BackgroundThe study of human movement within sports biomechanics and rehabilitation settings has made considerable progress over recent decades. However, developing a motion analysis system that collects accurate kinematic data in a timely, unobtrusive and externally valid manner remains an open challenge.Main bodyThis narrative review considers the evolution of methods for extracting kinematic information from images, observing how technology has progressed from laborious manual approaches to optoelectronic marker-based systems. The motion analysis systems which are currently most widely used in sports biomechanics and rehabilitation do not allow kinematic data to be collected automatically without the attachment of markers, controlled conditions and/or extensive processing times. These limitations can obstruct the routine use of motion capture in normal training or rehabilitation environments, and there is a clear desire for the development of automatic markerless systems. Such technology is emerging, often driven by the needs of the entertainment industry, and utilising many of the latest trends in computer vision and machine learning. However, the accuracy and practicality of these systems has yet to be fully scrutinised, meaning such markerless systems are not currently in widespread use within biomechanics.ConclusionsThis review aims to introduce the key state-of-the-art in markerless motion capture research from computer vision that is likely to have a future impact in biomechanics, while considering the challenges with accuracy and robustness that are yet to be addressed.
José Augusto Rodrigues dos Santos, Domingos José Lopes da Silva, Andreia Nogueira Pizarro
Firefighting requires high and multidimensional fitness to ensure operational readiness and public safety. In Portugal, there is limited data regarding firefighters’ fitness and exercise programs to improve readiness are lacking. This study evaluated the effects of a 6-month minimal-equipment exercise program on the physical fitness of firefighter recruits. Thirty-five male subjects (23.0 ± 2.72 years) were assessed at baseline,3 and 6 months for body composition, handgrip strength, running speed, cardiovascular endurance, anaerobic power, and upper- and lower-body strength. The intervention entailed daily sessions with 15 min of continuous running (50–65% HRmax) and active stretching, followed by alternating routines, including endurance running, free weights, interval sprints, calisthenics, and drills. A repeated-measures ANOVA and Bonferroni adjusted post hoc comparisons identified time-based changes. Significant improvements occurred across all fitness variables. Body fat fell by 8.4% and VO<sub>2</sub>max increased (<i>p</i> < 0.001), surpassing occupational thresholds required for extended suppression tasks. Bench press and sit-up performance improved by 88% and 81%, respectively, while countermovement jump showed double-digit gains (13%), all of which can translate directly to hose advancement, victim rescue, and forcible entry. These results highlight that resource-constrained departments can implement effective, low-cost exercise programs for enhancing pivotal fitness components, supporting policy initiatives to include structured training throughout firefighters’ careers.
Tendon-to-bone healing is considered as a critical determinant influencing the quality of anterior cruciate ligament (ACL) reconstruction. The establishment of a microenvironment conducive to tendon-bone healing remains an urgent challenge for rapidly restoring the structural integrity and functional capacity of damaged tissue. In this study, an injectable hydroxyapatite/collagen type I (HAp/Col I) composite was developed and optimized. Its efficacy in ACL reconstruction was verified in a beagle dog model. During the early postoperative period, this composite successfully established an optimal regenerative microenvironment, thereby promoting cell proliferation, adhesion, and extracellular matrix secretion. Micro CT analysis revealed that the HAp/Col I composite significantly accelerated the mineralization process of local tissue and facilitated the contraction of the artificial bone tunnel. Tensile pull-out tests and nanoindentation experiments demonstrated that HAp/Col I composite enhanced both the macroscopic tensile pull-out strength of the ligament and the elastic modulus at the microscopic level. Furthermore, Raman spectroscopy and histological evaluations indicated that the tendon-to-bone interface exhibited a composition and structure closely resembling native tissue in terms of inorganic components and fiber alignment. Additionally, the injectable HAp/Col I composite consisted of safe, non-toxic materials, featured a convenient injection process, and was compatible with arthroscopic procedures, suggesting promising clinical application prospects.
