Sports Health-A Multidisciplinary Approach最新文献

Background: Trail running has increased in popularity due to the benefits of physical activity in nature. However, trail running has an inherent risk of running-related injuries (RRI). It is known that athletes with certain psychological traits have a greater tendency to suffer injuries; however, this is unknown in trail runners. The main objective of this study was to identify trail runners' psychological profiles and to compare the proportion of RRI across these profiles.

Hypothesis: Trail runners with psychological profiles of high stress, precompetitive anxiety, mental fatigue, competitiveness, and poor sleep quality are at increased risk of RRI.

Study design: Prospective cohort study.

Level of evidence: Level 2.

Methods: A Gaussian mixture model cluster analysis was performed on 202 trail runners (55.5% male; aged 38.7 [33.4-46.2] years) with psychological stress, cognitive and somatic anxiety, self-confidence, mental fatigue, sleep quality, and competitiveness measured 4 weeks before participating in a race. The proportion of RRI during the race was recorded and compared across clusters.

Results: Overall RRI proportion during competition was 11.3% (n = 24). The most common RRI were muscle (41.7%) and tendon/bursa (16.7%) injuries, affecting primarily the knee (33.3%) and lower leg (20.8%). Five psychological profiles were identified. Cluster 1 (competitive runners with moderate psychological stress and mental fatigue, low sleep quality and anxiety, and high self-confidence) had a higher RRI proportion than Cluster 3 (similar traits but lower psychological stress, mental fatigue, and higher self-confidence; 21.2% vs 3.2%; P = 0.02).

Conclusion: Certain psychological profiles in trail runners were associated with higher RRI risk.

Clinical relevance: The medical team or trail running coaches should monitor runners with psychological profiles with higher psychological stress, mental fatigue, and cognitive anxiety, as well as lower self-confidence and sleep quality, to design strategies to reduce their risk of RRI.

Background: Quadriceps neuromuscular impairments are common after anterior cruciate ligament reconstruction (ACLR). Quadriceps function is typically characterized by peak torque (PT) assessment, and reported as limb symmetry index (LSI). Even when PT LSI is restored, high reinjury rates and abnormal biomechanics persist. Quadriceps rate of torque development (RTD) may have significant functional relevance, but direct comparisons of PT and RTD recovery post-ACLR are lacking.

Hypothesis: Quadriceps RTD LSI will recover more slowly than PT LSI post-ACLR.

Study design: Longitudinal cohort study.

Level of evidence: Level 3.

Methods: 42 athletes 4, 8, and 12 months post-ACLR completed maximal and rapid voluntary isometric knee extension contractions with both limbs. RTD was calculated as torque-time curve slopes from onset to 100 ms (RTD_0-100), 100 ms to 200 ms (RTD_100-200), onset to 200 ms (RTD_0-200), and 20% to 80% of PT (RTD_20-80). Between-limb differences were assessed with paired t tests (Bonferroni adjusted P < 0.003). Linear mixed models assessed the effect of time and variable on differences in PT and RTD LSIs and variable-by-time interactions. Least square mean differences and 95% CIs between PT and RTD LSIs are reported.

Results: Significant between-limb asymmetries were observed at all timepoints (P < 0.001) for all PT and RTD variables. No variable-by-time interactions were detected. There was a main effect of both time (P < 0.001) and variable (P < 0.001). RTD_0-100 LSI was not significantly different than PT LSI (P = 0.36). RTD_100-200, RTD_0-200, and RTD_20-80 LSIs were less than PT LSI by 10.4% (6.0, 14.9), 7.3% (2.8, 11.7), and 15.7% (11.2, 20.1), respectively (P < 0.002).

Conclusion: In collegiate athletes, RTD impairments are greater than PT impairments from 4 to 12 months post-ACLR, but the specific RTD metric is important.

Clinical relevance: Increased focus on the development and implementation of interventions to improve quadriceps RTD, beginning earlier post-ACLR, is warranted.

Background: The force-velocity profile (FVP) is essential for understanding sprint performance, capturing parameters such as maximum theoretical force (F₀), maximum theoretical velocity (V₀), and power (P_max). Effective horizontal force application, especially during acceleration, enhances sprinting outcomes. Resisted sprint training (RST) using varied loads (light, moderate, heavy) can improve neuromuscular adaptations, sprint mechanics, and sport-specific performance. This study explores the effects of RST with different load magnitudes.

Hypothesis: Heavy loads (HL) in athletes with no previous experience in RST are expected to promote better results on sprint performance than light loads (LL) and no loads (CON).

Study design: Randomized clinical trial.

Level of evidence: Level 3.

