Isokinetic Measurements Research Articles

Concurrent Validity and Reliability of a Handheld Dynamometer in Measuring Isometric Shoulder Rotational Strength.

Measuring isometric shoulder rotational strength is clinically important for evaluating motor disability in athletes with shoulder injuries. Recent evidence suggests that handheld dynamometry may provide a low-cost and portable method for the clinical assessment of isometric shoulder strength. To investigate the concurrent validity and the intrarater and interrater reliability of handheld dynamometry for measuring isometric shoulder rotational strength. Cross-sectional study. Biomechanics laboratory. Thirty-nine young, healthy participants. The peak isometric strength of the internal rotators and external rotators, measured by handheld dynamometry (in newton) and isokinetic dynamometry (in newton meter). Maximal isometric shoulder rotational strength was measured as participants lay supine with 90° shoulder abduction, neutral rotation, 90° elbow flexion, and forearm pronation. Measurements were performed independently by 2 different physiotherapists and in 3 different sessions to evaluate interrater and intrarater reliability. The data obtained by handheld dynamometry were compared with those obtained by isokinetic testing to evaluate concurrent validity. The intraclass correlation coefficients for interrater reliability in measuring maximum isometric shoulder external and internal rotation strength were .914 (95% confidence interval [CI], .842-.954) and .842 (95% CI, .720-.914), respectively. The intrarater reliability values of the method for measuring maximal shoulder external and internal rotation strength were 0.865 (95% CI, 0.757-0.927) and 0.901 (95% CI, 0.820-0.947), respectively. The Pearson correlation coefficients between the handheld and isokinetic dynamometer measurements were .792 (95% CI, .575-.905) for external rotation strength and .664 (95% CI, .419-.839) for internal rotation strength. The handheld dynamometer showed good to excellent reliability and moderate to good validity in measuring maximum isometric shoulder rotational strength. Therefore, handheld dynamometry could be acceptable for health and sports professionals in field situations to evaluate maximum isometric shoulder rotational strength.

Outcomes of Tibialis Anterior Tendon Reconstruction with Autograft or Allograft.

In cases of tibialis anterior tendon (TAT) ruptures associated with significant tendon defect, an interposition graft is often needed for reconstruction. Both auto- and allograft reconstructions have been described in the literature. Our hypothesis was that both graft types would have a good integrity and provide comparable outcomes. Patients who underwent TAT reconstruction using either an auto- or allograft were identified. Patient-reported outcomes (PROs) were collected using the 12-Item Short Form Health Survey (SF-12) questionnaire, the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, the Foot Function Index (FFI), and the Karlsson-Peterson score. Functional outcome was assessed by isokinetic strength measurement. Outcomes were further assessed with magnetic resonance imaging (MRI) evaluation of graft integrity. All measurements were also performed for the contralateral foot. Twenty-one patients with an average follow-up of 82 months (20-262 months), comprising 12 allograft and 9 autograft TAT reconstructions, were recruited. There were no significant differences in patient-reported outcomes between allograft reconstructions and autografts: SF-12 (30.7 vs 31.1, P = .77); AOFAS (83 vs 91.2, P = .19); FFI (20.7% vs 9.5%, P = .22); and Karlsson-Peterson (78.9 vs 87.1, P = .23). All grafts (100%) were intact on MRI with a well-preserved integrity and no signs of new rupture. There were no major differences in range of motion and functional outcomes as measured by strength testing between the operative and nonoperative side. Reconstructions of TAT achieved good PROs, as well as functional and imaging results with a preserved graft integrity in all cases. There were no substantial differences between allograft and autograft reconstructions. Level IV, retrospective case series.

Isokinetic and Isometric Assessment of the Knee Joint Extensors and Flexors of Professional Volleyball Players.

Purpose: The main objective of this study was to evaluate the level of muscle strength by using isokinetic and isometric measurements—more specifically, the force ratio between the knee flexors and extensors (values of the torques). Methods: An experimental group of elite volleyball players (n = 14) were compared to a control group (n = 14) of healthy non-athletes of comparable ages. Torque measurements were obtained under three concentric conditions (angular velocities of 60 °/s, 180 °/s, and 300 °/s) and one static condition by utilizing the Biodex System 3. Results: In all trials, the volleyball players achieved significantly higher peak torque (PT) values for both the extensors and flexors (p < 0.05) than those of the control group. However, the strength ratio of the flexors and extensors (H/Q) in the experimental group was only 83% of the standard reported in the literature. The most developed and dominating muscles in the knee joints of the volleyball players were the extensors, which accounted for the low strength ratio and dynamic instability of this joint. Conclusion: Based on a proper assessment of the strength ratio of the knee flexors and extensors, properly selected and implemented resistance training can improve the maximum strength and power production and reduce the incidence of injuries in volleyball.

