Different disc characteristics between young elite skiers with diverse training histories revealed with a novel quantitative magnetic resonance imaging method

Bone Marrow Aspirate Concentrate Combined with Ultra-Purified Alginate Bioresorbable Gel Enhances Intervertebral Disc Repair in a Canine Model: A Preclinical Proof-of-Concept Study

Although discectomy is commonly performed for lumbar intervertebral disc (IVD) herniation, the capacity for tissue repair after surgery is limited, resulting in residual lower back pain, recurrence of IVD herniation, and progression of IVD degeneration. Cell-based therapies, as one-step procedures, are desirable for enhancing IVD repair. This study aimed to investigate the therapeutic efficacy of a combination of newly developed ultra-purified alginate (UPAL) gel and bone marrow aspirate concentrate (BMAC) implantation for IVD repair after discectomy. Prior to an in vivo study, the cell concentration abilities of three commercially available preparation kits for creating the BMAC were compared by measuring the number of bone marrow mesenchymal stem cells harvested from the bone marrow of rabbits. Subsequently, canine-derived BMAC was tested in a canine model using a kit which had the highest concentration rate. At 24 weeks after implantation, we evaluated the changes in the magnetic resonance imaging (MRI) signals as well as histological degeneration grade and immunohistochemical analysis results for type II and type I collagen-positive cells in the treated IVDs. In all quantitative evaluations, such as MRI and histological and immunohistochemical analyses of IVD degeneration, BMAC-UPAL implantation significantly suppressed the progression of IVD degeneration compared to discectomy and UPAL alone. This preclinical proof-of-concept study demonstrated the potential efficacy of BMAC-UPAL gel as a therapeutic strategy for implementation after discectomy, which was superior to UPAL and discectomy alone in terms of tissue repair and regenerative potential.

We know a lot about little and little about a lot: A contextualized scoping review on injury prevention in alpine ski racing

BACKGROUND

Our goal was to summarize and contextualize the available literature on alpine ski racing injury epidemiology, injury etiology, injury prevention measures, injury prevention context, and implementation issues.

MATERIALS AND METHODS

We searched four electronic databases using predetermined search terms. We included original studies that assessed injury, injury risk factors, and injury mechanisms, and assessed and reported the effect of an injury prevention measure in alpine ski racing. Two authors independently conducted title-abstract screening, and one performed the full-text review. For data synthesis and categorization, we used the Translating Research into the Injury Prevention Practice framework and a modified and adapted version of the Haddon matrix.

RESULTS

Of the 157 included studies, most corresponded to injury epidemiology and etiology, whereas few studies encompassed injury prevention measure development, implementation and evaluation. Preventive interventions targeting equipment, rules and regulations, course design and snow preparation were the most prevalent in the literature. Furthermore, various contextual factors in the current literature have been found, including gender, competition level, countries and federations, and time periods within a season.

CONCLUSIONS

We provided an in-depth and comprehensive overview of the current state-of-the-art in the alpine ski racing context. We know a lot about little and little about a lot across all the areas associated with injury prevention in such context. The limitations in the literature yield a road map for designing future injury prevention studies to address the key gaps identified. A more comprehensive context-driven approach throughout all stages of injury prevention would benefit the ultimate implementation of effective preventive strategies.

Detailed MRI evaluation of the spine: a 2-year follow-up study of young individuals reporting different training doses

OBJECTIVE

To characterize the discs and vertebrae in detail over time in a group of adolescent individuals with varying training doses using magnetic resonance imaging (MRI).

METHOD

Thirty-five students were recruited from regular high schools (n=13) as well as schools with athlete competitive skiing programmes (n = 22). The thoraco-lumbar spine of all individuals was examined at baseline and at 2-year follow-up using the same 1.5T scanner and imaging protocol. The individuals were grouped based on their reported training dose: low-to-normal training dose (≤5 h/week, n = 11, mean age 16.5 ± 0.5 years) and high training dose (>5 h/week, n = 24, mean age 17.2 ± 0.6 years.) RESULTS: At baseline, the signal intensity in the discs and vertebrae were significantly lower in individuals reporting high compared to low-to-normal training dose. The vertebral signal changed significantly over the 2-year period in both groups. However, only individuals reporting low-to-normal training dose displayed an overall disc signal change. Interestingly, the regional analysis displayed at baseline high annular signals in the more training-active individuals followed by a reduction over the two-year period.

CONCLUSION

This study suggests that disc degeneration is manifested earlier in individuals reporting a higher training dose. Over a 2-year period, however, the degeneration process did not accelerate further. Also, a significant difference in the vertebral signal, at baseline and follow-up as well as over time, could be seen between groups of individuals reporting high versus low-to-normal training dose.

