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Background: Assessments of muscle strength help prescribe and monitor training loads in cyclists (e.g., triathletes). Some methods include repetition maximum, joint isokinetic tests, and indirect estimates. However, their specificity for cycling's dynamic force application and competitive cadences is lacking. This study aims to determine the influence of the cycling isokinetic peak force (cIPF) at different cadences on aerobic performance-related variables in trained triathletes. Methods: Eleven trained male athletes (33 ± 9.8 years, 173.1 ± 5.0 cm height, 73.9 ± 6.8 kg body mass, and ≥5 years of triathlon experience) were recruited. Maximal oxygen consumption (VO2 max), ventilatory thresholds (i.e., VT1 and VT2), and cIPF were assessed. cIPF testing involved 10 s sprints at varied cadences with 4 min rest intervals. Pedaling cadences were set at low (60 rpm), moderate (80 and 100 rpm), and high (120 and 140 rpm) cadences. A regression model approach identified cIPF related to aerobic performance. Results: IPF at 80 and 120 rpm explained 49% of the variability in power output at VT1, 55% of the variability in power output at VT2, 65% of the variability in power output at maximal aerobic power (MAP), and 39% of the variability in VO2 max. The cycling economy was not explained by cIPF. Conclusions: This study highlights the significance of cIPF, particularly at moderate to high cadences, as a determinant of aerobic-related variables in trained triathletes. Cycling cIPF should be tested to understand an athlete's profile during crank cycling, informing better practice for training specificity and ultimately supporting athletes in achieving optimal performance outcomes in competitive cycling events. [ABSTRACT FROM AUTHOR]

This study investigated the effect of plyometric training with and without additional load on young male soccer players' jumping ability and isokinetic strength. Methods: In this randomized controlled trial, 39 U-17 male trained soccer players were randomly divided into plyometric training with additional load (PT+AL), plyometric training with just bodyweight (PTBW) and control (CON) groups. PT+AL and PTBW were performed for six weeks (2 days/week). Absolute peak torque (APT), relative peak torque (RPT), average peak torque (AvPT), time-to-peak torque (TPT), average rate of force development (AvRFD), vertical jump height (VJH), standing long jump (SLJ) and 15-second repeated jump tests (RJ15s) were assessed before and after the interventions. The findings showed that the performance of knee extensors in TPT-60°/s and AvRFD-60°/s, and knee flexors in APT-60°/s, RPT-60°/s, AvPT-60°/s, AvPT-120°/s, AvRFD-60°/s and AvRFD-120°/s significantly increased after PT+AL, compared to the CON (p < 0.05). Also, a significant improvement in jumping ability was observed in PT+AL compared to CON (p < 0.05). Additionally, PTBW also improved the performance of knee flexors in TPT-120°/s and AvRFD-120°/s, as well as RJ15s performance compared to the CON (p < 0.05). Furthermore, knee flexors AvRFD-60°/s increased significantly after PT+AL, compared to PTBW (p < 0.05). SO, plyometric training, with or without additional load, improved young male soccer players' strength and jumping ability. However, strength parameters – especially the rate of force development – showed a greater increase following PT + AL compared to PTBW. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the relationships between upper extremity joint length, reaction time and shoulder strength in young canoe athletes. The study was carried out with the voluntary participation of 23 young canoe athletes. Within the scope of the research plan, height measurements, body weight measurements, length measurements of the upper extremities (arm and forearm length), arm span length measurements, reaction time measurements and isokinetic strength measurements of the athletes were carried out. The effect of joint length values on reaction time and shoulder strength parameters was examined by multiple linear regression analysis. The results show that joint length values have a significant effect on reaction time and shoulder strength values in canoe athletes (p<0.05). In conclusion, it is thought that an increase in joint length may also lead to an increase in reaction times. [ABSTRACT FROM AUTHOR]

In soccer, knee and hip muscle strength assessments have been recommended for injury prevention. The aims of this study were threefold: (1) to compare knee and hip muscle strength between professional players competing at different levels; (2) to compare strength performance according to the preferred leg (PL) and the non-preferred leg (NPL); and (3) to compare knee and hip muscle strength performance at two moments of the season. This study included 33 professional soccer players: 13 were in the elite group (EG), and 20 were in the sub-elite group (SEG). Body composition, isokinetic knee strength at 60°/s, and hip adduction strength were assessed at two different moments (M1 and M2). Values of peak torque (PT), peak torque/bodyweight (PT/BW), and the hamstring-to-quadriceps strength ratio (H:Q) for knee extensors (KEs) and knee flexors (KFs) for both legs were used for analysis. The statistical analysis included the Mann-Whitney U and the Wilcoxon Signed Rank tests. At M1, the EG presented a significantly better performance in KF PT/BW and in the squeeze strength test for the PL and the NPL (p ≤ 0.01). At M2, the EG performed substantially better in KE PT/BW and KF PT/BW (p ≤ 0.01). No substantial strength differences were observed in knee and hip muscle performance between the PL and the NPL. From M1 to M2, significant increases were found in knee strength in both groups (p ≤ 0.01). Overall, the EG players outperformed significantly their lower-division peers in strength assessments. The results indicate significant knee and hip muscle strength increases during the season, probably as a response to the exposure to training and competition. [ABSTRACT FROM AUTHOR]

Background: The limb symmetry index (LSI) is a metric of strength restoration. It is key to successfully return to sports after anterior cruciate ligament (ACL) reconstruction. The threshold for return to sports is generally considered an LSI of ≥85%. Purpose: To develop a statistical model for predicting the recovery of knee extension and flexion strength (with LSI ≥85%) at 6 months after ACL reconstruction. Study Design: Case-control study; Level of evidence: 3. Methods: Patients who underwent arthroscopic ACL reconstruction between November 2015 and December 2020 were included. The patients were classified into 2 groups: "pass" if the LSI at 6 months postoperatively was ≥85% and "fail" if the LSI was <85%. Factors in 25 categories with 74 levels, including patient characteristics, periarticular procedures, intra-articular lesions and treatment, and perioperative management, were collected. A multivariable logistic regression combined with backward variable elimination was used to determine the predictive parameters for recovery of knee extension and flexion strength. Results: A total of 948 patients were included. Graft site, preoperative isokinetic strength, treatment of meniscal injury, and injured side (left vs right) were identified as general predictors for both knee extension and flexion strength. For knee extension strength, age at injury and partial weightbearing duration were identified as additional predictors. For knee flexion strength, type of meniscal injury, surgeon volume, cartilage procedures, and periarticular procedures were identified as additional predictors. The Nagelkerke R 2 of the final model was 0.178, and the c -statistic was 0.716 (95% CI, 0.676-0.754). The Hosmer-Lemeshow test indicated good calibration (P =.879). Conclusion: Several factors including preoperative isokinetic strength, treatment of meniscal injuries, left vs. right side and graft site were found to predict recovery of ≥85% LSI in knee extension and flexion strength. Despite the numerous factors that were analyzed, the predictive power was moderate (c-statistic = 0.716), indicating there were other nonincluded factors that significantly influence strength performance at 6 months postoperatively. [ABSTRACT FROM AUTHOR]

This study develops a comprehensive genotype-phenotype model for predicting the effects of resistance training on leg press performance. A cohort of physically inactive adults (N=193) underwent 12 weeks of resistance training, and measurements of maximum isokinetic leg press peak force, muscle mass, and thickness were taken before and after the intervention. Whole-genome genotyping was performed, and genome-wide association analysis identified 85 novel SNPs significantly associated with changes in leg press strength after training. A prediction model was constructed using stepwise linear regression, incorporating seven lead SNPs that explained 40.4% of the training effect variance. The polygenic score showed a significant positive correlation with changes in leg press strength. By integrating genomic markers and phenotypic indicators, the comprehensive prediction model explained 75.4% of the variance in the training effect. Additionally, five SNPs were found to potentially impact muscle contraction, metabolism, growth, and development through their association with REACTOME pathways. Individual responses to resistance training varied, with changes in leg press strength ranging from −55.83% to 151.20%. The study highlights the importance of genetic factors in predicting training outcomes and provides insights into the potential biological functions underlying resistance training effects. The comprehensive model offers valuable guidance for personalized fitness programs based on individual genetic profiles and phenotypic characteristics. [ABSTRACT FROM AUTHOR]

