Search Results (371)

Background: This study examines balance, flexibility and self-esteem among healthy individuals who engage in surfing compared to those who do not surf. Methods: A cross-sectional study design was conducted with 124 participants divided into the following groups: Group 1: Surfers n = 42; Group 2: individuals performing over 3 h of physical activity per week n = 43; and Group 3: individuals performing fewer than 3 h of physical activity per week n = 39. To assess balance, the Star Excursion Balance Test (SEBT) and the Flamenco Test (FBT) were used, the sit-and-reach test (SRT) was used to measure hamstring extensibility, the Rosenberg Scale was used to measure self-esteem, and the International Physical Activity Questionnaire (IPAQ) was used to measure physical activity levels. Results: Regarding descriptive characteristics, G1 participants were significant older than those of G2 and G3 (p < 0.05 and p < 0.001, respectively). Moreover, there was a higher proportion of females in G3 than in G1 and G2 (p < 0.05). The results revealed significant differences in balance between the surfers and those engaging in fewer than 3 h of activity per week (p < 0.05). G1 obtained significantly higher results in SEBT-left leg than G2 and G3 (p < 0.001) and higher result in SEBT-right leg and FBT than G3 (p < 0.05) but no significant differences in self-esteem were found. Significant differences in flexibility were observed between males and females (p < 0.001). Conclusions: This result suggests that surfing could have a positive effect on balance. Full article

Background/Objectives: The co-existence of multiple compression sites on the same nerve can pose a clinical and diagnostic challenge, warranting a different treatment strategy. This so-called double crush syndrome (DCS) has mainly been investigated in the upper limb. Only a few studies have investigated DCS for the lower limb. In this article, a single-center illustrative clinical case series is presented, and current literature on L5 nerve root (NR) and concomitant common peroneal nerve (CPN) is reviewed. Methods: All patients presenting between 2019 and 2022 with L5 nerve root (NR) compression and, along their clinical courses, concomitant compression of the common peroneal nerve (CPN) at the fibular head were included. Information on clinical features, diagnostics and surgeries was obtained. The outcome was assessed at the last outpatient follow-up appointment. In addition, an extensive literature review has been conducted. Results: Fourteen patients were included with a mean follow-up of 6.8 months. The majority had pain (71%) or motor deficits (71%). Seven patients were referred for clinical and radiological L5 NR compression but were also found to have CPN compression; the other seven patients had persisting or recurrent symptoms after surgically or conservatively treated L5 NR compression, suggestive of additional peroneal neuropathy. All patients had CPN decompression at the fibular head, with successful results obtained in 93% of the patients. Pain of the lower leg improved in all patients, and dorsiflexion function improved in 78%. Conclusions: Concomitant L5 NR and CPN appear to occur more frequently than expected. Peroneal neuropathy can present simultaneously with L5 nerve radiculopathy or after surgically or conservatively treated L5 NR compression. Overlapping symptoms and variation in clinical presentations make it difficult to diagnose and, therefore, underrecognized. More awareness among treating physicians of this specific double crush syndrome is important to prevent any delay in treatment, in this case, a less invasive common peroneal nerve release at the fibular head, and to avoid unnecessary (additional) spinal surgery. Full article

Central pattern generators (CPGs) have been extensively researched and validated as a well-established methodology for bionic control, particularly within the field of legged robotics. However, investigations concerning octopod robots remain relatively sparse. This study presents the design of an octopod robotic system inspired by the biological characteristics of lobsters. The machine lobster utilizes remote sensing technology to execute designated tasks in subterranean and mining environments, with its motion regulated by CPGs, accompanied by a comprehensive simulation analysis. The research commenced with the modeling of a biomimetic lobster robot, which features a three-degree-of-freedom leg structure and torso, interconnected by shape memory alloys (SMAs) that serve as muscle actuators. Mathematically, both forward and inverse kinematics were formulated for the robot’s legs, and a 24-degree-of-freedom (DOF) gait pattern was designed and validated through MATLAB 2020a simulations. Subsequently, a multi-layer mesh CPG neural network model was developed utilizing the Kuramoto model, which incorporated frustration effects as the rhythm generator. The control model was constructed and evaluated in Simulink, while dynamic simulations were conducted using Adams 2022 software. The findings demonstrate the feasibility, robustness, and efficiency of the proposed CPG network in facilitating the forward locomotion of the lobster robot, thereby broadening the range of control methodologies applicable to octopod biomimetic robots. Full article

