisations in Metropolitan Development

    DEFF Research Database (Denmark)

    Larsen, Jacob Norvig

    While short-term enrolling of citizens in urban regeneration projects often has proven quite successful, permanent embedding of projects in voluntary community-based settings seems to be much more difficult to obtain. This has implications for long term sustainability of urban regeneration projec...

  7. Kinesio Taping does not improve the symptoms or function of older people with knee osteoarthritis: a randomised trial

    Directory of Open Access Journals (Sweden)

    Bruna Wageck

    2016-07-01

    Full Text Available Question: Does Kinesio Taping reduce pain and swelling, and increase muscle strength, function and knee-related health status in older people with knee osteoarthritis? Design: Randomised, controlled trial with concealed allocation, intention-to-treat analysis and blinded assessment. Participants: Seventy-six older people with knee osteoarthritis. Intervention: The experimental group received three simultaneous Kinesio Taping techniques to treat pain, strength and swelling. The control group received sham taping. All participants kept the taping on for 4 days. Outcome measures: The outcomes were: concentric muscle strength of knee extensors and flexors, measured by isokinetic dynamometry with an angular velocity of 60 deg/second normalised for body mass [(Nm/kg x 100 (%]; pressure pain threshold via digital pressure algometry (kgf/cm2; lower-limb swelling via volumetry (l and perimetry (cm; physical function via the Lysholm Knee Scoring Scale (0 = worst to 100 = best; and knee-related health status via the Western Ontario and McMaster (WOMAC osteoarthritis index (0 = best to 96 = worst. Outcomes were measured at Day 4 (end of the taping period and Day 19 (follow-up after the start of the treatment. Results: At Day 4, there were no significant between-group differences for knee extensor muscle strength (MD –1%, 95% CI –7 to 5, knee flexor muscle strength (MD 2%, 95% CI –3 to 7, the pressure pain threshold at any measured point, volumetry (MD 0.05 L, 95% CI –0.01 to 0.11, perimetry at any measured point, Lysholm score (MD –4 points, 95% CI –9 to 2, or WOMAC score (MD –2 points, 95% CI –8 to 4. The lack of significant between-group difference was also seen at the follow-up assessment on Day 19. Conclusion: The Kinesio Taping techniques investigated in this study provided no beneficial effects for older people with knee osteoarthritis on any of the assessed outcomes. Trial registration: Brazilian Registry of Clinical Trials, RBR

  8. Effect of stochastic modulation of inter-pulse interval during stimulated isokinetic leg extension

    Directory of Open Access Journals (Sweden)

    Efe Anil Aksöz

    2016-07-01

    Full Text Available Recumbent cycling exercise achieved by functional electrical stimulation (FES of the paralyzed leg muscles is effective for cardiopulmonary and musculoskeletal conditioning after spinal cord injury, but its full potential has not yet been realized. Mechanical power output and efficiency is very low and endurance is limited due to early onset of muscle fatigue. The aim of this work was to compare stochastic modulation of the inter-pulse interval (IPI to constant-frequency stimulation during an isokinetic leg extension task similar to FES-cycling. Seven able-bodied subjects participated: both quadriceps muscles were stimulated (n = 14 with two activation patterns (P1-constant frequency, P2-stochastic IPI. There was significantly higher power output with P2 during the first 30 s (p = 0.0092, the last 30 s (p = 0.018 and overall (p = 0.0057, but there was no overall effect on fatiguability when stimulation frequency was randomly modulated.

  9. Effect of Stochastic Modulation of Inter-Pulse Interval During Stimulated Isokinetic Leg Extension

    Science.gov (United States)

    Aksöz, Efe Anil; Laubacher, Marco; Binder-Macleod, Stuart; Hunt, Kenneth J.