The association of pre-participation knee muscle strength status with lower limb injury occurrence was investigated. Knee extensors and flexors muscle strength status including the traditional hamstrings/quadriceps (H/Q), Q/Q, H/H, and the non-dominant H/Q: dominant H/Q, HQ:HQ, ratios were recorded before the 10 month judo activity. Fifteen lower limb sport injuries were recorded for 53 judokas during the follow-up questionnaires. Significant accuracy of dominant H/Q ratio 60º/s (AUC 0.702, 95% CI 0.520 to.883, p = 0.023), as well as HQ:HQ ratios 300º/s (AUC.318, 95% CI 0.138 to 0.497, p = 0.040), and 60 º/s (AUC 0.311, 95% CI 0.130 to 0.491, p =.033) were revealed discriminating between injured and uninjured judokas. The optimum cut-off of dominant H/Q ratio associated with belonging to uninjured judokas group was 43.2% (sensitivity, 0.974; specificity, 0.533). Isokinetic knee muscle dynamometry is useful for predicting the likelihood of lower limb injuries in professional judokas during competitive activity. Pre-participation testing of ipsilateral and bilateral knee extensors and flexors strength ratios can contribute to an injury prevention program for judokas. Ipsilateral and bilateral strength ratios should be monitored at lower and higher angular isokinetic velocities. [ABSTRACT FROM AUTHOR]

Study aim: This study aimed to analyze the relationships between weekly training frequency, changes in training duration, and Maximal Aerobic Speed (MAS), Maximum Oxygen Uptake (VO2max), and Isokinetic Strength over an 8-week period (preseason 8 weeks). Material and methods: Eighteen hearing-impaired handball players (age: 26.78±2.26 years; height: 177.76±4.40 cm; body weight: 64.94±2.73 kg, training experience 13.1±2.6 years) were positioned in defense and offense based on their playing positions and were monitored for 8 weeks. Repeated Measures ANOVA test was performed for the pretest and post-test comparisons of defense and offense players, frequency and distribution is observed, average standard deviation, maximum, and minimum values were taken. Results: The analysis results revealed a significant large positive difference in the agonist/antagonist ratio in the right extremity (p < 0.01). Conclusion: Throughout the study, fluctuating changes in the numbers and durations of training sessions were observed to significantly increase and correlate with changes in the players' fitness status. There is a statistically significant difference between pre-test and post-test values for maximal oxygen consumption (VO2max), maximal aerobic speed (MAS), and maximal heart rate (HRmax) (p< 0.01). However, the variability in the large positive difference in the agonist/antagonist ratio in the right extremity suggests that it cannot be solely explained by the number and duration of training sessions in terms of fitness level. [ABSTRACT FROM AUTHOR]

To investigate whether lower limb strength is reduced in people with patellar tendinopathy (PT) compared with asymptomatic control individuals or the asymptomatic contralateral limb. MEDLINE, PubMed, Scopus, and Web of Science. To be included in the systematic review and meta-analysis, studies were required to be peer reviewed, published in the English language, and case control investigations; include participants with a clinical diagnosis of PT and an asymptomatic control or contralateral limb group; and include an objective measure of lower limb maximal strength. We extracted descriptive statistics for maximal strength for the symptomatic and asymptomatic limbs of individuals with PT and the limb(s) of the asymptomatic control group, inferential statistics for between-groups differences, participant characteristics, and details of the strength-testing protocol. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for analytical cross-sectional studies. Of the 23 included studies, 21 reported knee strength, 3 reported hip strength, and 1 reported ankle strength. Random-effects models (Hedges g) were used to calculate the pooled effect sizes (ESs) of muscle strength according to the direction of joint movement and type of contraction. The pooled ESs (95% CI) for maximal voluntary isometric contraction knee-extension strength, concentric knee-extension strength, and concentric knee-flexion strength were 0.54 (0.27, 0.80), 0.78 (0.30, 1.33), and 0.41 (0.04, 0.78), respectively, with all favoring greater strength in the asymptomatic control group. Researchers of 2 studies described maximal eccentric knee-extensor strength with no differences between the PT and asymptomatic control groups. In 3 studies, researchers measured maximal hip strength (abduction, extension, and external rotation), and all within-study ESs favored greater strength in the asymptomatic control group. Isometric and concentric knee-extensor strength are reduced in people with PT compared with asymptomatic control individuals. In contrast, evidence for reduced eccentric knee-extension strength in people with PT compared with asymptomatic control individuals is limited and inconsistent. Although evidence is emerging that both knee-flexion and hip strength may be reduced in people with PT, more examination is needed to confirm this observation. [ABSTRACT FROM AUTHOR]

Background and aim: Cricket is the most commonly played and followed sport in India and demands a high level of performance from the fast bowler. Large ground reaction forces generated at front foot contact put fast bowlers at high risk of lower limb and lumbar spine injury. Precise dynamic coordination of lower body segments is needed to absorb these forces and transfer the energy via the core to the upper limb to propel the ball at faster speeds. Thus, knowledge of lower quadrant strength, especially dynamic knee strength, can be useful for injury prevention and better performance in fast bowlers. There is a lack of literature on this subject in Indian fast bowlers despite the popularity of the sport. This study aims to evaluate isokinetic knee strength and determine the relevant asymmetries and strength imbalances in relation to injury risk in cricket fast bowlers. Methods: A total of 42 male Indian state-level fast bowlers underwent isokinetic knee strength testing. Peak torques (PT) normalized to body weight (BW) were obtained for quadriceps concentric (Qconc), quadriceps eccentric (Qecc), hamstring concentric (Hconc), and hamstring eccentric (Hecc). Bilateral strength asymmetries (BSA) and dynamic control ratio (DCR) (hamstring DCR (H-DCR) = Hecc/Qconc and quadriceps DCR (Q-DCR) = Qecc/Hconc) were evaluated. Descriptive statistical analysis of data was done. Results: Around 67% of bowlers had significant Qecc strength asymmetry. In addition, 40% had poor hamstrings DCR and 19% had poor Q-DCR on the front limb. Conclusion: A significant proportion of fast bowlers have unfavorable strength asymmetry and DCR and could be at risk of injury. Improving dynamic knee strength through plyometric training could help optimize performance and reduce injury risk. Clinical significance: This study highlights key areas of possible injury risk that can be targeted with strength and conditioning to prevent lower limb and lumbar spine injuries in fast bowlers. [ABSTRACT FROM AUTHOR]

Background: Foot stability is essential for performing various dynamic movements in sports. The contribution of ankle dorsiflexors and planter flexors co-contraction in maintenance of postural balance is mainly the focus of previous studies. However, whether there is any role of ankle evertors and invertors in maintaining foot stability while doing dynamic postural tasks is not well studied so far. Aim: The aim of this study was to find out if there is a correlation of isokinetic strength of ankle evertors and invertors with dynamic postural stability. Setting and Design: This cross-sectional study was conducted in the Strength Analysis Lab of the university. Subjects and Methods: Thirty-five male team sport players (9 – football, 9 – hockey, 9 – basketball, and 8 – volleyball) with mean age: 20.6 ± 1.83 years, body weight: 62.2 ± 8.36 kg, and height: 172.3 ± 8.07 cm were included. Balance was measured with lower quarter-Y-balance test whereas isokinetic strength of ankle evertors and invertors was measured with Biodex dynamometer. Statistical Analysis: In the statistical software SPSS, Kolmogorov–Smirnov test was applied to check the normality of data. As the data were normally distributed, the relationship between variables was found by Pearson's correlation coefficient. Results: Isokinetic strength of right ankle invertors was moderately correlated with composite reach of the left limb at 30°/s angular velocity (P = 0.027). Composite reach right limb was moderately correlated with isokinetic strength of the right ankle evertors at 30° and 60°/s angular velocities (P = 0.043 and 0.022). Composite reach of the right limb was moderately correlated with isokinetic strength of right ankle invertors at 60° and 90°/s angular velocities (P = 0.046 and 0.046). Conclusion: Isokinetic strength of ankle evertors and invertor is significantly related to dynamic postural stability and should be included in fitness programs, especially for injury prevention and to improve dynamic postural stability. [ABSTRACT FROM AUTHOR]

