Isokinetic Velocity Research Articles

지연성 근통증 유발 후 폼롤러 처치가 운동기능체력과 대퇴부 최대근력 및 통증에 미치는 효과

The purpose of this study was to investigate the effect of foam roller treatment on recovery physical performance and pain by inducing delayed onset muscle soreness(DOMS). This subjects of this study were 20 healthy adults. ter 24 hours and 48 hours after the delayed muscular pain, the subjects were classified into the control group who did not receive any treatment after the delayed muscular pain, and the group where the foam roller was treated after the delayed muscle pain induction. The statistic analysed SPSS ver. 22.0 was used for two-way repeated measures. As a result, at the isokinetic velocity load of 60 °/ sec, which represents the strength of prak torque, the extensor showed significant different groups and interaction. Also the flexor and H:Q ratio were significantly All of the roller treatment groups were significantly increased in the after 48 hours. The Sergeant jumps showing rapid performance were significantly higher in the foam roller group than in the control group. And there was no significant difference in reaction time. Also, Foam roller group showed that the VAS was significantly lower in the foam roller group than in the control group after 48 hours of delayed muscle pain. Therefore, Foam roller treatment for recovery of delayed muscular pain is positive for recovery of physical fitness, and relieves pain. Therefore, this study was found that the foam roller treatment was effective by the cool-down after acute eccentric exercise.

Knee extensor power asymmetry is unrelated to functional mobility of older adults

PurposeTo determine whether knee extensor power asymmetry limits functional mobility of older adults who possess muscle weakness. MethodsKnee extensor power was measured in 36 older men and women (76.0±7.6yr), for each leg, on an isokinetic dynamometer at 60, 180, and 300degs−1 and power asymmetry was calculated as the percent difference in power between strong and weak legs, at each isokinetic velocity. 400-m walk, stair ascent, and five-repetition chair rise tests were performed to assess functional mobility. Pearson correlations were used to examine the relationship between weak leg power, strong leg power, power asymmetry, and 400-m walk time, stair ascent time, and chair rise time. Participants were then stratified into low power-high asymmetry (LP-HA), low power-low asymmetry (LP-LA), high power-high asymmetry (HP-HA), and high power-low asymmetry (HP-LA) groups who were compared for functional mobility. ResultsKnee extensor power asymmetry was unrelated to 400-m walk time (r=0.16, p=0.180), stair ascent time (r=0.22, p=0.094), or chair rise time (r=0.03, p=0.437), whereas weak and strong leg powers were equally associated with 400-m time (r=−0.62, p<0.001; r=−0.62, p<0.001), stair ascent time (r=−0.55, p<0.001; r=−0.57, p<0.001), and chair rise time (r=−0.28, p=0.048; r=−0.31, p=0.032), respectively. Power asymmetry was lowest at 60degs−1 (12%), and increased with contraction velocity (p=0.001) to 15% at 180degs−1 and to 20% at 300degs−1. LP-HA exhibited 26% slower 400-walk time than HP-LA (p=0.015) and 19% slower than HP-HA (p=0.037). LP-HA had 31% slower stair ascent time than HP-LA (p=0.033). There were no differences in chair rise performance between groups. ConclusionsKnee extensor power asymmetry was unrelated to 400-m walk, stair ascent, and chair rise performance in older adults. Weak and strong limb powers were equally related to these functional measures, but a leftward shift of the power-mobility curve exists for the weak leg that may hinder clinical assessment if strength or power is measured on a single limb and symmetry is assumed. The greatest degree of knee extensor power asymmetry occurred at the fastest isokinetic velocity, which suggests high-speed muscle contractions may better differentiate laterality of function in older individuals.

