Enes Akdemir

Background: After anterior cruciate ligament reconstruction (ACLR), isokinetic strength and single-leg hop tests (SLHT) are used to assess return to sport readiness. This study examined the relationships and predictive effects of isokinetic knee extension (Ex) and flexion (Flx) strength with 5 SLHTs at 6 to 8 months post-ACLR. Hypothesis: There would be significant correlation between knee Ex and Flx strengths on the operated side and 5 different SLHTs; SLHTs would significantly predict knee isokinetic Ex and Flx strength. Study Design: Cross-sectional study. Level of Evidence: Level 3. Methods: Fifty-one male participants underwent unilateral ACLR. Lysholm, International Knee Documentation Committee (IKDC), and Tegner scales were assessed preoperatively and 6 to 8 months postoperatively. At the same follow-up, isokinetic strength at 60°/s, 180°/s, and 240°/s and 5 SLHTs were tested on both limbs. Data were analyzed with paired t tests, Pearson correlations, Fisher’s exact test, and simple linear regression; limb symmetry index (LSI) cut-off was ≥85%. Results: Isokinetic strength and single-leg hop (SH), crossover hop, and medial side triple-hop (TH) distances did not differ significantly between limbs ( P > 0.05), whereas TH and 90° medial rotation hop distances were significantly shorter on the operated side ( P < 0.05). Participants’ Lysholm and IKDC scores improved significantly at 6 to 8 months post-ACLR ( P < 0.001), but Tegner activity level did not change significantly ( P > 0.05). High correlation was found between Ex strength at 60°/s and SH and TH distances on the operated side, and high-moderate correlations were found at 180°/s and 240°/s. Flx strengths showed a similar but slightly lower degree of correlation. Simple linear regression models revealed that especially SH and TH distances significantly predicted both Ex and Flx strengths (adjusted R ² 0.26-0.52; P < 0.001). Among the LSI values, only a significant correlation was found between 60°/s Ex and TH LSI ratio ( P = 0.01). Conclusion: The findings show that SH and TH tests were highly predictive of isokinetic knee strength after ACLR. Clinical Relevance: SLHTs after ACLR can be used as a practical and accessible complement to isokinetic measurements.

This study aimed to examine the associations between gross motor coordination, agility, flexibility, and single-leg hop performance in children aged 12–14 years. A total of 964 healthy children aged 12–14 (47.82% girls, 52.18% boys) participated in the study. To assess children’s motor development levels, the KTK was used; flexibility was measured using the Sit and Reach Test, agility was assessed with the Pro-Agility Test, and three different Single-Leg Hop Tests were used to evaluate lower-extremity functional performance, muscle strength, dynamic balance, coordination, and motor control. Participants’ KTK total, KTK sub-parameter scores, single leg hop for distance, crossover hop for distance, and 90° medial rotation hop test results increased with age and showed significant differences across age groups and gender (p < .001). Agility performance increased significantly with age in both girls and boys, as seen in the reduction in Pro-Agility test times (p < .001). Flexibility improved significantly with age in girls (p < .001), whereas no significant age-related change was observed in boys (p > .05). Additionally, higher motor skill levels were associated with higher single leg hop for distance, crossover hop for distance, rotation hop, and agility scores in both genders, with significant gender differences (p < .001). These findings indicate that motor performance improved significantly with age and was positively associated with gross motor coordination. This finding supports the idea that motor coordination and jumping-based skills develop positively during childhood. The significant increase in agility scores in both girls and boys with age indicates that agility develops with age. In terms of flexibility, gender-based differences have been observed; this suggests that flexibility develops differently depending on gender-specific biomechanical and physiological factors. Cite this article as: Karadeniz, S., Akgün, S., Anıl, B., Akdemir, E., Salkılı., E. K., Kabadayı, M., Kumru, D., & Yılmaz, A. K. (2026). Associations between gross motor coordination and agility, flexibility, and single-leg hop performance in 12–14 year olds. Research in Sports Science, 16, 0025, doi: 10.5152/rss.2026.26025.