Background: Impaired quadriceps muscle strength after anterior cruciate ligament reconstruction (ACLR) is associated with worse clinical outcomes and a risk of reinjuries. Yet, we know little about quadriceps muscle strength in patients reconstructed with a quadriceps tendon (QT) graft, which is increasing in popularity worldwide. Purpose: To describe and compare isokinetic quadriceps strength in patients undergoing ACLR with a QT, hamstring tendon (HT), or bone–patellar tendon–bone (BPTB) autograft. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We included patients with QT grafts (n = 104) and matched them to patients with HT (n = 104) and BPTB (n = 104) grafts based on age, sex, and associated meniscal surgery. Data were collected through clinical strength testing at a mean of 7 ± 1 months postoperatively. Isokinetic strength was measured at 90 deg/s, and quadriceps strength was expressed as the limb symmetry index (LSI) for peak torque, total work, torque at 30° of knee flexion, and time to peak torque. Results: Patients with QT grafts had the most impaired isokinetic quadriceps strength, with the LSI ranging between 67.5% and 75.1%, followed by those with BPTB grafts (74.4%-81.5%) and HT grafts (84.0%-89.0%). Patients with QT grafts had a significantly lower LSI for all variables compared with patients with HT grafts (mean difference: peak torque: −17.4% [95% CI, −21.7 to −13.2], P <.001; total work: −15.9% [95% CI, −20.6 to −11.1], P <.001; torque at 30° of knee flexion: −8.8% [95% CI, −14.7 to −2.9], P =.001; time to peak torque: −17.7% [95% CI, −25.8 to −9.6], P <.001). Compared with patients with BPTB grafts, patients with QT grafts had a significantly lower LSI for all variables (mean difference: peak torque: −6.9% [95% CI, −11.2 to −2.7], P <.001; total work: −7.7% [95% CI, −12.4 to −2.9], P <.001; torque at 30° of knee flexion: −6.3% [95% CI, −12.2 to −0.5], P =.03; time to peak torque: −8.8% [95% CI, −16.9 to −0.7], P =.03). None of the graft groups reached a mean LSI of >90% for peak torque (QT: 67.5% [95% CI, 64.8-70.1]; HT: 84.9% [95% CI, 82.4-87.4]; BPTB: 74.4% [95% CI, 72.0-76.9]). Conclusion: At 7 months after ACLR, patients with QT grafts had significantly worse isokinetic quadriceps strength than patients with HT and BPTB grafts. None of the 3 graft groups reached a mean LSI of >90% in quadriceps strength. [ABSTRACT FROM AUTHOR]

The shot performance of female soccer players is one of the most critical factors in winning a soccer match. It is essential to thoroughly clarify the kinetic factors that can improve shot performance. This study explores the connections between ball velocity post-shooting and isokinetic knee extension (EXT) and flexion (FLX) strength performances among female soccer players. Thirteen voluntary players from professional leagues took part in the research study. The study analyzed the average and peak concentric (Con) and eccentric (Ecc) torques, isometric (Iso) strength performances at angular velocities of 60°/s, 180°/s and 300°/s, the time required to reach peak torque, and ball velocities during shooting. The relationships among these variables were investigated separately for the dominant (D) and non-dominant (ND) legs. The analysis unveiled significant correlations between ball velocities and D-EXT (Absolute) peak torque at an angular velocity of 60°/s (r = 0.597; p < 0.05), D-%IPS (r = −0.580; p < 0.05), and ND-FLX (Absolute) average torque (r = 0.559; p < 0.05). Moreover, notable associations were observed between ball velocities and ND-EXT (Absolute) (r = 0.581; p < 0.05), as well as ND-FLX (Absolute) (r = 0.602; p < 0.05) average torques at an angular velocity of 180°/s. Additionally, significant relationships were found between ball velocities and peak (r = 0.664; p = 0.013) and average (r = 0.660; p = 0.014) torques generated during ND-EXT (Absolute) at an angular velocity of 300°/s. However, the connections between the time to reach peak torque, eccentric and isometric forces, and ball velocities were not statistically significant (p > 0.05). The results of the study indicate that enhancing concentric isokinetic strength development at 60°/s, 180°/s, and 300°/s angular velocities, along with balanced strengthening of the ND extremity, holds paramount importance in elevating shot performance among female soccer players, particularly in the context of rapid shot strategies. [ABSTRACT FROM AUTHOR]

The aim was to analyse the relationship between isokinetic strength, dynamic stability, muscular extensibility and impacts transmission during fatigued running. Low- and high-frequency impacts—related to body movements and the severity of impacts, respectively—were assessed in 17 male recreational runners, before and after a treadmill running fatigue protocol, using a triaxial accelerometry system. High-frequency impacts in the tibia were negatively correlated to the knee angle at which the quadriceps peak torque was reached (p = 0.014), and also to the extensibility of the hamstrings and soleus (p = 0.001 and p = 0.023, respectively). The increases of high-frequency impacts in tibia caused by fatigue were positively related to the knee angle at which the hamstrings peak torque was reached (p = 0.001) and to stability after landing (p = 0.007). The attenuation of high-frequency impacts was positively related to hamstrings/quadriceps ratio of strength (p = 0.010) and to stability (p = 0.006). Limiting possible deficits in hamstring and soleus range of motion, improving stability after landing, developing hamstring and quadriceps strength in elongated muscle range, and maintaining a balanced ratio of hamstring/quadriceps strength could help to reduce the injury risk in running. [ABSTRACT FROM AUTHOR]

Introduction: The recovery of periarticular strength is a major criterion in return-to-play testing. The rationale of the study was to assess the impact of the delay of surgery (∆ between injury and surgery) on knee extensor and knee flexor strength of anterior cruciate ligament (ACL)-deficient patients six months after reconstruction. Materials and methods: In a retrospective cohort study, all patients with ACL ruptures between 03/2015 and 12/2019 were analyzed. Inclusion criteria were isolated ACL rupture without any associated lesions undergoing a reconstruction using ipsilateral hamstring tendon autograft and adherence to isokinetic strength testing before and at 5–7 months postoperatively. These patients were then clustered into three groups: EARLY reconstruction (∆ < 42 days), DELAYED reconstruction (∆42-180d), and CHRONIC (∆ > 180d). Knee extensor and flexor strength of the ipsi- and contralateral leg were analyzed by concentric isokinetic measurement (60°/s). Primary outcomes were the maximal knee extension and flexion torque, hamstrings-to-quadriceps ratio (H/Q) ratio), and the corresponding limb symmetry indices. Results: n = 444 patients met the inclusion criteria. From EARLY to DELAYED to CHRONIC, a progressive reduction in postoperative strength performance was observed in knee extension (1.65 ± 0.45 to 1.62 ± 0.52 to 1.51 ± 0.5 Nm/kg resp.) and flexion (1.22 ± 0.29 to 1.18 ± 0.3 to 1.13 ± 0.31 Nm/kg resp.) strength on the ACL reconstructed leg. This general loss in periarticular strength was already apparent in the preoperative performance even on the healthy side. When controlling for the preoperative performance using ANCOVA analysis, EARLY performed significantly better than DELAYED (extension p = 0.001, flexion p =.02) and CHRONIC (extension p = 0.005, flexion p < 0.001). Also, there were significantly higher values for H/Q ratio in the injured leg across all groups where the H/Q ratio increased from EARLY to CHRONIC and from pre- to postoperative values. Conclusions: With respect to the force generating capacity when returning-to-play, it is advantageous to seek for an early ACL reconstruction within the first 12 weeks after the injury. The increasing loss of thigh muscle strength observed in delayed or chronic cases affects the injured and also the non-injured leg. Level of Evidence: III, retrospective cohort study. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to demonstrate that patients undergoing ACL reconstruction with quadrupled semitendinosus suspensory femoral and tibial fixation have comparable results in muscle strength and knee function to those undergoing ACL reconstruction with four-strand semitendinosus-gracilis suspensory femoral fixation and a bioabsorbable tibial interference screw fixation. Materials and Methods: Between 2017 and 2019, 64 patients who were operated on by the same surgeon were included. Patients underwent ACL reconstruction technique with quadrupled semitendinosus suspensory femoral and tibial button fixation in Group 1, and patients underwent ACL reconstruction with coupled four-strand semitendinosus-gracilis suspensory femoral fixation and a bioabsorbable tibial interference screw in Group 2. Evaluation of patients was performed with the Lysholm and Tegner activity scale preoperatively and at the 1st and 6th months postoperatively. At the 6-month visit, isokinetic testing of the operated and non-operated limbs was performed in both groups. Results: There was no significant difference in the age, weight, and BMI values of the patients in Groups 1 and 2 (p < 0.05). According to the strength values of the operated sides of the patients in Group 1 and Group 2, there was no significant difference in the angular velocities of 60° s−1, 180° s−1, and 240° s−1 in both extension and flexion phases between the operated sides of Groups 1 and 2 (p < 0.05). Conclusions: Patients who have ACL reconstruction with quadrupled semitendinosus suspensory femoral and tibial fixation have comparable muscle strength and knee function to those who undergo ACL reconstruction with four-strand semitendinosus-gracilis suspensory femoral fixation and a bioabsorbable tibial interference screw. [ABSTRACT FROM AUTHOR]