Impact of Patellar Tendinopathy on Isokinetic Knee Strength and Jumps in Professional Basketball Players.

Patellar tendinopathy is characterized by tendon pain which may reduce the level of performance. This study’s main aim was to compare isokinetic knee strength and jump performances at the start of the sport season between players with patellar tendinopathy and those without. Secondary aims were to assess the relationship between knee strength and jump function. Sixty-two professional basketball players were enrolled (mean age: 25.0 ± 4.0). All players performed knee isokinetic measurements, single leg countermovement jumps, and one leg hop tests. Correlations between knee strength and jump performances were examined. Twenty-four players declared a patellar tendinopathy and were compared to the 38 players without tendinopathy. The isokinetic quadriceps strength was lower in cases of patellar tendinopathy, and a camel’s back curve was observed in 58% of the cases of patellar tendinopathy. However, jump performances were preserved. No link was found between quadriceps and hamstring limb symmetry indexes at 60 and 180°/s with jumps. This preseason screening enabled us to identify the absence of consequences of patellar tendinopathy in professional basketball players. Jump performances were not altered, possibly due to compensatory strategies.

Relationship of the knee extensor strength but not the quadriceps femoris muscularity with sprint performance in sprinters: a reexamination and extension

PurposeThis study examined the relationships of knee extensor strength and quadriceps femoris size with sprint performance in sprinters.MethodsFifty-eight male sprinters and 40 body size-matched male non-sprinters participated in this study. The knee extensor isometric and isokinetic strengths were measured using a dynamometer. The isokinetic strength measurements were performed with slow and fast velocities at 60°/s and 180°/s, respectively. The quadriceps femoris muscle volume (MV) was measured using magnetic resonance imaging. The relative knee extensor strengths and quadriceps femoris MV were calculated by normalizing to body mass.ResultsAbsolute and relative knee extensor strengths during two velocity isokinetic contractions, but not during isometric contraction, were significantly higher in sprinters than in non-sprinters (P = 0.047 to < 0.001 for all). Such a significant difference was also observed for relative quadriceps femoris MV (P = 0.018). In sprinters, there were positive correlations between all three knee extensor strengths and quadriceps femoris MV (r = 0.421 to 0.531, P = 0.001 to < 0.001 for all). The absolute and relative strengths of the fast-velocity isokinetic knee extension correlated negatively with personal best 100-m sprint time (r = −0.477 and −0.409, P = 0.001 and < 0.001, respectively). In contrast, no such significant correlations were observed between absolute and relative quadriceps femoris MVs and personal best 100-m sprint time.ConclusionsThese findings suggest that despite the presence of the relationship between muscle strength and size, the knee extensor strength may be related to superior sprint performance in sprinters independently of the quadriceps femoris muscularity.

Bilateral Differences in Anthropometric Measurements and Isokinetic Strength Variables of Female University Netball Players

The unilateral demands on the dominant (D) limbs in netball players, may lead to developments and changes that differs from that of the non-dominant (ND) limbs. An individual who is constantly exposed to unilateral movements or repeated use of the D limb, can also develop bilateral differences between the D and ND limbs. The purpose of the study was to determine if any significant bilateral differences in anthropometric and isokinetic strength measurements occurred between the D and ND limbs of the upper and lower parts of the body in female university netball players.

Bilateral Differences in Anthropometric Measurements and Isokinetic Strength Variables of Female University Netball Players

The unilateral demands on the dominant (D) limbs in netball players, may lead to developments and changes that differs from that of the non-dominant (ND) limbs. An individual who is constantly exposed to unilateral movements or repeated use of the D limb, can also develop bilateral differences between the D and ND limbs. The purpose of the study was to determine if any significant bilateral differences in anthropometric and isokinetic strength measurements occurred between the D and ND limbs of the upper and lower parts of the body in female university netball players.