Purpose This study aimed to comprehensively compare the effects of peroneus longus tendon (PLT) and semitendinosus tendon (ST) autografts on knee and ankle isometric strength asymmetries, jump performance, postural stability, and patient-reported outcome measures (PROMs) in patients 12 months after isolated anterior cruciate ligament reconstruction (ACLR). Methods In this retrospective study, 98 eligible patients underwent propensity score matching. After dropouts, 60 patients (ST: n = 30; PLT: n = 30) were evaluated 12 months postoperatively. Clinical outcomes were assessed using the International Knee Documentation Committee (IKDC), Lysholm, Tegner, and American Orthopaedic Foot and Ankle Society (AOFAS) scales. Functional assessments included single-leg hop tests (SLHTs), countermovement jump (CMJ), drop jump (DJ), single-leg jump (SLJ), single-leg drop jump (SLDJ), land-and-hold (LH), and single-leg stance (SLS) tests. Isometric strength for knee flexion/extension and ankle plantar flexion/eversion was measured. Two separate 2 × 2 mixed-design ANOVAs were utilized to evaluate time-dependent and inter-limb (operative vs. contralateral) differences across groups. Results Both groups demonstrated significant time-dependent improvements in IKDC, Lysholm, and Tegner scores (p < 0.05), with no significant inter-group differences. However, the PLT group showed significantly higher inter-limb functional asymmetry in SLHTs (14.06%–21.34%) compared to the ST group (3.95%–7.85%). Significant group × limb interactions were observed for knee extension strength (p = 0.025), along with considerable deficits in ankle plantar flexion (p < 0.001) and eversion (p < 0.001) strengths specifically in the PLT group. Inter-limb asymmetry in jump height and landing force was considerably more pronounced in the PLT group in all vertical jump variations. Furthermore, the PLT group showed significantly impaired dynamic stabilization, with longer time to stabilization (TTS) and increased anterior–posterior postural sway during LH and SLS (p < 0.05). Conclusions While subjective clinical scores are comparable, PLT autografts result in significant donor-site strength deficits and increased inter-limb functional asymmetry at the 12-month follow-up. These functional deficits suggest that PLT autografts should be used with caution, particularly in athletes who depend on optimal ankle stability for athletic performance.

Background: To evaluate the short-term clinical and functional effects of local peloid therapy combined with exercise compared with exercise alone in patients with knee osteoarthritis (OA), using routinely collected clinical data. Methods: This retrospective comparative study included 70 patients with knee OA. Patients who received local knee peloid applications (30 minutes/day, 5 days/week for 3 weeks) combined with a standardized home exercise program (peloid + exercise; n = 35) were compared with patients who performed the same exercise program alone (exercise-only; n = 35) as part of routine clinical care. Outcome measures included pain [Visual Analogue Scale (VAS)], function [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score–Physical Function Short Form (KOOS-PS), Oxford Knee Score (OKS)], quality of life [Short Form-36 (SF-36)], functional performance [Five Times Sit-to-Stand Test (5xSTS)], range of motion (ROM), muscle strength, and selected systemic inflammatory markers [high-sensitivity C-reactive protein (hsCRP), tumor necrosis factor-alpha (TNF-α), Interleukin-6 (IL-6)]. Results: Outcome data at week 3 were available for 60 participants (peloid + exercise n = 35; exercise-only n = 25). Both groups showed improvement in pain and functional outcomes, with more pronounced short-term improvements observed in the peloid + exercise group, particularly for pain scores, functional performance, muscle strength, and quality-of-life measures. No consistent between-group differences were observed in systemic inflammatory markers. Conclusions: In this retrospective analysis, the addition of local peloid therapy to exercise was associated with numerically and clinically more pronounced short-term clinical and functional improvements compared with exercise alone, while systemic inflammatory markers showed limited change. These findings support a potential complementary role for local peloid therapy in the short-term rehabilitation of knee OA.

