bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of different resistive training modalities on blood pressure and heart rate responses of healthy subjects
Authors: Lamotte M. , Strulens G. , Niset G. , van de Borne Ph.
Published: October 2018

Background: Resistive training has been introduced in exercise programs to improve the results of traditional rehabilitation. Changes in blood pressure (BP) and heart rate (HR) during resistive have mainly been measured out of the rehabilitation context, using discontinuous monitoring of BP, while exercising small muscular mass during isometric exercise or low intensity contraction.

Method: The BP and HR responses to low, moderate and high intensity resistive training were continuously assessed in 21 healthy subjects. The total amount of work was the same for the three modalities, hence the number of repetition was inversely related to exercise intensity.

Results: Blood pressure and HR increased from set 1 to set 3 for all 3 training modalities and were highest, intermediate and lowest during low, moderate and high intensity training respectively (all p<0.001).

Conclusions: BP and HR changes during resistive training are related principally to exercise duration. Short sets using heavy weights is preferable to limit BP and HR rises.
Effects of vibration on maximal isometric muscle contraction at different joint angles
Authors: Kin-Isler Ayse , Acikada Caner , Aritan Serdar
Published: October 2018

The purpose of the present study was to determine the effects vibration, applied with different frequencies at different joint angles, on maximal isometric muscle contraction. Forty male volunteers were randomly and equally assigned to one of the four different vibration stimulation groups as 6 Hz, 12 Hz, 24 Hz and 48 Hz. Subjects performed three consecutive isometric maximal voluntary contractions (MVC) with and without vibration for six seconds with one-minute interval at 90, 120 and 150 degrees of elbow angles in random order. During MVC with vibration tests vibration was applied to upper arm 10 seconds before the contraction begins and continued throughout the MVC. According to results of 4 × 3 × 2 ANOVA with repeated measures, significant joint angle effect(p<0.001), contraction type effect p<0.001) and significant frequency × contraction type interaction (p<0.001) was found. It can be concluded that vibration stimulation resulted in increased isometric MVC. Results also suggested that stimulating muscles with 6, 12 and 24 Hz of vibration resulted in increased isometric MVC, 48 Hz of vibration on the other hand resulted in decreased isometric MVC. In addition, the length of the contracting muscle did not affect the vibration load that was applied with different frequencies.
Comparison of the roles of common constitutional and behavioural parameters in back performance estimates
Authors: Ropponen Annina
Published: October 2018

Objective: To compare the associations between different physical activity histories and anthropometric measures in isokinetic lifting performance, isometric back extension endurance and psychophysical lifting tests.

Background: The relative roles and interaction of these factors related to back function are largely unknown.

Methods: The subjects consisted of a population-based sample of 210 working-age males. Paraspinal muscle cross-sectional areas were obtained by magnetic resonance imaging; anthropometric measures, isokinetic and psychophysical lifting capacity, and isometric back extension endurance tests were performed and current and physical activity histories and occupational loading were enquired by structured interview. Stepwise multiple regression analyses were used to study the associations.

Results: Lean body weight, body weight and sum of the paraspinal muscle CSAs at L3-L4 level predicted the highest amount of the variance(R $^2$ =10–25%) and the different models of anthropometric measures and physical activity 7–33% of the variance in the back function tests.

Conclusions: The models of physical activity and anthropometric measures or their combination predicted isokinetic lifting performances weakly and other back function test results even worse. As a single predictive factor, lean body weight showed weak ability to predict isokinetic lifting performances. Collecting current or past data of physical activity parameters does not add anything for predicting back function.
Effect of two acute static stretching durations of the rectus femoris muscle on quadriceps isokinetic peak torque in professional soccer players
Authors: Zakas Athanasios , Galazoulas Christos , Doganis George , Zakas Nikolaos
Published: October 2018

While athletes routinely perform warm-up and stretching exercise, it has been suggested that prolonged stretching, immediately prior to an activity, might affect negatively the force production. Fifteen professional soccer players participated in the study to examine whether a routine duration of acute static stretching may account for losses in isokinetic peak torque production. All participants performed two static stretching protocols on the rectus femoris muscle tendon unit (MTU), at different training sessions, with a week interval. The first stretching protocol was performed four times for 15 s(4 × 15 s), and the second 32 times for 15 s (32× 15 s). Range of motion (ROM) was determined during knee flexion, with a pendular Myrin flexometer. The peak torque of the dominant leg extensors was measured on a Cybex Norm dynamometer at 60, 90, 150, 210 and 270°/s angular velocities. The 2× 2 analysis of variance showed that peak torque remained unchanged, following the total static stretching for 60 s in all angular velocities, while it decreased in all angular velocities, following a total static stretching for 8 minutes (p<0.001). The findings suggest that an acute static stretching exercise of short duration, as performed by soccer players, during warming up procedures, does not produce decreases in peak torque, compared to multiple stretches of an 8 minute long duration.
Five-repetition sit-to-stand test performance by community-dwelling adults: A preliminary investigation of times, determinants, and relationship with self-reported physical performance
Authors: Bohannon Richard W. , Shove Megan E. , Barreca Susan R. , Masters Lisa M. , Sigouin Christopher S.
Published: October 2018