The aim of this study was to clarify the effect of different breathing frequencies with breath-holding on muscle activity and coordination during butterfly swimming in competitive swimmers. Eight national-level female swimmers participated in this study. They performed 25-m maximal butterfly swims with two breathing frequencies (task 1: swimming with the frontal breathing action for every stroke, and task 2: swimming while alternating the cycles with frontal breathing action and with breath-holding). From these tasks, the three different cycles (breathing cycle in task 1, breathing and breath-holding cycles in task 2) were analyzed. Surface electromyography was measured from 12 muscles of the right upper and lower limb, and trunk. A nonnegative factorization algorithm was used for muscle synergy analysis from the electromyographic data. Our results showed the activity timing for Triceps brachii, Deltoideus anterior, Latissimus dorsi, Biceps femoris and Gastrocnemius became earlier in the breath-holding cycle compared to those in the breathing cycle of task 1. However, the activity timing of all the muscles did not change between the breathing and breath-holding cycles of task 2. The number of muscle synergies was the same across the three cycles, except for one swimmer. The muscle combination of all the synergies was very similar across the three cycles. In contrast, the drive timing of the two synergies, which relate to the arm-pull movement and the first and second upward kicks, respectively, became earlier in the breath-holding cycle compared to those in the breathing cycle of task 1, while the drive timing did not change between the breathing and breath-holding cycles of task 2. These results suggest that the temporal characteristics of muscle activity and synergies are more influenced by different breathing frequencies than by frontal breathing action. Therefore, researchers should consider these effects when analyzing muscle activity during butterfly swimming.
In order to indirectly prove the nature of sports vagotonia, an analysis of 15 indicators of heart rate variability (HRV) was performed, recorded using the VNS-Micro system (Neurosoft, Ivanovo) by 5-minute cardiointervalography (CIG) under conditions of active orthostasis (ortho-CIG, ortho-HRV) at the 8 elite cross-country skiers (MS, MSMC) of the team of the Republic of Tatarstan during the preparatory and competitive periods, as well as a member of this team, athlete K.D. (MS, the first author of the article), whose ortho-CIG registration was carried out during the transition period. It was found that elite skiers in all three periods (especially in the preparatory and competitive periods) are characterized by high median values of such ortho-HRV indices as TP, AMVLF, pNN50%, RRNN, RMSSD, SDNN, MxDn, and low median values of HR and SI., which, judging by the literature data, are significantly they differ from the ortho-KIG of nonathletes, novice skiers, and representatives of other sports not related to endurance development. It is concluded that sports vagotonia is detected not only during the registration of clino-HRV, but also during the registration of ortho-HRV; it is due to the high level of activity of the parasympathetic division of the autonomic nervous system and, probably, the presence of synthesis of non-neuronal acetylcholine by cardiomyocytes.
Abstract Blood Flow Restriction Training (BFRT) is a low-load training technique that involves applying pressure to partially restrict arterial blood flow while occluding venous return. Despite its growing popularity, there is still no consensus on how combining BFRT with resistance or aerobic training influences hemodynamic responses, or on the safest and most effective methods for implementing it. This review aims to systematically identify the effects of BFRT on hemodynamic parameters. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement guidelines. The Chinese literature search was performed in the China National Knowledge Infrastructure (CNKI) database. English literature search was conducted in the Web of Science, PubMed, and Google Scholar databases. The studies included human subjects, the outcome indicators included hemodynamic evaluation indicators, and only randomized controlled trials and randomized crossover trials were considered. Non-Chinese or English literature, duplicate studies, and those with missing data were excluded. The adapted STROBE checklist was used to assess the risk of bias, 44 articles were included in this review. Results indicated that BFRT has increased heart rate and blood lactate levels, while its effect on blood oxygen saturation varies. Additionally, BFRT significantly enhances cardiac output but may either have no significant effect or cause a decrease in stroke volume. Furthermore, BFRT improves pulse wave velocity from the femur to the posterior tibia, suggesting a positive influence on cardiovascular function. BFRT induces changes in arterial structure and function, with these indicators interacting to produce both positive and negative effects on cardiovascular health. The primary mechanisms by which BFRT influences hemodynamics include the activation of the sympathetic and vagus nerves, as well as the regulation of chemical mediators in body fluids that modulate cardiovascular function. Convenient, economical, non-invasive, and easily measurable hemodynamic indicators are expected to become an efficient tool for evaluating the effects of exercise training. Further research is needed to establish the optimal compression thresholds and durations for different populations and exercise types, as well as to assess the long-term impact of BFRT on hemodynamic parameters.