Methods: Professional male and female football players and referees without experience in sled sprint, allocated into HL (80% of body mass [BM]), LL (20% of BM), and CON (0% of BM) groups, performed RST twice weekly over 6weeks, with pre- and postintervention assessments of sprint performance.

Results: RST with HL significantly improves acceleration, maximum velocity, and horizontal force application. The HL group demonstrated reduced sprint times, enhanced force production during the acceleration phase, and improvements in maximum velocity metrics such as V₀ and maximum velocity (V_max). The LL group showed small benefits in V₀ and decreased times in the 10 meter to 20 meter and 20 meter to 30 meter splits. Intergroup comparisons revealed that the HL group obtained better results compared with the LL and CON groups.

Conclusion: Both LL and HL improved the right spectrum of the FVP. However, the HL group also improved the acceleration phase variables and force production at low velocity.

Clinical relevance: These findings suggest that HL provides superior neuromuscular adaptations and mechanical outputs compared with lighter loads in athletes without previous experience in RST. The inclusion of professional female football players expands the applicability of these results.

Background: The gold standard for measuring hip and knee strength is isokinetic dynamometry. This study evaluated the reliability and concurrent validity of a handheld dynamometer (HHD) and a externally fixated dynamometer (ForceFrame [FF]) against isokinetic dynamometry, considering their practicality, cost-effectiveness, and ease of use in clinical practice.

Hypothesis: The FF and HHD are reliable and valid for assessing hip and knee strength.

Study design: Controlled laboratory study.

Level of evidence: Level 4.

Methods: Maximal isometric hip strength (extension, flexion, abduction, adduction, internal and external rotation) and knee strength (extension and flexion) of 14 healthy persons (7 men; age, 24.4 ± 3.1 years; height, 176.3 ± 9.7 cm; weight, 68.5 ± 10.8 kg) was assessed with an isokinetic dynamometer, HHD, and FF. Measurements were repeated on 2 different days for test-retest reliability and by 2 different investigators on 1 day for interrater reliability. Intraclass correlations (ICC) were calculated, and Pearson correlation coefficients assessed concurrent validity.

Results: Moderate to good test-retest reliability was found for both the HHD (ICC, 0.62-0.88; MDC, 10-21%) and FF (ICC, 0.61-0.82; MDC, 15-38%). Interrater reliability was poor to good (HHD ICC, 0.15-0.80; FF ICC, 0.14-0.77). Concurrent validity was better for the HHD than FF.

Conclusion: Both the HHD and FF provide stable measurements of hip and knee strength over a 1-week interval. The calculated MDCs (HHD, 10-21%; FF, 15-38%) suggest that only differences exceeding these thresholds can be interpreted as true changes, rather than measurement errors. Inter-rater reliability was rather low, indicating that repeated evaluations are best performed by the same tester. Poor concurrent validity cautions against substituting the HHD and FF for isokinetic dynamometry.

Clinical relevance: HHD and FF offer practical and cost-effective alternatives for a single tester to evaluate strength changes over time.

Background: The latissimus dorsi (LD) comprises 2 neuromuscular regions-the thoracic and lumbar-pelvic-costal (LPC)-that may exhibit distinct activation patterns during shoulder and trunk exercises. A detailed understanding of these regional differences is crucial for optimizing therapeutic interventions due to their potential impact on muscle imbalances and rehabilitation outcomes in people with musculoskeletal conditions.

Hypothesis: Increasing contraction levels are expected to amplify differences between the thoracic and LPC regions, with the thoracic region demonstrating greater activation, particularly during shoulder extension and internal rotation tasks.

Study design: Descriptive laboratory study.

Level of evidence: Level 5.

Methods: A total of 20 healthy participants (15 men and 5 women) were recruited. High-density surface electromyography (HD-sEMG) electrode grids were positioned over the LD. Participants performed isometric contractions for shoulder extension, adduction, internal rotation, and lateral trunk bending at 10%, 30%, 50%, 70%, and 100% of their maximum voluntary contraction (MVC). The variables assessed included sEMG amplitude for each region and the spatial distribution of muscle activation (x- and y-axis barycenter).

Results: During shoulder extension, the thoracic region showed greater sEMG amplitudes than the LPC region at 50% (P = 0.02), 70% (P = 0.01), and 100% MVC (P < 0.01). Furthermore, shoulder extension generated greater amplitudes than all other exercises across both regions (P < 0.05). Barycenter analysis revealed a significant cephalomedial shift in the x-axis during both shoulder extension and internal rotation.

Conclusion: The thoracic region is preferentially recruited during isometric shoulder extension and internal rotation. This spatial redistribution of muscle activity suggests a functional specialization within the LD, which has important implications for the development of targeted shoulder rehabilitation strategies.

