Plane Stability Research Articles

Localized electrocortical activity as a function of single-leg squat phases and its relationship to knee frontal plane stability.

This study investigated differences in electroencephalography (EEG) activity within motor-related brain areas during three phases of a single-leg squat (SLS)-i.e., descending, holding, and ascending phases. Specifically, utilizing advanced magnetic resonance imaging guided EEG source localization techniques and markerless motion capture technology, we explored the interplay between concurrently recorded lower-extremity biomechanics and brain activity. Among the phases of a nondominant leg SLS, differences in contralateral brain activity (right hemisphere) were found in the activity of the precentral gyrus, the postcentral gyrus, and the sensory motor area. Alternatively, during the dominant SLS leg, differences among the three SLS phases in contralateral brain activity were fewer. Hemispheric dependent brain activity also significantly correlated with participants' knee valgus angle range of motion (right hemisphere) and peak knee valgus angles (left hemisphere). In addition to the novel brain and biomechanical findings, this study sheds light on the technical feasibility of recording EEG during complex multi-joint movements and its potential applications in understanding sensorimotor behavior.

A survey on the use of total intravenous anaesthesia in small animals by veterinary anaesthesiologists

ObjectiveTo describe the use of total intravenous anaesthesia (TIVA) in dogs and cats by veterinary anaesthesiologists. Study designA cross-sectional online, voluntary, anonymous survey. PopulationData from 153 answered questionnaires. MethodsAn anonymous questionnaire was sent via e-mail to diplomates, residents and residency-trained individuals from the American and European Colleges of Veterinary An(a)esthesia and Analgesia, to gather information on the use, perceived advantages, reasons for the use or not of TIVA and attitudes towards this technique in dogs and cats. Descriptive statistics and logistic regression analysis to detect significant associations were performed. The effect size was estimated using the odds ratio (OR) and 95% confidence interval (CI). A significance level of p < 0.05 was used. ResultsWe obtained 153/703 responses (66% diplomates, 34% residents; overall response rate of 21.7%). Although 99% and 94% of respondents used TIVA in dogs and cats, respectively, only 14% used it frequently (several times a week) in dogs, and < 1% in cats. Most respondents used propofol (97%, dogs) and alfaxalone (85%, cats), mostly combined with opioids. Reasons for not using TIVA more frequently included prolonged recovery (49%, dogs; 61%, cats), higher cost (46%, dogs) and concerns about drug accumulation (44%, cats). Frequent TIVA use was driven by clinical indications (100%) and greater haemodynamic stability (87%). A higher proportion of respondents using TIVA frequently reported the high stability of the anaesthetic plane (20%; OR = 5.0; 95% CI: 1.4–17.8; p = 0.013) and disagreed with using TIVA only when a specific clinical indication existed (OR = 3.3; 95% CI: 1.4–10.0; p = 0.013). Conclusions and clinical relevanceAlthough occasional, TIVA use is reported among veterinary anaesthesiologists. Clinical indications for TIVA are the most likely reason for its use, whereas factors such as a prolonged recovery or higher cost might limit its use.

The deltotrapezial fascia stabilizes the AC-Joint and its reconstruction restores the horizontal stability in AC-joint separations—a biomechanical comparison

BackgroundVarious techniques are available for the reconstruction of acromioclavicular joint (ACJ) dislocations, with the main focus being on restoration of the AC capsule or coracoclavicular (CC) ligaments. Recent research has underlined the significance of the deltotrapezial fascia (DTF) and related muscles as dynamic stabilizers of the ACJ. HypothesisReconstruction of the DTF increases the stability of the ACJ in the horizontal plane more than a complete transection of the fascia, while not restoring the stability of the native state. MethodsFive pairs of human cadaveric shoulders including the torsos were included in the study and underwent cyclic anterior-posterior loading using an electromechanical testing machine. The shoulders were put into three groups: group N (n = 10): native ACJ; group T (n = 10): ACJ with transected DTF; group R (n = 10): ACJ with reconstruction of the DTF after transection. The dislocation was recorded with an 3D optical measuring system. ResultsGroup N showed a mean horizontal displacement of 2.94 mm (± 1.26), group T showed a mean anterior displacement of 3.33 mm (± 1.37) and group R showed a mean anterior displacement of 2.95 mm (± 1.08). The mean anterior displacement for group T was significantly higher after every measured number of cycles compared with groups N and R. There was no significant difference in mean anterior displacement between groups N and R. ConclusionThe transection of the DTF results in significantly reduced stability in the horizontal plane of the ACJ. A reconstruction of the DTF restores the stability of the native ACJ in the horizontal plane. Further clinical and biomechanical investigations should focus on reconstruction techniques of the DTF.