Does resistance training promote enough muscular strength increases to move weak older women to better strength categories?

We compared the magnitude of muscular strength changes among older women occupants of different strength tertiles in response to progressive resistance-training (RT). Additionally, we examined the possibility of older women initially characterized as weak (occupants of the lower tertile of strength status) can achieve a higher muscular strength level to be inserted into a better category (middle or upper tertiles). The present investigation was attended by 113 physically independent older women (>60years old). Muscular strength was assessed by one-repetition maximum (1RM) tests on chest press, preacher curl, leg extension exercises, and by the isokinetic (ISOK) peak torque of knee extension and flexion at 60 and 180°/s angular velocities. The RT lasted 12weeks (3 x/week) and consisted of eight exercises for the whole body. The participants were divided into tertiles (LOWER, MIDDLE, and UPPER) according to the performance at baseline for each strength measure. After RT, the LOWER tertile showed more significant magnitude gains than the UPPER tertile to the 1RM in leg extension and preacher curl and isokinetic measurements (6.9-36.3%). A considerable number of older women increased muscular strength enough to move from LOWER to MIDDLE or UPPER tertiles. From our results, it can be inferred that older women occupants of the lower strength tertile show more significant muscular strength gains when compared to their stronger counterparts. Moreover, 12weeks of RT seem to be sufficient to transfer older women previously characterized as "weak" to a better category.

Effect of oral isotretinoin on muscle strength in patients with acne vulgaris: a prospective controlled study

BackgroundMusculoskeletal side effects related to isotretinoin are frequently reported. This study aimed to investigate the effect of oral isotretinoin treatment on muscle strength. Our second aim was to evaluate whether there was a correlation between the serum creatine phosphokinase (CPK) level, a specific marker of muscle breakdown, and muscle strength.MethodsThis study included 30 patients who presented to our hospital and were started on oral isotretinoin treatment for acne vulgaris and 30 patients in the control group who were given local treatment. Age, sex, height and weight of the patients were recorded, and the body mass index (BMI) was calculated. The hamstring and quadriceps muscle strengths of the non-dominant side were evaluated in all patients using an isokinetic dynamometer, and the peak torque (PT) values ​​were recorded. In the isotretinoin group, isokinetic measurements were performed again in those that completed six-month drug treatment and compared with the initial PT values.ResultsThe two groups were similar in terms of age, sex, and BMI (p > 0.05). There was no significant difference between the isotretinoin and control groups in terms of muscle strength at the beginning of the treatment (p > 0.05). No significant change was observed in hamstring and quadriceps PT values in the isotretinoin group after 6 months of treatment compared to baseline (p > 0.05). No statistically significant correlation was found between the serum CPK level and hamstring and quadriceps muscle strength (p > 0.05).ConclusionOral isotretinoin doesn’t alter muscle strength. There is no relationship between the serum CPK levels and muscle strength.

Effect of Acupuncture on the Timeliness of Explosive Forces Generated by the Male Shoulder Joint.

Athletes aim to improve muscle strength to optimize sports performance and gain a competitive edge. Although modern sports medicine includes rehabilitation treatment methods for improving the explosive force of athletes, including acupuncture, a common alternative therapy, research on the effectiveness of acupuncture in improving the timeliness of explosive forces is limited. There is uncertainty regarding how long the effects of acupuncture treatment persist after treatment. Therefore, the purpose of this study was to explore the effect of acupuncture on the timeliness of explosive forces generated by the male shoulder joint. Eighteen healthy men underwent tests of shoulder adduction/abduction (Add/Abd) and flexion/extension (Flex/Ext) through an isokinetic measurement system. Acupuncture was used to stimulate LU1 (Zhongfu), LU3 (Tianfu), LU4 (Xiabai), LI14 (Binao), SJ13 (Naohui), SJ14 (Jianliao), and SJ12 (Xiaoluo), and the isokinetic parameters were recorded before and after acupuncture. After acupuncture, isokinetic muscle force parameters including the maximum (Max) torque, the average power, the average peak power, the average work, and the total work increased significantly (P < 0.05), whereas the average max torque Abd/Flex did not. Additionally, the preintervention values of the shoulder joints for Add/Abd and Flex/Ext were significantly greater than those at post 1 and post 2 (P < 0.05). The isokinetic results suggest that acupuncture can increase the explosive force of the male shoulder joint Add/Abd and Flex/Ext. Muscle cannot be fully activated when calcium saturation is below the maximal level. In this case, the postactivation potentiation (PAP) may enhance voluntary muscle force production. The effect of acupuncture is time-dependent, that is, the effects of acupuncture gradually weaken and disappear by approximately 10 minutes after acupuncture. Therefore, we suggest that acupuncture is used as an alternative therapy in sports competitions to increase the explosive forces of the shoulder joint, thereby improving sports performance.