The 5-repetition sit-to-stand (STS) test is a widely used, but insufficiently evaluated, test for lower limb strength. We therefore described STS test times for a sample of community-dwelling adults, examined the association of age, gender, height, weight, and body mass index (BMI) with STS time, and determined the relationship of STS time with self-reported physical functioning. Ninety-four community dwelling adults participated. Repeated measures of STS time were reliable (intraclass correlation coefficient =0.957). The mean STS time for all 94 subjects was 7.6 seconds. Age, weight, and BMI were (r=0.281–0.528), but gender and height were not(r=−0.074–0.007), correlated significantly with STS time. Regression analysis showed that age and BMI explained 43.7 percent of the variance in STS time. The correlation between STS time and physical functioning r=−0.474) was significant (p<0.001). Regression analysis showed that age and BMI added slightly to the explanation of variance in physical functioning provided by STS time.

In conclusion, this study provides STS times that might be useful for interpreting performance of adults screened with the test. Such performance should be considered in light of age and BMI. The relationship of STS time with physical functioning provides evidence of the validity of the measure.
Measurement of the effect of hamstring muscle force on knee cruciate ligament loading patterns during simulated extension motions: An in vitro study
Authors: Ostermeier Sven , Stein Christian , Hurschler Christof , Windhagen Henning , Stukenborg-Colsman Christina
Published: October 2018

Background: The objective of this study was to investigate dynamically the load on the cruciate ligaments and the effect of simulated co-contraction of the hamstrings muscles on quadriceps force and load on the cruciate ligaments.

Methods: Load transducers were fixed in the fibers of the anterior and posterior cruciate ligament of seven knee specimens. Isokinetic extension motions applying an extension moment of 31 Nm, representing an extension moment capable by healthy human volunteers in isokinetic extension tests, were simulated in a knee simulator from 120° to full knee extension. Quadriceps force and load on the cruciate ligaments were measured in the absence and presence of a 200 N hamstrings co-contraction.

Results: Quadriceps force significantly (p=0.04) increased under the application of hamstrings co-contraction. Anterior cruciate ligament load significantly increased below 20° knee flexion up to 161 N and was significantly (p=0.04) reduced to 29 N under hamstrings co-contraction at full knee extension. Posterior cruciate ligament load without hamstrings co-contraction showed a maximum load at 112° knee flexion of 38 N, reducing to knee extension and was not significantly increased(p=0.20) under hamstrings co-contraction, showing a maximum load of 66 N near knee flexion.

Conclusions: This dynamic in vitro study revealed the dependency of anterior cruciate ligament load on knee flexion angle during an isokinetic extension cycle. With a co-contraction of hamstring muscles the peak load on the anterior cruciate ligament was significantly decreased in knee extension with a non significant concomitant increase of posterior cruciate load at knee flexion. These findings have implications for graft donor site selection and postoperative rehabilitation, e.g. after anterior cruciate ligament reconstructions.
Testing isometric fatigue in the trunk muscles
Authors: Crowther Alexander , McGregor Alison H. , Strutton Paul H.
Published: October 2018

Muscle fatigue has high relevance in human performance and may contribute to the high incidence of back pain amongst athletes. However, the term fatigue is often poorly defined and is used inconsistently, frequently being interchanged with endurance. This study aimed to establish whether the Biering-Sorensen test and a test of fatigue for the abdominal muscles were effective at inducing fatigue using a well established definition. Twenty medical students were subjected to two protocols (A & B). Using a Cybex norm isokinetic dynamometer, the isometric peak torques during extension and flexion were measured before and after each protocol. Protocol A involved a 45 second maximal isometric contraction within the dynamometer while Protocol B entailed a Biering-Sorensen (submaximal) test for extension and a sit up crunch for flexion. Extension testing followed flexion testing. Significant reduction in peak mean torque occurred only in flexion for both protocols. The Biering-Sorensen test did not result in a decrease in peak torque suggesting minimal fatigue (using the definition used in this study). A weak correlation was found between the length of time the Biering-Sorensen test was held and the fatigue index. The Biering-Sorensen test does not appear to reduce maximum voluntary contraction strength and remains a test of endurance. However, a similar test for the abdominal muscles did induce fatigue. Further research is required to develop an effective protocol to assess trunk extensor fatigue.
Agonist and antagonist EMG activity of neck muscles during maximal isometric flexion and extension at different positions in young healthy men and women
Authors: Lecompte J. , Maisetti O. , Guillaume A. , Skalli and W. , Portero P.
Published: October 2018

