Background: Large maximum hip flexion and extension range of motion is considered effective in preventing injury in pole vaulters. Nonetheless, whether the improvement in hip flexion and extension range of motion changes their hip joint angle during pole vaulting remains unclear. Objectives: The present study aimed to clarify the acute effects of intervention for hip flexion and extension range of motion in pole vaulters on the maximum hip joint angle during pole vaulting. Methods: Seventeen male pole vaulters who underwent the same intervention for hip range of motion were included. The maximumhip joint angle during the pole vault from the touchdown of the last step of the run-up to the pole straightening was calculated from videos taken pre-and post-intervention and was subsequently compared. The pole vaulters cleared bungee bars that were set at the height of 90% of their personal best record. Three types of self-massages were used to improve the hip flexion and extension range of motion, and an active straight leg raise exercise was also performed. All intervention programs were completed in approximately 25 min on an experimental day, and all interventions were monitored by the examiner. Results: No significant improvements were observed between pre and post-intervention hip range of motion. The magnitude of change in the range of motion of active hip flexion was significantly correlated with the magnitude of change in the maximum hip flexion angle during pole vaulting pre-and post-intervention (P = 0. 002, r = 0. 687). Conclusions: Athletes should find ways to improve their active range of motion to prevent injuries and improve their performance. Coaches and athletic trainers should adopt an active range of motion as an indicator to control athlete conditioning.

Background: Osteoporosis is a disease, which causes bone loss and fractures. Although glucocorticoids effectively suppress inflammation, their chronic use is accompanied by bone loss with a tendency toward secondary osteoporosis.Objectives: This study took into consideration the importance of cortical bone in the entire bone's mechanical competence. Hence, the aim of this study was to assess the effects of different protocols of glucocorticoid administration on the biomechanical properties of tibial bone diaphysis in rats compared to control and low-level laser-treated rats.Materials and Methods: This experimental study was conducted at Shahid Beheshti University of Medical Sciences, Tehran, Iran. We used systematic random sampling to divide 40 adult male rats into 8 groups with 5 rats in each group. Groups were as follows: 1) control, 2) dexamethasone (7 mg/week), 3) dexamethasone (0.7 mg/week), 4) methylprednisolone (7 mg/kg/week), 5) methylprednisolone (5 mg/kg twice weekly), 6) dexamethasone (7 mg/kg three times per week), 7) dexamethasone (0.7 mg/kg thrice per week), and 8) low-level laser-treated rats. The study periods were 4-7 weeks. At the end of the treatment periods, we examined the mechanical properties of tibial bone diaphysis. Data were analyzed by statistical analyses.Results: Glucocorticoid-treated rats showed weight loss and considerable mortality (21%). The biomechanical properties (maximum force) of glucocorticoid-treated rats in groups 4 (62±2.9), 6 (63±5.1), and 7 (60±5.3) were comparable with the control (46±1.5) and low-level laser-treated (57±3.2) rats.Conclusions: In contrast to the findings in humans and certain other species, glucocorticoid administration caused anabolic effect on the cortical bone of tibia diaphysis bone in rats.

Introduction Devices that allow using the functionality of natural hand movements are of the greatest interest. The purpose of this study was to select areas of research at the intersection of several fields of science –,biomechanics and cybernetics to develop scientific and technical approaches to track the movements of the operator’, s fingers and form feedback tactile and force communication received from the control object to achieve a new level of accuracy in work with virtual and with real objects by converting virtual contact action into physical. Methods of force feedback were implemented according which they can be divided into two groups: active and passive feedback. The main technologies used to implement various functionalities of the virtual reality glove were identified: measuring hand positions and feedback generation. The main advantages of the planned development were also identified: the ability to digitize up to 16 finger joints, tactile and force feedback, and moderate cost, a benchmark for the mass market. on R commander 3. 4. 1 was used with the Kruskal-Wallis h-criterion and Pearson’, s χ, ²,-test. Conclusion The development of the design of the glove will be implemented using a kinematic scheme based on the kinematics of the human hand, considering the requirements of aesthetics and ergonomics of the solution. As a sensor system, it is planned to use digital Hall sensors with a capacity of up to 14 bits, high speed and, at the same time, small dimensions, allowing them to be installed directly inside the swivel joints.