The Age-related Changes In Multi- And Single-joint Measures Of Power Output

Many previous studies have demonstrated age-related reductions in power output. However, few studies have identified if the age-related declines in power output during a functional lower body movement are similar to single-joint isokinetic testing. PURPOSE: To compare the relationships between the age-related reduction in power output using a single-joint isokinetic muscle action versus a more functional multi-joint vertical jump (VJ) assessment. METHODS: Forty middle- to older-aged men (mean±SD; age=59.2±7.8 years; range= 50-74 years) visited the lab on two occasions, separated by 48-72 hours. During the second visit, and following a familiarization session on visit one, participants performed 2-3 maximal countermovement VJ attempts while attached to commercially available equipment designed to examine lower body power output. The equipment was placed on the floor behind the subject to allow the cord to be extended without impeding the VJ technique. Following the VJ assessment, the participants performed three maximal concentric isokinetic muscle actions of the right leg extensors at 240°·sec-1 using a calibrated isokinetic dynamometer. The torque and position signals were sampled from the dynamometer at 2 kHz and were processed offline using custom written software. Isokinetic mean power (MP) was calculated as the product of the average torque (Nm) during the load range and isokinetic velocity (°·sec-1). Pearson correlation coefficients (r) were used to evaluate the relationships between age and VJ, and age and isokinetic MP. The Steiger Z calculation and an effect size was used to determine the difference between the relationships. The alpha level was set at P≤0.05. RESULTS: There were significant relationships between age and VJ power output (r=-0.633; P<0.001) and age and isokinetic MP (r=-0.410; P=0.009). The correlation coefficients were similar (P=0.112), however, there is a moderate difference (effect size=0.31) between the relationships. CONCLUSIONS: Single-joint isokinetic power output may demonstrate a weaker, but similar relationship with age when compared with more functional VJ assessments.

Eccentric Exercise Program Design: A Periodization Model for Rehabilitation Applications.

The applied use of eccentric muscle actions for physical rehabilitation may utilize the framework of periodization. This approach may facilitate the safe introduction of eccentric exercise and appropriate management of the workload progression. The purpose of this data-driven Hypothesis and Theory paper is to present a periodization model for isokinetic eccentric strengthening of older adults in an outpatient rehabilitation setting. Exemplar and group data are used to describe the initial eccentric exercise prescription, structured familiarization procedures, workload progression algorithm, and feasibility of the exercise regimen. Twenty-four men (61.8 ± 6.3 years of age) completed a 12-week isokinetic eccentric strengthening regimen involving the knee extensors. Feasibility and safety of the regimen was evaluated using serial visual analog scale (VAS, 0–10) values for self-reported pain, and examining changes in the magnitude of mean eccentric power as a function of movement velocity. Motor learning associated with the familiarization sessions was characterized through torque-time curve analysis. Total work was analyzed to identify relative training plateaus or diminished exercise capacity during the progressive phase of the macrocycle. Variability in the mean repetition interval decreased from 68 to 12% during the familiarization phase of the macrocycle. The mean VAS values were 2.9 ± 2.7 at the start of the regimen and 2.6 ± 2.9 following 12 weeks of eccentric strength training. During the progressive phase of the macrocycle, exercise workload increased from 70% of the estimated eccentric peak torque to 141% and total work increased by 185% during this training phase. The slope of the total work performed across the progressive phase of the macrocycle ranged from −5.5 to 29.6, with the lowest slope values occurring during microcycles 8 and 11. Also, mean power generation increased by 25% when eccentric isokinetic velocity increased from 60 to 90° s−1 while maintaining the same workload target. The periodization model used in this study for eccentric exercise familiarization and workload progression was feasible and safe to implement within an outpatient rehabilitation setting. Cyclic implementation of higher eccentric movement velocities, and the addition of active recovery periods, are featured in the proposed theoretical periodization model for isokinetic eccentric strengthening.

The Ca2+ sensitizer CK-2066260 increases myofibrillar Ca2+ sensitivity and submaximal force selectively in fast skeletal muscle.