Background and Objectives: This study aims to investigate the relationship between isokinetic knee strength and competition performance in elite male ski mountaineering sprint athletes and to identify strength parameters that predict performance and contribute to injury prevention. Materials and Methods: Thirteen male athletes participating in the Ski Mountaineering Turkey Cup final stage were included. Isokinetic knee flexion (FLX) and extension (EXT) strength of dominant (DM) and non-dominant (NDM) legs were measured at angular velocities of 60°/s and 180°/s using the DIERS-Myolin Isometric Muscle Strength Analysis System. Competition performance was evaluated using the ISMF scoring system. Data were analyzed using SPSS 26.0 with Pearson correlation and multiple regression analyses after normality, linearity, and homoscedasticity checks. Results: Strong positive correlations were found between hamstring strength at high angular velocities (180°/s) and performance (DM FLX: r = 0.809; NDM FLX: r = 0.880). Extension strength showed moderate correlations at low velocities (60°/s) (DM EXT: r = 0.677; NDM EXT: r = 0.699). Regression analysis revealed that DM FLX at 180°/s and DM EXT at 60°/s explained 49% of performance variance (Adj. R² = 0.498). For NDM legs, only 180°/s FLX was a significant predictor (β = 1.468). Conclusions: High-velocity hamstring strength plays a critical role in ski mountaineering sprint performance, particularly during sudden directional changes and dynamic balance. Quadriceps strength at low velocities contributes to prolonged climbing phases. Moreover, identifying and addressing bilateral strength asymmetries may support injury prevention strategies in elite ski mountaineering athletes. These findings provide scientific support for designing training programs targeting explosive hamstring strength, bilateral symmetry, and injury risk reduction, essential for optimizing performance in the 2026 Winter Olympics sprint discipline. Full article

Background: The efficacy of postoperative exercise rehabilitation after spine surgery is controversial, and a protocol for exercise treatment and detailed outcomes based on functional activity have not yet been established. This study aimed to determine the efficacy of exercise rehabilitation after lumbar spine surgery. Methods: A prospective, randomized controlled trial was conducted in 40 patients who underwent lumbar spine surgery (20 patients each in the exercise and control groups) for 12 weeks. Clinical outcomes were assessed using the visual analog scale (VAS) for pain and EuroQol-5 Dimensions 5-Level version (EQ-5D-5L). Body proportions, including body mass index, total muscle mass, and body fat percentage were analyzed. Functional activity was evaluated based on the range of motion of the lumbar spine, strength and endurance of lumbar flexion/extension, flexibility, 6 min walking test, single-leg stance, coordination, and gait pattern analysis. Results: The exercise group showed significantly greater improvement in VAS for pain (66.67% versus 20.00%, p < 0.001) and EQ-5D-5L (45.56% versus 20.00, p = 0.039) compared to the control group. Serial assessment revealed significant improvement in strength of lumbar flexion/extension, 6 min walking test, single-leg stance, coordination, and gait patterns in the exercise group compared to the control group. In particular, the single-leg stance time for the affected leg improved more markedly in the exercise group (280.9% versus 48.7%, p < 0.001). Conclusion: Tailored postoperative exercise after lumbar spine surgery is effective in reducing pain and enhancing functional recovery, including strength and balance. Full article

This study aimed to (1) determine and compare the magnitude and direction of asymmetry in lower limbs neuromuscular properties, range of motion, strength and muscle electrical activity (EMG) in well-trained male road cyclist across categories (elite, under-23 and junior); (2) establish test- and age-specific asymmetry thresholds for these variables to enable individualized classification; and (3) examine the relationship between these lateral asymmetries and performance in a maximal incremental cycle ergometer test. Fifty-five well-trained road cyclists were assessed through tensiomyography (TMG), active knee extension test (AKE), leg press and EMG of vastus lateralis (VL-EMG) during a maximal incremental cycling test. Junior cyclists showed lower asymmetry in VM than elite cyclists, but greater asymmetry in AKE. No significant differences were found in strength or VL-EMG during the maximal incremental cycle ergometer test. The magnitude and direction of lateral asymmetry differs between tests (TMG: 11.3–21.3%; AKE: 2.3%; leg-press: 9.8–31.9%; VL-EMG: 20.8–22.7%). Multiple linear regression revealed a significant predictive model for maximal incremental cycling ergometer performance based on lateral asymmetry in AKE, leg press and VL and rectus femoris contraction time (R²_a = 0.23). These reference data can support trainers in monitoring and managing lateral asymmetry throughout the cyclists’ season. Full article