    2016-01-01

    Recumbent cycling exercise achieved by functional electrical stimulation (FES) of the paralyzed leg muscles is effective for cardiopulmonary and musculoskeletal conditioning after spinal cord injury, but its full potential has not yet been realized. Mechanical power output and efficiency is very low and endurance is limited due to early onset of muscle fatigue. The aim of this work was to compare stochastic modulation of the inter-pulse interval (IPI) to constant-frequency stimulation during an isokinetic leg extension task similar to FES-cycling. Seven able-bodied subjects participated: both quadriceps muscles were stimulated (n = 14) with two activation patterns (P1-constant frequency, P2-stochastic IPI). There was significantly higher power output with P2 during the first 30 s (p = 0.0092), the last 30 s (p = 0.018) and overall (p = 0.0057), but there was no overall effect on fatiguability when stimulation frequency was randomly modulated. PMID:27990242

  10. Treatment of knee osteoarthritis.

    Science.gov (United States)

    Ringdahl, Erika; Pandit, Sandesh

    2011-06-01

    Knee osteoarthritis is a common disabling condition that affects more than one-third of persons older than 65 years. Exercise, weight loss, physical therapy, intra-articular corticosteroid injections, and the use of nonsteroidal anti-inflammatory drugs and braces or heel wedges decrease pain and improve function. Acetaminophen, glucosamine, ginger, S-adenosylmethionine (SAM-e), capsaicin cream, topical nonsteroidal anti-inflammatory drugs, acupuncture, and tai chi may offer some benefit. Tramadol has a poor trade-off between risks and benefits and is not routinely recommended. Opioids are being used more often in patients with moderate to severe pain or diminished quality of life, but patients receiving these drugs must be carefully selected and monitored because of the inherent adverse effects. Intra-articular corticosteroid injections are effective, but evidence for injection of hyaluronic acid is mixed. Arthroscopic surgery has been shown to have no benefit in knee osteoarthritis. Total joint arthroplasty of the knee should be considered when conservative symptomatic management is ineffective.

  11. Eligibility and Exclusion of Hemochromatosis Patients as Voluntary Blood Donors

    Directory of Open Access Journals (Sweden)

    M Levstik

    1998-01-01

    Full Text Available BACKGROUND: Hereditary hemochromatosis patients are excluded in many countries as voluntary blood donors. In 1991, changes in the Canadian Red Cross policy allowed healthy hemochromatosis patients to become voluntary donors.

  12. Results of the global survey on Voluntary Sustainability Standards

    OpenAIRE

    Lernoud, Julia

    2015-01-01

    Results of the global survey on Voluntary Sustainability Standards: - Voluntary Sustainability Standards (VSS) area worldwide and selected commodities - Cocoa: Area growth by VSS 2008-2014 - Growth of VSS compliant area worldwide 2008-2013 (selected crops)

  13. China Initiates Voluntary Certification of Public Security Products

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Reporters learned from the Certification and Accreditation Administration of China(CNCA)that burglar-proof door became the first batch of voluntary certification product in public security products.China has formally initiated voluntary certification of public security products.

  14. Voluntary sterilization in Serbia: Unmet need?

    Directory of Open Access Journals (Sweden)

    Rašević Mirjana M.

    2002-01-01

    Full Text Available Is voluntary sterilization as a birth control method accepted in Serbia? This is certainly a question that is being imposed for research, regardless of the fact that voluntary sterilization is neither accessible nor promoted. Most importantly because there is no understanding in the social nor political sphere for legalization of voluntary sterilization as a form of birth control, apart from the clear necessity for this, first, step. They are: the recognition that voluntary sterilization is an efficient and safe birth control method, respectability of basic human as well as sexual and reproductive rights, spreading of sterilization as a form of birth control among population of both developed and developing countries and an epidemic diffusion of repeated induced abortions in Serbia. Thus individual recognition of the advantages of relying on voluntary sterilization, in a non-encouraging atmosphere, certainly represents one more argument to enable couples to prevent conception by sterilization. Since it was impossible to carry out a representative research among the population of men and women who are at risk for conception, an attempt was made to obtain a reply to the set question among women who decided to induce abortion. It was done out of at least two reasons. The first being that women with induced abortion in their reproductive history were the target group for voluntary sterilization. The second reason was based on the assumption that bringing a decision on induced abortion is preceded by the reconsideration of an earlier adopted strategy regarding children, giving birth and contraception and thus its rational component is revealed more and therefore more easily measurable. The research was carried out in the University Clinic of Obstetrics and Gynecology 'Narodni front' in Belgrade from January 21st o March 1st 2002, and included 296 women. By comparing the social and demographic characteristics of the female respondents, as well as