The aim of this study was to compare maximal isometric torque and EMG activity of neck flexors and extensors in flexed and extended positions between men and women. Twenty four non-trained young healthy subjects (12 men vs. 12 women) performed maximal isometric neck flexion and extension within 30° around the neutral position in a sitting posture using a modified isokinetic dynamometer. Surface EMG activity of sternocleidomastoid, scalenus, paraspinal and upper trapezius muscles was recorded bilaterally. Men exhibited higher normalized-to-lean body weight torque than women mainly during neck flexion (44%, P<0.001) compared to extension (18%, P<0.05). In addition, torque increased from extended to flexed positions in women only(+17%, P<0.001). This was associated with a decrease in EMG of neck extensors and upper trapezius muscles (from 35% to 20% and from 18% to 7%, P< 0.001, respectively) without changes in agonistic activity of neck flexors with neck position. In contrast, men displayed similar torque and muscle activation level within 30° of range of motion around the neutral position for both directions. These findings demonstrate gender-specific differences in neck function that was probably linked to higher coactivation level in antagonist muscles (neck extensors) and stabilizers (upper trapezius muscles).
Isokinetic strength values, conventional ratio and dynamic control ratio of shoulder rotator muscles in elite badminton players
Authors: van Cingel Robert , Kleinrensink Gert Jan , Mulder Paul , de Bie Rob , Kuipers Harm
Published: October 2018

Nine male and seven female asymptomatic elite badminton players were tested bilaterally to determine concentric and eccentric strength values, conventional ratio and dynamic control ratio of shoulder rotator muscles. All tests were performed at 60 and 120°/sec. The study shows significant differences that were similar for men and women: the dominant arm was stronger than the non-dominant arm, normalised peak torque values at 60°/sec were higher than at 120°/sec, the concentric internal rotator strength(IRS) was larger than the concentric external rotator strength (ERS) and the eccentric ERS was larger than the concentric ERS. For females the eccentric ERS was larger than the concentric IRS as opposed to men in whom the concentric IRS was larger than the eccentric ERS. For both sexes the CVR for the dominant arm was significantly higher than for the non-dominant arm. The DCR at 60°/sec was significantly lower than at 120°/sec and the DCR for females was significantly higher than for men. Data presented are important for interpreting isokinetic shoulder rotator strength tests in elite badminton players and could be relevant in rehabilitation and prevention of shoulder injuries.
Reproducibility of isokinetic single- and multi-joint strength measurements in healthy and injured athletes
Authors: Müller Steffen , Baur Heiner , König Timo , Hirschmüller Anja , Mayer Frank
Published: October 2018

The purpose of this study was to analyse the reproducibility of isokinetic single-joint (knee and ankle) and multi-joint (leg-press configuration) strength findings in healthy athletes and a group of athletes with chronic unilateral tendon injuries at the lower limb, over a clinically meaningful time interval of 8 weeks. Concentric and eccentric strength performance capacity of knee extensors/flexors, ankle dorsi-/plantarflexors as well as the extensors of the total lower limb was assessed twice in 19 healthy(H) and 10 injured (I) athletes. Calculation of ICC, standard error of measurement SEM, Bland and Altman's 95% limits of agreement and Test-Retest Variability (TRV) served as main outcome variables. The results showed a small systematic bias and random error [mean bias: 3.25 ± 4.02(H) 4.25 ± 4.56 (I); TRV 12.34 ± 10.20% (H) 14.27 ± 9.42% (I)] except for plantarflexion measurements and the eccentric mode of the total lower limb strength in injured athletes(TRV � 20%). The present findings delineate clinically relevant cutoff values in the evaluation of valid intervention effects of strength training and rehabilitation in healthy athletes and athletes suffering from tendon-related injuries.
Biomechanical and physiological descriptions of the elliptical cycle locomotion
Authors: Horvais Nicolas , Samozino Pierre , Textoris Vincent , Hautier Christophe , Hintzy Frederique
Published: October 2018

The aim of this study was to describe elliptical cycle locomotion by muscular, kinematics, physiological and perceptual parameters during submaximal and maximal exercises. Seven men performed an incremental test until exhaustion. Pulse rate, ratings of perceived exertion (6–20 Borg's scale), muscular activity of 8 muscles (higher and lower limbs muscles) and elbow, shoulder, hip and knee joint amplitudes were continuously recorded. Pulse rate reached about 70% of the theoretical maximal pulse rate after 3 minutes of submaximal exercise and about 95% at the end of the maximal exercise; the sensation of this effort being respectively described as "weak" and "very hard". EMG analysis indicated that all investigated muscles were activated, especially knee and hip extensor muscles. Kinematic analysis showed that all joints were activated especially the elbow, shoulder and knee. The elliptical cycle locomotion led to global body activation (both higher and lower limbs activity) and therefore induced a relatively significant cardiac activation even at low intensity. We therefore suggest that elliptical cycle locomotion is a unique pattern.
Effect of the chronically unstable ankle on knee joint position sense
Authors: Tsiganos G. , Kalamvoki E. , Smirniotis J.
Published: October 2018

Purpose: to determine whether subjects with chronic ankle instability (CAI) suffer proprioceptive deficits (joint position sense) in the proximal joint (knee) of the injured ankle.

Methods: Fourteen subjects with unilateral CAI and 14 healthy controls participated in this study. We tested knee joint position sense using an isokinetic dynamometer. Knee joint position testing was carried out at 30°, 45° and 70° knee flexion. The difference between perceived angle and actual angle was recorded as the error.

Results: Mean value of error was statistically significant in subjects with CAI compared with control subjects (30° p< 0.001, 45° p< 0.023 and 70° p< 0.050). Mean error value at 30° was also statistically greater than mean error value at 70° (p< 0.015).