Mai M. A. Shehata, Dalia M. Kamel, Nisreen A. Helmy
et al.
Background and Study Aim. Premenstrual syndrome (PMS) affects a significant proportion of women, impacting their daily lives and well-being. The association between physical activity levels, the prevalence of premenstrual syndrome (PMS), and the severity of PMS remains debatable. Therefore, this study aimed to identify physical activity levels among a cohort of Egyptian females with PMS.
Material and Methods. This study included one hundred females with PMS. Physical activity levels, anaerobic power, aerobic capacity, BMI, and dysmenorrhea were investigated. PMS severity was assessed using the Premenstrual Syndrome Scale (PMSS), and the females' physical activity was evaluated using the International Physical Activity Questionnaire (IPAQ). The 1-mile submaximal test and the Running-Based Anaerobic Sprint Test (RAST) were used to assess aerobic capacity and anaerobic power, respectively.
Results. The findings revealed a significant association between PMS severity and physical activity (p < 0.05). There was no significant difference in aerobic capacity among those with mild, moderate, and severe PMS (p > 0.05). There was no significant association between PMS severity and marital status (p > 0.05), whereas there was a significant association with dysmenorrhea (p < 0.05), especially among moderate and severe PMS sufferers. Females with severe PMS had a significantly higher BMI than those with mild PMS (p < 0.05) and those with moderate PMS (p < 0.05). Mild and moderate PMS females showed no significant difference in BMI (p > 0.05).
Conclusions. It can be concluded that physical activity levels and BMI may affect PMS. Therefore, being physically active and maintaining a normal-range BMI might reduce PMS severity.
Nabil Mehta, Alexander J Acuna, Johnathon R McCormick
et al.
# Background
In 2020, the American Society of Shoulder and Elbow Therapists (ASSET) published an evidence-based consensus statement outlining postoperative rehabilitation guidelines following anatomic total shoulder arthroplasty (TSA).
# Purpose
The purpose of this study was to (1) quantify the variability in online anatomic TSA rehabilitation protocols, and (2) assess their congruence with the ASSET consensus guidelines.
# Methods
This study was a cross-sectional investigation of publicly available, online rehabilitation protocols for anatomic TSA. A web-based search was conducted in April 2022 of publicly available rehabilitation protocols for TSA. Each collected protocol was independently reviewed by two authors to identify recommendations regarding immobilization, initiation, and progression of passive (PROM) and active range of motion (AROM), as well as the initiation and progression of strengthening and post-operative exercises and activities. The time to initiation of various components of rehabilitation was recorded as the time at which the activity or motion threshold was permitted by the protocol. Comparisons between ASSET start dates and mean start dates from included protocols were performed.
# Results
Of the 191 academic institutions included, 46 (24.08%) had publicly available protocols online, and a total of 91 unique protocols were included in the final analysis. There were large variations seen among included protocols for the duration and type of immobilization post-operatively, as well as for the initiation of early stretching, PROM, AROM, resistance exercises, and return to sport. Of the 37 recommendations reported by both the ASSET and included protocols, 31 (83.78%) were found to be significantly different between groups (p\<0.05).