The main aims of this study were to compare the magnitude of inter-limb asymmetry (ILA) and the relation with self-reported knee function between maximal and explosive knee extensor strength outcomes in professional soccer players. Forty-six male soccer players completed different maximal isokinetic and isometric contractions of the knee extensors for the assessment of maximal strength (peak torque and maximal voluntary contraction (MVC) torque) and explosive strength (early, intermediate, late, and peak rate of torque development (RTD)). Self-reported knee function was assessed with the International Knee Documentation Committee (IKDC) and Lysholm knee scoring scales. Peak torque and MVC torque showed comparable ILAs (8-9%), both being significantly lower than all RTD ILAs (16% on average; p < 0.001). ILAs for early RTD (21%) and peak RTD (19%) were significantly higher than all the other variables (p < 0.05). Only early and intermediate RTD were significantly correlated – though weakly – with both IKDC (rho = 0.32 for both) and Lysholm (rho = 0.36 and 0.30, respectively) scores. We conclude that explosive knee extensor strength – early RTD in particular – exhibited larger ILAs and better relations with self-reported knee function than peak torque and MVC torque in professional soccer players. These results confirm the validity and functional relevance of early RTD and the need for its inclusion in routine performance testing for soccer players. Highlights Professional soccer players exhibited larger inter-limb deficits in knee extension strength for explosive actions than for the widely-used isokinetic test. Self-reported knee function was significantly correlated with explosive strength of the knee extensor muscles but not with maximal strength. The first 50 ms of an explosive knee extension seem to be crucial for self-perceived sport performance and possibly for injury prevention. [ABSTRACT FROM AUTHOR]

BACKGROUND: Muscle strength in the upper and lower limbs is a major contributing factor to punch force and is one of the keys to success in boxing. OBJECTIVE: This study aimed to investigate the relationship between knee and shoulder strength and punching force in boxers. METHODS: Twenty-one boxers completed knee flexion, knee extension, shoulder external rotation and internal rotation isokinetic concentric contractions at slow (60 ∘ /s) and fast (180 ∘ /s) angular velocities. Maximal punch force tests included lead and rear straight arm punching were assessed using a force platform. RESULTS: Pearson's correlation coefficients revealed that knee extension (r = 0.646–0.848) and knee flexion (r = 0.470–0.646) peak torques were moderately to very strongly correlated with maximal punching force in lead and rear arms. The shoulder internal rotation (r = 0.492–0.634) and shoulder external rotation (r = 0.441–0.588) peak torques were moderate to strongly correlated with maximal punching force. Moreover, knee extension peak torques at 60 ∘ /s had higher correlation with maximal punching force. In contrast, shoulder internal rotation peak torques at 180 ∘ /s had a larger correlation with maximal punching force. CONCLUSIONS: The main findings indicated the importance of the capacity to generate maximum knee extension and rapid shoulder internal rotation strength, contributing to punch force production. [ABSTRACT FROM AUTHOR]

Background: Both Kinesio Tape (KT) and Compression Sleeves (CS) can relieve Delayed Onset Muscle Soreness (DOMS) to a certain extent, but there is no study report on the difference in the effectiveness of the KT and CS whether the effect is better when used at the same time. The purpose of this study was to compare the effects of KT and CS on the recovery of muscle soreness, isokinetic strength, and body fatigue after DOMS. Methods: In this single-blinded randomized controlled trial, 32 participants aged 18 to 24 years were randomly divided into Control group (CG), Compression Sleeves group (CSG), Kinesio Tape group (KTG), Compression Sleeves and Kinesio Tape group (CSKTG), between October 2021 and January 2022. KTG uses Kinesio Tape, CSG wears Compression Sleeves, and CSKTG uses both Compression Sleeves and Kinesio Tape. Outcomes were performed at five-time points (baseline, 0 h, 24 h, 48 h, 72 h), Primary outcome was pain level Visual Analogue Scale (VAS), and Secondary outcomes were Interleukin 6, Peak Torque/Body Weight, Work Fatigue. Statistical analyses were performed using the repeated measures analysis of variance method. Setting: Laboratory. Results: After the intervention, VAS reached the highest at 24 h after exercise-induced muscle soreness, while the KTG and CSG at each time point were less than CG, and the scores of CSKTG at 24 h and 48 h were less than those of KTG and CSG in the same period (P < 0.05). Interleukin 6, at 24 h, CSKTG is lower than KTG 0.71(95%CI: 0.43 to 1.86) and CG 1.68(95%CI: 0.06 to 3.29). Peak Torque/Body Weight, at 24 h, CG was lower than CSKTG 0.99(95%CI: 0.42 to 1.56), KTG 0.94(95%CI: 0.37 to 1.52), and CSG 0.72(95%CI: 0.14 to 1.29); at 72 h, CG was lower than CSKTG 0.65(95%CI: 0.13 to 1.17) and KTG 0.58(95%CI: 0.06 to 1.10). Work Fatigue, at 24 h, CG was lower than KTG 0.10(95%CI: 0.02 to 1.78) and CSKTG 0.01(95%CI: -0.07 to 0.09). At 48 h, CG was lower than KTG 0.10(95%CI: 0.13 to 1.17) and CSKTG 0.11(95%CI: 0.03 to 0.18). Conclusions: Kinesio Tape can significantly reduce DOMS pain, and Kinesio Tape has a better recovery effect on Delayed Onset Muscle Soreness than Compression Sleeves. Kinesio Tape combined with Compression Sleeves is helpful to alleviate the Delayed Onset Muscle Soreness pain, speeding up the recovery of muscle strength, and shortening the recovery time after Delayed Onset Muscle Soreness. Trial registration: Registration number: This study was also registered on 11/10/2021, at the Chinese Clinical Trial Registry (ChiCTR2100051973). [ABSTRACT FROM AUTHOR]

Background: Both Kinesio Tape (KT) and Compression Sleeves (CS) can relieve Delayed Onset Muscle Soreness (DOMS) to a certain extent, but there is no study report on the difference in the effectiveness of the KT and CS whether the effect is better when used at the same time. The purpose of this study was to compare the effects of KT and CS on the recovery of muscle soreness, isokinetic strength, and body fatigue after DOMS. Methods: In this single-blinded randomized controlled trial, 32 participants aged 18 to 24 years were randomly divided into Control group (CG), Compression Sleeves group (CSG), Kinesio Tape group (KTG), Compression Sleeves and Kinesio Tape group (CSKTG), between October 2021 and January 2022. KTG uses Kinesio Tape, CSG wears Compression Sleeves, and CSKTG uses both Compression Sleeves and Kinesio Tape. Outcomes were performed at five-time points (baseline, 0 h, 24 h, 48 h, 72 h), Primary outcome was pain level Visual Analogue Scale (VAS), and Secondary outcomes were Interleukin 6, Peak Torque/Body Weight, Work Fatigue. Statistical analyses were performed using the repeated measures analysis of variance method. Setting: Laboratory. Results: After the intervention, VAS reached the highest at 24 h after exercise-induced muscle soreness, while the KTG and CSG at each time point were less than CG, and the scores of CSKTG at 24 h and 48 h were less than those of KTG and CSG in the same period (P < 0.05). Interleukin 6, at 24 h, CSKTG is lower than KTG 0.71(95%CI: 0.43 to 1.86) and CG 1.68(95%CI: 0.06 to 3.29). Peak Torque/Body Weight, at 24 h, CG was lower than CSKTG 0.99(95%CI: 0.42 to 1.56), KTG 0.94(95%CI: 0.37 to 1.52), and CSG 0.72(95%CI: 0.14 to 1.29); at 72 h, CG was lower than CSKTG 0.65(95%CI: 0.13 to 1.17) and KTG 0.58(95%CI: 0.06 to 1.10). Work Fatigue, at 24 h, CG was lower than KTG 0.10(95%CI: 0.02 to 1.78) and CSKTG 0.01(95%CI: -0.07 to 0.09). At 48 h, CG was lower than KTG 0.10(95%CI: 0.13 to 1.17) and CSKTG 0.11(95%CI: 0.03 to 0.18). Conclusions: Kinesio Tape can significantly reduce DOMS pain, and Kinesio Tape has a better recovery effect on Delayed Onset Muscle Soreness than Compression Sleeves. Kinesio Tape combined with Compression Sleeves is helpful to alleviate the Delayed Onset Muscle Soreness pain, speeding up the recovery of muscle strength, and shortening the recovery time after Delayed Onset Muscle Soreness. Trial registration: Registration number: This study was also registered on 11/10/2021, at the Chinese Clinical Trial Registry (ChiCTR2100051973). [ABSTRACT FROM AUTHOR]