  15. Knee extension and flexion muscle power after anterior cruciate ligament reconstruction with patellar tendon graft or hamstring tendons graft: a cross-sectional comparison 3 years post surgery

    DEFF Research Database (Denmark)

    Ageberg, Eva; Roos, Harald; Silbernagel, Karin

    2008-01-01

    to 2 years post surgery, but not later. In these studies, isokinetic muscle torque was used. However, muscle power has been suggested to be a more sensitive and sport-specific measures of strength. The aim was to study quadriceps and hamstring muscle power in patients with ACL injury treated...... for at least 4 months, were assessed with reliable, valid, and responsive tests of quadriceps and hamstring muscle power at 3 years (SD 0.9, range 2-5) after surgery. The mean difference between legs (injured minus uninjured), the hamstring to quadriceps (H:Q, hamstring divided by quadriceps) ratio....... The lower hamstring muscle power, and the lower hamstring to quadriceps ratio in the HT graft group than in the PT graft group 3 years (range 2-5) after ACL reconstruction, reflect imbalance of knee muscles after reconstruction with HT graft that may have a negative effect on dynamic knee...

  16. Effects of photobiomodulation on the fatigue level in elderly women: an isokinetic dynamometry evaluation.

    Science.gov (United States)

    Vassão, P G; Toma, R L; Antunes, H K M; Tucci, H T; Renno, A C M

    2016-02-01

    Aging is responsible by a series of morphological and functional modifications that lead to a decline of muscle function, particularly in females. Muscle tissue in elderly people is more susceptible to fatigue and, consequently, to an increased inability to maintain strength and motor control. In this context, therapeutic approaches able of attenuating muscle fatigue have been investigated. Among these, the photobiomodulation demonstrate positive results to interacts with biological tissues, promoting the increase in cell energy production. Thus, the aim of this study was to investigate the effects of photobiomodulation (808 nm, 250 J/cm(2), 100 mW, 7 J each point) in the fatigue level and muscle performance in elderly women. Thirty subjects entered a crossover randomized double-blinded placebo-controlled trial. Photobiomodulation was delivered on the rectus femoris muscle of the dominant limb immediately before the fatigue protocol. In both sessions, peripheral muscle fatigue was analyzed by surface electromyography (EMG) and blood lactate analysis. Muscle performance was evaluated using an isokinetic dynamometer. The results showed that photobiomodulation was able of reducing muscle fatigue by a significant increase of electromyographic fatigue index (EFI) (p = 0.047) and decreasing significantly lactate concentration 6 min after the performance of the fatigue protocol (p = 0. 0006) compared the placebo laser session. However, the photobiomodulation was not able of increasing muscle performance measured by the isokinetic dynamometer. Thus, it can be conclude that the photobiomodulation was effective in reducing fatigue levels. However, no effects of photobiomodulation on muscle performance was observed.

  17. Effects of transcranial magnetic stimulation during voluntary and non-voluntary stepping movements in humans.

    Science.gov (United States)

    Solopova, I A; Selionov, V A; Kazennikov, O V; Ivanenko, Y P

    2014-09-05

    Here, we compared motor evoked potentials (MEP) in response to transcranial magnetic stimulation of the motor cortex and the H-reflex during voluntary and vibration-induced air-stepping movements in humans. Both the MEPs (in mm biceps femoris, rectus femoris and tibialis anterior) and H-reflex (in m soleus) were significantly smaller during vibration-induced cyclic leg movements at matched amplitudes of angular motion and muscle activity. These findings highlight differences between voluntary and non-voluntary activation of the spinal pattern generator circuitry in humans, presumably due to an extra facilitatory effect of voluntary control/triggering of stepping on spinal motoneurons and interneurons. The results support the idea of active engagement of supraspinal motor areas in developing central pattern generator-modulating therapies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. An estimation of the influence of force decrease on the mean power spectral frequency shift of the EMG during repetitive maximum dynamic knee extensions.