FITNESS TRAINING OF ATHLETES IN FREESTYLE SKIING

ABSTRACT Introduction: Physical training is essential to physical fitness in freestyle skiers. The domain of stability in the technical movements is a determinant of the competition, always constantly improving. Objective: Develop a physical training program adapted to freestyle skiing. Methods: Twelve freestyle skiers were selected as volunteers for the experiment. This paper compares athletes’ physical qualities and individual abilities before and after physical training. Through recent research, the athletes’ physical condition was comprehensively evaluated to test the effectiveness of their physical training. results: Freestyle skiers showed good anaerobic fitness. A relationship was found between the maximum number of thrusts, the degree of spin in the air, the maximum power duration, and the power decay rate (P<0.05). In the body balance test, the lower limbs showed deficiencies in anteroposterior mobility, while bipodal balance showed no significantly statistical differences (P>0.05). Conclusion: This paper systematically studies body composition, the center of gravity strength, anaerobic capacity, and balance in freestyle skiers. The results provide a good assessment of the effect of fitness training on freestyle ski athletes. These results have particular guiding significance for formulating and implementing training programs focused on the sport. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

POWER SUPPLY CHARACTERISTICS OF BASKETBALL PLAYERS AT DIFFERENT TRAINING INTENSITIES

ABSTRACT Introduction: In competitive basketball sports, athletes must repeatedly perform movements of maximum intensity quickly, followed by rest. A training mode called high-intensity interval training (HIIT) has the same characteristics. Objective: Explore basketball players’ energy supply characteristics and training changes under different exercise intensities. Methods: The effects of different recovery methods in the intermittent period on exercise capacity and aerobic metabolic energy supply of young male basketball players during high-intensity intermittent interval training (HIIT) were presented. Results: Increased aerobic energy production during HIIT was closely related to the acceleration of kinetics. However, although the time to exhaustion, a parameter characterizing exercise capacity, increased by 3.5% and 4.6%, respectively, in the HIITa group compared to HIITs and HIITp, there was no significant difference. After analyzing each group for the 30s, a gradual increase in strength was noticed. Conclusion: The use of HIIT as training is an important way to improve the physical performance of athletes. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

APPLICATION OF SPORTS BIOMECHANICS IN THE TECHNICAL ANALYSIS OF TAEKWONDO KICKING

ABSTRACT Introduction: With the gradual improvement of the theoretical system of sports biomechanics and the high requirements of Taekwondo development, the scientific research of Taekwondo is no longer restricted to a monothematic perspective; sports biomechanics is a combination of the complex forms of movement and body changes in the sport, a discipline that combines the principles of mechanics and biology for research. This discipline, allied to the study of sport, contributes to the correct understanding, training, and mastery of movement techniques. Objective: Apply a technical analysis of the taekwondo kick through a sports biomechanics approach. Methods: Using a three-dimensional kinematic motion capture system, volunteers of 58kg, 68kg, 80kg, and three other weight classes, in a total of 30 athletes, participated in this research. The movements included technical kicks and the collection of motion trajectories when hitting the target. Results: There were significant differences in the angle, angular velocity, torque, action time, displacement, and velocity of the lower limb joints of the three weight classes (P<0.05). Conclusion: The higher the athlete’s weight, the lower the body agility; although the striking distance is relatively long, the impact on movement speed is relatively minor. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

No Significant Change in MRI Abnormalities or Back Pain Prevalence in the Thoraco-Lumbar Spine of Young Elite Skiers Over a 2-Year Follow-Up

Background

Young athletes are at increasing risk for spinal column injuries due to overloading the spine with excessive sports activities, with potential development of complications later in life.

Purpose

The purpose of this 2-year follow-up study of young elite skiers and non-athletes was to investigate any potential change in the thoraco-lumbar findings on MRI and to outline any change in back pain prevalence with continuing sporting activity and age.

Study Design

Longitudinal cross-sectional study.

Methods

MRI of the thoraco-lumbar spine was performed on 30 skiers (mean age 20 years, female 43%) and 16 non-athletes (mean age 19, female 75%), available for the 2-year follow-up. The intervertebral discs were evaluated for signal, height, bulge/herniation, and additionally according to Pfirrmann classification, and the endplates were graded according to endplate defect score. Any of the following disc findings was defined as disc degenerative change: reduced signal, reduced height, bulge, or herniation. All participants answered a specific back pain questionnaire.

Results

No significant difference in spinal column abnormalities, nor back pain, was found between baseline and 2-year follow-up in neither skiers nor controls. There was significantly higher prevalence of disc degenerative changes in skiers (73%) than in non-athletes (44%, p=0.05). Skiers (63%) had significantly more Pfirrmann grade ≥3 discs compared to non-athletes (25%) (p=0.03). There was no significant difference in number of endplates with score ≥4 between skiers and non-athletes (50% vs 38%, p=0.40) nor in lifetime prevalence of back pain between skiers (46%) and non-athletes (40%).

Conclusion

There was no significant change over time of the spinal column MRI abnormalities, nor back pain prevalence, during a 2-year follow-up of skiers and non-athletes. Young skiers had significantly higher prevalence of spine abnormalities compared with non-athletes. There was no significant difference of the back pain lifetime prevalence in skiers compared with non-athletes.