Copyright of Online Journal of Recreation & Sports is the property of Online Journal of Recreation & Sports and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this review was to perform a meta-analysis examining the effects of cold-water immersion (CWI) coupled with resistance training on gains in muscular strength. Four databases were searched to find relevant studies. Their methodological quality and risk of bias were evaluated using the PEDro checklist. The effects of CWI vs. control on muscular strength were examined in a random-effects meta-analysis. Ten studies (n = 170; 92% males), with 11 comparisons across 22 groups, were included in the analysis. Studies were classified as of good or fair methodological quality. The main meta-analysis found that CWI attenuated muscular strength gains (effect size [ES]: –0.23; 95% confidence interval [CI]: –0.45, –0.01; p = 0.041). In the analysis of data from studies applying CWI only to the trained limbs, CWI attenuated muscular strength gains (ES: –0.31; 95% CI: –0.61, –0.01; p = 0.041). In the analysis of data from studies using whole-body CWI, there was no significant difference in muscular strength gains between CWI and control (ES: –0.08; 95% CI: –0.53, 0.38; p = 0.743). In summary, this meta-analysis found that the use of CWI following resistance exercise sessions attenuates muscular strength gains in males. However, when CWI was applied to the whole body, there was no significant difference between CWI and control for muscular strength. Due to the attenuated gains in muscular strength found with single limb CWI, the use and/or timing of CWI in resistance training should be carefully considered and individualized. [ABSTRACT FROM AUTHOR]

Purpose: The recovery of strength is a key element in successfully returning to sports after ACL reconstruction. The type of anaesthesia has been suspected an influential factor in the post-operative recovery of muscle function. Methods: In this retrospective analysis, n = 442 consecutive patients undergoing primary isolated ACL reconstruction using a hamstring autograft were analysed by pre- and post-operative isokinetic tests in a single orthopaedic centre. These were subdivided into four cohorts: (1) general anaesthesia (n = 47), (2) general anaesthesia with prolonged (48 h) on-demand femoral nerve block (n = 37), (3) spinal anaesthesia (n = 169) and (4) spinal anaesthesia with prolonged (48 h) on-demand femoral nerve block (n = 185). Primary outcome was the change from pre- to post-operative isokinetic strength during knee extension and flexion. Results: Using one-way ANOVA, there was no significant influence of the type of anaesthesia. The main effect of anaesthesia on change in extension forces was not significant, and effect sizes were very small (n.s.). Similarly, the main effect of anaesthesia on change in flexion forces was statistically not significant (n.s.). Conclusions: The findings of this study support the interpretation that the type of anaesthesia has no significant effect on the ability to recover thigh muscle strength 6 months after isolated hamstring ACL reconstruction. With regard to the recovery of athletic performance and return-to-sports testing criteria, there is no reason to avoid regional anaesthesia. Level of evidence: III. [ABSTRACT FROM AUTHOR]

This study aims to compare the physical and physiological profiles between elite men and women wrestlers of free style category. The research group consist of twenty-nine men and twenty-one women freestyle wrestlers who camped for performance tests at the Turkish Olympic Preparation Center in Ankara 2 months before the European Wrestling Championship in Budapest on March 28-April 3, 2022. Subjects performed the leg and arm Wingate anaerobic test (anaerobic power and capacity), VO2max (aerobic endurance), Reactive agility, isokinetic and isometric strength test. The results showed that Lower Extremity anaerobic power obtained from men, knee flexor at VO2max, 60°/s and 180°/s peak torque, isometric force values of arm and trunk extensor muscles, are higher than in women (p<0.05). In contrast, upper extremity anaerobic power values seem to be similar (p>0.05). As a result, it can be said that the endurance capacity, isometric, and isokinetic strength parameters are more effective than the force parameter in gender. These results can be used by coaches, strength and conditioning specialists, and sport scientists to create a comprehensive physical and physiological profile of wrestlers that will help them adapt their training programs. [ABSTRACT FROM AUTHOR]

Later-stage rehabilitation following anterior cruciate ligament (ACL) reconstruction (ACLR) provides a valuable opportunity to target performance deficits before return to sport. This study aimed to: (1) evaluate bilateral counter-movement jump (CMJ) phase-specific impulse and isokinetic strength inter-limb asymmetry progression from 6 to 9 months post-ACLR; and (2) examine the extent to which individual changes in strength asymmetry could explain changes in impulse asymmetry. Male athletes (n = 44) with a hamstring tendon or bone-patellar tendon-bone autograft were tested 6 and 9 months post-ACLR. Two-way mixed-model ANOVAs were used to identify inter-session and inter-graft differences in CMJ phase-specific impulse asymmetries and knee isokinetic flexor and extensor strength asymmetries, as well as in absolute impulse and strength values of independent (ACLR/uninvolved) limbs. Linear regression models were used to assess the relationship between changes in impulse asymmetry and strength asymmetry. Reductions in strength asymmetry arose from improved ACLR-limb performance, whereas concentric impulse asymmetry reduced consequent to decreased uninvolved-limb performance and eccentric deceleration impulses decreased bilaterally. Graft type did not modulate findings. Changes in strength asymmetry had little or no ability to explain changes in impulse asymmetry. Consideration of approaches that may influence persisting deficits observed bi-laterally throughout vertical jumping performance post-ACLR may enhance rehabilitation practice. [ABSTRACT FROM AUTHOR]

BACKGROUND: Dynamic stretching (DS) and ballistic stretching (BS) are similar stretching methods, but the differences between them are unclear. OBJECTIVE: To examine the immediate effects of unilateral hamstring DS and BS on straight leg raise (SLR), knee flexion range of motion (KF-ROM), and KF and knee extension maximal isokinetic peak torque (KF-MIPT and KE-MIPT) of the bilateral limbs. METHODS: Twelve healthy adult men performed four sets of 2 min each of non-stretching, DS, or BS of the right lower extremity. Bilateral SLR, KF-ROM, KF-MIPT, and KE-MIPT were measured pre- and post-intervention; a three-way (intervention ) limb ) time) repeated-measures analysis of variance (ANOVA) was used. RESULTS: The SLR of the stretched limb (p < 0.01) was higher with DS than that pre-intervention. SLR (p < 0.01) and KF-ROM (p < 0.05) of the stretched limb and SLR (p < 0.05) and KF-ROM (p < 0.05) of the contralateral limb were higher with BS than those pre-intervention. There was no significant main effect or interaction between KF-MIPT and KE-MIPT. CONCLUSION: DS and BS had slightly different effects on ROM, and neither affected muscle strength; thus, combining the techniques during warm-up might be helpful. [ABSTRACT FROM AUTHOR]

Kicking is a fundamental skill and a primary noncontact mechanism of injury in soccer, with injury incidence increasing during the latter stages of match-play. Ten male professional soccer players completed a 90-minute treadmill protocol based on the velocity profile of soccer match-play. Preexercise, and at 15-minute intervals, players completed a maximal velocity kick subjected to kinematic analysis at 200 Hz. Preexercise, and at the end of each half, players also completed isokinetic concentric knee extensor repetitions at 180°·s−1, 300°·s−1, and 60°·s−1. Kicking foot speed was maintained at ∼19 m·s−1, with no main effect for exercise duration. In relation to proximal–distal sequencing during the kicking action, there was a significant increase in the duration (but not magnitude) of thigh rotation, with a compensatory decrease in the duration (but not magnitude) of shank rotation during the latter stages of the exercise protocol. In relation to long-axis rotation, pelvic orientation at ball contact was maintained at ∼6°, representing a total pelvic rotation in the order of ∼15° during the kicking action. Peak knee extensor torque at all speeds was also maintained throughout the protocol, such that kinematic modifications are not attributable to a decline in knee extensor strength. [ABSTRACT FROM AUTHOR]

Copyright of Motricidade is the property of Silabas Didaticas LDA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Knee strength weakness is a major problem frequently observed in patients during postoperative rehabilitation following anterior cruciate ligament reconstruction (ACLR). OBJECTIVE: To investigate whether knee strength normalized to muscle volume could better detect side-to-side differences than that normalized to body weight following ACLR. METHOD: This study included 17 patients who had undergone primary ACLR (11.6 ± 2.3 months). Body weight and total muscle volume were measured using a bioelectrical impedance analysis composition scale. Isokinetic knee extension and flexion moment were measured at 60 ∘ /s and 180 ∘ /s, respectively. Bivariate correlation analysis was used to examine correlations between body composition and knee strength. Differences in knee strength between the operated and unoperated legs were analyzed using a paired t -test, which calculated the effect size. RESULTS: There was a significant correlation between knee strength and body weight (r = 0.53–0.67); however, a stronger correlation was observed between knee strength and total muscle volume (ρ = 0.80–0.87). The effect size was larger for knee strength expressed as % total muscle volume than for knee strength expressed as % body weight. CONCLUSION: Strength expressed as % total muscle volume may be more accurate than that expressed as % body weight for detecting side-to-side differences in knee strength following ACLR. [ABSTRACT FROM AUTHOR]