Background: The aim of this study was to assess the isokinetic measures of surgically repaired ruptures of the pectoralis major muscle in contrast to non-injured side of the patients and specify the most affected movement of the injured side.Methods: Nine pectoralis major muscle tears in nine patients were studied. They were all operated by the same surgeon and after 2.4 years (1-4 years) of follow up they were clinically examined. They completed a standard questionair and isokinetic dynamometry were carried out bilaterally. There was also a group of six non-injured bodybuilders who were assessed by isokinetic dynamometry to give us normal differences in the values of both limbs.Results: In the patient group, the mean torque of flexion was not different between the injured and uninjured sides (p≥.05). For the extension movements, the difference was significant (p<.034) but for the other movements was not. None of the results fell into the excellent or poor categories according to Kakwani classification. Six patients were categorized as good and three patients as fair. The main reason for the three “fair” patients was cosmetic complaints in the cases who were operated on three months post injury.Conclusions: The surgical repair of ruptured pectoralis major is beneficial and focusing on strengthening exercises for flexion and extension is essential to achieve the best results.

Objectives: The aim of this study was to evaluate the validity and reliability of introducing a new activity-based balance index using a triaxial accelerometer during activity. Methods: Twenty seven soccer players (age: 14. 5  0. 4 years old, body mass: 58. 3  9. 3 kg, height: 172  8 cm) who participated in the national premier league were recruited. The participants were tested for their balance, activity, and skill in four tests: (I) one leg stance; (II) dynamic Y balance; (III) running; and (IV) dribbling slalom. The acceleration of the body was recorded using an accelerometer during those tests. By processing acceleration data, a new activity-based balance index (ABI) was calculated based on the velocity, acceleration, and position index of soccer players. Using intra-class correlation coefficients (ICC), reliability was calculated. Results: Reliability was high (ICC = 0. 87-0. 89; 95% CI = 0. 77-0. 93) in calculating ABI for the three activities performed in the tests. A significant positive correlation between ABI and both static and dynamic balance scores (r = 0. 62, P = 0. 002) was observed. Furthermore, negative correlation was found significantly between ABI and dribbling scores (r =-0. 61, P = 0. 026) and Y Balance test (r = 0. 6, P = 0. 002). Conclusions: In conclusion, the introduced ABI demonstrates great potential to determine balance and skill scores based on accelerometer-based measures.

Background: Controlling pelvic excursions is the focus of stabilization exercises such as legs loading tasks in rehabilitation of non-specific chronic low back pain (NSCLBP) patients. Progression of these exercises is based on the ability to perform tasks with minimal sagittal pelvic excursions. In spite of emphasis on minimizing pelvic motions, no previous studies have investigated kinematic analysis of the pelvic excursions during leg loading exercises in NSCLBP patients. Objective: This study aims to investigate the sagittal pelvis excursion during performing asymmetric leg loading tasks in individuals with and without NSCLBP. Material and Methods: In this cross-sectional study, kinematic data were collected from 15 NSCLBP patients and 15 asymptomatic participants by a motion analysis system during right and left leg loading tasks with 2 levels of difficulty. Pelvis segments were modeled using Visual3D motion analysis software. Maximum pelvic excursion in the sagittal plane was calculated during each task. Mixed model analysis of variances (group, task difficulty level, side) was performed for statistical analysis. Results: The maximum sagittal pelvic excursion values of all tasks in NSCLBP were smaller than those in the control group; however, no significant main effects and interactions were found between two groups. Conclusion: These results suggest that NSCLBP patients completed loading tasks without differences in sagittal pelvic excursions as compared to controls. Assessment of NSCLBP patients only based on pelvic angular excursion may not be sufficient for clinical decision making. Furthermore, asymptomatic individuals may need to practice for controlling pelvic excursion during leg loading exercises similar to the CLBP patients.

