bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association of strength with patellar tendinopathy in female runners
Authors: Krauss I. , Grau S. , Rombach S. , Janssen P. , Maiwald C. , Axmann D. , Horstmann T. 
Published: October 2018

Muscle weakness and muscle imbalance may lead to musculotendinous injuries since the energy absorption capacity of the affected muscle tendon unit is reduced. The purpose of this study was to investigate the maximum strength and strength endurance of the thigh musculature in healthy female runners (F: n=26) and female runners suffering from patellar tendinopathy (PT: n=20). Isokinetic strength measurements were recorded in a seated position. Primary outcome variables were maximum concentric and eccentric peak torque (at 60°/s) and concentric hamstrings-quadriceps-quotient (HQQ). Secondary outcome variables were relative peak torques [Nm/kilogram] and eccentric endurance quotient calculated as the ratio of muscle strength at the end of a 1-minute exercise compared to at the beginning of the exercise period. The primary outcome variables were analyzed using Student's t-test for each measure(α = 0.05). Secondary outcome variables were qualified descriptively. The results showed no statistically significant differences between injured and healthy female runners in concentric and eccentric peak torque or HQQ. Secondary outcome variables also failed to show inter-group differences. We therefore conclude that these variables are not relevant with respect to PT in female runners.
Effects of a non circular chainring on muscular, mechanical and physiological parameters during cycle ergometer tests
Authors: Horvais Nicolas , Samozino Pierre , Zameziati Karim , Hautier Christophe , Hintzy Frederique 
Published: October 2018

This study analysed muscular, mechanical and physiological parameters using a circular chainring (CC) and a non circular Osymetric chainring (OC). OC was characterized by the use of a lower radius during top and bottom dead center and a higher radius during downstroke and upstroke phases. Twelve triathletes performed (i) an 8 min submaximal test and (ii) two 8 s maximal sprint tests. Gross efficiency was calculated during the submaximal test. Instantaneous external force and pedalling rate were recorded and the instantaneous net crank torque was calculated during both tests. Lower limb muscles coordination pattern (timing and magnitude) were also recorded. During the submaximal test, the only significant differences were the lower net crank torque of OC vs. CC at 0° and 180° and the higher net crank torque of OC vs. CC at 90° (P< 0.05). Concerning the sprint test, the only significant difference was the higher burst duration of the biceps femoris muscle with OC (P< 0.05). Present results indicate that OC facilitated mechanically the foot path at 0° and 180°. Nevertheless, this mechanical effect did not seem to be sufficient to improve performance since the muscles coordination pattern was not modified.
Isokinetic ankle plantarflexion and dorsiflexion strength in patients with rheumatoid arthritis
Authors: Eyigor Sibel , Kirazli Yesim , Capaci Kazım , Oder Gonca , Tarhan Figen , Inal Vedat 
Published: October 2018

Backgroud and objectives: In patients with rheumatoid arthritis(RA), some muscle groups are affected in different stages of disease, especially those related to the affected joint. However, data on associations between functional performance and muscle strength in RA are few. Therefore we sought to determine whether isokinetic ankle plantarflexion (PF) and dorsiflexion (DF) strength was affected in RA patients and to study the association between isokinetic strength and other clinical indicators of disability such as walking and stair-climbing time and disease activity in patients with RA. Methods: Thirty three patients diagnosed with RA in the chronic phase were selected from a rheumatology outpatient clinic and matched for age and gender with 33 healthy subjects. Isometric and isokinetic muscle strength was measured in DF and PF. The subjects were also evaluated through the Stanford Health Assessment Questionaire (HAQ), walking and stair-climbing time. Cumulative and current steroid doses (CSD) were calculated. Results: No significant correlations were found between muscle strength and visual analogue scale (VAS) scores, HAQ, ankle involvement, CSD (p>0.05). With respect to the isokinetic parameters, no differences have been been observed between RA and control groups (p>0.05). Walking and stair-climbing time increased significantly (p<0.05) in patients with RA. Conclusions: Ankle isokinetic muscle strength is not affected in inactive RA patients while negative effects of steroids on muscle strength were not demonstrated. Important determinators of walking ability in RA patients should be defined in future studies.
The effect of gravitational correction on shoulder internal and external rotation strength
Authors: Edouard Pascal , Calmels Paul , Degache Francis 
Published: October 2018