Key points We report that the small molecule CK‐2066260 selectively slows the off‐rate of Ca2 + from fast skeletal muscle troponin, leading to increased myofibrillar Ca2 + sensitivity in fast skeletal muscle.Rodents dosed with CK‐2066260 show increased hindlimb muscle force and power in response to submaximal rates of nerve stimulation in situ.CK‐2066260 has no effect on free cytosolic [Ca2 +] during contractions of isolated muscle fibres.We conclude that fast skeletal muscle troponin sensitizers constitute a potential therapy to address an unmet need of improving muscle function in conditions of weakness and premature muscle fatigue. Skeletal muscle dysfunction occurs in many diseases and can lead to muscle weakness and premature muscle fatigue. Here we show that the fast skeletal troponin activator, CK‐2066260, counteracts muscle weakness by increasing troponin Ca2+ affinity, thereby increasing myofibrillar Ca2+ sensitivity. Exposure to CK‐2066260 resulted in a concentration‐dependent increase in the Ca2+ sensitivity of ATPase activity in isolated myofibrils and reconstituted hybrid sarcomeres containing fast skeletal muscle troponin C. Stopped‐flow experiments revealed a ∼2.7‐fold decrease in the Ca2+ off‐rate of isolated troponin complexes in the presence of CK‐2066260 (6 vs. 17 s−1 under control conditions). Isolated mouse flexor digitorum brevis fibres showed a rapidly developing, reversible and concentration‐dependent force increase at submaximal stimulation frequencies. This force increase was not accompanied by any changes in the free cytosolic [Ca2+] or its kinetics. CK‐2066260 induced a slowing of relaxation, which was markedly larger at 26°C than at 31°C and could be linked to the decreased Ca2+ off‐rate of troponin C. Rats dosed with CK‐2066260 showed increased hindlimb isometric and isokinetic force in response to submaximal rates of nerve stimulation in situ producing significantly higher absolute forces at low isokinetic velocities, whereas there was no difference in force at the highest velocities. Overall muscle power was increased and the findings are consistent with a lack of effect on crossbridge kinetics. In conclusion, CK‐2066260 acts as a fast skeletal troponin activator that may be used to increase muscle force and power in conditions of muscle weakness.

Effects of Stable and Unstable Resistance Training in an Altered-G Environment on Muscle Power.

The study evaluated the effect of 4 weeks of combined resistance-balance training and resistance training alone in a 90° tilted environment on muscle power. Two groups of healthy young subjects performed leg extensions while in a supine position, either on a firm surface along a linear track or on an unstable surface requiring mediolateral balancing movements. Power and force during squats were measured at isokinetic velocities of 10 and 35 deg/s. Results showed significantly greater gains in peak force (44.1%; F(1,21)=8.876, p=0.026), mean force (58.6%; F(1,21)=16.136, p=0.013), peak power (58.7%; F(1,21)=18.754, p=0.009), and mean power (59.2%; F(1,21)=23.114, p=0.007) at the velocity of 35 deg/s after stable than unstable resistance training. However, there were no significant between-groups differences in pre-post training gains in peak force (10.4%; F(1,21)=1.965, p=0.74), mean force (10.3%; F(1,21)=1.889, p=0.80), peak power (12.9%; F(1,21)=2.980, p=0.49), and mean power (19.1%; F(1,21)=3.454, p=0.36) during squats at the velocity of 10 deg/s. Resistance exercises under stable conditions performed in a 90° tilted environment are more effective in the improvement of high velocity muscle power than their use in combination with balance exercises. Such training may be applicable in pre- and in-flight exercise regimens for astronauts and in functional rehabilitation of bed-ridden patients.

Relative differences in strength and power from slow to fast isokinetic velocities may reflect dynapenia.