To analyze the frequency of main keratotopographic patterns at the 1st, 2nd, and 3rd stages of keratoconus and investigate corneal biomechanical properties across different patterns. Methods: The study comprised two stages. The first stage was computational-experimental, where we utilized COMSOL Multiphysics® software (COMSOL AB, Stockholm, Sweden) to mathematically model corneal mechanical behavior under intraocular pressure and pulsed air jet action in both normal and keratoconic conditions. The second stage was the clinical phase, during which we retrospectively analyzed the examination results of both healthy subjects and patients with keratoconus. In total, the study included 256 eyes (256 subjects). Among them, 174 eyes (174 healthy individuals) had normal corneas with different refractions, and 82 eyes (82 individuals) had stages 1, 2, and 3 of keratoconus based on Amsler–Krumeich classification. The keratotopographic characteristics of the participants were assessed using Sirius (Schwind, Germany) and Pentacam AXL (OCULUS Optikgeräte GmbH, Germany) keratotomographs, while the corneal biomechanical properties were studied using noncontact tonometry with the Corvis ST device (OCULUS Optikgeräte GmbH, Germany). The study focused on evaluating corneal stiffness index values in the central optical zone under various keratotopographic patterns. In addition, it compared the elastic coefficient values c1, c2, and c3 for the model of hyperelastic behavior of corneal material outside the keratoconus zone. Furthermore, the study examined the values of reduced stiffness zone characteristics, including the stiffness reduction factor ψmax, effective radius Rk, and the ratio of maximum and minimum strain intensity in keratoconus of different stages. Results: The mean age of the patients in the study was 30. 16 ± 8. 31 years, with 166 men and 90 women participating. The study revealed typical keratotopographic patterns in the examined keratoconus stages, as well as their occurrence frequency. In the 1st stage of keratoconus, the pattern of asymmetric astigmatism was noted more frequently (in 75% of cases). In the 2nd stage, the pattern with an ectasia zone in the lower cornea was observed in 80% of cases, and in the 3rd stage, a centrally located keratotopographic ectasia pattern was found in 42% of cases. Comparative analysis showed that the greatest decrease in stiffness parameter (SpA1) and stress–strain index occurred in the central pattern (by 64% and 46%, respectively), while the least decrease was observed in local corneal radius reduction in the lower cornea (by 42% and 33%, respectively). Conclusions: The decrease in strength properties in keratoconus occurs in a local area, the size and degree of which are determined by the disease stage. The indicated biomechanical parameters are consistent regardless of the shape and localization of keratotopographic patterns but are relevant to diagnostic specifications using the Corvis ST pneumotonometer, which assesses corneal properties in the apical zone.

Statement of Problem: Placement of mini-dental implants when single-tooth restorations are needed and the space is not sufficient to insert a standard diameter implant is indicated.There are many different mini-implant brands with various materials and surface characteristics; however, there are just few studies comparing them with each other.Objectives: In this study, finite element analysis (FEA) was applied to evaluate stress distribution in two different types of bone (D2, D3) around three different mini-implant systems (Dio, Dentis, and Osteocare).Materials and Methods: Three different mini- implant systems consisting of Dentis (Dentis Co., Ltd., Dalseo-gu, Daegu, Korea), Dio (DIO Medical Co., Jungwon-gu Seongnam-si, Kyunggi-do, S.Korea) and Osteocare (OsteoCareTM, Slough, Berkshire, UK) were evaluated using FEA. At the same time, a vertical loading of 100N and a lateral loading of 30N at an angle of 45o were applied on the coronal part of the abutment in 2 different bone qualities: D2 bone quality, a thick layer (2 mm) of the compact bone surrounding a core of dense trabecular bone; and D3 bone quality, a thin layer (1 mm) of the cortical bone surrounding a core of dense trabecular bone of favorable strength. Stress levels in the bone surrounding mini-implants were analyzed using Ansys software (Ver.14), which provides the ability to simulate every structural aspect of a product. Descriptive statistics were used to compare the results.Results: After applying the loads and performing FEA, it was observed that in all three types of mini-implants for both static and dynamic analyses, the Von Mises stress values in D3 bone were more than those in D2 bone. The stresses in the cortical bone were obtained more than cancellous bone stresses.Conclusions: In all the studied systems, stress remained in the physiologic limits of the bone. In the cortical bone, stress distribution pattern in the three kinds of mini-implant was similar. Crestal bone stress, according to the amount of force applied, remained in acceptable levels.