The aim was to investigate the effects of high-intensity calisthenics training (HCT) on the neuromuscular performance, change of direction ability, and dynamic balance of adolescent judokas. Methods: This study used a controlled experimental design that included pre- and post-test measurements. Twenty-two judokas (age 12.54 years, height 1.46 m, weight 42.54 kg and body mass index (BMI) 19.77 kg/m²) voluntarily participated in the study. Participants were randomly assigned to either a control group (CG) or an experimental group (EG). While the CG group continued with routine judo training, the EG group underwent HCT training for 8 weeks in addition to routine judo training. Participants performed the T Agility Test (T-test), 20 m. Sprint Test, Standing Long Jump Test (SLJ), Vertical Jump Test (VJ), Y Balance Test (YBT), and 5 different single-leg hop tests (SLHT) [single-leg hop for distance (SH), triple-leg hop for distance (TH), crossover hop for distance (CH), medial side triple hop for distance (MSTH), and 90° medial rotation hop for distance (MRH)] tests for pre- and post-test measurements. Results: The results of the intra-group comparison of SLHT data before and after intervention showed significant differences in both groups in the SH, TH, MSTH, and MRH tests on the right and left sides (p0.05). The results of both within-group and between-group comparisons in the 20-meter sprint, T-test, SLJ, and VJ tests showed no significant difference (p>0.05). Additionally, the results of the within-group comparisons in the YBT test showed that there were significant differences in the ANT data in both groups, in the PL data only in the EG group, and in the PM data on the left side only in the EG group (p0.05). Conclusions: In conclusion, high-intensity calisthenic exercises incorporated into traditional judo training led to within-group improvements in the experimental group’s dynamic balance performance and single-leg jumping ability. However, since the group × time interaction was not found to be significant in between-group comparisons, the observed improvement cannot be attributed solely to calisthenic exercises. Therefore, future studies with larger sample sizes and longer intervention periods are recommended. Additionally, coaches and athletes may consider integrating calisthenic exercises into training programs to support strength development and performance enhancement.

Background: Small-sided games (SSG) and running-based high-intensity interval training (HIIT) are commonly used in soccer conditioning to improve aerobic fitness and performance. Although both modalities induce high cardiovascular stress, their acute neuromuscular, perceptual, and cognitive responses remain incompletely understood when examined within the same cohort. This study compared the acute physical, psychophysiological, and cognitive responses to SSG and Tabata-type HIIT in amateur male soccer players. Methods: Thirty-two male amateur players (n = 32; age: 20.53 ± 1.65 years) completed a counterbalanced within-subject crossover design. Participants performed a 4v4 SSG protocol and a running-based Tabata-HIIT protocol (8 × 20 s, 10 s recovery) on separate days (48 h apart). Countermovement jump (CMJ), squat jump (SJ), 20-m sprint, agility t-test, heart rate, perceived exertion (Borg CR-10), mental effort, and cognitive performance (d2 test) were assessed pre- and post-exercise. Parametric variables were analyzed using 2 × 2 repeated-measures ANOVA (time × protocol; η²p), and non-parametric data were analyzed using Friedman and Wilcoxon tests (r) (p < 0.05). Results: Both protocols elicited similar cardiovascular responses (~90% HR_max). A significant protocol × time interaction was observed for CMJ (p < 0.001), showing a decline after Tabata-HIIT, whereas performance was maintained after SSG. No inter-protocol differences were found for SJ, sprint, or agility. Perceived exertion and mental effort during recovery were higher following Tabata-HIIT (p < 0.05). Cognitive performance improved after both protocols (p < 0.001), with no between-protocol differences. Conclusions: Despite comparable cardiovascular load, Tabata-HIIT was associated with greater acute neuromuscular and perceptual strain, whereas SSG preserved neuromuscular performance. Perceptual and mental responses may therefore differ despite similar physiological intensity, which may inform soccer training prescription.