We compared the acute effects of parallel back squat performed from different resistance training configurations on neuromuscular performance. Twenty-eight young adults underwent 4 experimental conditions: inter-repetition rest, traditional, traditional to failure, and rest-pause in the parallel back squat in a randomized, counterbalanced, and cross-over design. The neuromuscular performance was assessed through peak torque of knee extensors and flexors at two angular velocities (90 and 120 º/s) in three moments (before, post, and post-30 min). The peak torque of the knee extensors and flexors at 90 and 120 º/s decreased immediately after training for traditional, traditional to failure, and rest-pause (–8.1% to –17.7%, P <0.001). A greater reduction in the extensor peak torque was found at 120 º/s (P <0.05) in the rest-pause (–17.7%) when compared to traditional (–10.8%). The peak torque returned to baseline values only at post-30 min for the traditional configuration for the knee flexion action at 120 º/s. The peak torque remained similar for the muscular actions and angular velocities for the inter-repetition rest (P >0.05). Our results suggest the inter-repetition rest configuration seems to be a more appropriate strategy for maintaining the lower limb neuromuscular performance after a resistance training session. [ABSTRACT FROM AUTHOR]

Background: Wrestling is considered one of the oldest sports in the world. There is a high rate of injuries in Wrestling. To prevent injuries, it is necessary to identify the risk factors. Despite the functional importance of strength in wrestling, few studies have investigated the relationship between isokinetic strength and the rate of injuries in the sport. Objectives: The objective of the present study was to investigate the relationship between the isokinetic strength of elite wrestlers and the rate of injuries prospectively. Method: A total of 72 young wrestlers with at least 2 years of experience in the Tehran Wrestling Premier League participated in this study. Before the start of the competition season, the isokinetic strength of flexor and extensor muscles of the knee and shoulder were measured at different velocities by an isokinetic dynamometer. The injuries and training hours of these wrestlers were then recorded for nine months. Results: The study results showed no significant relationship between isokinetic strength of flexor and extensor muscles of the knee or shoulder at different angular speeds of 60, 180, and 300°/s. There was neither significant between the ratio of the strength flexor/extensor for knee and/or shoulder in young elite wrestlers with injuries. Conclusion: Isokinetic strength of lower and upper limb muscles alone cannot predict wrestlers' injuries. Therefore, the use of these tests is not recommended to evaluate the risk of injury in this population. [ABSTRACT FROM AUTHOR]

Background: Pilates-based core stability training (PBCST) is a controlled form of exercise that may improve the transmission of torque from the upper extremities and trunk to the lower extremities by enabling the core muscles to activate effectively. Objectives: The aim of this study was to investigate the effects of PBCST given as supervised or home-based on lower extremity strength and postural control in multiple sclerosis. Methods: Fifty individuals were enrolled and randomly allocated into two groups. Primary outcome measures were knee muscle strength and postural sway in different conditions. The supervised group received PBCST 2 days per week for 8 weeks at the clinic, and the other group performed PBCST at home. Exercises were progressed every 2 weeks in both groups. Results: Between groups, the supervised group was mostly superior to the home group (p < 0.05). A significant improvement was noted in all parameters in both groups, except some sub-parameters of postural sway in home PBCST (p < 0.05). Conclusions: Supervised PBCST was determined to be more effective than home PBCST in improving strength, postural control, core stability, physical capacity, and fatigue. Although supervised training is the primary choice, home training can be recommended to patients who have limitations attending supervised sessions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Knee strength weakness is a major problem frequently observed in patients during postoperative rehabilitation following anterior cruciate ligament reconstruction (ACLR). OBJECTIVE: To investigate whether knee strength normalized to muscle volume could better detect side-to-side differences than that normalized to body weight following ACLR. METHOD: This study included 17 patients who had undergone primary ACLR (11.6 ± 2.3 months). Body weight and total muscle volume were measured using a bioelectrical impedance analysis composition scale. Isokinetic knee extension and flexion moment were measured at 60 ∘ /s and 180 ∘ /s, respectively. Bivariate correlation analysis was used to examine correlations between body composition and knee strength. Differences in knee strength between the operated and unoperated legs were analyzed using a paired t -test, which calculated the effect size. RESULTS: There was a significant correlation between knee strength and body weight (r = 0.53–0.67); however, a stronger correlation was observed between knee strength and total muscle volume (ρ = 0.80–0.87). The effect size was larger for knee strength expressed as % total muscle volume than for knee strength expressed as % body weight. CONCLUSION: Strength expressed as % total muscle volume may be more accurate than that expressed as % body weight for detecting side-to-side differences in knee strength following ACLR. [ABSTRACT FROM AUTHOR]

Purpose. Patient satisfaction with total knee replacement has been commonly assessed with self-reported surveys. Up to 19% of patients were dissatisfied with total knee replacement outcomes; however, very little is known about their objective physical abilities. Restoring knee strength is crucial for an increase in functional abilities. Improved balance is an essential measure of total knee replacement success. However, it is unknown how dissatisfied patients differ from satisfied ones with respect to strength and balance abilities. The purpose of this study was to examine how knee flexor and extensor strength and balance abilities differed for dissatisfied total knee replacement patients compared with satisfied patients and healthy controls. Methods. The study involved 9 dissatisfied and 15 satisfied total knee replacement patients and 15 healthy controls. Participants performed isokinetic knee flexion and extension tests at 60°/s and 180°/s using an isokinetic dynamometer. Bilateral and unilateral static and dynamic balance trials employed a Biodex Balance System. Stair ascent/descent tests and a chair rise test served to examine speed of activity. Results. Dissatisfied patients showed reduced peak extension (180°/s) and flexion (60°/s) torque compared with satisfied patients. No balance differences were evident, although an increased percentage of dissatisfied patients were unable to complete the static and dynamic unilateral balance tests. Stair ascent and descent times and pain levels were increased in the dissatisfied group. Conclusions. Strength increase may provide a more symmetrical movement pattern and better function. The inability to balance and longer functional test times indicate reduced functional ability and continuous pain. [ABSTRACT FROM AUTHOR]

BACKGROUND: Strength-power tests are commonly used to monitor performance improvement and to assess preparedness for competition in weightlifters. Previous studies were limited to male weightlifters, consisted of a small number of tests, or used small samples of female weightlifters. OBJECTIVE: The purpose of this study is to determine the strongest indicators of weightlifting performance (WPER) and to reveal the relationships between competition performance and strength-power tests in junior female weightlifters. METHODS: Forty-two female weightlifters (age: 17.8 ± 2.3 years, body mass: 56.6 ± 8.1 kg; height: 156.1 ± 5.8) participated in this study. Participants were tested on a series of performance indicators including Wingate anaerobic power (lower and upper body), isokinetic leg force, vertical jumps, handgrip strength, and isometric leg strength following a national weightlifting competition. Competition performance was calculated with the Sinclair equation. Pearson correlation analysis was used to reveal the relationships between strength-power variables and Sinclair score, and Ridge regression analysis was used to determine the strongest indicators of WPER. RESULTS: The main results showed that Wingate leg peak power (L-PP) and countermovement jump height (CMJ) were the strongest indicators for WPER. They accounted for 74% of the common variance. Additionally, there was a significant correlation between strength-power variables (r = 0.41–0.846) and Sinclair score. CONCLUSIONS: This study's findings suggest that the strongest predictors of WPER are L-PP and CMJ, and these tests can be used to monitor WPER in junior female weightlifters. [ABSTRACT FROM AUTHOR]