Background/Objectives: Beetroot juice is a popular nutritional resource in sports due to its ergogenic effects, promoting vasodilation, hypotension, improved energy efficiency, and reduced oxygen cost. However, its role in modulating the autonomic nervous system during strength training remains understudied. This study assessed the effects of acute nitrate-rich beetroot juice supplementation on cardiovascular and hemodynamic responses to flywheel resistance exercise. Methods: Fifteen male participants (age 22 ± 3.64 years) from the Federal University of Viçosa completed a crossover, double-blind, placebo-controlled trial. Each participant consumed either 400 mg of standardized nitrate or a placebo before performing 4 sets of 8–12 repetitions at 100% of their maximum concentric strength using a leg extension exercise, with 90 s recovery intervals. Heart rate, blood pressure, oxygen saturation, and subjective perception of effort were measured after each set. Data were analyzed using SPSS 23, employing the Shapiro–Wilk normality test, t-test for related samples, and MANOVA with time and supplement factors. Results: NO₃⁻ supplementation led to a smaller increase in systolic blood pressure (SBP) during exercise compared to the placebo and reduced diastolic blood pressure (DBP) in the last set, reflecting decreased peripheral vascular resistance. However, no significant effects were observed for heart rate, rate–pressure product, oxygen saturation, time under tension, or subjective perception of effort. Conclusions: These findings suggest that NO₃⁻ supplementation can offer cardiovascular benefits by attenuating blood pressure increases during strength training, highlighting its potential as a low-risk ergogenic aid for healthy young men. Full article

Background/Objectives: Despite extensive research on caffeine’s (CAF’s) ergogenic effects, evidence regarding its impact on anaerobic performance in female athletes remains limited and inconclusive. The aim of this study was to investigate the acute effects of 6 mg/kg⁻¹ caffeine on anaerobic performance, functional strength, agility, and ball speed in female soccer players. Methods: A randomized, double-blind, placebo-controlled crossover design was employed. Thirteen moderately trained female soccer players (age: 21.08 ± 1.11 years; height: 161.69 ± 6.30 cm; weight: 59.69 ± 10.52 kg; body mass index (BMI): 22.77 ± 3.50 kg/m²; training age: 7.77 ± 1.16 years; habitual caffeine intake: 319 ± 160 mg/day) completed two experimental trials (caffeine vs. placebo (PLA)), separated by at least 48 h. Testing sessions included performance assessments in vertical jump (VJ), running-based anaerobic sprint test (RAST), bilateral leg strength (LS), handgrip strength (HS), single hop for distance (SH), medial rotation (90°) hop for distance (MRH), change of direction (COD), and ball speed. Rating of perceived exertion (RPE) was also recorded. Results: CAF ingestion significantly improved minimum (p = 0.011; d = 0.35) and average power (p = 0.007; d = 0.29) during RAST. A significant increase was also observed in SHR (single leg hop for distance right) performance (p = 0.045; d = 0.44). No significant differences were found in VJ, COD, ball speed, LS, HS, SHL, MRHR, or MRHL (p > 0.05). RPE showed a moderate effect size (d = 0.65) favoring the CAF condition, though not statistically significant (p = 0.110). Conclusions: In conclusion, acute CAF intake at a dose of 6 mg/kg⁻¹ may enhance anaerobic capacity and lower-limb functional strength in female soccer players, with no significant effects on jump height, agility, or upper-body strength. Full article

Bilateral (BL) and unilateral (UL) muscle actions are commonly incorporated in training programs to achieve distinct goals, however, the mechanisms driving modality-specific training adaptations remain unclear. This study examined peak force, electromyographic (EMG) amplitude (AMP), and mean power frequency (MPF) of the non-dominant leg during isokinetic leg extensions performed as either a BL or BLUL combined modality. Twelve recreationally trained men (Mean ± SD; age = 20.8 ± 1.7 years; weight = 83.1 ± 15.7 kg; height = 178.2 ± 7.8 cm) attended 2 test visits that included BL and UL maximal isokinetic leg extensions at 180°·s⁻¹ followed by a fatiguing task of either 50 BL or 25 BL followed immediately by 25 UL (BLUL) maximal, isokinetic leg extensions at 180°·s⁻¹, in random order on separate days. The results demonstrated a 33.3% decline in peak force with a concomitant increase in EMG AMP across the fatiguing task, but there were no significant differences between conditions. For EMG MPF, the BLUL condition exhibited a 19.39% decline versus a 10.97% decline in the BL condition. Overall, the present study suggested there were no significant differences in neuromuscular activation strategies between the tested modalities. However, our findings indicated that incorporating UL muscle actions after a BL task may induce a greater degree of peripheral fatigue compared to sustained BL muscle actions. Practitioners might consider implementing UL exercises at the end of a training bout to induce greater metabolic stress. Full article