Biomechanical but Not Strength or Performance Measures Differentiate Male Athletes Who Experience ACL Reinjury on Return to Level 1 Sports

Background: Performance measures such as strength, jump height/length, and change of direction (CoD) time during anterior cruciate ligament (ACL) rehabilitation have been used to determine readiness to return to play and identify those who may be at risk of rerupture. However, athletes may reach these criteria despite ongoing biomechanical deficits when performing these tests. Combining return-to-play criteria with an assessment of movement through 3-dimensional (3D) biomechanics in male field sports athletes to identify risk factors for ACL rerupture has not been explored previously. Purpose: To prospectively examine differences in strength, jump, and CoD performance and movement using 3D biomechanics in a cohort of male athletes playing level 1 sports (ie, multidirectional field sports that involve landing, pivoting, or CoD) between those who reinjured the reconstructed ACL (RI group) and those with no reinjury (NRI group) after 2 years of follow-up and to examine the ability of these differences to predict reinjury. Study Design: Cohort study; Level of evidence, 2. Methods: After primary ACL reconstruction (ACLR), 1045 male athletes were recruited and underwent testing 9 months after surgery including isokinetic strength, jump, and CoD performance measures as well as patient-reported outcomes and 3D biomechanical analyses. Participants were followed up after 2 years regarding ACL reinjury status. Differences were determined between the RI and NRI groups in patient-reported outcomes, performance measures, and 3D biomechanics on the ACLR side and symmetry between limbs. The ability of these measures to predict ACL reinjury was determined through logistic regression. Results: No differences were identified in strength and performance measures on the ACLR side or in symmetry. Biomechanical analysis indicated differences on the ACLR side primarily in the sagittal plane for the double-leg drop jump (effect size, 0.59-0.64) and greater asymmetry primarily in the frontal plane during unplanned CoD (effect size, 0.61-0.69) in the RI group. While these biomechanical test results were different between groups, multivariate regression modeling demonstrated limited ability (area under the curve, 0.67 and 0.75, respectively) to prospectively predict ACL reinjury. Conclusion: Commonly reported return-to-play strength, jump, and timed CoD performance measures did not differ between the RI and NRI groups. Differences in movement based on biomechanical measures during double-leg drop jump and unplanned CoD were identified, although they had limited ability to predict reinjury. Targeting these variables during rehabilitation may reduce reinjury risk in male athletes returning to level 1 sports after ACLR. Registration: NCT02771548 (ClinicalTrials.gov identifier).

Clinical and Functional Outcomes of Peroneus Longus to Brevis Tendon Transfer.

Peroneal tendon lesions can cause debilitating pain, but operative treatment remains controversial. Some studies recommend peroneal tenodesis or transfer if more than half of the tendon is affected. However, clinical outcomes and inversion/eversion motion after peroneal transfer have not been investigated yet. Patients who underwent distal peroneus longus to brevis transfer for major peroneus brevis tendon tears with a minimum follow-up of 2 years were included. Clinical outcome parameters included the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, the German Foot Function Index (FFI-D), and Karlsson-Peterson score. Functional outcome was tested with a standardized active range-of-motion (ROM) and isokinetic strength measurement protocol, including concentric and eccentric eversion and inversion tests. Of total 23 eligible patients, 14 (61%) were available for follow-up. Clinical outcome scores were good with AOFAS 86 ± 16 points, FFI-D pain 26% and FFI-D disability 26%, and Karlsson-Peterson score 78 ± 23 points. There was no difference in strength in comparison to the contralateral foot (all P > .05). Isokinetic strength was 16.3 ± 4.9 Nm (108% of contralateral side) and 18.8 ± 4.5 Nm (101%) at concentric 30 deg/s and eccentric 30 deg/s eversion tests, as well as 15.7 ± 5.2 Nm (102%) and 18.7 ± 3.3 Nm (103%) at concentric 30 deg/s and eccentric 30 deg/s inversion tests, respectively. There was no difference in ROM compared to the contralateral side (eversion/inversion 14.5-0-18.7 vs 14.1-0-16.1 degrees). Peroneus longus to brevis transfer is a viable option for treating severe peroneus brevis tendon tears and does not compromise measurable strength or ROM in inversion or eversion in comparison to the contralateral ankle joint. Level IV, prospective case series.