We compared absolute and normalized values for peak torque (PT), mean power (MP), rate of velocity development, and electromyography (EMG) amplitude during maximal isometric and concentric isokinetic leg extension muscle actions, as well as the %decrease in PT and %increase in MP from 1.05 to 3.14 rad·s(-1) in younger versus older men. Measurements were performed twice for reliability. Isokinetic measurements were normalized to the isometric muscle actions. Absolute isometric PT, isokinetic PT and MP, and EMG amplitudes at 1.05 and 3.14 rad·s(-1) were greater in the younger men, although normalizing to isometric PT eliminated the age differences. The older men exhibited greater %decrease in PT (37.2% vs. 31.3%) and lower %increase in MP (87.6% vs. 126.4%) regardless of normalization. Normalization eliminated absolute differences in isokinetic strength and power, but the relative differences from slow to fast velocities may reflect dynapenia characterized by age-related decreases in fast-twitch fiber function.

Does Blood Flow Restriction Enhance Exercise-mediated Changes In The Plantar Flexors?

The plantar flexor muscle group readily atrophies when exposed to an unloaded environment (i.e. microgravity). There is evidence that the plantar flexors are also resistant to exercise stimuli when compared to other musculature. A rather novel training method called Kaatsu, or blood flow restriction (BFR) training, may potentially provide a substantial resistance training stimulus to the plantar flexors. PURPOSE: To determine if there are differences in strength and body composition after five weeks of training utilizing fatiguing protocols with or without BFR. METHODS: Seven physically inactive subjects (6 male, 1 female) engaged in five weeks of resistance training for the plantar flexors. Each leg was randomly assigned to one of three protocols: 1) high intensity (HIT), 2) low intensity (LIT), or 3) low intensity with blood flow restriction (BFR). Exercise sessions consisted of three sets to fatigue with 1.5 minutes of rest between sets. Each repetition consisted of a maximal shortening contraction followed by a controlled lengthening contraction regulated audibly by a metronome. Exercise was conducted unilaterally on hack squat equipment. Sets were terminated when 80% of full ROM was not obtained for two consecutive repetitions. For BFR, pressure was applied just superior to the proximal patella at 1.3 x systolic blood pressure and was maintained through the duration of the protocol. RESULTS: No significant differences were found with isometric torque although % changes pre-post in peak power across isokinetic velocities ranging from 30 to 240 degrees were significantly greater with LIT. One repetition max (1RM) increased post-training in all groups with a trend towards increased strength at the mid-assessment for BFR only (p=0.0537). Total reps completed were significantly lower and total training volume higher with HIT. Session RPE was not different among protocols. There were no changes in lower leg lean or fat mass as assessed by DXA. CONCLUSIONS: In general, all three training protocols resulted in increased 1RM strength following five weeks of training with no changes in body composition. Supported by NIH grant UL1 TR00153 and the Undergraduate Research Opportunities Program at UCI.

Usefulness of measuring isokinetic torque and balance ability for exercise rehabilitation

Usefulness of measuring isokinetic torque and balance ability for exercise rehabilitation

Comparison of Different Isokinetic Velocity Spectrum Exercises on Peak Torque Quadriceps Muscle

Isokinetic exercises are those exercises, which are performed with a specialized apparatus that provides variable resistance to movement so that no maer how much effort is entered, the movement takes place at a constant speed. The Isokinetic peak torque is one of the important parameters to evaluate the athletic performance or to prevent knee injury. The clinical application of Isokinetic include documentation of patient progress, rehabilitation exercise regimens the use of normative data and analysis of force velocity or power velocity relationships. In the following study total of 40 patients were taken and were divided in four groups Group A (n=10) (Isokinetic training protocol I), Group B (N=10), Group C (n=10) (Isokinetic training protocol III) and Group D (n=10) (Isokinetic training protocol IV). Paired t-test was used to compare the effectiveness of peak torque within the groups. ANOVA test was used to find the relation between two variables i.e. different Isokinetic velocity spectrum exercises and peak torque. On applying ANOVA the result was found to be significant with F-vale 7.58 at p<0.05. In conclusion, modified velocity spectrum protocol starting from high velocity is more effective in increasing quadriceps peak torque than other three protocols.