Copyright of Spor Hekimligi Dergisi/Turkish Journal of Sports Medicine is the property of Turkish Journal of Sports Medicine / Spor Hekimleri Dernegi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Data about lower extremities' strength and power asymmetries in fencers, and their relationships to fencing performance are limited and inconsistent. OBJECTIVE: The aim of the present study was to investigate asymmetries, between dominant (D) and non-dom (ND) legs of elite young male and female fencers, in relation to performance in fencing specific tests. METHODS: Anthropometric characteristics, unilateral vertical-horizontal jumping, isokinetic strength, lunge and step lunge performances were evaluated in 16 male and 22 female elite fencers. RESULTS: Significant differences between genders were found for all anthropometric measurements (p < 0.05). No significant bilateral asymmetries and gender x laterality effects were observed (p > 0.05). Fencing performance was negatively correlated with the D leg's flexion/extension (F/E) ratio at 300 ∘ /s (r: - 0.564 to - 0.619, p < 0.05). In addition, D leg's F/E ratio at 300 ∘ /s was positively related to lung peak velocity and power in female fencers (r: 0.562–0.649; p < 0.05). Finally, only in female fencers, unilateral triple hop distance was significantly related to lung peak velocity and power (r: 0.442–0.500; p < 0.05). CONCLUSIONS: The results of the present study suggest that the differential activation/movement pattern of the D and ND leg muscles do not lead to anatomical, dynamic and functional lower extremities asymmetries. [ABSTRACT FROM AUTHOR]

The purpose of this study was to understand the impact of lower-extremity strength on the shoulder tackle ability of Chinese elite female rugby players. The impact strength of a tackle and the lower-extremity strength were measured by force sensors and an isokinetic strength tester. The results provide a theoretical reference for the specialized strength training of shoulder tackle techniques, relevant technical learning, and sports injury prevention, as well as for improving the defensive ability of shoulder tackles. The lower-extremity isokinetic strengths of the hip, knee, and ankle and the shoulder tackle impact force of 18 Chinese elite female rugby players were measured at fixed angular velocities of 60 and 180°/s by an IsoMed 2000 strength testing instrument and an impact force tester. SPSS 25 software was used to test for a normal distribution by single-sample Kolmogorov-Smirnov (K-S) and independent-sample t-tests and the Pearson correlation test. The following findings were obtained. (1) The bilateral lowerextremity hip, knee, and ankle flexors and extensors had an extremely significant difference (P < 0.01) at fixed angular velocities of 60 and 180°/s, and the test results of the extensors were greater than those of the flexors. (2) The right knee and left ankle extensors of the lowerextremity isokinetic strength were related to the shoulder tackle impact force. On the basis of these findings, it is suggested that (1) the lower-extremity isokinetic strengths of the front knee and back ankle in dominant-side tackles should be used as indexes to evaluate shoulder tackle ability, and (2) the balanced development of lower-extremity strength can help athletes enhance the defensive capacity of shoulder tackles, promote technical learning, improve the stability of actions, and prevent sports injuries. [ABSTRACT FROM AUTHOR]

Background: When planning rehabilitation and conditioning for performance enhancement and a return to sports after anterior cruciate ligament reconstruction, identifying the elements of physical function associated with single-leg hop is important. The purpose of this study was to clarify the relationship between single-leg hop distances in three directions and knee extensor and flexor strengths at 6 months after reconstruction. Methods: Participants were 47 patients taking part in training sessions for sports involving cutting, pivoting, and jump-landing 6 months after reconstruction using a hamstring tendon. Single-leg hop distances in 3 directions (anterior, lateral, and medial) and isokinetic concentric strengths of knee extension and flexion were assessed at an angular velocity of 60°/s and 180°/s. Simple regression analyses using Spearman's rank correlation coefficient were performed to assess relationships between single-leg hop distances and knee strengths. Results: In the involved limb, correlations between single-leg hop distances in 3 directions and knee strengths were significant (P < 0.01) and correlation coefficients ranged from 0.48 to 0.65. Correlation coefficients between all single-leg hop parameters and knee extension/flexion strengths at an angular velocity of 180°/s were greater than those of 60°/s. Conclusions: In this cross-sectional study of patients who participated in sports training sessions that required jump-landings and cutting approximately 6 months after reconstruction using hamstring grafts, isokinetic knee flexor, and extensor torques were moderately to strongly associated with single-leg hop distances in lateral, medial, and anterior directions. Given these relationships, assessments and exercises for knee strength and single-leg hop distances should be planned. [ABSTRACT FROM AUTHOR]

To study the long-term evolution of patients with lower-limb Complex Regional Pain Syndrome (CRPS), focusing on functional and proprioceptive aspects and quality of life. In 20 patients suffering from chronic distal lower-limb CRPS diagnosed using Budapest criteria, we assessed joint position sense and strength of the knee muscles at the CRPS and unaffected leg, functional exercise capacity, pain, CRPS severity score, quality of life and kinesiophobia. Similar assessments were performed in 20 age-matched controls. The joint position performance (at 45°) was significantly lower for the CRPS leg as compared to controls. The knee extensor strength of the CRPS leg was significantly reduced as compared to the unaffected leg (−27%) and controls (−42%). CRPS patients showed significantly reduced performance at the 6 min-walk test as compared to their age group predicted value and controls. Patients suffering from CRPS for 3.8 years in average still exhibit high pain, severity and kinesiophobia scores. Long-term deficits in strength and proprioceptive impairments are observed at the knee joint of the CRPS leg. This persistent functional disability has significant repercussions on the quality of life. We highlight the importance of including strength and proprioceptive exercises in the therapeutic approaches for CPRS patients. The long-term evolution of patients suffering from lower-limb Complex Regional Pain Syndrome is associated with persistent disability, pain and impacts the quality of life. Strength, proprioceptive, functional and subjective assessments are necessary to better identify deficits. Rehabilitation should focus on the overall deficit of the affected and contralateral limb. [ABSTRACT FROM AUTHOR]

Copyright of Ido Movement for Culture. Journal of Martial Arts Anthropology is the property of Idokan Poland Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study of baseball pitchers was conducted to: 1) investigate the relationship between lower limb muscle endurance and the rate of decrease in delivered ball velocity, and 2) develop a simple field test (FT) for evaluation of lower limb muscle endurance. Eight collegiate baseball pitchers participated, and each threw 50 consecutive balls at intervals of 12 seconds. During this task, the rate of decrease in ball velocity was determined. The muscle endurance required for flexion and extension of the hip and knee joints was measured using an isokinetic dynamometer. The number of repeated back-lunges to exhaustion was used as an indicator of lower limb muscle endurance obtained from the FT. The rate of decrease in ball velocity was significantly correlated with the isokinetic muscle endurance in knee flexion and the number of back-lunge repetitions. The number of back-lunge repetitions was significantly correlated with the isokinetic muscle endurance of knee flexion. These results suggest that 1) pitchers with a low rate of decrease in ball velocity have superior knee flexion muscular endurance, and 2) the FT proposed in this study is useful as a simple test to evaluate the knee flexion muscular endurance related to the rate of decrease in ball velocity. [ABSTRACT FROM AUTHOR]

Background: A considerable portion of the elderly population are increasingly afflicted by degenerative spinal deformity (DSD), which seriously affects patient health-related quality of life (HRQoL). HRQoL index is used across many studies to show correlations between radio-graphical alignment, disability, and pain in patients with DSD. However, imaged structural deformity represents only one aspect for consideration, namely, the disability effect of DSD. We assessed the isokinetic strength of trunk muscle in patients with degenerative spinal deformity (DSD), and investigated its relationship with HRQoL.Methods: In total, 38 patients with DSD (DSD group) and 32 healthy individuals (control group) were recruited. Both groups were homogeneous for age, weight, height and body mass index (BMI). Assessments were performed using the isokinetic dynamometer IsoMed-2000; trunk extensor, flexor strength and flexion/extension (F/E) ratios were explored concentrically at speeds of 30°, 60° and 120° per second. The grip strength of both hands was measured using a hand-held dynamometer. Visual analogue scale (VAS) scores, the Oswestry Disability Index (ODI), a Roland-Morris disability questionnaire (RDQ), and a 36-item Short Form Health Survey (SF-36) evaluated patient HRQoL. Correlations between trunk strength and HRQoL were analyzed.Results: When compared with the control group, the DSD group showed lower trunk extensor strength at three velocity movements, and higher F/E ratios at 60° and 120°/s (p < 0.05). Both groups exhibited similar trunk flexor strength and grip strength (p > 0.05). In DSD group, trunk extensor strength at 60°/s was negatively associated with ODI and RDQ (p < 0.05). A negative relationship between trunk flexor strength at 120°/s and ODI was also recorded (p < 0.05). In addition, trunk extensor strength at 60°/s and trunk flexor strength at 120°/s were positively correlated with physical functioning and role-physical scores according to the SF-36 (p < 0.05).Conclusions: We identified isolated trunk extensor myopathy in DSD, which causes an imbalance in trunk muscle strength. Isokinetic trunk extensor strength at 60°/s and trunk flexor strength at 120°/s can predict disability, and decrease physical HRQoL in DSD patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Neuromuscular electrical stimulation (NMES) is a complementary tool for therapeutic exercise for muscle strengthening and may potentially enhance exercise performance. OBJECTIVE: To determine whether high-intensity interval training (HIIT) and continuous aerobic training (CA) coupled with NMES enhance the changes in the eccentric/concentric muscle contraction patterns of hamstring and quadriceps. METHODS: Forty-five healthy sedentary male participants performed cycling training 3 times per week for 8 weeks combined with/without NMES performed at a load equivalent to 65% and 120% of I VO 2max (intensity associated with the achievement of maximal oxygen uptake). Anthropometrics, blood lactate measurements, I VO 2max , T Lim VO 2max (time-to-exhaustion) and isokinetic strength parameters were measured at baseline and post-training using a randomized controlled trial. RESULTS: The conventional hamstring-to-quadriceps-ratio (HQR: Hcon/Qcon) at 60 ∘ /s and the Dynamic Control Ratio (DCR: Hecc/Qcon) at 180 ∘ /s significantly increased both in the dominant (D) and non-dominant (ND) limb in the HIIT + NMES group (p < 0.05). There was a positive significant correlation between the individual changes in D HQR at 60 ∘ /s and I VO 2max (r = 0.94, p = 0.005) and the DCR at 180 ∘ /s and T Lim VO 2max (r = 0.90, p = 0.015), respectively. CONCLUSIONS: The increases in the eccentric muscle contraction and DCR following HIIT + NMES seem to improve fatigue tolerance, cause less fatigue and oxidative stress on the lower limb during pedaling at high intensities. [ABSTRACT FROM AUTHOR]