Clinical relevance: Exercises emphasizing shoulder extension may preferentially activate the thoracic region of the LD, thereby enhancing scapular stability while reducing strain on the rotator cuff tendons.

Background: Adolescent sport culture is moving away from multisport participation, emphasizing sport specialization for improved skill development despite concern of injury. This study examined biomechanical differences among low-, moderate-, and high-level specialized pitchers.

Hypothesis: Kinetics, kinematics, and peak velocities will vary with specialization level.

Study design: Descriptive laboratory study.

Level of evidence: Level 3.

Methods: Adolescent male baseball pitchers' (N = 46) pain, injury, baseball exposure history, and pitching biomechanics were measured during a single pitching session. Means and standard deviations were calculated for all metrics (significance, P ≤ 0.05) and compared among low-, moderate-, and high-level specialization groups.

Results: Stride length increased significantly (P = 0.03) from low- (mean, 74% height; SD, 13.6; 95% CI, 64.3-83.8) to high-level (mean, 92.9% height; SD, 6.3; 95% CI, 79.7-86.1) specialization. Hip-shoulder separation at foot contact increased significantly (P = 0.01), with low-, moderate-, and high-level specialization demonstrating means of 21.9° (SD, 12.1; 95% CI, 13.3-30.6), 31.1° (SD, 7.0; 95% CI, 27.7-34.4) and 30.0° (SD, 5.3; 95% CI, 27.3-32.8), respectively. Maximum torso rotation velocity and maximum shoulder internal rotation (IR) velocity increased significantly (P = 0.03) from low- to high-level specialization rising from 930.5 deg/s (SD, 68.4) to 1020.0 deg/s (SD, 75.7), and from 4284.2 deg/s (SD, 311.6) to 4827 deg/s (SD, 512.2), respectively. Peak shoulder distraction force also increased significantly from low- to high-level specialization (P = 0.03), rising from 0.81 N (% bodyweight) (SD, 0.13; 95% CI, 0.72-0.91) to 0.96 N (% bodyweight) (SD, 0.12; 95% CI, 0.89-1.02). There were no significant differences among age, height, weight, or pitch speed across pitching specialization level.

Conclusion: Differences in pitching biomechanics were observed among low-, moderate-, and high-level specialized high school baseball pitchers.

Clinical relevance: Recognizing the impact of sport specialization and negative influences on pitching biomechanics will contribute positively to performance training and injury prevention strategies.

Background: Preseason training plays a pivotal role in preparing athletes for the competitive season and reducing the risk of hamstring strain injuries (HSI). This study evaluated the protective effect of preseason running workload on the risk of in-season HSI in elite soccer players.

Hypothesis: Higher preseason sprint-related metric is associated with reduced risk of in-season HSI in elite soccer players.

Study design: Cohort study.

Level of evidence: Level 3.

Methods: Global positioning system data and HSI records from 67 elite Japanese soccer players between 2021 and 2023 were analyzed. Variables included internal workload, total distance, high-speed distance, sprint distance, sprint count, and acceleration/deceleration count. Multivariable logistic regression analysis determined the association between workload metrics and HSI risk.

Results: A total of 17 HSI incidents were recorded during the study period. Increased preseason sprint distance was associated significantly with a reduced risk of in-season HSI (odds ratio [OR], 0.896; 95% CI, 0.822-0.976; P = 0.01), even after adjustment (model 1: OR, 0.892; 95% CI, 0.814-0.979; P = 0.02, model 2: OR, 0.899; 95% CI, 0.822-0.983; P = 0.02). Higher sprint count was associated with decreased HSI risk (OR, 0.761; 95% CI, 0.633-0.916; P = 0.004), with consistent findings after adjustments (model 1: OR, 0.755; 95% CI, 0.623-0.916; P = 0.004, model 2: OR, 0.763; 95% CI, 0.631-0.923; P = 0.005). The area under the curve values for sprint distance and sprint count were 0.721 and 0.739, respectively.

Conclusion: Preseason training marked by higher sprint distances and counts demonstrates a protective effect against in-season HSI in elite soccer players, supporting comprehensive preseason running workload as an essential strategy for reducing injury risk and enhancing season readiness.

Clinical relevance: Incorporating sprint-focused training during the preseason may reduce HSI incidence and minimize injury-related absences in elite soccer players.

Background: Tracking systems have revolutionized the analysis of physical demands in professional soccer. Monitoring external load parameters through global positioning systems is crucial for monitoring fatigue, technical-tactical factors, and preventing injuries, especially during disruptions such as COVID-19 and midseason tournaments.

Hypothesis: The FIFA World Cup Qatar 2022 would lead to significant changes in external load parameters among LaLiga players, either positively or negatively, when comparing pre- and post-tournament match performance.