Seismic performance of slit steel plate shear walls strengthened by FRP laminate

Steel plate shear walls with slits are widely used in high–rise building structures due to their flexible arrangement and high ductility. After long-term service, cracks may occur in the slit steel plate shear walls due to repeated buckling and stress concentration. In this study, an FRP–steel composite slit steel plate shear wall was proposed to improve its mechanical performance and service function. Experimental and finite element analysis were conducted to investigate the performance of slit steel plate shear walls reinforced with FRP under low cycle reciprocating load. It was shown that the use of FRP to strengthen slit steel plates can effectively improve the out–of–plane stability of the structure and reduce the stress concentration at the slits. The stiffness and load–bearing capacity of the reinforced slit steel plate shear walls were significantly enhanced. The reinforcement effect of FRP did not significantly affect the energy dissipation capacity of the shear walls. A numerical study was performed to investigate the optimal orientation of the FRP arrangement. The analysis revealed that when the carbon fibers were arranged horizontally and vertically orthogonally, the structure exhibited better seismic properties. This study can not only improve the seismic performance of slit steel plate shear walls, but also have engineering implications for the seismic reinforcement of existing slit steel plate shear walls.

Coronal plane stability of cruciate-retaining total knee arthroplasty in valgus gonarthrosis patients: A mid-term evaluation using stress radiographs.

Total knee arthroplasty (TKA) using implants with a high level of constraint has generally been recommended for patients with osteoarthritis (OA) who have valgus alignment. However, studies have reported favorable outcomes even with cruciate-retaining (CR) implants. To evaluate the coronal plane stability of CR-TKA in patients with valgus OA at the mid-term follow-up. Patients with primary valgus OA of the knee who underwent TKA from January 2014 to January 2021 were evaluated through stress radiography using a digital stress device with 100 N of force on both the medial and lateral side. Gap openings and degrees of angulation change were determined. Descriptive statistical analysis was performed for both continuous and categorical variables. Inter-rater reliability of the radiographic measurements was evaluated using Cronbach's alpha. This study included 25 patients (28 knees) with a mean preoperative mechanical valgus axis of 11.3 (3.6-27.3) degrees. The mean follow-up duration was 3.4 (1.04-7.4) years. Stress radiographs showed a median varus and valgus gap opening of 1.6 (IQR 0.6-3.0) mm and 1.7 (IQR 1.3-2.3) mm and varus and valgus angulation changes of 2.5 (IQR 1.3-4.8) degrees and 2.3 (IQR 2.0-3.6) degrees, respectively. No clinical signs of instability, implant loosening, or revision due to instability were observed throughout this case series. The present study demonstrated that using CR-TKA for patients with valgus OA of the knee promoted excellent coronal plane stability.