Background: Total Hip Replacement (THR) is a standard treatment for advanced hip osteoarthritis; yet, its effects on gait recovery remain understudied. This study examines gait pattern changes in women undergoing monitored rehabilitation after unilateral THR, using Statistical Parametric Mapping (SPM) to detect significant motion differences over time. Methods: This longitudinal study included 32 women who underwent primary cementless THR. Gait was assessed preoperatively and postoperatively at 6 weeks, 3 months, 6 months, and 12 months using a motion analysis system. Repeated measures ANOVA and post hoc SPM{t} analyses were conducted to evaluate significant gait changes across time points. Results: Significant improvements (p < 0.05) were observed in spatio-temporal parameters. Velocity increased from 0.42 ± 0.10 m/s (Ex1) to 0.72 ± 0.06 m/s (Ex5), stride length from 0.85 ± 0.12 m to 1.15 ± 0.07 m, and step length (involved leg) from 0.32 ± 0.08 m to 0.48 ± 0.05 m. Cycle time decreased from 1.50 ± 0.20 s to 1.22 ± 0.10 s, indicating improved gait efficiency. Post hoc SPM{t} analysis revealed significant kinematic changes in hip flexion-extension, knee flexion, and pelvic tilt, particularly between Ex2 and Ex3. Statistically significant improvements (p < 0.001) were observed in key spatio-temporal parameters. Conclusions: Gait parameters improved significantly within the first year post-THR, with the most pronounced changes occurring between the early and mid-term recovery phases. These findings support the need for targeted rehabilitation strategies in the first six months post-surgery. SPM analysis provides a robust method for detecting subtle gait adaptations, contributing to the refinement of post-THR rehabilitation strategies. Full article

Hydraulic legged robots, with advantages such as high load capacity and power density, have become a strategic driving force in advancing intelligent mobile platform technologies. However, their high energy consumption significantly limits long-duration endurance and efficient operational performance. In this paper, inspired by the excellent autonomous energy-efficient consciousness of mammals endowed by natural evolution, a bionic energy-efficient inverse kinematics method based on neural networks (EIKNN) is proposed for the energy-efficient motion planning of hydraulic legged robots with redundant degrees of freedom (RDOFs). Firstly, the dynamic programming (DP) algorithm is used to solve the optimal joint configuration with minimum energy loss as the goal, and the training data set is generated. Subsequently, the inverse kinematic model of the leg with minimum energy loss is learned based on neural network (NN) simulation of the autonomous energy-efficient consciousness endowed to mammals by natural evolution. Finally, extensive comparative experiments validate the effectiveness and superiority of the proposed method. This method not only significantly reduces energy dissipation in hydraulic legged robots but also lays a crucial foundation for advancing hydraulic legged robot technology toward high efficiency, environmental sustainability, and long-term developmental viability. Full article

This study examines the impact of support leg kinematics on kicking performance and its direct relationship with ball velocity and spin. Seventy-eight players performed maximal instep kicks each with their preferred and non-preferred leg, which were recorded with a three-dimensional motion capture system. Linear mixed models were used to analyze the effects of discrete data of lower limb on ball velocity and spin. Professional male players exhibited significantly smaller hip internal-external rotation range of motion (ROM) and angular velocity compared to other groups (p < 0.05). In professional players, the preferred leg kicks showed greater knee flexion-extension ROM, flexion angular velocity, and extension angular velocity than the non-preferred leg kicks (p < 0.01). Regression analysis revealed that hip and knee extension angular velocities, as well as knee flexion-extension ROM, positively influenced kicking performance, while hip adduction-abduction ROM had a negative impact. These findings emphasize the critical role of the support leg in modulating ball velocity, ball spin, and stability during instep kicking. Training should prioritize hip and knee extension strength for power generation and frontal plane stability for postural control. This study offers novel insights into support leg kinematics across competitive levels, with implications for coaching and performance enhancement. Future research should explore phase-specific support leg dynamics during kicking. Full article