Objective: To study the influence of gravitational correction on the internal (IR) and external rotators (ER) shoulder strength. Methods: The IR and ER isokinetic strength, measured in 30° scapation, was evaluated concentrically at 60 and 240°/s and eccentrically at 60°/s in 33 healthy volunteers. Strength scores were expressed either by incorporating gravitational correction (GC) or without it. Results: With GC, IR strength was significantly lower and ER strength significantly higher than without incorporation of this procedure. Conclusion: The GC procedure has a significant influence on IR and ER strength and should be incorporated when strength deficits of the rotator cuff are expected.
Performed vs. predicted static endurance of the back extensors: Correlation or conflict
Authors: Mbada C.E. , Ayanniyi O. 
Published: October 2018

Background and objective: Identifying methods of accurately predicting endurance capacity of the back extensor muscles is of immense value to both patients and clinicians. This study aimed to develop a multiple regression equation using demographic and anthropometric measurements to predict back endurance and to investigate the association between performed back endurance results and back endurance predictions. Materials and methods: 376 healthy women and men aged 21–62 y were recruited consecutively. All participants underwent the Biering-Sørenson test of Static Muscular Endurance. Height and weight were measured using standard procedures. Percentage body fat was estimated using bioelectrical impedance analysis. Body mass index, lean body mass and body fat mass were calculated. Based on these a regression model was used to generate predictive equation for endurance time. Results: The final regression model which included demographic and anthropometric variables could account for 43% of the variability in back muscle endurance. Pearson's product correlation coefficient for the association between performed static endurance and the predicted endurance were(r = −0.129; p = 0.074) and (r = 0.671; p = 0.000) for male and female participants respectively. Paired t-test showed significant difference (p = 0.000) between the performed static endurance and predicted endurance among the male participants but not among the female counterparts (p = 0.959). Endurance time of males (119 ± 49.8 secs.) was significantly greater (p = 0.014) than that of the females (106 ± 47.6 secs.). Conclusion: Regression equation seems to be moderately valid in predicting endurance time of the back extensors among females only. We conclude that simple anthropometric measures cannot accurately predict back endurance without significant errors. The larger error of prediction obtained for the male participants could be indicative of an increasing influence of motivational/psychosocial factors that are known to be independent of motor ability in physical performance testing.
Cardiovascular responses during isokinetic knee extension testing in chronic heart failure patients
Authors: Degache Francis , Roche Frédéric , Bernard Pierrick , Calmels Paul 
Published: October 2018

Background: Isokinetic testing imposes severe cardiovascular stress which must be taken into consideration particularly when at risk patients are involved. Objective: To assess the effects of isokinetic tests on heart rate(HR) in stable chronic heart failure (CHF) patients. Subjects: Twenty five CHF patients, 23 men, 2 women. Intervention: After a 10-min warm-up on a cycle ergometer, one lower limb was tested isokinetically using 3 successive repetitions of knee flexion-extension at 60 and 180°/s and 20-repetitions at 240°/s. Heart rate was recorded on average over 5 sec and was analyzed at the start and end of each exercise. Peak ˙VO $_{2}$ was assessed during maximal incremental test on the ergometer. Results: Maximal values (117.6 ± 22.0 bpm) of HR were obtained during incremental exercise testing which corresponded to 97.6 ± 14.0% of maximal HR noted at peak ˙VO $_{2}$ . Conclusion: Isokinetic muscle strength testing in CHF patients must be performed under the supervision of an experienced clinician who should judge the value and feasibility of the endurance test.
Hemodynamic response of an isokinetic testing and training∼session
Authors: Lamotte M. , Chevalier A. , Jamon A. , Brassine E. , van de Borne Ph. 
Published: October 2018

