Open Access Journal of Sports Medicine最新文献

Background: Blood lactate (BL) is a critical biomarker for assessing anaerobic metabolism and fatigue. Sweat lactate (SWL) and sweat rate (SWR) have been explored as non-invasive alternatives, but their capacity to estimate BL dynamics after short-term high-intensity exercise remains unclear.

Purpose: This pilot study aimed to evaluate whether BL dynamics can be predicted using a regression model based on the time-series patterns of SWL and SWR measured by wearable sensors.

Methods: Five healthy male athletes (three sprinters and two endurance runners) performed a 30-second Wingate anaerobic test. SWL and SWR were continuously monitored using a wearable electrochemical sensor and a ventilated capsule-type sweat rate meter. Capillary BL was sampled for 30 minutes post-exercise.

Results: BL showed a delayed peak at 6.4 ± 1.2 min, while SWL and SWR exhibited biphasic responses. The second SWL peak (7.5 ± 2.2 min) aligned with the BL peak. Although peak-based correlations were not significant, Pearson correlations using time-series data revealed strong associations (r = 0.501-0.933 for SWL; r = 0.515-0.805 for SWR; all p < 0.001). A multivariate regression model using both variables predicted BL with high accuracy (R² = 0.763, RMSE = 1.612, MAE = 0.995, p < 0.001).

Conclusion: These findings support the feasibility of a regression-based approach using sweat-derived time-series data to non-invasively estimate BL dynamics after high-intensity exercise.

Background: In Japan, pitch count recommendations were proposed to prevent throwing injuries. In our laboratory, 10 years ago, the knowledge and compliance with pitch count recommendations were assessed among coaches in Kyoto Prefecture and compared with those in the US Since then, the youth baseball environment has changed, including the formal implementation of pitch count rules by the Japan Boys League Foundation. However, no studies have examined how such changes have influenced coaches' knowledge and compliance over time. Although it is important for coaches to have prior knowledge of injuries in order to prevent the incidence of Little League Elbow, few studies have assessed the actual experience of coaches.

Methods: Of the 242 coaches belonging to the Kyoto Boys' Baseball Association who participated, 172 with valid responses were analyzed. The questionnaire, consistent with a previous study conducted 10 years ago, assessed knowledge and compliance with pitch count recommendations, as well as coaching background and seminar participation.

Results: The proportion of coaches who reported having knowledge of the recommendations significantly increased from 39.8% to 52.3% (p = 0.04), while the compliance rate decreased from 28.3% to 22.1% (p = 0.23). Coaches with knowledge tended to be older and have longer coaching experience, while those who complied were significantly younger and less experienced. Seminar participation was associated with increased knowledge but did not result in higher compliance. Moreover, 70% of coaches were also parents of players; these individuals were younger, had less coaching experience, and were less likely to have attended seminars.

Conclusion: Despite increased knowledge among youth baseball coaches, compliance with pitch count recommendations remains limited. This knowledge-behavior gap suggests the need for educational interventions that address not only the dissemination of information but also cultural and psychological barriers to behavior change. Tailored support may be especially beneficial for younger and less experienced coaches.

Purpose: To report the prevalence of hip pain in elite badminton players, describe their hip pathologies, and evaluate expectations regarding hip pain.

Patients and methods: All badminton players registered at the national sports institute (Institut national du sport, de l'expertise et de la performance; INSEP) in France on 01/09/2023 were contacted by the medical team to complete a questionnaire comprising training information, prevalence of hip pain, and expectations regarding hip pain. The medical database was reviewed to identify all hip pathologies recorded.

Results: Of the 20 elite badminton players registered at the national sports institute (10 females and 10 males, aged 23.8±3.9 years), 9 (45%) reported experiencing hip pain while registered at the institute, 4 at their dominant side only and 5 bilaterally. Six players had cam-type femoroacetabular impingement (FAI), concomitant with coxofemoral chondropathy and/or muscle tears in 3 athletes (requiring femoroplasty in 3). Furthermore, 3 more players had coxofemoral chondropathy and/or muscle tears. Before playing badminton at a high-level, 12 (60%) thought that becoming elite players could cause joint pain; however, none (0%) thought that it would cause pain specifically at their hip joint.

Conclusion: Nine of 20 elite badminton players have experienced hip pain while registered at a national sports institute, with the most common hip pathologies being cam-type FAI (n=6; 30%) and muscle tears (n=4; 20%). Although before playing badminton at a high-level, none of the athletes thought that becoming an elite badminton player could cause pain specifically at the hip joint, at the time of the questionnaire, 19 athletes (95%) thought this was common. These findings could allow coaches and medical staff to align expectations regarding the likelihood of hip pain and hip pathologies in badminton players training at an elite level, by adjusting training regimens or implementing early screening.

Purpose: The modified Star Excursion Balance Test (mSEBT) is a clinical tool for dynamic balance assessment. While researchers have examined individual joint kinematic predictors of dynamic balance performance, limited data exist on body and joint sway during the test execution. Further investigation of kinematic predictors' influence on dynamic balance is needed to improve assessment methodologies. This study aimed to examine the relationship between the center of mass and lower limb kinematics as predictors of mSEBT performance.