    Science.gov (United States)

    Karlsson, J S; Ostlund, N; Larsson, B; Gerdle, B

    2003-10-01

    Frequency analysis of myoelectric (ME) signals, using the mean power spectral frequency (MNF), has been widely used to characterize peripheral muscle fatigue during isometric contractions assuming constant force. However, during repetitive isokinetic contractions performed with maximum effort, output (force or torque) will decrease markedly during the initial 40-60 contractions, followed by a phase with little or no change. MNF shows a similar pattern. In situations where there exist a significant relationship between MNF and output, part of the decrease in MNF may per se be related to the decrease in force during dynamic contractions. This study estimated force effects on the MNF shifts during repetitive dynamic knee extensions. Twenty healthy volunteers participated in the study and both surface ME signals (from the right vastus lateralis, vastus medialis, and rectus femoris muscles) and the biomechanical signals (force, position, and velocity) of an isokinetic dynamometer were measured. Two tests were performed: (i) 100 repetitive maximum isokinetic contractions of the right knee extensors, and (ii) five gradually increasing static knee extensions before and after (i). The corresponding ME signal time-frequency representations were calculated using the continuous wavelet transform. Compensation of the MNF variables of the repetitive contractions was performed with respect to the individual MNF-force relation based on an average of five gradually increasing contractions. Whether or not compensation was necessary was based on the shape of the MNF-force relationship. A significant compensation of the MNF was found for the repetitive isokinetic contractions. In conclusion, when investigating maximum dynamic contractions, decreases in MNF can be due to mechanisms similar to those found during sustained static contractions (force-independent component of fatigue) and in some subjects due to a direct effect of the change in force (force-dependent component of fatigue

  19. Development of a knee joint motion simulator to evaluate deep knee flexion of artificial knee joints.

    Science.gov (United States)

    Takano, Y; Ueno, M; Kiguchi, K; Ito, J; Mawatari, M; Hotokebuchi, T

    2008-01-01

    A purpose of this study is to examine the effect that quadriceps femoris force gives to rotation angle and joint reaction force of total knee prosthesis during deep knee flexion such as a unique sitting style called 'seiza' in Japanese. For the evaluation, we developed the knee motion simulator which could bend to 180 degrees continually simulating the passive flexion performed by clinicians. A total knee prosthesis, which is a specially-devised posterior stabilized type and capable of flexion up to 180 degrees, was inserted into bone model. And this prosthesis pulled by three kinds of quadriceps femoris forces to perform parameter study. The results obtained in this study were showed the same tendency with those in the past cadaveric experiment. It is suggested that the rotation angle and joint reaction force of total knee prosthesis are affected by shape of prosthesis, a vector of quadriceps femoris force, and bony aliments during deep knee flexion.

  20. Knee and ankle joint torque-angle relationships of multi-joint leg extension.

    Science.gov (United States)

    Hahn, Daniel; Olvermann, Matthias; Richtberg, Jan; Seiberl, Wolfgang; Schwirtz, Ansgar

    2011-07-28

    The force-length-relation (F-l-r) is an important property of skeletal muscle to characterise its function, whereas for in vivo human muscles, torque-angle relationships (T-a-r) represent the maximum muscular capacity as a function of joint angle. However, since in vivo force/torque-length data is only available for rotational single-joint movements the purpose of the present study was to identify torque-angle-relationships for multi-joint leg extension. Therefore, inverse dynamics served for calculation of ankle and knee joint torques of 18 male subjects when performing maximum voluntary isometric contractions in a seated leg press. Measurements in increments of 10° knee angle from 30° to 100° knee flexion resulted in eight discrete angle configurations of hip, knee and ankle joints. For the knee joint we found an ascending-descending T-a-r with a maximum torque of 289.5° ± 43.3 Nm, which closely matches literature data from rotational knee extension. In comparison to literature we observed a shift of optimum knee angle towards knee extension. In contrast, the T-a-r of the ankle joint vastly differed from relationships obtained for isolated plantar flexion. For the ankle T-a-r derived from multi-joint leg extension subjects operated over different sections of the force-length curve, but the ankle T-a-r derived from isolated joint efforts was over the ascending limb for all subjects. Moreover, mean maximum torque of 234.7 ± 56.6 Nm exceeded maximal strength of isolated plantar flexion (185.7 ± 27.8 Nm). From these findings we conclude that muscle function between isolated and more physiological multi-joint tasks differs. This should be considered for ergonomic and sports optimisation as well as for modelling and simulation of human movement.