Surgical management strategies for unstable sacral fractures: Case series and surgical guideline

IntroductionUnstable sacral fractures usually have posterior pelvic and spinopelvic instability, which usually be classified as AO type C. There are many controversial points concerning the management of these fractures due to their rarity. Herein, we retrospectively review cases of this injury and propose a surgical guideline. Case presentationA 37-year-old female experienced back pain after a motor vehicle accident. Diagnostic imaging revealed an AO type C1 sacral fracture, Isler subtype 2a (case No. 7). Preoperative CT scan and CT reconstruction images showed a longitudinal fracture with a simple intraarticular fracture of the left S1 superior facet. Although the patient sustains a lumbosacral facet joint injury, the lumbosacral motion seems preservable after healing. The triangular osteosynthesis was chosen because it provides both transverse plane and vertical plane stability. The patient was allowed to continue weight-bearing ambulation after the operation. To maintain lumbosacral motion, the spinopelvic rod was removed in the postoperative seventh month. DiscussionThe unstable sacral fracture might have instability in both the vertical and transverse planes. The fixation construct should provide both vertical and transverse stability. Regarding vertical fixation, it might cost a loss of lumbosacral motion, which the treating surgeon has to consider. The lumbosacral injury is sometimes trivial, and long-term lumbosacral motion is expectable. So, permanent spinopelvic fixation is not necessary. The patient's character is also an important factor. Whether the patient needs or does not need early progressive weight bearing after the operation determines the fixation method. ConclusionUnstable sacral fractures are rare conditions usually resulting from a high-energy injury. We have proposed a surgical management strategy for this group of fractures with an optimal fixation method based on three factors: 1) fracture morphology, 2) lumbosacral integrity, and 3) concomitant injury.

Design and fabrication of a large-aperture electrowetting liquid zoom system

In this paper, a continuous zoom system based on large-aperture electrowetting liquid lenses is designed and fabricated. The inner diameter of the electrowetting lens is up to 20 mm, which can tune stably from a focal length of −328.49mm to −∞ with applied voltages of 0 to 115 V. The zoom system mainly consists of two large-aperture electrowetting liquid lenses and a glass lens, getting continuous zoom images by adjusting the voltages applied to the two liquid lenses without any mechanical movement, ensuring a more compact structure than conventional zoom systems. The theoretical formulas of the zoom ratio and image plane stability condition for this optical system are systematically derived based on the matrix optics, laying the foundation for guiding system regulation and finding methods to improve zoom ratio, and corresponding influence factors on the zoom ratio are verified by experiments. The system zoom ratio can reach 1.52 at a fixed working distance, close to the theoretical derivation result. The system is expected to be used for imaging in a variety of scenarios, such as special photography, dynamic measurement, etc.

Distributed Drive Electric Vehicle Handling Stability Coordination Control Framework Based on Adaptive Model Predictive Control.

Distributed drive electric vehicles improve steering response and enhance overall vehicle stability by independently controlling each motor. This paper introduces a control framework based on Adaptive Model Predictive Control (AMPC) for coordinating handling stability, consisting of three layers: the dynamic supervision layer, online optimization layer, and low-level control layer. The dynamic supervision layer considers the yaw rate and maneuverability limits when establishing the β-β˙ phase plane stability boundary and designs variable weight factors based on this stability boundary. The online optimization layer constructs the target weight-adaptive AMPC strategy, which can adjust the control weights for maneuverability and lateral stability in real time based on the variable weight factors provided by the dynamic supervision layer. The low-level control layer precisely allocates the driver's requested driving force and additional yaw moment by using torque distribution error and tire utilization as the cost function. Finally, experiments are conducted on a Simulink-CarSim co-simulation platform to assess the performance of AMPC. Simulation results show that, compared to the traditional MPC strategy, this control strategy not only enhances maneuverability under normal conditions but also improves lateral stability control under extreme conditions.

Behavior of steel plate shear walls reinforced with stiffened FRP plates

Steel plate shear walls require retrofitting due to factors such as corrosion, long–term loading and functional changes. In an effort to modernise the technology used for strengthening and retrofitting steel plate shear walls, fibre–reinforced polymer (FRP) plates with additional stiffeners are employed to enhance the shear capacity of steel structures. In this study, the static properties of steel plates reinforced with these stiffened FRP plates were experimentally investigated. The application of this strengthening methodology substantially enhanced the out–of–plane stability, shear stiffness and bearing capacity of the plates, while also reducing fatigue damage. Equations for estimating the buckling and ultimate load of steel plates reinforced with stiffened FRP plates have been derived, enabling predictions of their practical performance. Finite element models incorporating the potential failure of epoxy at the FRP–steel interface were developed for further analysis. A numerical study was performed to investigate the optimal thickness of the FRP stiffener. The analysis revealed that stiffener thicknesses exceeding 6 mm did not significantly contribute to the enhancement of the load–bearing capacity or to the prevention of debonding. When the FRP rib thickness exceeds 6 mm, the economy was poor. The aforementioned findings are of considerable engineering importance, especially in the context of improving fatigue properties and shear load–bearing capacity of thin steel plates.