Conclusions: Changes in knee joint position sense in subjects with CAI suggest further emphasis on assessment of the joint proximal to the level of injury and subsequent planning of a rehabilitation program. Further research is required to determine the exact contributions to knee joint proprioception.
Bilateral deficits in muscle contraction parameters during shoulder scaption in patients with unilateral subacromial impingement syndrome
Authors: Camargo Paula R. , Haik Melina N. , Filho Raul B. , Mattiello-Rosa Stela M.G. , Salvini Tania F.
Published: October 2018

Objective: To evaluate muscle contraction parameters during scaption of the shoulder in patients with subacromial impingement syndrome (SIS).

Method: Thirty-three male subjects were evaluated. The impingement group consisted of 17 assembly line workers (31.6 ± 6.4 years) with unilateral SIS. The control group consisted of 16 healthy and active subjects (29.5 ± 6.2 years). Acceleration time, time to peak torque, peak torque, total work and power were measured bilaterally during isokinetic concentric scaption, at 60°/s and 180°/s.

Results: None of the isokinetic parameters differed bilaterally in the SIS group but compared to the control group showed impaired muscle activity in all parameters at both speeds (P< 0.05).

Conclusions: Muscle contraction parameters are altered in both involved and uninvolved shoulders during scaption in patients with SIS.
Alterations in torque and hamstrings agonist and antagonist activity over repeated maximum effort, reciprocal isokinetic flexion-extension movements
Authors: Croce R.V. , Miller J.P. , Horvat M.
Published: October 2018

Examining the effects of fatigue on hamstrings' functioning can provide useful information regarding their role in stabilizing the knee joint. The purpose of the present investigation was to determine the effect of fatiguing, maximum effort, reciprocal isokinetic flexion-extension movements on peak torque (PT) and average torque (AVT) of the knee flexors and extensors, and agonist and antagonist medial hamstrings (MH) and biceps femoris (BF) surface electromyography (SEMG), as measured by the root mean square amplitude(RMS) and median frequency of the frequency spectrum (MDF). Ten healthy adult female university students (age=22.5 ± 2.0 years) performed 32 maximal effort contractions of the quadriceps (extension) followed by maximal effort contractions of the hamstrings (flexion) at an angular velocity of 400°· s $^{-1}$ . Data were normalized (as a percentage) and compared to maximum voluntary contractions(MVC) at repetitions 8, 16, 24, and 32. Separate repeated measures analyses of variance were performed on data to determine changes from MVC levels. Results indicated: (1) there were significant declines in PT and AVT from MVC levels across repetitions tested; (2) when acting as agonists MH and BF displayed increased RMS across repetitions tested, except from repetition 8-to-16; (3) when acting as antagonists MH and BF displayed no significant differences in RMS across repetitions tested; and, (4) there was a steady decline in MDF across repetitions tested in both MH and BF muscles when acting as agonists and antagonists, indicating a shift in motor unit recruitment from fast-to-slow twitch units. Based on the results, it appears that the MH and BF behave in unison when acting as either agonists or antagonists but as a muscle pair, they behave differently when acting in agonist or antagonist mode. As agonists, the MH and BF displayed increased amplitude and decreased spectral frequency over the course of a fatiguing, maximum effort, reciprocal isokinetic flexion-extension test performed at 400°·s $^{-1}$ . However, when acting as antagonists, they displayed stable amplitude with decreasing spectral frequency.
Blood lactate responses to exercise performed on a high-speed inertial device
Authors: Caruso John F. , Monda Julie K. , Ramey Elizabeth , Hastings Lori P. , Coday Michael A. , McLagan Jessica R. , Wickel Eric E.
Published: October 2018

To assess blood lactate and performance variables obtained from high-speed exercise performed on a device (Impulse Training Systems; Newnan GA) that imposes loads without gravitational resistance, subjects(n = 45) completed two tonic and two phasic workouts. Each high-speed workout entailed two 60-second sets of seated knee- and hip-extension repetitions separated by a 90-second rest period. Pre- and five minutes post-exercise, lactate concentration was measured from a fingertip blood drop with a calibrated analyzer (Accusport, Sports Resource Group, Hawthorne, NY). Mean blood lactate values were compared with a 2(contractile mode: tonic, phasic) × 2(time)× 2 (gender) ANOVA, with repeated measures applied to workout mode and time. Resistance exercise performance variables were assessed with 2 (contractile mode: tonic, phasic) × 2 (gender) ANOVAs. With α ⩽ 0.05, results showed a time (post > pre) effect for blood lactate. Exercise performance values were impacted by workout mode and gender, yet those independent variables had no impact on blood lactate. Results concur with prior resistance exercise studies that show significant blood lactate increases over time. Additional inquiry is warranted as to why gender and workout mode influenced resistance exercise performance variables, but did not impact blood lactate.
How informative are manual muscle test scores obtained from home-care patients?
Authors: Bohannon Richard W.
Published: October 2018

This retrospective study examined the initial therapy notes of home-care patients to determine the ability of manual muscle testing (MMT) to identify muscle weakness and explain functional independence. Manual muscle test scores for trunk flexion and 3 lower limb muscle actions (hip flexion, knee extension, and ankle dorsiflexion) were obtained bilaterally as was independence in sit-to-stand and walking 50 feet. All 31 patients (mean age 72.8) demonstrated muscle weakness in some tested muscle group. Less than maximum MMT scores were most common for hip flexion (100%) and least common for knee extension (51.6%). All but 2 individual and combined strength measures correlated significantly with both sit-to-stand and walking independence. The correlations ranged from 0.308 to 0.748. Based on its ability to identify weakness and explain functional independence, MMT appears to be an appropriate measure for use with patients seen in a home-care setting.
The impact of resistive exercise training on the relationship between anthropometry and jump-based power indices
Authors: Caruso John F. , Coday Michael A. , Ramsey Charles A. , McLagan Jessica R.
Published: October 2018

Objective: To examine the impact resistive exercise (RE) training has on the ability of anthropometry to predict power output from jump tests.