The effectiveness of high-intensity laser therapy on pain, range of motion, functional capacity, quality of life, and muscle strength in subacromial impingement syndrome: a 3-month follow-up, double-blinded, randomized, placebo-controlled trial.

The aim of this study was to perform a placebo-controlled assessment of the short- and long-term efficiency of high-intensity laser therapy (HILT) in treatment of subacromial impingement syndrome (SAIS). Sixty-three patients (32 in HILT + exercise and 31 in sham HILT + exercise group) who were diagnosed with SAIS were included. The assessments were performed before (baseline, 0) and after treatment (3rd week/12th week). Active range of motion (ROM) with goniometric measurement, pain with visual analog scale (VAS), shoulder function with Constant-Murley score (CMS), quality of life with SF-36 (short-form 36) health survey, muscle strength using isokinetic device (including peak torque level measurements at shoulder internal rotation (IR) and external rotation (ER) at 120, 180, and 210 degrees) were assessed. Significant improvements were determined in the assessments at the 3rd and 12th week controls in both HILT and control groups. In the comparison of the values of the groups (3rd/12th week), the HILT group had a statistically significant improvement compared with the placebo group; in the active shoulder flexion, IR, and ER ROM measurements; in VAS scores; in CMS activities of daily living, ROM, strength and total scores; in all the sub-parameters of SF-36; and in IR 120,180, 210 and ER 120,180 degree/s peak torque values of isokinetic measurements. In the comparison of both groups, HILT + exercise treatment is more effective in reducing pain and increasing the ROM, functioning, quality of life, and the muscular strength assessed with isokinetic in the short and long term.

No functional differences in anatomic reconstruction using a one- versus a two-point fixation for distal biceps tendon rupture through a single-incision anterior approach: A prospective randomized trial.

The distal biceps brachii tendon rupture is a rare injury of the musculoskeletal system. Multiple surgical techniques have been described for distal biceps brachii tendon repairs including suture anchors. The aim of this study was to evaluate the outcome of anatomical distal biceps tendon refixation using either one or two suture anchors for reattachment and to determine whether there are significant clinically important differences on the number of anchors used for refixation. A monocentric, randomized controlled trial was conducted, including 16 male patients with a mean age of 47.4years (range, 31.0 to 58.0) in Group 1 (two suture anchors for refixation) and 15 male patients with a mean age of 47.4 (range, 35.0 to 59.0) in Group 2 (one suture anchor for refixation). All surgeries were performed through an anterior approach. The outcome was assessed using the Oxford Elbow Score (OES), the Mayo Elbow Performance Score (MEPS), the Disabilities of the Arm, Shoulder and Hand (DASH) score, the Andrews Carson Score (ACS) and by isokinetic strength measurement for the elbow flexion after six, twelve, 24 and 48 weeks. Radiographic controls were performed after 24 and 48 weeks. No significant differences between both groups were evident at any point during the follow-up period. A continuous improvement in outcome for both groups could be detected, reaching an OES: 46.3 (39.0 to 48.0) vs. 45.5 (30.0 to 48.0), MEPS: 98.0 (85.0 to 100.0) vs. 99.0 (85.0 to 100.0), DASH: 3.1 (0.0 to 16.7) vs. 2.9 (0.0 to 26.7), ACS: 197.0 (175.0 to 200.0) vs. 197.7.