Patients and methods: Twenty-seven participants with no history of lower limb joint instability were recruited for this study. The inertial sensors were positioned on the non-dominant leg: trunk, thigh, shank, and foot. The participants completed the mSEBT barefoot following standardized practice trials with three test trials per direction. The reach distance and lower limb kinematic data were recorded. Spearman rank's correlation and stepwise multiple regression analyses identified key predictors of dynamic balance performance.

Results: Ankle dorsiflexion was a strong predictor of normalized reach distance in the anterior direction (r² = 0.34, p < 0.001). Body center of mass displacement was the strongest predictor of posteromedial and posterolateral reach (r² = 0.55, p < 0.001; r² = 0.57, p = < 0.001, respectively). The combined influence of the body center of mass and hip flexion accounted for 65% of the variance in the posterior reach assessments.

Conclusion: This study highlights the key biomechanical factors that influence dynamic balance, focusing on the interaction between joint mobility and segmental control. Ankle dorsiflexion is critical for anterior balance, whereas hip flexion and body center of mass displacement are essential for posterior balance.

Shoulder instability is a common injury in athletes that often requires surgical stabilization. While RTS rates after shoulder stabilization may be around 81%, approximately 19-52% of athletes do not return to their preinjury level of play. Psychological factors like fear of reinjury, lack of motivation, and change in priorities are key barriers to RTS after shoulder surgery. The Shoulder Instability Return to Sport after Injury (SIRSI) scale quantitatively assesses athletes' psychological readiness to return to sport following shoulder stabilization. Higher SIRSI scores correlate with increased likelihood of returning to preinjury level of play. However, current RTS guidelines rely heavily on time-based criteria and lack consensus on assessing psychological readiness. Adopting a more comprehensive approach that incorporates physical and psychological evaluations may better determine athletes' readiness to RTS. Incorporating the SIRSI scale into the RTS decision-making process, alongside physical evaluations, can potentially improve RTS outcomes in athletes after shoulder stabilization surgery. Further research is needed to establish standardized protocols and validate the effectiveness of interventions aimed at optimizing psychological readiness.

Multiple computed tomography (CT) scans are required to diagnose lumbar spondylolysis stage and confirm fusion degree. However, multiple CT scans should be avoided because of radiation exposure. There are no case reports of complete diagnosis and treatment of pediatric lumbar spondylolysis without the use of CT. Fast field echo resembling a CT using restricted echo-spacing (FRACTURE) is a magnetic resonance imaging (MRI) sequence used to evaluate bone lesions. Here we report the case of a pediatric patient with lumbar spondylolysis who was able to return to sports after diagnosis, treatment, and bone union confirmation using MRI and FRACTURE.

The negative effects of dehydration or overhydration on exercise performance and health are widely recognized. However, the interindividual variability of fluid imbalances among athletes and across various sports is large, due to the complex interactions of physiological, environmental, and sport-specific factors. Such complexity not only makes it difficult to predict fluid needs prior to competition or training sessions, but also supports the creation of an individualized hydration plan (IHP) for each athlete. Measurements of valid, field-expedient biomarkers such as body mass change, urine concentration, and thirst enable ongoing monitoring of an athlete's hydration state and are integral components of an IHP. Unfortunately, no extensive repository of sport-relevant hydration biomarker data exists. Therefore, this narrative review presents a novel inventory of pre- and post-exercise reference values for body mass change, urine specific gravity, and subjective rating of thirst. These reference values were identified via electronic database searches that discovered field studies of competitive events, weight category sports, training sessions, and routine daily activities. We propose that comparing an athlete's real-time body mass change, urine specific gravity, and thirst rating to previously published reference values will clarify the extent of dehydration or overhydration, guide rehydration efforts, and optimize subsequent exercise performance, recovery, and health.

Introduction: Athletic peak performance is increasingly focused on cognitive and mental factors. In the current study, cognitive performance was measured by neurophysiological responses in elite Junior-A hockey players.

Methods: Neurophysiological brain vital signs were extracted from event-related potentials (ERPs) to evaluate auditory sensation (the N100), basic attention (the P300), and cognitive processing (the N400). In total, we evaluated 348 athletes, across 17 teams, throughout different hockey arenas in British Columbia, Canada. While brain vital signs were collected to help manage concussion, the current investigation focused on a retrospective performance analysis of cognitive processing differences.

Results: The results revealed three interesting findings: 1) Player position differences were detectable in sensory N100 latency, with significantly faster responses for forwards compared to defense; 2) Goalies showed significantly higher attention P300 amplitude compared to all other positions; and 3) Cognitive N400 processing differences were detectable only during competitive combine testing, showing 60ms latency differences between forwards and defense on average.

Discussion: The current findings suggest that neurophysiological responses, which are also sensitive to concussion, may be used to identify sensory, attentional, and cognitive processing differences to help optimize peak performance.