Background: Isokinetic evaluation and training are commonly used. Hemodynamic response during this type of exercise is unknown and therefore usually not recommended in some patients (elderly, patients with risk factors or with cardio-vascular disease). The aim of this study was to evaluate the hemodynamic response during a classical testing and training isokinetic session. Method: 20 healthy young male participated to this study. The hemodynamic response wa continuously and non invasively (Task Force Monitor) measured on a Cybex Norm (knee extension and flexion). The hemodynamic parameters were systolic blood pressure (SBP), heart rate (HR) and cardiac output (Q). Results: A low speed (60°/s) test was more exhausting than one at higher speed (180°/s) which is probably related to its duration. Whereas rest periods seemed sufficient for muscle recovery allowing during training, maintenance of performance over the different sets, changes in hemodynamic parameters (HR, SBP & Q) were observed over successive sets and did not recover totally during rest. Systolic ejection volume did neither change nor contribute to the increase of cardiac output (+ 70 to 84% compared to rest). Values measured during test and training were high but not excessive (HR max=135 ± 20 bpm or 70% of HRmax predicted; SBP max=185 ± 26 mmHg; Q=11.2 ± 2.2 l/min). Conclusions: Values measured during test and training are high but not excessive. Isokinetic training in cardio-vascular risk patients should be composed of shorter set duration and longer rest periods as generally applied, without loosing maximal muscle contraction over the entire rage of motion.
Cardiovascular and metabolic responses during isokinetic shoulder rotators strength testing in healthy subjects
Authors: Edouard Pascal , Castells Josiane , Calmels Paul , Roche Frédéric , Degache Francis 
Published: October 2018

Background: Although there have been many studies on isokinetic shoulder exercises in evaluation and rehabilitation programs, the cardiovascular and metabolic responses of those modes of muscle strength exercises have been poorly investigated. Objective: To analyze cardiovascular and metabolic responses during a standardized test used to study the internal (IR) and external (ER) rotators maximal isokinetic strength. Methods: Four days after an incremental exercise test on cycle ergometer, ten healthy subjects performed an isokinetic shoulder strength evaluation with cardiovascular (Heart rate, HR) and metabolic gas exchange (�O $_{2}$ ) analysis. The IR and ER isokinetic strength, measured in seated position with 45° of shoulder abduction in scapular plane, was evaluated concentrically at 60, 120 and 240°/s and eccentrically at 60°/s, for both shoulder sides. An endurance test with 30 repetitions at 240°/s was performed at the end of each shoulder side testing. Results: There was a significant increase of mean HR with isokinetic exercise (P< 0.05). Increases of HR was 42–71% over the resting values. During endurance testing, increases of HR was 77–105% over the resting values, and corresponded to 85–86% of the maximal HR during incremental test. Increase of �O $_{2}$ during isokinetic exercises was from 6–11 ml/min/kg to 20–43 ml/min/kg. Conclusion: This study performed significant cardiovascular and metabolic responses to isokinetic exercise of rotators shoulder muscles. A warm-up should be performed before maximal high-intensity isokinetic shoulder testing. Our results indicated that observation and supervision are important during testing and/or training sessions, especially in subjects with risk for cardiovascular disorders.
Effects of acute and 4-week submaximal exercise on leukocyte and leukocyte subgroups
Authors: Patlar Suleyman 
Published: October 2018

The aim of this study is to investigate how does an acute 4-week submaximal exercise affect both leukocyte and leukocyte subgroups. The study registered 8 healthy male subjects. The subjects were exercised on Monark 814-E and 818 model ergometric bicycles 3 times a week for 4 weeks at above threshold heart rate and 75% of Max VO $_{2}$ . Blood samples were collected three times from the subjects, before starting the exercise, immediately after finishing the last exercise and 2 hours after the last exercise. The samples were analyzed in HemaCell Counter (Skits) apparatus to quantify leukocyte, neutrophil, monocyte, eosinophil and basophil levels. Leukocyte counts obtained in both post-exercise measurements were significantly higher than those before the exercise (p< 0.05). Neutrophil percentages two hours after exercise were higher than those before and immediately after exercise (p< 0.05). Lymphocyte percentages obtained just after exercise were elevated in comparison to those both before and two hours after exercise (p< 0.05). However, lymphocyte percentages two hours after exercise were significantly lower than the pre- and post-exercise percentages(p< 0.05). Percentages of monocytes, eosinophils and basophils in both post-exercise measurements were lower relative to pre-exercise values(p<0.05). In conclusion both acute and 4-week submaximal exercise have significant effects on leukocyte and leukocyte subgroups.
Does knee joint alignment with the axis of the isokinetic dynamometer affect peak torque?
Authors: Houweling Taco A.W. , Hamzeh Maher A. 
Published: October 2018