Effect of different lumbar–iliac fixation and sacral slope for Tile C1.3 pelvic fractures: a biomechanical study

BackgroundLumbar–iliac fixation (LIF) is a common treatment for Tile C1.3 pelvic fractures, but different techniques, including L4–L5/L5 unilateral LIF (L4–L5/L5 ULIF), bilateral LIF (BLIF), and L4–L5/L5 triangular osteosynthesis (L4–L5/L5 TOS), still lack biomechanical evaluation. The sacral slope (SS) is key to the vertical shear of the sacrum but has not been investigated for its biomechanical role in lumbar–iliac fixation. The aim of this study is to evaluate the biomechanical effects of different LIF and SS on Tile C1.3 pelvic fracture under two-legged standing load in human cadavers.MethodsEight male fresh-frozen human lumbar–pelvic specimens were used in this study. Compressive force of 500 N was applied to the L4 vertebrae in the two-legged standing position of the pelvis. The Tile C1.3 pelvic fracture was prepared, and the posterior pelvic ring was fixed with L5 ULIF, L4–L5 ULIF, L5 TOS, L4–L5 TOS, and L4–L5 BLIF, respectively. Displacement and rotation of the anterior S1 foramen at 30° and 40° sacral slope (SS) were analyzed.ResultsThe displacement of L4–L5/L5 TOS in the left–right and vertical direction, total displacement, and rotation in lateral bending decreased significantly, which is more pronounced at 40° SS. The difference in stability between L4–L5 and L5 ULIF was not significant. BLIF significantly limited left–right displacement. The ULIF vertical displacement at 40° SS was significantly higher than that at 30° SS.ConclusionsThis study developed an in vitro two-legged standing pelvic model and demonstrated that TOS enhanced pelvic stability in the coronal plane and cephalad–caudal direction, and BLIF enhanced stability in the left–right direction. L4–L5 ULIF did not further improve the immediate stability, whereas TOS is required to increase the vertical stability at greater SS.

Neuromuscular Electrical Stimulation of Peroneal Longus on Balance Control Ability in Young Adults with Chronic Ankle Instability: A Randomized Controlled Trial.

This study aimed to investigate the effects of six weeks of peroneal longus neuromuscular electrical stimulation (NMES) on the balance control ability in young adults with chronic ankle instability (CAI). This study is a double blind randomized controlled trial. Six weeks of NMES and placebo intervention were conducted in the NMES and control groups for 20 minutes, three times a week, respectively. Thirty-eight participants successfully completed the whole intervention and single-leg standing tests. The kinetics data of the center of pressure (COP) trajectory during static single-leg stance were measured using a Kistler force platform. Two-way repeated measures ANOVA was used to analyze the electrical stimulation effects. Significant interactions were detected in CAIT scores and all balance parameters including Displacement X (Dx), Displacement Y(Dy), 95% confidence ellipse area (95%AREA), root-mean-square (RMS) and COP mean displacement velocity (MV) (p < 0.05, 0.103 ≤ η2 ≤ 0.201). Significant between-group differences were found in CAIT scores (p = 0.003, Cohen's d = 0.215), Dx (p = 0.045, Cohen's d = 0.107), RMS-ml (p = 0.019, Cohen's d = 0.143) and 95%AREA (p = 0.031, Cohen's d = 0.123) after the six weeks interventions. Six weeks of NMES on the peroneus longus can improve static balance control ability in young adults with CAI, especially the stability of ankle frontal plane.