  1. Moving from voluntary euthanasia to non-voluntary euthanasia: equality and compassion.

    Science.gov (United States)

    Amaraskekara, Kumar; Bagaric, Mirko

    2004-09-01

    The recent Dutch law legalising active voluntary euthanasia will reignite the euthanasia debate. An illuminating method for evaluating the moral status of a practice is to follow the implications of the practice to its logical conclusion. The argument for compassion is one of the central arguments in favour of voluntary active euthanasia. This argument applies perhaps even more forcefully in relation to incompetent patients. If active voluntary euthanasia is legalised, arguments based on compassion and equality will be directed towards legalising active non-voluntary euthanasia in order to make accelerated termination of death available also to the incompetent. The removal of discrimination against the incompetent has the potential to become as potent a catch-cry as the right to die. However, the legalisation of non-voluntary euthanasia is undesirable. A review of the relevant authorities reveals that there is no coherent and workable "best interests" test which can be invoked to decide whether an incompetent patient is better off dead. This provides a strong reason for not stepping onto the slippery path of permitting active voluntary euthanasia.

  2. 5 CFR 919.1020 - Voluntary exclusion or voluntarily excluded.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Voluntary exclusion or voluntarily excluded. 919.1020 Section 919.1020 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED...) Definitions § 919.1020 Voluntary exclusion or voluntarily excluded. (a) Voluntary exclusion means a person's...

  3. 37 CFR 351.2 - Voluntary negotiation period; settlement.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Voluntary negotiation period... CONGRESS COPYRIGHT ROYALTY JUDGES RULES AND PROCEDURES PROCEEDINGS § 351.2 Voluntary negotiation period..., the Copyright Royalty Judges will announce the beginning of a voluntary negotiation period and...

  4. 15 CFR 12.3 - Development of voluntary product standards.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Development of voluntary product... AND LABELING § 12.3 Development of voluntary product standards. (a) Invitation to participate in the development of a voluntary product standard. Whenever the Secretary publishes a final determination of...

  5. Cosmetic effect of knee joint in a knee disarticulation prosthesis

    NARCIS (Netherlands)

    de laat, Fred A.; van der Pluijm, Mark J.; van Kuijk, Annette A.; Geertzen, Jan H.; Roorda, Leo D.

    2014-01-01

    Despite numerous advantages, knee disarticulations (KDs) are rarely performed because of the anticipated KD prosthesis fitting problems that include the positioning of the knee joint distally from the KD socket. This results in lengthening of the thigh and subsequent shortening of the shank. The obj

  6. Does knee awareness differ between different knee arthroplasty prostheses?

    DEFF Research Database (Denmark)

    Thomsen, Morten G; Latifi, Roshan; Kallemose, Thomas

    2016-01-01

    BACKGROUND: Low knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations. To accommodate this manufacturers of TKAs have developed new prosthetic designs that potentially could give patients a more...... natural feeling knee during activities. The purpose af this study was to compare the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) of patients treated with a previous generation standard Cruciate Retaining (CR) TKA to the scores obtained by patients treated with a newer generation CR TKA...... or a mobile bearing CR TKA. METHODS: We identified all patients receiving a new generation CR TKA or mobile bearing TKA at our institution between 2010 and 2012. These were matched to a population of patients receiving a standard CR TKA regarding age, gender, year of surgery, Kellgren-Lawrence (KL) grade...

  7. Magnification bone scan of knees for knee pain evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myoung Hoon; Park, Chan H.; Yoon, Seok Nam; Hwang, Kyung Hoon [College of Medicine, Ajou Univ., Suwon (Korea, Republic of)

    2001-07-01

    Knee pain is one of the common complaints of patients seen in our orthopedic clinic. Routine anterior and posterior views of whole body bone scan (WBBS) is often not sufficient in the evaluation of these patients. An ideal bone scan using pinhole collimator or single photon emission tomography (SPECT), however, is impractical and time consuming in busy nuclear medicine department with limited resources. Therefore, the aim of the study is to assess limited bone scan of