# Conclusion
Considerable variability was found among online post-operative protocols for TSA with substantial deviation from the ASSET guidelines. These findings highlight the lack of standardization in rehabilitation protocols following anatomic TSA.
# Level of Evidence
3b
This study aims to investigate the level of emotional quotient (EQ) and its impact on the performance of employees in the Student Sports Education and Training Technical Implementation Unit for Students and Students of Bogor District. The research method employed surveys and data analysis using SPSS. The results indicate that EQ significantly influences the performance of employees in the unit, accounting for 63.8%, while other factors contribute to the remainder. Further analysis using SPSS reveals that emotional intelligence factors, such as emotional stability, emotional strength, and emotional satisfaction, have significant values confirming their impact on performance. These findings provide valuable insights for human resource management in understanding the importance of EQ in enhancing the productivity and quality of employee performance within the organizational environment.
Mark A. Glover, B.S., Jeffery D. St. Jeor, M.D., Nihir Parikh, B.S.
et al.
Purpose: To identify prognostic factors associated with a delayed return-to-sport (RTS) time in amateur athletes who return to full participation after a primary isolated anterior cruciate ligament (ACL) reconstruction. Methods: A retrospective review was performed among athletes who underwent ACL reconstruction between October 2014 and October 2021. Inclusion criteria were any amateur athletes with an ACL reconstruction who had a documented RTS and greater than 1-year follow-up. Nonathletes, those with multiligamentous knee injury, and those missing documented RTS timelines were excluded. RTS was defined as participation in athletics at a level equivalent to or greater than the preinjury level participation. Demographic and prognostic factors, including previous knee surgery, meniscal involvement, level of participation, surgical approach, and graft type, were recorded along with RTS time and analyzed via Poisson regression. Results: In total, 91 athletes, average age 18.8 (± 6.7) years, who underwent ACL reconstruction at a single institution from 2014 to 2021 were identified with an average follow-up time of 4.6 (± 2.5) years (range 1.1, 9.0). Meniscal involvement (1.11; 95% confidence interval [CI] 1.08-1.15, P < .001) and previous knee surgery (1.43; 95% CI 1.29-1.58; P < .001) were related to a delayed RTS. Quadriceps tendon and bone–patellar tendon–bone autografts, as well as allograft, showed a significant association with a longer RTS time when compared with hamstring autograft (1.16, 95% CI 1.13-1.20, P < .001; 1.04, 95% CI 1.01-1.07, P = .020; 1.11, 95% CI 1.03-1.19, P = .004, respectively), as did anteromedial portal drilling, when compared with the outside in approach for femoral drilling (1.19, 95% CI 1.16-1.23, P < .001). Conclusions: Previous knee surgery, anteromedial femoral drilling, quadriceps tendon autograft, and meniscus tear were most associated with a delayed timeline for RTS among young athletes who were able to return. Level of Evidence: Level IV, prognostic case series.
Introducción: el presente artículo se realizó a partir de detectar insuficiencias teórico-metodológicas y prácticas en el proceso de preparación técnica de la natación artística escolar.
Objetivo: elaborar una concepción teórica con una nueva forma de reestructurar el contenido para el entrenamiento de las figuras, sobre la base de su periodización, que favorezca el incremento del rendimiento deportivo en nadadores artísticos categoría escolar.
Materiales y métodos: se emplearon como métodos teóricos de la investigación científica el analítico-sintético y el sistémico estructural funcional. De los empíricos, el análisis documental y el criterio de expertos. Como métodos matemático-estadísticos, la estadística descriptiva e inferencial, con la Prueba de W de Kendall.
Resultados: la calidad de la concepción teórica quedó corroborada por la evaluación emitida por los 15 expertos seleccionados, que tuvieran relación directa ya sea con el entrenamiento deportivo o de modo particular en el entrenamiento de la natación artística cubana.