Influence of the medial longitudinal arch of the foot in adult women in ankle isokinetic performance: a cross-sectional study

BackgroundMaintenance of the medial longitudinal arch (MLA) of the foot is fundamental during functional tasks and disorders can lead to clinical alterations. Studies have demonstrated that deficits in ankle isokinetic performance can predispose an individual to lower limb injuries.ObjectivesTo evaluate the muscular performance of cavus, planus, and normal feet by means of torque/body mass and the isokinetic phases, to generate 3D surface map analysis, and to verify whether there is a relationship between MLA height and arch height flexibility with isokinetic performance.MethodsThe sample consisted of 105 healthy adult women, divided into three groups: normal, cavus, and planus. Assessment in concentric mode at 30, 60, and 90 °/s in the dorsiflexion and plantarflexion of the ankle joint were analyzed during the three isokinetic phases (acceleration, sustained velocity, and deceleration). The variables total range of motion, peak of torque (PT), and angle of PT were extracted within the sustained velocity.ResultsIn dorsiflexion at 60 °/s, the phase where the velocicty is sustained (load range phase) was higher in the planus group (MeanDifference=10.9 %; ω2p = 0.06) when compared with the cavus group. Deficits in the peak torque/body mass in dorsiflexion at 60 °/s (cavus feet: MD=-3 N.m/kg; ω2p = 0.06; and planus feet: MD=-1.1 N.m/kg; ω2p = 0.06) were also observed as well as in the 3D surface maps, when compared with the normal group. The flexibility of MLA had a negative correlation of PT at 30 °/s in cavus group. The heigth of MLA had a postive correlation with the PT for the cavus and planus group ate 60 °/s. All other results did not show differences between the groups.ConclusionsThe planus groups showed a better capacity of attain and sustained the velocity in dorsiflexion in relation the cavus group. The cavus and planus group had deficts in torque in relation the normal. The correlations were weak between the measures of MLA and PT. Thereby, in general the differences between foot types showed small effect in isokinetic muscle performance measures of the plantar and dorsi flexores.Trial registrationStudy design was approved by the IRB (#90238618.8.0000.5231).

Comparison of Isokinetic Muscle Function and Anaerobic Exercise Capacity in the Knee According to Kukki Taekwondo Training Type

Introduction: This study’s purpose was to measure and compare isokinetic muscle function and anaerobic exercise capacity of knee joints according to the three Kukki Taekwondo competition types. Methods: A total of 21 elite Korean male poomsae (forms), gyorugi (sparring), and demonstration athletes majoring in Taekwondo were selected as the subjects of the study. Subjects’ physical fitness levels were measured using standardized strength, endurance, agility, balance, and flexibility tests. In particular, the isokinetic muscle function measurement system was used to measure the muscle function of subjects’ knee joints, and the Wingate test was used to measure their anaerobic exercise ability. Results: Gyorugi athletes showed better results than their poomsae and demonstration counterparts in nearly all metrics, including body composition, physical fitness factors, isokinetic muscle function (60°/sec), muscle power (180°/sec), and anaerobic exercise capacity. Gyorugi athletes were also taller and showed higher muscle mass, strength, muscular endurance, and agility. However, poomsae athletes showed a higher level of flexibility. The results found isokinetic muscle function and anaerobic exercise capacity of the knee joint to be most important for gyorugi athletes and then for demonstration and poomsae athletes, in that order. Conclusions: This study provides useful information needed to identify the physical fitness factors of the different Kukki Taekwondo athletes, and, in turn, it is may serve as important fundamental data for developing future systematic Taekwondo training programs.

Isometric and isokinetic muscle strength measurements of the lumbar flexors and extensors with BioniX Sim3 Pro in patients with chronic low back pain: A pilot study.

The World Health Organization states that low back pain is the leading cause for disability worldwide. Patients with chronic low back pain (CLBP) show important decreases in lumbar strength and can now be assessed by using the new isokinetic dynamometer BioniX Sim3 Pro which offers very detailed measurements. To compare lumbar flexion and extension strength values, as well as extension-flexion ratio (EFR) based on isokinetic velocity and gender, for patients with CLBP on the BioniX Sim3 Pro. A retrospective analysis was performed on data from 20 men and 22 women with CLBP. Maximum torque in flexion and extension was measured isometrically and isokinetically. Statistical analysis was performed on these parameters. EFR shows a downward trend with increasing speed of measurement (isometric to isokinetic 30∘/s and isokinetic 30∘/s to isokinetic 90∘/s, respectively): in men from 1.21 to 1.04 (p< 0.001) and from 1.04 to 0.93 (p= 0.207). In women, EFR decreased from 1.41 to 1.13 (p< 0.001) and from 1.13 to 1.00 (p= 0.144). Patients with CLBP have a decreased strength in lumbar extension and flexion compared to the age-corrected normal values of Bionix Sim3 Pro. With increasing speed of testing protocol, a decrease in EFR is observed in this population.