Background :Comparisons between meniscectomy and meniscal repair have been studied; however, no studies focus on their biomechanical outcomes and functional effects in cases of longitudinal meniscal tears. Objectives :We aimed to assess biomechanical indices, function, balance, and proprioception in patients with longitudinal meniscal tears one year post-meniscectomy and meniscal repair. Methods :A cross-sectional study was conducted involving 48 patients with meniscal injuries, of whom 24 underwent meniscus repair and 24 received meniscectomy, both assessed one year post-surgery. The knee evaluations were performed using standardized tools, including the Knee Injury and Osteoarthritis Outcome Score (KOOS) to evaluate function, the Star test for functional balance, and digital photography for proprioception. Furthermore, biomechanical parameters, including eyes-opened/closed conditions, were studied using a force plate. All tests were conducted in a single session on surgical and non-surgical knees for all patients. Results :Our results indicate that mediolateral velocity and anterior-posterior displacement in static balance were significantly higher under eyes-opened conditions in meniscal repair compared to meniscectomy (P < 0.05), with no significant differences between the surgical and non-surgical knees (P > 0.05 for all parameters). The two groups had no significant differences in dynamic balance parameters (vertical P = 0.37, anterior P = 0.74, and overall axis P = 0.18) and knee function scores (symptoms P = 0.72, pain P = 0.56, daily living activities (ADL) P = 0.20, sport P = 0.72, quality of life (QOL) P = 0.16, total P = 0.71). Proprioception was significantly different in three ranges of knee motion (30°, 45°, and 90°) in intragroup (P < 0.05), with no significant differences between the surgical knee methods (30° P = 0.17, 45° P = 0.77, and 90° P = 0.19). Functional balance also showed intergroup differences for the 8-reach distance of meniscectomy and meniscal repair was significant (P < 0.05), but did not significantly differ between the two surgical methods. Conclusions :At one-year follow-up, both groups exhibited residual biomechanical, functional balance, and proprioceptive impairments in the surgical knee compared to the contralateral, healthy knee. The type of surgery (meniscectomy vs. meniscal repair) does not significantly change the assessed outcomes one year following either surgical procedure.

Purpose: Volleyball is a complex sport with specific muscular demands and a variety of explosive physical characteristics. The present study aimed to examine the effect of double-density insoles on the frequency of muscle activity during running and side cutting in volleyball players. Methods: This quasi-experimental study was conducted with 30 teenage boys and girls, divided into two groups of 15 participants. The electrical activity of seven lower limb muscles was recorded during six running attempts and lateral sliding attempts using a biometric 8-channel electromyography device with 2-pole surface electrodes, according to the SENIAM European protocol.  Results: The results revealed that double-density insoles significantly influenced the frequency of BF muscle activity during running (P=0.045, d=0.136). Group differences significantly affected the frequency of tibialis anterior (TA) muscle activity (P=0.027, d=0.163) and vastus medialis (VM) muscle activity (P=0.006, d=0.239) during lateral sliding. Additionally, the interaction between double-density insoles and group classification significantly influenced semitendinosus (ST) muscle activity during lateral sliding (P=0.037, d=0.146), with boys showing increased ST activity but not girls. Conclusion: The use of double-density insoles at the frequency of the biceps femoris (BF) muscle can prevent anterior cruciate ligament (ACL) damage and acute muscle injuries during running. At the frequency of the ST muscle during sliding, it can be effective in preventing genu varum injury in volleyball players.