Evaporator with horizontal water plane stabilization

Evaporation plays an important role in maintaining water balance and managing water resources in reservoirs. This problem is relevant in hot regions with a lack of fresh water. In addition, reliable operation of evaporators plays an important role in preventing overheating and ensuring safe cooling of reactors which is critical to maintaining nuclear safety. The complete control and accurate measurement of the evaporation process provided by the developed device enables efficient water management ensuring the stability of nuclear power plants and minimising environmental risks. Evaporators are used to control the evaporation process in reservoirs. Based on the analysis of existing evaporators and their shortcomings, an evaporator with horizontal plane stabilization in the pan is developed. Due to this function the developed device allows to control the evaporation process with higher accuracy by reducing fluctuations in the water level in the evaporator. The developed device contains an autonomous power supply that uses energy-saving technology based on a solar battery which ensures operation without additional sources. The use of such a power supply increases the evaporator reliability. One of the important advantages of this device is the use of a cellular-based information transmission channel to the control center which allows to transmit the results of evaporation quickly monitoring and make water management decisions accordingly. In addition, the use of a GPS navigation system allows to set or determine the coordinates of the evaporator installation in the reservoir accurately. The developed device can be included in an intelligent energy resource management system; its use will significantly improve the safety and sustainability of nuclear power plants by improving evaporation process control. It will also optimize the nuclear power plants operation, promote efficient management of water resources and ensure safety in the nuclear energy field.

Boundary Frustration in Double-Gyroid Thin Films.

Self-consistent field theory for thin films of AB diblock polymers in the double-gyroid phase reveals that in the absence of preferential wetting of monomer species at the film boundaries, films with the (211) plane oriented parallel to the boundaries are more stable than other orientations, consistent with experimental results. This preferred orientation is explained in the context of boundary frustration. Specifically, the angle of intersection between the A/B interface and the film boundary, the wetting angle, is thermodynamically restricted to a narrow range of values. Most termination planes in the double gyroid cannot accommodate this narrow range of wetting angles without significant local distortion relative to the bulk morphology; the (211)-oriented termination plane with the "double-wave" pattern produces relatively minimal distortion, making it the least frustrated boundary. The principle of boundary frustration provides a framework to understand the relative stability of termination planes for complex ordered block polymer phases confined between flat, nonpreferential boundaries.

Investigation of Co-Extrusion Using a Coat Hanger Die with Different Feedblock Cross-Section

When using the coat hanger die method for co-extrusion, the biggest challenges often involve maintaining the uniformity of the velocity distribution at the outlet of the die and ensuring the stability of the interface plane. This paper investigates the effect of different cross-section of feed channels connected to the coat hanger die on the velocity and pressure distribution of the flow at different parts of the die. Co-extrusion of LLDPE (Linear Low Density Polyethylene) and HDPE (High Density Polyethylene) polymers is simulated using ANSYS software 2020 R2 for coat hanger die design with rectangular and circular cross-sections inlet geometry; the results are compared for Carreau-Yasuda model to observe the result differences between rectangular and circular coextrusion channels connected to coat hanger die. Our results showed that rectangular cross-section feedblock generated higher values for pressure in comparison with the pressure generated by the circular cross-section feedblock. The maximum velocity generated in the circular feedblock is lower than that generated in the rectangular one, nevertheless there is more uniformity in velocity distribution in circular than rectangular cross-section.

Vestibular input modulates stepping balance reactions early in the pre-step phase through to post-recovery.