The aim of this study was to determine the reliability of five positions of alignment of the knee joint with the axis of a Cybex Norm isokinetic dynamometer. Seventeen physically active males volunteered for this study. The knee joint was positioned in five xy-plane coordinates from the rotational axis of the dynamometer (cm): (0,0); (2,0); (4,0); (0,-2) and(0;-4). Repeated measures Analysis of Variance (ANOVA) and Ratio Limits of Agreement (RLOA) were calculated for knee extension and flexion peak torque in all positions of alignment. The ANOVA demonstrated no significant differences in peak torque for knee extension (F(4,64) = 1.813, P> 0.05) and significant differences in peak torque for knee flexion (F(4,64) =5.760, P < 0.05). The RLOA showed a standard bias ranging from −7 to−12% and systematic error ranging from 21 to 29% for knee flexion. Knee extension peak torque did not significantly change when the knee joint was misaligned with the axis of the dynamometer. However, knee flexion peak torque was significantly affected when the knee was moved away both horizontally and vertically from the centre of the axis of the dynamometer.
Does kinesiotaping increase knee muscles strength and functional performance?
Authors: Aktas Gulcan , Baltaci Gul 
Published: October 2018

Context: Knee injuries which are the most common disabling injuries in both athletic and physically active people, can be expected to occur with all sporting activities especially contact sports. Therefore, knee braces and taping techniques are widely used to reduce and/or prevent the severity and incidence of knee injuries in sports. Objective: To determine which application, knee brace, kinesiotaping (KT) or both, is more effective regarding muscular strength and functional performance. Design: A prospective, criterion-based controlled study. Setting: University research laboratory. Patients or other participants: Twenty (11 F, 9M) healthy subjects with no previous history of lower extremity injuries and using knee brace and KT were included in this study. Main outcome measures: Muscular strength, and jump performance were tested with knee brace, kinesiotaping and both applications. Repeated measures ANOVA was performed to determine if there were differences between braced, taped and both conditions. Participants filled in a questionnaire regarding demographic and lower extremity problems. Results: Kinesiotape application brought about a significant increase in hop distance (p=0.015, P=0.018) in both the dominant and non-dominant extremity and in isokinetic knee extension peak torque (p=0.034) at 180°/s. Conclusion: KT application was more effective in terms of muscular strength and jump performance than knee brace and KT plus knee brace. Physical therapists and athletic trainers may apply KT to a patient during or after treatment and rehabilitation to support knee musculature, to encourage the tissue healing process, and to avoid limiting the enhancement of improved knee muscle performance.
The effects of 6-weeks patellofemoral bracing on quadriceps muscle function
Authors: Van Tiggelen D. , Coorevits P. , Bernard E. , Thijs Y. , Witvrouw E. 
Published: October 2018

Background: Previous studies have indicated that wearing a patellofemoral brace during strenuous training resulted in a decreased incidence of anterior knee pain (AKP). However whether this effect is derived from quadriceps enhancement remains unknown. Study design: Randomized controlled clinical trial. Methods: Ninety-eight military recruits, 35 'with-brace' and 63 without, underwent concentric isokinetic tests at 60 and 240°/s of the quadriceps prior to and following a 6-week basic military training (BMT). The randomly selected 35 subjects 'with brace' received a pair of patellofemoral braces (On-Track, DJ Ortho) and were instructed to wear these braces throughout training. Results: Baseline strength characteristics of the quadriceps were not significantly different between the braced and non-braced group (p > 0.05). No significant time-effect was observed in the braced group. There was a significant decrease in quadriceps strength at 60°/s after BMT in the non-braced subjects (p < 0.001) while at this speed these subjects had a significantly (p =0.02) lower strength compared to their non-braced counterparts. Conclusion: Patellofemoral bracing may be effective in preventing a decrease in quadriceps strength after prolonged strenuous training.
Comparison of an accelerometer and piezoelectric contact sensor for examining the mechanomyographic signal from the vastus medialis during isometric muscle actions
Authors: Coburn Jared W. , Malek Moh H. , Housh Terry J. , Johnson Glen O. , Beck Travis W. 
Published: October 2018