This study aimed to investigate the potential relationship between maturity offset and cardiopulmonary responses, and to determine at which relative time points these responses differ markedly throughout the exercise duration. Ninety-two trained youth male soccer players performed progressive cycling to exhaustion on an ergometer with simultaneous breath-by-breath assessment of key cardiopulmonary parameters, including oxygen uptake (VO ₂ ), carbon dioxide production (VCO ₂ ), minute ventilation (VE), oxygen saturation (SpO ₂ ), heart rate (HR), and heart rate reserve (HRR). The quantile and functional concurrent regression analyses revealed that maturity offset significantly and variably associated with the magnitude, distribution, and time-dependent changes in cardiopulmonary responses. The findings revealed maturity-dependent cardiopulmonary response patterns; VO ₂ and VCO ₂ showed positive maturity effects across all quantiles, and inter-individual variability decreased with advancing maturation as the lower (τ = 0.10) and upper (τ = 0.90) quantiles converged toward the median at later maturity stages. Furthermore, functional concurrent regression analyses revealed that relationships with maturity offset were more pronounced in VO ₂ and VCO ₂ from the 10% iso-time onward (p < 0.001), and in VE from the 40% iso-time onward (p < 0.001). In contrast, estimated maturity offset effects on VO ₂ peak, HR and HRR were only transient, appearing in early-to-mid exercise stages (p < 0.050) but diminishing toward later time points. These findings suggest that maturity advantages in cardiopulmonary responses become more pronounced at starting or relatively moderate intensities (≥10−40% of iso-time points), whereas cardiovascular capacity showed smaller differences and tended to converge toward maximum effort. Practitioners should consider maturity offset when interpreting CPET profiles in youth athletes.

The menstrual cycle (MC) is a process in the female reproductive system that recurs at regular intervals from puberty to menopause, thereby rendering the uterus suitable for potential pregnancy. Th...

Background: The purpose of this study was to examine the effects of an 8-week core training program on the lower-extremity, upper-extremity, and core strength of judokas. Methods: This study is based on a pre-test/post-test experimental design involving repeated measures and a control group. The study was conducted with the voluntary participation of 20 judo athletes (10 females and 10 males) aged between 18 and 22 years (mean age: 18.60 years; height: 163 cm; body weight: 59.40 kg; BMI: 22.30 kg/m²). Participants were divided into two groups: a control group that continued routine judo training and an experimental group that performed core training in addition to routine judo training. Participants performed Medial Push-Ups (MPUs) to assess upper-extremity muscle strength; sit-ups and Plank Tests (PTs) to assess core strength; five different Single-Leg Hop Tests (SLHTs) to assess lower-extremity muscle strength; and the Y Balance Test (YBT) to assess balance. These tests were conducted before and after the 8-week core training program. Results: PT performance improved significantly in both groups, with a significant group × time interaction (p < 0.001, η²p = 0.623), indicating greater improvement in the core training group compared to the control group. No significant interaction was observed for MPU and Sit-up tests; however, a significant main effect of time was detected for MPU (p = 0.032, η²p = 0.231), suggesting general improvements in both groups. For SLHT parameters, no significant group × time interactions were detected (p > 0.050); improvements were observed over time across groups. In balance performance, a significant group × time interaction was found only in the NDS postero-medial (PM) direction (p = 0.020, η²p = 0.267), whereas the other parameters demonstrated time-related improvements without between-group differences. Conclusions: Core stability training resulted in greater improvements in PT performance and influenced balance performance in the NDS PM direction. Improvements observed in other performance parameters appeared to be time-related rather than intervention-specific. Overall, core stability training may contribute to core endurance and certain aspects of lower-extremity function in judokas.

The aim of this study was to investigate the effect of circadian rhythmicity (CR) on lower extremity strength and balance performance in 22 female athletes (19-24 y). Participants underwent isokinetic knee strength, Single Leg Hop Tests (SLHT), Y Balance Test (YBT), and isokinetic static/dynamic balance tests. All measurements were randomized and performed at 9:00, 14:00, and 19:00 to assess CR variation. In total, 3 angular strength, 5 jump, and 2 balance tests were analyzed. When comparing results across time zones, body temperature, isokinetic 60°/sec extension (Ext) strength, and several bipedal static balance parameters Forward-Backward Standard Deviation (SBFD), Average Forward-Backward Speed (AFBS), and Ellipse Area (EA)) showed statistical significance (p>0.05). No significant differences were found in other isokinetic strength tests, all SLHTs, Y balance, or dynamic balance tests (p>0.05). Significant CR effects on lower extremity strength were observed only in the 60 sec extension, with overall strength peaking at 14:00. Strength asymmetry remained similar across time points. These findings suggest that time-sensitive performance parameters like strength and static balance are influenced by CR, while balance and coordination parameters appear more stable. Accordingly, scheduling strength-based training during midday hours may optimize performance by leveraging CR-related variations.