Methods: With a matched-pairs design, subjects (n = 19) were assigned to six weeks of leg and calf press workouts. With no crossover, subjects either performed RE on a traditional seated leg press device to which free weights (FW) were added, or on a flywheel ergometer (FERG). Before and after the intervention, subjects performed jump-based tests and were measured for anthropometric dimensions. Tests included a standing vertical jump, a repetitive four-jump protocol, and a depth jump from a platform; power outputs from each were calculated.

Results: The six-week intervention weakened the correlation between anthropometry and jump-based power indices from FERG workouts, while the opposite was true for the FW group.

Conclusions: While several reasons may have led to the stark group differences in the ability to account for jump-based power variance, the two most important factors appear to be the degree of workout progression and the rate RE repetitions were performed. FW subjects incurred significantly greater strength gains, as evidenced by the degree of workout progression over the intervention, versus the FERG group. The manner in which the devices operated permitted FW repetitions to occur at faster rates and was more movement-specific to jump-based tests. Thus anthropometry increased the degree of explained variance in jump-based power indices from FW workouts at the conclusion of the six-week intervention.
An algorithm for directly fitting a moment-angle-angular velocity model to maximum voluntary muscular moments measured with an isokinetic dynamometer
Authors: Anderson Dennis E. , Madigan Michael L. , Nussbaum Maury A.
Published: October 2018

Joint kinematics influence maximum voluntary muscular moment of force about a joint, and can thereby have substantial effects on available muscle moment during dynamic activities. A model of maximum voluntary muscle moment as a function of joint angle and angular velocity has been described previously. Originally, a computational optimization approach was used to fit this model to muscle moment data collected using an isokinetic dynamometer. To make this model more practical and accessible, an algorithm was developed to directly determine the model parameters without requiring optimization. This algorithm was compared with the optimization method for fitting measured muscle moment data from six different lower limb exertions in 14 healthy adults. Both methods produced models that fit the measured moment data reasonably well(r $^{2}$ typically > 0.75), and the direct calculation method reduced r $^{2}$ only slightly compared to optimization (by an average of 1.14%). The direct calculation algorithm presented here may be preferable to the optimization approach used previously, as it displays comparable performance but requires less time and expertise to employ.
The effect of ankle taping on isokinetic strength and vertical jumping performance in elite taekwondo athletes
Authors: Sanioglu Ahmet , Ergun Soner , Erkmen Nurtekin , Taskin Halil , Goktepe A. Salim , Kaplan Turgut
Published: October 2018

The aim of the study is to examine the effect of ankle taping on ankle plantarflexion (PF) and dorsiflexion (DF) isokinetic strength and vertical jump height in elite taekwondo athletes. Seven women and 9 men taekwondo athletes forming the Turkish National Taekwondo Team participated in this study. A closed basket weave taping technique was applied to the dominant and non-dominant ankle. Tests were performed both in un-taped and taped conditions. Peak torques values at 60 and 180°/s were nonsignificantly lower in the taped condition (p > 0.05). Ankle taping resulted also is a significant reduction in jump height(p < 0.05). The findings of this study suggest that ankle taping affect detrimentally performance in this group of taekwondo athletes.
Reproducibility and validity of Hacettepe Intermittent Jumping Test
Authors: Tınazcı Cevdet , Açı kada Caner
Published: October 2018

High test retest reproducibility is essential in tests used for monitoring athletic performance. The purpose of this study was to establish the reproducibility (R) and validity (V) of Hacettepe Intermittent Jumping Test(HIJT) applied in order to determine physiological and mechanical changes during maximal intermittent jumping exercise (5*15 s maximal jumping and 60 s passive recovery between series). Subjects were measured 3 times on separate days to test the R and once in random order to test the V of the HIJT. Subjects performed HIJT on a platform with their hands on their waist. During the study, total and mean power outputs, fatigue index, rest and maximal heart rate were calculated. Three different testing groups (n = 34) joined the R study while only one of these groups joined the V study in which subjects jumped for a minute (60CJT) with their maximum effort. During this stage blood samples were taken from the earlobes of subjects, at the beginning and at the end of the test. A significant correlation was found among tests of different groups on different days (p < 0.05) and HIJT gave similar results during different trials (p > 0.05). The relationships between HIJT and 60CJT were significant (p < 0.05). Based on correlational analysis HIJT demonstrated satisfactory R and V and may thus be used both under laboratory and field conditions to evaluate anaerobic fitness.
Wingate anaerobic testing with a modified electromagnetically braked elliptical trainer. Part I: Methodological considerations
Authors: Ozkaya Ozgur , Colakoglu Muzaffer , Ozgonenel Okan , Fowler Dianne , Colakoglu Sule , Tekat Atilla
Published: October 2018