Background and objective: The purpose of this study was to compare an accelerometer (ACC) and a piezoelectric contact sensor (PEC) for the measurement of mechanomyographic (MMG) signals during submaximal to maximal isometric muscle actions of the vastus medialis. Materials and methods: Following the determination of maximal isometric strength (MVC), eight subjects (20.4 ± 1.3 years) performed isometric muscle actions at 10 to 90% isometric MVC in random order. An ACC and PEC were used to simultaneously record the MMG signal. Results: For the composite data, there were linear increases in normalized MMG amplitude for both the ACC(r ^{2} = 0.930) and PEC (r ^{2} = 0.875), with no difference in slope coefficients (p > 0.05). Similarly, there were linear increases in MMG mean power frequency (MPF) for the ACC (r ^{2} = 0.957) and PEC (r ^{2} = 0.982), with no difference in slope coefficients (p > 0.05). Analysis of individual subject data revealed there were no significant differences in slope coefficients between sensors for MMG amplitude or MPF for any subject with the exception of a significant difference (p < 0.05) for MMG MPF for one subject. In addition, there were no significant (p > 0.05) mean differences between the ACC and PEC for normalized MMG amplitude or MPF. Conclusion: These results indicated that the ACC and PEC provide comparable information regarding MMG amplitude and MPF vs. isometric torque relationships of the vastus medialis.
Knee muscles isokinetic evaluation in short distance elite swimmers: A comparison between symmetric and asymmetric swimming styles
Authors: Secchi Leonardo L. B. , Muratt Mavi Diehl , Ciolac Emmanuel G. , Greve Júlia M. D. 
Published: October 2018

Objective: To compare knee extension-flexion isokinetic performance between elite swimmers of simultaneous (SS – butterfly and breaststroke) and alternated swimming (AS – front crawl and backstroke) styles. Method: Nineteen short distance elite swimmers (50 m, 100 m and 200 m events), divided into SS (n=7; 23.3 ± 5.6 years) and AS (n=12; 22.6 ± 1.4 years) were tested for knee extension-flexion isokinetic strength at 60°/s (4 repetitions) and endurance at 300°/s (30 repetitions). Results: There were no significant differences between groups or legs for concentric knee extension and flexion variables. However, the agonist/antagonist (HQ) ratio was lower (p=0.032) in AS than SS group for both legs. Conclusion: These results indicate the need for training programs to improve strength balance between hamstrings and quadriceps muscles in short distance elite swimmers.
The influence of Nordic walking exercise on upper extremity strength and the volume of lymphoedema in women following breast cancer treatment
Authors: Malicka Iwona , Stefańska Małgorzata , Rudziak Marta , Jarmoluk Paweł , Pawłowska Katarzyna , Szczepańska-Gieracha Joanna , Woźniewski Marek 
Published: October 2018

The aim of this study was to examine the effect of Nordic walking on upper extremity strength and the level of lymphoedema in women following treatment for breast cancer (BC). A group of 38 women with treated BC were assigned to two groups: a study group of 23 women taking part in 8 weeks of Nordic walking and a control group of 15 women. Each participant was assessed for bilateral muscle strength using an upper limb push-pull attachment. Circumference measurement served for determination of the volume of the lymphoedema. In women after the surgical procedure on the right side statistically significant changes in the strength of pushing motion of both the right and the left were observed. In women after the surgical procedure on the left side these values were statistically significant only for the left extremity. No significant changes were demonstrated for the treated side; we did not record either the occurrence or the intensification of lymphoedema in women after BC treatment. So, Nordic walking can be considered as safe form of rehabilitation for this group of patients.