Differences in Isokinetic Strength of the Knee Extensors and Flexors in Men With Isolated and Combined Cruciate-Ligament Knee Injury.

The extent of knee extensor and flexor weakness after disruption of knee ligaments affects a rehabilitation output and functional recovery and may give prognostic information on a possible risk of development of knee osteoarthritis. The hypothesis tested was whether patients with a multiple-ligament tear would have larger abnormalities in strength of the knee extensors and flexors than patients with an isolated-ligament rupture. Cross-sectional study, level III. Outpatient orthopedic clinic. 3 groups of recreationally active men: noninjured control (CON, n = 12), with an anterior cruciate ligament injury (ACLI, n = 10), and with combined anterior and posterior cruciate ligament injury (APCLI, n = 9), matched according to age, body mass, and height. All patients received conservative treatment and rehabilitation and awaited ligament reconstruction surgery. Isokinetic maximum-repetition peak torque per body mass (PT/BM) and total work (TW), PT and TW limb-symmetry index (LSI), and flexor-to- extensor PT ratio were evaluated during concentric knee extension-flexion movements at lower (60°/s) and higher (240°/s) isokinetic velocities. The main finding was that compared with the individuals with ACLI, patients with APCLI produced in their injured limbs lower mean TW (extension: 30.3%, flexion: 28.2%) and had lower mean TW LSI (extension 74% in APCLI vs. 91.6% in ACLI; flexion 61.3% in APCLI vs. 90.8% in ACLI) at the higher but not lower speed of isokinetic testing. However, at the lower velocity the quantified size of reduction in PT/BM and TW was greater in subjects with APCLI than ACLI as compared with the CON individuals. After bi-cruciate-ligament injury the capacity to produce torque by concentric muscle contractions throughout knee-extension and -flexion movements performed with high speed is lower in injured limbs than after isolated anterior cruciate ligament tear.

Strength, Speed and Power Characteristics of Elite Rugby League Players

The purpose of this article was to compare strength, speed, and power characteristics between playing position (forwards and backs) in elite rugby league players. A total of 39 first team players (height, 183.8 ± 5.95 cm; body mass, 100.3 ± 10.7 kg; age, 24 ± 3 years) from a National Rugby League club participated in this study. Testing included 10-, 40-m sprint times, sprint mechanics on an instrumented nonmotorized treadmill, and concentric isokinetic hip and knee extension and flexion. Backs, observed to have significantly (p ≤ 0.05) lighter body mass (effect size [ES] = 0.98), were significantly faster (10-m ES = 1.26; 40-m ES = 1.61) and produced significantly greater relative horizontal force and power (ES = 0.87 and 1.04) compared with forwards. However, no significant differences were found between forwards and backs during relative isokinetic knee extension, knee flexion, relative isokinetic hip extension, flexion, prowler sprints, sprint velocity, contact time, or flight time. The findings demonstrate that backs have similar relative strength in comparison with forwards, but run faster overground and produce significantly greater relative horizontal force and power when sprinting on a nonmotorized instrumented treadmill. Developing force and power in the horizontal direction may be beneficial for improving sprint performance in professional rugby league players.

ISOKINETIC RELATIVE STRENGTH PROFILE OF POLISH ELITE AND SUB-ELITE FEMALE AND MALE SOCCER PLAYERS – A CROSS SECTIONAL STUDY

BackgroundHowever the isokinetic strength is well described in the literature, there is still little know about the relative isokinetic strength values in sub-elite and elite soccer players of both sexes....

Influence of Functional Knee Bracing on the Isokinetic and Functional Tests of Anterior Cruciate Ligament Deficient Patients

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 some enhancement regarding the extension peak torques and power generating capacity of the ACL-deficient subjects that could be helpful in reducing the bilateral asymmetry in these patients.