Study design: Retrospective observational study.

Level of evidence: Level 3.

Methods: External load metrics (ie, minutes of game, accelerations, decelerations, sprints, and high-speed running [HSR]) were analyzed to compare performance in 8 pre- versus postleague tournament matches in those soccer players who competed in FIFA World Cup Qatar 2022. The sample consisted of players from the Spanish LaLiga elite soccer league who participated in the Qatar 2022 World Cup.

Results: FIFA World Cup Qatar 2022 did not negatively impact external load variables. Post-tournament values showed improvements in (1) number and distance covered at HSR, (2) distance and number of sprints, (3) number of high-intensity actions performed, and (4) number and distance covered at high-intensity deceleration, without significant differences in total distance covered or maximal speed reached during matches.

Conclusion: FIFA World Cup Qatar 2022 did not negatively affect the performance of Spanish LaLiga players. On the contrary, several external load metrics such as HSR, sprinting, accelerations, and decelerations showed improved performance post-tournament.

Clinical relevance: These results may help clarify the effects of future in-season league stoppages due to international competitions.

Background: High-intensity exercises, such as CrossFit (CF), may increase risk of pelvic organ prolapse (POP) due to pelvic floor muscle (PFM) overload.

Hypothesis: There is no significant difference in the prevalence, severity, or affected compartment of POP between women who practice CF and those engaged in other sports of similar intensity.

Study design: Cross-sectional.

Level of evidence: Level 3.

Methods: A total of 36 women (age, 32.7 ± 7.7 years) participated in the study-18 CF practitioners and 18 engaging in other forms of high-intensity exercise (non-CF [NCF]). A sample-characterization form and the International Consultation on Incontinence Questionnaire-Vaginal Symptoms (ICIQ-VS) assessed vaginal symptoms. The Pelvic Organ Prolapse Quantification (POP-Q) system, and maximum voluntary contraction (MVC) and endurance of PFM assessed POP and PFM variables, respectively.

Results: According to POP-Q, 38.9% and 44.4% of women in the CF and NCF groups, respectively, had POP (P = 0.73). Using ICIQ-VS, the prevalence was higher in both groups: 66.7% and 61.1% in CF and NCF, respectively (P = 0.69). First-degree POP was the most common, affecting 27.8% of women in each group. The most affected compartment was the anterior (22.2% [CF], 27.8% [NCF]). Using ICIQ-VS, "dragging pain or heaviness in the lower abdomen" and "very dry vagina" were most reported in both groups. MVC using modified Oxford scale (3 ± 3 vs 3 ± 2), MVC manometer (28.1 ± 25.8 vs 29.9 ± 22.5) and endurance (3.4 ± 1.7 vs 3.4 ± 2.3) were similar between both groups.

Conclusion: The prevalence, degree, and symptoms of POP and PFM variables in women practicing CF are similar to those in women engaging in other forms of high-intensity exercise.

Clinical relevance: Trainers, clinicians, and physiotherapists should understand the impact of high-intensity exercise on PFM and inform women about these dysfunctions to ensure they exercise safely.

Context: The Star Excursion Balance Test (SEBT) is recognized for simultaneously assessing strength, range of motion (ROM), balance, neuromuscular control, and functional performance of the lower extremity. Although there is evidence to support the SEBT, a contemporary systematic review to define its clinically relevant psychometric properties is needed.

Objective: To define clinically relevant psychometric values for the SEBT.

Data sources: PubMed, Embase, Medline, CINAHL, SPORTDiscus, and Scopus databases were searched from database inception through November 2023.

Study selection: Clinical studies reporting reliability, validity, and responsiveness of SEBT were included.

Study design: Systematic review.

Level of evidence: Level 3.

Data extraction: Intra-class correlation coefficient (ICC), minimal detectable difference (MDD), minimal detectable change (MDC), evidence of validity, and minimal clinically important difference (MCID) values were recorded.

Results: Out of 3982 identified studies, a total of 102 were included; 20 studies of reliability found the SEBT to have ICC values ranging from 0.51 to 0.99. Out of these 20 studies, 5 reported MDC or MDD values in an injured population. Based on these studies, a standardized protocol for SEBT was compiled. A total of 81 studies of validity found that the SEBT could differentiate reaching distances between healthy people and those with lower extremity injuries with correlations with patient-report outcome measure, functional performance test, muscle strength, muscle activation, ROM, and motor strategies. One study of responsiveness identified MCID values of 4.2 cm to 10.9 cm for SEBT in the 2 weeks after anterior cruciate ligament reconstruction.

Conclusion: The reliability, validity, and responsiveness with MDD, MDC, and MCID values for the SEBT can be used in clinical practice.