Conclusiones: los expertos en la evaluación de los indicadores, resaltan su funcionabilidad, pertinencia y factibilidad.
Ashley E. Disantis, RobRoy L. Martin, Keelan Enseki
et al.
# Background
Acetabular dysplasia (AD) is defined as a structurally deficient acetabulum and is a well-recognized cause of hip pain in young adults. While treatment of severe AD with a periacetabular osteotomy has demonstrated good long-term outcomes, a trial of non-operative management is often recommended in this population. This may be especially true in patients with milder deformities. Currently, there is a paucity of research pertaining to non-operative management of individuals with AD.
# Purpose
To present expert-driven non-operative rehabilitation guidelines for use in individuals with AD.
# Study Design
Delphi study
# Methods
A panel of 15 physiotherapists from North America who were identified as experts in non-operative rehabilitation of individuals with AD by a high-volume hip preservation surgeon participated in this Delphi study. Panelists were presented with 16 questions regarding evaluation and treatment principles of individuals with AD. A three-step Delphi method was utilized to establish consensus on non-operative rehabilitation principles for individuals presenting with AD.
# Results
Total (100%) participation was achieved for all three survey rounds. Consensus, defined a piori as > 75%, was reached for 16/16 questions regarding evaluation principles, activity modifications, appropriate therapeutic exercise progression, return to activity/sport criteria, and indications for physician referral.
# Conclusion
This North American based Delphi study presents expert-based consensus on non-operative rehabilitation principles for use in individuals with AD. Establishing guidelines for non-operative management in this population will help reduce practice variation and is the first step in stratifying individuals who would benefit from non-operative management. Future research should focus on patient-reported outcomes and rate of subsequent surgical intervention to determine the success of the guidelines reported in this study.
# Level of Evidence
Level V
A. Kasielska-Trojan, J. T. Manning, M. Jabłkowski
et al.
Abstract COVID-19 presents with mild symptoms in the majority of patients but in a minority it progresses to acute illness and hospitalization. Here we consider whether markers for prenatal sex hormones and postnatal stressors on developmental instability, i.e. digit ratios and their directional and unsigned asymmetries, are predictive of hospitalization. We focus on six ratios: 2D:3D; 2D:4D; 2D:5D; 3D:4D; 3D:5D; 4D:5D and compare hospitalized patient and control means for right, and left ratios, directional asymmetries (right–left) and unsigned asymmetries [|(right–left)|]. There were 54 patients and 100 controls. We found (i) patients differed in their digit ratios from controls (patients > controls) in all three ratios that included 5D (2D:5D, 3D:5D and 4D:5D) with small to medium effect sizes (d = 0.3 to 0.64), (ii) they did not differ in their directional asymmetries, and (iii) patients had greater |(right–left)| asymmetry than controls for 2D:4D (d = .74) , and all ratios that included 5D; 2D:5D (d = 0.66), 3D:5D (d = .79), 4D:5D (d = 0.47). The Composite Asymmetry of the two largest effects (2D:4D + 3D:5D) gave a patient and control difference with effect size d = 1.04. All patient versus control differences were independent of sex. We conclude that digit ratio patterns differ between patients and controls and this was most evident in ratios that included 5D. Large |(right–left)| asymmetries in the patients are likely to be a marker for postnatal stressors resulting in developmental perturbations and for potential severity of COVID-19.
Cristian Homar Blacio-Aguilar, Cecilia Ivonne Narváez-Zurita, Juan Carlos Erazo-Álvarez
This research aims to design a guide of accounting procedures for the soccer players’ recognition and measurement in sport clubs in Ecuador. To achieve this, a qualitative approach of inquiry has been used; as well as an interview with the Cuenca sport Club and a document review form that have contributed significantly to this work and its proposal. The results of the investigation indicate that the clubs do not reflect their intangible assets in their financial statements. Based on international methodologies and guidelines of IFRS 38, a guide has been established for the accounting treatment of soccer players in their recognition and measurement stages. The first step would be the revaluation of their current workforce followed by all the processes established in this work to achieve the transparency, reasonableness and comparability which are essential characteristics in accounting.