The aim of this study was to modify an elliptical trainer and determine a suitable test load with it in order to perform Wingate anaerobic testing (WAnTet). Modifications were made to an electromagnetically braked elliptical trainer. Study participants were forty-eight physically active male college athletes (mean age 20 ± 1 years). Two pilot studies (n = 8) were administered to determine electrical signalling errors and to select the range of potentially suitable test loads (between 0.5 to 1.3 watt/kg). The 1.0 watt/kg WAnTet load was determined to be the most suitable for WAnTet applications amongst 0.8 to 1.1 watt/kg loads (n = 40; p < 0.05). Test-retest results using the 1.0 watt/kg load for peak power (PP) (1477 ± 258 and 1484 ± 271 watts), average power (AP) (1134 ± 209 and 1120± 208 watts), fatigue index ratio (FI%) (49 ± 10% and 49 ± 10%) and change in lactate levels (12.6 ± 1.7 and 12.4 ± 2.1 mM) were highly correlated (r: 0.94, 0.94, 0.80 and 0.74, respectively; p < 0.001). An electromagnetically braked elliptical trainer may be used to measure anaerobic power and anaerobic capacity of athletes and may be substituted for the usual Wingate anaerobic test performed on a cycle ergometer.
Pedaling cadence effects on joint mechanical work during cycling
Authors: Bini Rodrigo Rico , Rossato Mateus , Diefenthaeler Fernando , Carpes Felipe P. , dos Reis Diogo Cunha , Moro Antônio Renato Pereira
Published: October 2018

The aim of the present study was to compare the effects of small changes in pedaling cadence (20% higher and lower than the freely chosen) on hip, knee, and ankle mechanical parameters. Right pedal forces and lower limb kinematics of cyclists were measured with workload at 80% of peak power output, for three pedaling cadences (freely chosen cadence – FCC; 20% below the FCC – FCC −20%; and 20% higher than the FCC – FCC +20%). Forces, kinematics and mechanical work were calculated for hip, knee and ankle joints. Knee joint mechanical work decreased at FCC +20% (55 ± 13 J, compared to FCC – 66 ± 11 J and to FCC −20% – 72± 7 J), while the contribution of each joint to the total mechanical work (TMW) was not affected by pedaling cadence. Joint forces were not influenced by pedaling cadence. Ankle joint angle increased (155 ± 3° compared to FCC – 152 ± 2° and to FCC−20%–149 ± 3°), while knee (59 ± 3° compared to FCC – 62 ± 2° and to FCC −20% – 64 ± 1°), and ankle (15 ± 4° compared to FCC – 18 ± 1° and to FCC −20% – 20 ± 2°) range of motion (ROM) decreased at FCC +20%. The effects of pedaling cadence on joint mechanical work and kinematics indicate that the FCC does not minimize joint mechanical work and force production for all lower limb joints. The knee joint tunes the power production by the mechanical work while the ankle function seems to be dependent on joint kinematics when pedaling cadence is increased.
The effect of a calisthenic exercise bout on oxidant and antioxidant status in middle-aged and postmenopausal women
Authors: Karacan Selma , Cetin Ferihan , Colakoglu F. Filiz
Published: October 2018

Exercise increases the generation of oxygen free radicals and lipid peroxidation. The aim of this study was to investigate the oxidant and antioxidant status in sedentary middle-aged (36.8 ± 5.4 years, n=20) and postmenopausal women (51.4 ± 3.3 years, n=11) before and after acute calisthenic exercise. Both subject groups performed an acute calisthenic exercise for 55 minutes. The intensity of the exercise was 60–70% of maximal heart rate, as determined by Karvonen et al. Plasma malondialdehyde(MDA), gluathione (GSH), ascorbic acid (AA) and nitric oxide (NOx) levels were determined spectrophotometrically.

The postmenopausal group's pre-exercise MDA levels were high and GSH levels were low, compared with those of the middle aged group. This result indicated increased lipid peroxidation after menopause. In both groups, plasma MDA levels and NOx levels increased and plasma AA levels decreased following calisthenic exercise. The present study indicates for the first time that plasma MDA levels increase significantly after a bout of acute calisthenic exercise, involving all large muscle groups at 60–70% of maximal heart rate while plasma AA levels decrease concurrently. These effects may be due to increased lipid peroxidation in both middle aged and postmenopausal women. The finding of low plasma GSH levels and high plasma MDA levels in the postmenopausal group suggests the possible development of a disturbance in the oxidant and antioxidant status after menopause. Reduced levels of AA following acute calisthenic exercise might indicate the consumption of plasma antioxidants protecting the plasma lipids against the damage of lipid peroxidation.
Within-day and between-days reproducibility of isokinetic parameters of knee, trunk and shoulder movements
Authors: Blacker Sam D. , Fallowfield Joanne L. , Bilzon James L.J. , Willems Mark E.T.
Published: October 2018