INFLUENCE OF CORE STRENGTH TRAINING ON PEAK MUSCLE TORQUE OF QUADRICEPS AND HAMSTRING IN YOUNG SOCCER PLAYERS

The purpose of the present study was to investigate the effect of eight week core strength training (CST) on quadriceps and hamstring muscle strength and H/Q ratio. The study included a total of 20 young soccer players, 10 in the experimental group (EG) and 10 in the control group (CG). Isokinetic knee strength measurements at angular velocities of 60°sec−1 , 180°sec−1 and 240°sec−1 were performed on the subjects. Independent sample t-test and 2x2 ANOVA test were used for statistical analysis. No significance was found between the pre-test results of both EG and CG (p&gt;0.05). In post-test results, a difference was found in favour of EG group in RPM 60o EX value (p&lt;0.05). When the pre-test and posttest results of the groups were compared separately, a significant difference was found in RPM 60o EX, LPM 180o EX and LPM 240o EX parameters in EG (p&lt;0.05). A significant progress was found in LPM 180o EX, LPM 180o FLX and LPM 240o FLX values in CG (p&lt;0.05). It was found that CST applied on young soccer players affected knee isokinetic strength in different velocity and this effect caused significance especially in different angular speeds of EX phase. In addition, although significant progress was not observed in all parameters in EG after CST, it was found that there weren’t decreases in any parameters and at least strength was maintained.

AN INVESTIGATION OF KNEE ISOKINETIC TIME TO PEAK TORQUE AND JOINT ANGLE AT PEAK TORQUE: DIFFERENT BODY POSITION EFFECT

The purpose of study was to investigate the effects of isokinetic knee measurement with different positions (prone and sitting) on knee isokinetic time to peak torque and joint angle at peak torque. For this purpose, 15 health sedentary male participated in the study. Isokinetic measurements were performed with isokinetic dynamometer (CSMI Cybex Humac Norm, USA). Isokinetic tests were performed at 3 different motion angles (60os-1 / 180os-1 / 240os-1). The test was carried out with 10 repetitions at 240os-1and 180os-1 and 5 repetitions at 60os-1. Each movement angle was performed 45 second rest intervals. SPSS 20.0 package program was used for the analysis of the data. Significance level was accepted as p Article visualizations:

STRENGTH AND FATIGUE MEASUREMENTS OF THE HIP FLEXOR AND HIP EXTENSOR MUSCLES: TEST-RETEST RELIABILITY AND LIMB DOMINANCE EFFECT.

Standardized testing of hip muscle strength and fatigue in the sagittal plane is important for assessing, treating and preventing a number of trunk and lower extremity pathologies. Furthermore, individuals displaying asymmetries of muscle strength between limbs are more likely to sustain an injury. To evaluate the test-retest reliability of isometric strength and isokinetic fatigue measurements of the hip flexor and hip extensor muscles, and to examine whether there is a significant limb dominance effect on strength, fatigue and flexor-extensor ratios. Cross-sectional study. To evaluate reliability, 30 healthy individuals (33.2 + /- 13.1 years) were included. On a separate occasion, 24 healthy individuals (29.0 + /- 10.3 years) participated to assess between-limb differences. Reliability was established using intraclass correlation coefficients (ICCs), standard error of measurements (SEM) and minimal detectable change (MDC). Isometric strength (best peak torque of three maximal contractions; Nm/kg), isokinetic fatigue (total work of 20 consecutive maximal concentric flexor-extensor contractions at 120 °/s; Joule/kg), and flexor-extensor ratios, were recorded using a Biodex dynamometer. Reliability was good-to-excellent (ICCs>0.83) and measurement errors were acceptable (SEM<13.6% and MDC%<37.8%). No significant between-limb differences in strength, fatigue and flexor-extensor ratios were detected. Isometric strength and isokinetic fatigue of the hip flexor and hip extensor muscles can be reliably assessed in healthy individuals using the Biodex dynamometer. Limb dominance did not significantly affect strength, fatigue or flexor-extensor ratios. 2b.