The Effect of Velocity on Load Range during Isokinetic Hip Abduction and Adduction Exercise

The purpose of this study was to quantify the components of acceleration, load range and deceleration through a velocity spectrum during concentric hip abduction and adduction isokinetic exercise, and to investigate the effect of load range on peak torque and work done. 16 male healthy subjects performed 3 maximal concentric reciprocal hip abduction and adduction gravity corrected repetitions in a fixed order at 60, 120, 180, 240, 300, 360 and 420° · s-1, with a 30 s rest between velocities. Hip abduction and adduction results revealed that load range significantly decreased while acceleration and deceleration ROM significantly increased (p<0.05) with each increase in velocity. When the total peak torque data was corrected for load range there was a significant decrease (p<0.05) in peak torque at velocities of 300° · s-1 and above, for both hip abduction and adduction. Load range correction also resulted in a significant decrease (p<0.05) in work done at velocities of 120° · s-1 and above, for both hip abduction and adduction. The results demonstrate an inverse relationship between isokinetic velocity and load range during concentric hip abduction and adduction, and suggest a need for the clinician to carefully consider velocity selection when performing exercise on an isokinetic device.

Involuntary and voluntary muscle activation in children with unilateral cerebral palsy – Relationship to upper limb activity

BackgroundSpasticity and reduced strength are both primary neuromuscular impairments associated with cerebral palsy (CP). However, it is unclear whether spasticity or reduced strength is the strongest contributor to activity limitations. AimTo study whether involuntary activation of the biceps brachii muscle, in addition to reduced strength, contributes to limitations in upper limb activity in children with CP. MethodFifteen children with unilateral CP (9 males and 6 females, age range 8–17 years) participated in this study. Involuntary activation, reflecting spasticity, was studied as biceps brachii activity during passive elbow extension at four isokinetic velocities (10, 90, 180 and 300°/s). Elbow flexion peak torque, reflecting strength, was measured during maximal voluntary isometric contraction, and concurrent biceps brachii activity was registered reflecting voluntary muscle activation. Bimanual upper limb activity was assessed in the performance domain using the Assisting Hand Assessment (AHA). ResultsBoth involuntary and voluntary muscle activation were related to activity, the former negatively, but voluntary activation showed the strongest relationship (Spearmans rho = .84). Involuntary muscle activation at 10, 90 and 180°/s was negatively related to muscle strength (Spearmans rho = −.63, −.58 and −.62, respectively). ConclusionsOur results do not indicate that spasticity affects upper limb activity in addition to strength. Most likely, muscle weakness and spasticity jointly contribute to activity limitations, reflected by the strong relationship between the ability to voluntarily activate a muscle and activity performance.

Long-term basketball playing enhances bone mass and isokinetic muscle strength

Aim: To evaluate bone mass in female basketball players and the relationship between bone mineral density (BMD) and isokinetic muscle strength. Methods: We investigated 29 female basketball players, age 21.9± 9.1 years, training for about 6–8 hours per week. The reference group consisted of 22 non-active female, age 21.4 ± 1.5 years. BMD was measured using dual-energy-X-ray absorptiometry in total body, lumbar spine, the whole femur and humerus. Isokinetic peak torque of the quadriceps and hamstring muscles were measured at 60 and 180◦/s. Osteocalcin (OC) and cross-linked C-telopeptide (CTX) were measured by radioimmunoassay and electrochimiluminescence, respectively. Results: Compared to the controls, the basketball group had significantly (P < 0.001) a higher BMD in the total body (11.6%), the lumbar spine (9.83%), the dominant femur (16.8%), the non-dominant femur (15.8%) and the dominant humerus (8.47%). The female basketball players had also significantly higher peak torques at both isokinetic velocities (60 and 180◦/s) and for both lower limbs. All muscle peak torque measured for the female basketball players were significantly correlated with correspondent leg BMD and for both velocities tested. However, no significant correlations were noted for the control group. Values of formation (OC) and resorption (CTX) markers were significantly higher in the athletic females (P < 0.01 and P < 0.05, respectively). Conclusion: Our results show clearly that practice of basketball is associated with the improvement of bone mass. In addition, the most important finding of our study is that isokinetic muscle strength seems to be correlated with correspondent BMD in female basketball players.