Compensatory stepping reactions to recover balance are frequently performed, however, the role of sensory feedback in regulating these responses is not fully understood. Specifically, it is unknown whether vestibular input influences compensatory stepping. Here, we aimed to assess whether step responses utilize vestibular input by combining medio-lateral galvanic vestibular stimulation (GVS) with step-inducing balance perturbations via unpredictable anterior-posterior platform translations. Step responses were assessed for any lateral differences due to the illusory sense of left (LGVS) or rightward (RGVS) postural motion in terms of pre-step weight-shifts, center of mass (COM) motion and step-placement as well as lateral stability when recovering balance. GVS evoked clear differences from the pre-step phase onwards, in an asymmetrical pattern depending on the GVS direction relative to the right step-leg side. RGVS induced a leftwards postural shift to create a larger stability margin to the right (p<0.0007), opposing the illusory motion and reducing the fall towards the unsupported side during the step; however, RGVS caused no change in step-width. Conversely, LGVS evoked a leftward step placement (p<0.0001) in the direction of the mis-sensed motion, but without any rightward shift in postural motion. This asymmetry is consistent with vestibular input predictively modulating pre-step lateral weight-shifts and foot-placement in accordance with step mechanics, specifically in controlling frontal plane stability when lifting the foot to step.

Study the Structure of Phase Space in the Frame Work of Planar Circular Restricted Three-Body Problem

The numerical technique of Poincare surface of sections is used to create the surface of sections and to investigate the stability of the phase plane in various systems. This includes investigating the dependence of mass ratio and amplitude of stability areas in the Sun-Jupiter, Sun-Mercury, Sun-Io, and Sun-Uranus systems on the Jacobi constant. The amplitude of the stability areas diminishes with decreasing mass ratio. The phase plane structure differs for smaller mass ratios than it does for larger mass ratios.

Vehicle Lateral Control Based on Dynamic Boundary of Phase Plane Based on Tire Characteristics

Lateral control is an essential safety control technology for autonomous vehicles, but the effectiveness of lateral control technology relies heavily on the precision of vehicle motion state judgements. In order to achieve accurate judgements of the vehicle motion state and to improve the control effectiveness of vehicle maneuverability and the stability controller, this paper starts with an analysis of phase plane stability. A simulation analysis is conducted to investigate the effect of the vehicle steering angle of the front wheels, the longitudinal velocity, and the tire–road adhesion coefficient on the boundary of the stability area. The stable area of the phase plane was partitioned using the proposed novel quadrilateral method, and we established a stability area regression model using machine learning methods. We analyzed the inherent connection between the lateral tire forces and the principles of vehicle maneuverability and stability control, indirectly combining the characteristics of tire forces with vehicle maneuverability and stability control. An allocation algorithm for maneuverability and stability control was designed. A co-simulation indicates that the vehicle stability controller not only accurately assesses the motion state of the vehicle but also demonstrates a considerably better performance in maneuverability and stability control compared to a controller using the traditional partitioning method of stable regions. The suggested allocation method enhances vehicle maneuverability and stability by enabling a seamless transition between the two and improving the effectiveness of stability control.

MENISCAL ANOMALIES IN CONGENITAL CRUCIATE LIGAMENT DEFICIENCY: EXPERIENCE IN A TERTIARY CHILDREN'S KNEE UNIT

ObjectivesCongenital cruciate ligament deficiency is a rare condition that may occur in isolation or in association with longitudinal limb deficiencies such as fibular hemimelia or proximal femoral focal deficiency. Often anomalies of the menisci and their attachments can be very abnormal and impact on surgical management by standard techniques. Arthroscopic surgical knee reconstruction is undertaken to improve symptomatic instability and/or to stabilise and protect the knee for future planned limb lengthening surgery.The aim of this study is to evaluate the arthroscopic findings of patients undergoing surgery for congenital cruciate ligament deficiency, and specifically to determine the frequency and types of meniscal anatomical variations seen in these cases.MethodsPatients undergoing surgery for congenital cruciate ligament deficiency were identified from a prospectively collated database. Diagnosis was confirmed through review of the clinical notes and imaging. Operative notes and 4K saved arthroscopic images and video recordings for these cases were reviewed.ResultsOver a six-year period (July 2017 – September 2023), 42 patients underwent surgery for congenital ligament deficiency and tibiofemoral instability (45 surgical episodes). Median age of patients at time of surgery was 10 years (range 4 – 17 years). The most frequent diagnosis was congenital longitudinal limb deficiency syndromes in 27 cases, with the most frequent being fibular hemimelia. Isolated congenital ligament deficiency without any other associated extra-articular manifestations occurred in 11 cases. Absence of meniscal root attachments or hypertrophy of meniscofemoral ligaments acting as ‘pseudo-cruciates’ were seen in over 25% of patients. In isolated ACL deficiency these were injured causing onset of instability symptoms and pain following trauma. Often these abnormal structures required addressing to allow surgical reconstruction.ConclusionsOur findings demonstrate that there are often meniscal variations seen in association with congenital absence or hypoplasia of the cruciate ligaments. In these patients hypertrophied meniscofemoral ligaments may act as cruciate-like structures and play a role in providing a degree of sagittal plane stability to the knee. However, when the knee becomes unstable to the point that cruciate ligament reconstruction is indicated, these meniscal variants may often require stabilisation using complex meniscal root repair techniques or variations to standard cruciate ligament reconstruction techniques to accommodate the variant anatomy.