Background: Childhood obesity is one of the most critical global health challenges. Poor knee extensor strength is associated with disability and difficulties with physical function in obese patients. The objective of this study was to evaluate the test-retest reliability of peak torque and total work in concentric flexion and concentric extension in obese children. Methods: 25 obese children aged between 6 and 11 years performed 3F maximal unilateral isokinetic repetitions with the knee extensors/flexors performing concentric actions at 60°/s. Peak torque (Nm), total work (J), and the ratio antagonist/agonist were recorded and normalized by total and lean mass. The intraclass correlation coefficient (ICC), standard error of measurement (SEM), and smallest real difference (SRD) were computed. Results: Reliability was excellent for almost all variables. The highest ICC values were observed when work or peak torque were not divided by any other variable. However, SEM (%) and SRD (%) were lower when peak torque and work were divided by the total mass or lean mass. The antagonist/agonist ratio showed an ICC value of 0.873. Conclusion: Peak torque, total work, and the antagonist/agonist ratio are reliable in obese children. [ABSTRACT FROM AUTHOR]

Copyright of Spor Hekimligi Dergisi/Turkish Journal of Sports Medicine is the property of Turkish Journal of Sports Medicine / Spor Hekimleri Dernegi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: The objective of this single-center randomized single-blinded trial was to assess the hypothesis that anterior cruciate ligament reconstruction (ACLR) using a four-strand semitendinosus (ST) graft with adjustable femoral and tibial cortical fixation produced good outcomes compared to an ST/gracilis (ST/G) graft with femoral pin transfixation and tibial bioscrew fixation. Follow-up was 2 years. Methods: Patients older than 16 years who underwent primary isolated ACLR included for 1 year until August 2017 were eligible. The primary outcome measures were the subjective International Knee Documentation Committee (IKDC) score, isokinetic muscle strength recovery, and return to work within 2 years. The study was approved by the ethics committee. Results: Of 66 eligible patients, 60 completed the study and were included, 33 in the 4ST group and 27 in the ST/G group. Mean age was 30.5 ± 8.9 years in the 4ST group and 30.3 ± 8.5 in the ST/G group (n.s.). No significant between-group differences were found for mean postoperative subjective IKDC (4ST group, 80.2 ± 12.5; ST/G group, 83.6 ± 13.6; n.s.), side-to-side percentage deficits in isokinetic hamstring strength (at 60°/s: ST group, 17% ± 16%; ST/G group, 14% ± 11%; n.s.) or quadriceps strength (at 60°/s: ST group, 14% ± 12%; ST/G group, 19% ± 17%; n.s.), return to work, pain during physical activities, side-to-side differential laxity, balance, loss of flexion/extension, or surgical complications. Conclusion: This trial demonstrates that functional outcomes after 4ST for ACLR with cortical fixations could be as good, although not better, than those obtained using ST/G. The 4ST technique spares the gracilis tendon, which thus preserves the medial sided muscle and thereby could improve function and limit donor-side morbidity. Level of evidence: Level I. [ABSTRACT FROM AUTHOR]

Introduction: Ruptures of the anterior cruciate ligament (ACL) can be accompanied by meniscal lesions. Generally, the rehabilitation protocols are altered by meniscal repair. Therefore, the aim of this study was to investigate the effect of meniscal repair on the early recovery of thigh muscle strength in ACL reconstruction (ACLR).Materials and Methods: We performed a matched cohort analysis of n = 122 isolated ACLR (CON) compared to n = 61 ACLR with meniscal repair (ACLR + MR). The subgroups of meniscal repair consisted of 30 patients who had undergone medial meniscus repairs (MM), 19 lateral meniscus repairs (LM) and 12 repairs of medial and lateral meniscus (BM). Isokinetic strength measurement was performed pre-operatively and 6 months post-surgery to perform a cross-sectional and a longitudinal analysis. All injuries were unilateral, and the outcome measures were compared to the non-affected contralateral leg.Results: Six months postoperatively overall there is no significant difference between the groups (extension strength MR 82% vs. CON 85% and flexion strength 86% vs. 88%, resp.). Subgroup analysis showed that medial repairs exhibit a comparable leg symmetry while lateral repairs performed worse with leg symmetry being 76% in extension and 81% in flexion strength. Patients undergoing BM repair performed in between lateral and medial repairs (82% extension, 86% flexion).Conclusion: Generally, meniscal repair in conjunction with ACLR does not significantly alter the recovery of limb symmetry in strength at 6 months postoperatively. Interestingly, medial repairs seem to perform superior to lateral meniscal repair and repair of both menisci. Since the recovery of symmetric strength is a major factor in rehabilitation testing, these results will help to advise surgeons on appropriate rehabilitation protocols and setting realistic goals for the injured athlete.Level Of Evidence: III, retrospective cohort study. [ABSTRACT FROM AUTHOR]

Context: Fatigue of the shoulder rotator muscles may negatively affect joint position sense (JPS) and ultimately lead to injury. Objective: Recovery of shoulder JPS after muscle fatigue. Design: A repeated-measures study. Setting: Musculoskeletal research laboratory. Patients: Thirteen subjects participated in joint position error tests and isokinetic concentric strength assessment in shoulder rotation, before and after rotator muscle fatigue. Interventions: Local muscle fatigue was induced using isokinetic concentric contractions of the shoulder rotator muscles. Main Outcome Measurements: Shoulder rotator strength and JPS error signals were measured before fatigue, immediately after fatigue, and every ten minutes thereafter for one hour. Results: Before shoulder rotation muscle fatigue, the accuracy of shoulder JPS was 2.79 ± 1.67 degrees. After muscle fatigue, the accuracy decreased to 6.39 ± 2.90 degrees. Shoulder JPS was influenced up to 40 minutes after muscle fatigue, but shoulder strength was only affected for 10 minutes after muscle fatigue. Conclusions: Proprioceptive recovery was slower than strength following fatigue of the shoulder rotators. [ABSTRACT FROM AUTHOR]

Competitive swimmers usually undergo large mileage of daily training, in which propulsive force is produced mainly by the upper limbs. Some studies claim that dry-land shoulder rotators injury prevention programs before the in-water swim practice are paramount. However, the effect of shoulder strengthening prior to water training is unclear. This study aimed to analyse the acute effects of training programs conducted on dry land with the goal of preventing shoulder rotators injuries. A group of young swimmers (N = 23) was recruited to participate in this research. The peak torques of shoulder internal and external rotators were assessed before and after the completion of the compensatory strength training program. The isokinetic assessment was performed using two different protocols: 3 repetitions at 60⍛/s and 20 repetitions at 180⍛/s. Except for a trivial reduction in strength after the training program, there were no other significant differences in any of the studied variables (shoulders rotators endurance, strength and muscle balance). All results showed trivial to small effect sizes. Our findings suggest that a compensatory strength training program does not have a significant acute effect on the strength, endurance and muscle balance of shoulder rotators in young swimmers. [ABSTRACT FROM AUTHOR]