The purpose of this study was to examine the within-day and between-days reproducibility of isokinetic parameters of knee, shoulder and trunk movements. Ten healthy males (age 30 ± 8 years, height 1.79± 0.05 m, body mass 79.4 ± 8.3 kg) performed isokinetic concentric contractions (knee: 60 and 180°/s; shoulder: 60 and 180°/s: and; trunk: 15 and 60°/s) at 0 (baseline), 2, 24, 48 and 72 hours. Reproducibility of the baseline peak moment, mean peak moment and maximum work was assessed using Bland and Altman limits of agreement and pre-planned paired t-tests (P< 0.05). Peak moment of knee, trunk and shoulder extensors at low velocities had highest reproducibility within and between days over a time period of 3 days. Peak moment at high and low velocities of knee extensors was consistently the most reliable parameter over a 3 day period. It is concluded that isokinetic parameters can be reproducibly measured in a combined session of knee, shoulder and trunk movements in healthy male subjects over a 3-day time period.
Isometric medial and lateral rotations torque steadiness in female workers with shoulder impingement
Authors: Zanca Gisele G. , Camargo Paula R. , Oliveira Ana B. , Serrão Paula R.M.S. , Mattiello-Rosa Stela M.
Published: October 2018

This study compared peak torque and torque steadiness during isometric lateral and medial rotations in workers with shoulder impingement syndrome (SIS) and those with no upper limb disorders. Twenty-nine female workers were evaluated. The SIS group consisted of 14 workers (36.57 ± 5.23 years) with unilateral SIS. The control group consisted of 15 healthy workers (35.53 ± 5.46 years). Three maximal voluntary isometric contractions (MVIC) of 5-s duration were performed to determine the peak torque, which was used to calculate the target torque (50% MVIC). For assessment of the torque steadiness 3 trials were performed at the target torque for 5 s each, with visual feedback. Standard deviation (SD) and coefficient of variation (CV) were measured from the steadiness trials. Peak torque, SD and CV were not different (P> 0.05) between groups neither between affected and unaffected sides of the SIS group for both rotations. It was possible to suggest that torque steadiness, during isometric medial and lateral rotations of the shoulder, is not altered in workers with SIS when compared to healthy workers, and that maintenance of regular work activities may play an important role in preservation of the steadiness in this population.
Minimal detectable change of measures of knee extension force obtained by hand-held dynamometry from five patient groups: A systematic review
Authors: Bohannon Richard W.
Published: October 2018

This review used published data to describe the minimal detectable change for make test measurements of knee extension force obtained by hand-held dynamometry. Five studies involving patients contributed data. Depending on the study and side, the minimal detectable change ranged from 7.6 to 92.1 Newtons. These values provide an indication of how much a patient's knee extension force would need to change to conclude that a real alteration in status had occurred.
Isokinetic strength of the neck muscles
Authors: Olivier Pierre , du Toit Ettienne , du Randt Rosa , Venter Danie
Published: October 2018

The variety of measurement devices and protocols being used to assess neck muscle strength hampers the comparison of data and the generation of reference data. Little is known about dynamic neck muscle strength because a limited amount of research using isokinetic dynamometry as assessment method has been published. The purpose of the research on which this article is based was therefore to delineate and generate reference data for the dynamic isokinetic neck muscle strength of adults aged 19 to 69 years old, based on a purpose-built isokinetic measurement device. Measurements were made through the frontal and sagittal planes of movement. Furthermore, the data, categorised into ten gender discriminate age categories of ten years each, were statistically analysed to detect significant differences between the categories. Four hundred and fifty-two volunteers, consisting of 221 males and 231 females, were assessed. Reference data stratified according to the gender discriminate age categories and based on 95% confidence intervals were generated. Statistical analyses however indicated that significant differences were predominantly between males and females, irrespective of age. This justifies the use of reference data grouped according to gender and questions whether age should be considered as a stratification factor when generating neck muscle strength reference data.
The effect of two exercise programs on various functional outcome measures in patients with osteoarthritis of the knee: A randomized controlled clinical trial
Authors: Salli Ali , Sahin Nilay , Baskent Akin , Ugurlu Hatice
Published: October 2018

We aimed to investigate the effects of isometric and combined concentric-eccentric (C-E) isokinetic types of exercise applied to the knee muscles in patients with knee osteoarthritis (OA) in an attempt to identify which type of exercise would be most effective in terms of pain relief, functional status, quality of life, and muscular strength. This was a controlled trial in which 71 patients were randomized into three groups. The first group was assigned to C-E, the second group to isometric isokinetic exercises, while the third, control group, was only given paracetamol. A visual analog scale for pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Short From-36 (SF-36) for functional status and quality of life, and the isokinetic test for muscular strength were evaluated. Significant improvements were recorded in all groups for pre and post-treatment pain, the WOMAC and the SF-36 (P< 0.001). Among the exercise groups, improvement was significantly better in the C-E, isokinetic exercise group as compared with the isometric exercise group (P < 0.001). Isokinetic exercises are recommended as a treatment modality. However, the long-term effects of these exercises on pain and osteoarthritis progression need to be investigated.
Reproducibility of concentric isokinetic and isometric strength measurements at the hip in patients with hip osteoarthritis: A preliminary study
Authors: Steinhilber Benjamin , Haupt Georg , Boeer Johannes , Grau Stefan , Krauss Inga
Published: October 2018

To determine the reproducibility of isokinetic and isometric hip flexion, extension, abduction and adduction strength scores in patients with hip osteoarthritis (N=16) and healthy subjects, testing was conducted twice 7 days apart. The patient group (PG) consisted of 16 subjects with unilateral or bilateral osteoarthritis of the hip (11 women, 5 men; age 56–75y). The control group (CG) included 13 age-matched healthy subjects (9 women, 4 men; age 54–73y). The standard error of measurement (SEM) served as the reproducibility outcome parameter.