Evaluation of the relationship between isokinetic strength and two different soccer throw-in performances

The aim of the current study was to determine ball velocity and throwing distance in standing and running throw-in techniques, and to correlate this performances with isokinetic torques of the, elbow, shoulder, and trunk extensors and flexors. 14 male amateur soccer players volunteered to participate to the current study. Concentric Isokinetic tests were measured at 60 and 180 ◦ /s angular velocities for elbow and shoulder, 30 and 120 ◦ /s angular velocities for trunk. Ball velocity was measured by a radar gun and the throwing distance was measured regarding throw-in performance. Unpaired t-test was used to analyze ball velocity and throwing distance differences between two different throwing techniques. To clarify relationship between isokinetic strength values and ball velocities and distance which occur during two types of throwing techniques Pearson Correlation Analyze was used. There were no statistical significant differences regarding throwing velocity and distance between two different throw-in tech- niques. Eventhough, theisokineticvaluesandthrowingvelocitiesdidnotcorrelatewitheachother, therewasapositivecorrelation between standing throw-in distance with elbow (non-dominant flexion at 60 and 180 ◦ s −1 ), shoulder (dominant flexion-extension at 60 and 180 ◦ s −1 , non-dominant extension at 60 and 180 ◦ s −1 ) and trunk (flexion at 30 and 120 ◦ s −1 ). The only correlation between running throw-in and throwing distance occurred in shoulder (dominant extension at 60 ◦ s −1 ) and trunk (flexion at 30 ◦ s −1 ). In conclusion, the isokinetic strength values regarding upper extremity is strong factor that describes standing throw-in performance. However; it is not highly correlated with the running throw-in performance in soccer.

Torque-angle relationship are better preserved during eccentric compared to concentric contractions in patients with stroke

The aim of this study was to compare the effect of isokinetic contraction mode and velocity on the torque-angle relationship during maximum voluntary elbow flexion in patients with stroke, age-matc ...

Comparison of Recovery Strategies on Maximal Force-Generating Capacity and Electromyographic Activity Level of the Knee Extensor Muscles

With regard to intermittent training exercise, the effects of the mode of recovery on subsequent performance are equivocal. To compare the effects of 3 types of recovery intervention on peak torque (PT) and electromyographic (EMG) activity of the knee extensor muscles after fatiguing isokinetic intermittent concentric exercise. Crossover study. Research laboratory. Eight elite judo players (age = 18.4 ± 1.4 years, height = 180 ± 3 cm, mass = 77.0 ± 4.2 kg). Participants completed 3 randomized sessions within 7 days. Each session consisted of 5 sets of 10 concentric knee extensions at 80% PT at 120°/s, with 3 minutes of recovery between sets. Recovery interventions were passive, active, and electromyostimulation. The PT and maximal EMG activity were recorded simultaneously while participants performed isokinetic dynamometer trials before and 3 minutes after the resistance exercise. The PT and maximal EMG activity from the knee extensors were quantified at isokinetic velocities of 60°/s, 120°/s, and 180°/s, with 5 repetitions at each velocity. The reduction in PT observed after electromyostimulation was less than that seen after passive (P < .001) or active recovery (P < .001). The reduction in PT was less after passive recovery than after active recovery (P < .001). The maximal EMG activity level observed after electromyostimulation was higher than that seen after active recovery (P < .05). Electromyostimulation was an effective recovery tool in decreasing neuromuscular fatigue after high-intensity, intermittent isokinetic concentric exercise for the knee extensor muscles. Also, active recovery induced the greatest amount of neuromuscular fatigue.