Electromyography (EMG) Analysis of Multi-Regional Lower Extremity and Trunk Musculature During Sidelying Hip Abduction With Frontal Plane Stabilization.

Sidelying hip abduction (SHA) is a common exercise utilized in rehabilitation to strengthen thegluteus medius (GMed). Alterations in the exercise can produce different patterns of muscularactivity. No studies have examined the effect of mechanical pelvic stabilization during SHA.This study enrolled 19 participants (male = 11, female = 8) who performed the same SHA exercise under two randomized conditions: standard and with a mechanical block to prevent frontal-plane movement. Electromyographic amplitudes during exercise were obtained through surface electrodes and compared against maximum voluntary isometric contraction (MVIC) testing: GMed, gluteus maximus, biceps femoris, tensor fascia latae, quadratus lumborum, and vastus lateralis. While no significant differences were found in GMedactivity during SHA with or without pelvic stabilization, reduced concomitant activation of other musculature was observed, potentially producing a more isolated exercise for the GMed with lesscompensatory activity.

Effects of Foot Structure Type on Core Stability in University Athletes.

This study assessed the impact of different types of medial foot arch on postural stability and core center of gravity muscle activity among collegiate athletes. The study sample included 103 university-level athletes across various sports (soccer, rugby, basketball, volleyball, field tennis, table tennis, karate, and cheerleading) from the College of Magdalena (Colombia) who exhibited distinct types of medial foot arch: 32 high, 35 low, and 36 neutral arches. Surface electromyography (sEMG) was employed to assess conduction velocity, magnitude values, latency, and fatigue in focal muscles including the spinal erector (SE), internal oblique (IO), external oblique (EO), and rectus abdominis (AR), while measurements of static and dynamic postural control were also considered. Post hoc analysis was performed with Bonferroni correction for all electromyographically measured muscle groups, as well as for measurements of static and dynamic postural stability. Pearson's or Spearman's correlation tests were used to compare the different types of feet. There were no substantial differences observed between the distinct types of feet in terms of focal muscle activity, static stability, or dynamics. Even though the mean values indicated higher muscle activity and stability among those with high foot arches and lower values among those with low arches compared to the neutral foot type, this observed difference was deemed statistically insignificant. We also observed a positive correlation between internal oblique muscle activity and the average power of dynamic postural stability, which remained consistent across all foot types. Our findings indicate that static instability is directly correlated with dynamic instability in the anteroposterior direction, while a clear inverse relationship was established in the lateral direction upon examining the variable correlations. The presence of high or low foot arches did not significantly impact the activity of the muscles responsible for maintaining the body's center of gravity or postural stability among university-level athletes. This suggests the existence of neuromuscular compensation mechanisms that attempt to restore balance and compensate for any changes in postural stability caused by varying foot types. Through targeted training that emphasizes activation of the internal oblique muscle, athletes may see improved postural stability. Our findings indicate that static stabilization exercises can also prove beneficial in improving dynamic stability in the anteroposterior plane, while a more dynamic approach may be required to improve dynamic stability in the lateral plane.