Witalo Kassiano, Cláudio Assumpção, Ulisses Cunha
et al.
The present study aimed to compare the intensity planned by the Personal Trainers (PTs) with that perceived by subjects in resistance training. Six male and female practicing resistance training (4 males and 2 females with mean age 33.0 ± 6.16 years, 1.3 ± 0.55 years training with follow-up) and two PTs participated in the study (average 32.0 ± 4.0 years, postgraduates, with a five -year or more experience). The comparison between the intensity planned by the PT and the intensity experienced by the subjects was determined by the Rating of Perceived Exertion (RPE). Previously, at the beginning of each training, the PT should respond individually to the RPE estimated for each student in that training session. At the end of each session, 30 minutes after its completion, this same scale was answered by the subjects. To compare the intensity of the sessions perceived by the subjects and that planned by the PTs, we used descriptive statistics, standardized mean differences and their confidence intervals. Results have showed that subjects reported substantially higher intensities (small effect size) when compared to PTs. It has been concluded that the intensity experienced by the subjects was substantially higher than that planned by the PTs.
Natalia Santanielo, Sanmy Nóbrega, Maíra Scarpelli
et al.
The aim of this study was to compare the effects of resistance training to muscle failure (RT-F) and non-failure (RT-NF) on muscle mass, strength and activation of trained individuals. We also compared the effects of these protocols on muscle architecture parameters. A within-subjects design was used in which 14 participants had one leg randomly assigned to RT-F and the other to RT-NF. Each leg was trained 2 days per week for 10 weeks. Vastus lateralis (VL) muscle cross-sectional area (CSA), pennation angle (PA), fascicle length (FL) and 1-repetition maximum (1-RM) were assessed at baseline (Pre) and after 20 sessions (Post). The electromyographic signal (EMG) was assessed after the training period. RT-F and RT-NF protocols showed significant and similar increases in CSA (RT-F: 13.5% and RT-NF: 18.1%; P < 0.0001), PA (RT-F: 13.7% and RT-NF: 14.4%; P < 0.0001) and FL (RT-F: 11.8% and RT-NF: 8.6%; P < 0.0001). All protocols showed significant and similar increases in leg press (RT-F: 22.3% and RT-NF: 26.7%; P < 0.0001) and leg extension (RT-F: 33.3%, P < 0.0001 and RT-NF: 33.7%; P 0.05). In conclusion, RT-F and RT-NF are similarly effective in promoting increases in muscle mass, PA, FL, strength and activation.
Benedikt Fasel, Matthias Gilgien, Matthias Gilgien
et al.
In this study we present and validate a method to correct velocity and position drift for inertial sensor-based measurements in the context of alpine ski racing. Magnets were placed at each gate and their position determined using a land surveying method. The time point of gate crossings of the athlete were detected with a magnetometer attached to the athlete’s lower back. A full body inertial sensor setup allowed to track the athlete’s posture, and the magnet positions were used as anchor points to correct position and velocity drift from the integration of the acceleration. Center of mass (CoM) position errors (mean ± standard deviation) were 0.24 m ± 0.09 m and CoM velocity errors were 0.00 m/s ± 0.18 m/s. For extracted turn entrance and exit speeds the 95% limits of agreements (LoAs) were between −0.19 and 0.33 m/s. LoA for the total path length of a turn were between −0.06 and 0.16 m. The proposed setup and processing allowed estimating the CoM kinematics with similar errors than known for differential global navigation satellite systems (GNSS), even though the athlete’s movement was measured with inertial and magnetic sensors only. Moreover, as the gate positions can also be obtained with non-GNSS based land surveying methods, CoM kinematics may be estimated in areas with reduced or no GNSS signal reception, such as in forests or indoors.