Innovative demand-responsive transport services are spreading in most urban areas, allowing dynamic matching between demand and supply and enabling travellers to request shared rides in real-time via mobile applications. They are used both as an alternative to public transport and as an access/egress leg to mass transit stations, i.e., acting as a feeder service. In low-demand areas and small-sized cities, it is often difficult to provide effective and cost-efficient public transport, thus resulting in an extensive use of private vehicles. Using an agent-based modelling approach, this study compares the performance of fixed-route transit (FRT) and demand-responsive transit (DRT), where optional stops can be activated on demand. The aim is to identify the conditions allowing DRT to become more advantageous than FRT in small-sized cities, both for travellers and the transport operator. A real-time matching algorithm identifies optimal trip chains (i.e., public transport lines; pick-up, drop-off and transfer stops; and time windows) for travel requests, dynamically updating vehicles’ routes and schedules. The model is applied to the city of Caltanissetta, Italy, where a transit service with six FRT urban lines is currently operating. Travel patterns were reconstructed from thousands of travel requests collected by a Mobility-as-a-Service platform within one-year. The main findings demonstrate the benefits of DRT in providing a higher quality of service, reducing riding times for passengers, and enhancing service efficiency without burdening operating costs. The DRT reduced the vehicle-kilometres travelled by up to 5% compared to FRT while decreasing passenger ride times by approximately 10%. An economic analysis showed reductions in operator unit costs of up to 3.4% for low-demand rates, confirming the advantages of flexible operations in small-sized cities. Full article

Background: Total knee arthroplasty (TKA) is a widely performed procedure to alleviate pain and restore function in patients with advanced knee osteoarthritis. Two common implant designs are cruciate-retaining (CR) and posterior-stabilized (PS) knees. Despite extensive research, the superiority of one design over the other remains inconclusive. Methods: A prospective analysis was conducted on 123 patients who underwent total knee arthroplasty (TKA) between June 2022 and June 2023 at a university hospital. Demographic data, mobility, the use of walking aids, pre- and postoperative range of motion and leg axis as well as surgical and systemic complications were collected and compared between CR and PS-TKA. Results: The mean age of the patients was 67.94 ± 10.14 years and 65.9% were women. The time of operation was significantly different between PS- and CR-TKA (PS: 83.31 ± 25.65 min; CR: 95.26 ± 24.61 min; p = 0.011). The pre- to postoperative leg axis after six months was significantly different in both groups (PS: 7.06° ± 4.76°; CR: 6.25° ± 3.13°; p = 0.001). The range of motion (ROM) (PS: 105.19° ± 15.56°; CR: 93.29° ± 15.09°; p = 0.001) as well as the deficit after six months (PS: 23.56° ± 19.73°; CR: 37.57° ± 23.33°; p = 0.003) between patients with PS and CR-TKA were significantly different. Gender (male vs. female PS/CR) and age (<75 years vs. >75 years PS/CR) differences were shown for the ROM and flexion deficit after six months (p = 0.003; p = 0.005). For age, a significant difference was shown for the quality of life (mean ranks: <75 y: 47.96; >75 y: 31.03; p = 0.009) and WOMAC score (mean ranks: <75 y: 38.27; >75 y: 61.75; p = 0.001) after six months. Conclusions: This study shows the different outcomes for posterior-stabilized versus cruciate-retaining TKA with regard to time of surgery, range of motion, and flexion deficit after 6 months with PS-TKA yielding better results. The gender analyses revealed similar outcomes after six months between both arthroplasty groups, whereas the age analyses revealed significant differences. The standardized use of PS-TKA for the elderly is recommended. Full article

This study aims to evaluate the reliability and validity of the Leg Strength Analyzer (IB-LS) in assessing isometric knee flexion and extension strength in elderly adults, compare its performance with that of the CSMI dynamometer, and examine its agreement with isokinetic knee strength measurements. A total of 21 elderly participants (mean age: 65.10 ± 4.56 years) were recruited. Participants underwent knee flexion and extension strength assessments using both the IB-LS and CSMI devices, with isokinetic strength at 60°/s measured in a follow-up session at least one day later. The IB-LS demonstrated high test–retest reliability in elderly adults (ICC = 0.856–0.987). The validity analysis comparing IB-LS isometric peak torque with CSMI isometric peak torque showed moderate to high validity (ICC = 0.826–0.946). Furthermore, IB-LS isometric peak torque and CSMI isokinetic 60°/s peak torque demonstrated high agreement (ICC = 0.775–0.881), demonstrating its strong association with isokinetic strength assessments. Bland–Altman analysis revealed that mean differences between IB-LS and CSMI isometric peak torque values ranged from 13.2 to 93.5 Nm, with limits of agreement (LoA) spanning from −55.8 to 192.5 Nm. When comparing IB-LS isometric peak torque with CSMI isokinetic 60°/s peak torque, mean differences ranged from 31.0 to 56.0 Nm, with LoA from −28.5 to 138.9 Nm. The IB-LS is a reliable and valid tool for evaluating isometric knee strength in elderly adults. Its strong agreement with the CSMI dynamometer and close correlation with isokinetic strength measurements indicate that IB-LS can be a feasible alternative for assessing knee strength in clinical and research settings focused on elderly populations. Full article