The highest SEM values were obtained for hip extension measurements (15.4–16.7 Nm), followed by hip adduction (7.9–11.8 Nm) and hip flexion measurements (5.2–7.5 Nm). The smallest values were quantified for hip abduction measurements (4.7–7.7 Nm). PG showed larger values in all isometric measures except for hip extension and isokinetic hip abduction. When the 95% confidence interval is incorporated, these SEMs become significant.

Thus clinicians should be aware of the large measurement error in patients with hip OA. Adequate preparations and firm fixation of the pelvis are key elements to achieve reproducible results.
Altered hamstring strength profile in Gaelic footballers with a previous hamstring injury
Authors: Mackey Colum , O'Sullivan Kieran , O'Connor Anne , Clifford Amanda
Published: October 2018

Hamstring injuries are common in many sports involving high-load eccentric hamstring activation, including Gaelic football. Eccentric hamstring peak torque (PT) and hamstring angle to peak torque (AngPT) have not been examined in previously injured Gaelic footballers. This study aimed to determine whether significant hamstring and quadriceps PT deficits were present in Gaelic footballers after a hamstring injury. Concentric hamstring and quadriceps PT at 60 and 180 degrees/second (°/s) and eccentric hamstring PT at 30°/s were measured using an isokinetic dynamometer in 18 male Gaelic footballers (nine previously injured, nine controls). Hamstring AngPT, as well as hamstring and quadriceps PT and PT ratios were analysed. For previously injured limbs, hamstring AngPT occurred at significantly shorter muscle lengths (p=0.038) than for the contralateral uninjured limbs in eccentric testing only. There were no other significant differences (p > 0.05) at any velocity, for within-subject or between-subject comparisons. The results showed that the previously injured hamstrings generated their eccentric hamstring AngPT at significantly shorter muscle lengths than the contralateral hamstrings. The results imply footballers with a previous hamstring injury who have returned to full participation may remain at increased risk of re-injury because of an alteration in their eccentric hamstring AngPT.
Reproducibility of vertical jump data from an instrumented platform
Authors: Caruso J.F. , Daily J.S. , Olson N.M. , Shepherd C.M. , McLagan J.R. , Drummond J.L. , Walker R.H. , West J.O.
Published: October 2018

To assess the reproducibility of data collected from a newly created instrumented platform that measures vertical jump performance, healthy college-age subjects (n=178) made three visits to our laboratory. Per jump, the platform offered six performance-related variables: static weight, time to takeoff, peak takeoff force, and maximum jump heights as they ascended, remained in the air and landed. Per subject, the two highest jumps from the final two visits were used to assess data reproducibility. Prior to the reproducibility assessment, Z-scores identified statistical outliers that were removed from subsequent analyses. Paired intra- and inter-jump session data per variable were assessed with the following statistical test-retest tools: intraclass correlation coefficients, coefficient of variation, standard error of measurement, smallest real difference and critical difference. Current results show most data had a high level of reproducibility with few exceptions. Since the platform also has potential applicability in the rehabilitation of disabled persons, future research should assess the data reproducibility associated with gait, balance and mobility collected from the device.
No deficit in hip isometric strength or concentric endurance in young females with mild patellofemoral pain
Authors: McMoreland Aidan , O'Sullivan Kieran , Sainsbury David , Clifford Amanda , McCreesh Karen
Published: October 2018

Previous research has linked deficits in hip muscle strength and endurance to patellofemoral pain syndrome (PFPS). This study investigated if females with mild PFPS displayed hip isometric strength and endurance deficits compared to uninjured controls. Hip abduction, internal rotation (IR) and external rotation (ER) were assessed using an isokinetic dynamometer in 12 females with PFPS and 12 age- and gender-matched controls. Independent t-tests were used to examine between-group differences and Pearson's Correlation Coefficient examined the relationship between isometric strength and endurance. No significant between-group differences for IR, ER and abduction strength or endurance were found (all p > 0.05). Strength and endurance measurements showed significant moderate correlations for abduction (R=0.496, p =0.014) and ER (R =0.592, p =0.002) only. The PFPS subjects had mild pain(Numerical Rating Scale: mean 1.3 cm) and disability (Anterior Knee Pain Scale: mean 81/100), which may partly explain the lack of significant between-group differences. The results suggest that female subjects with PFPS associated with mild pain and disability do not demonstrate hip IR, ER or abduction endurance or isometric strength deficits. Further research is required to clarify the role of factors including hip strength and endurance in the management of more severe PFPS.