Masaru Teramoto

Electrocutaneous (EC) stimulation is a promising modality for noninvasive tactile feedback. Increasing the pulse frequency of EC stimulation has been shown to increase the perceived intensity in a nonlinear way. However, it is unclear why the relationship is nonlinear and how the nonlinearity impacts the theoretical number of discriminable sensory gradations that can be evoked by EC stimulation, as would be necessary to effectively convey the magnitude of tactile interactions. To address this, we systematically quantify just-noticeable differences (JNDs) and corresponding Weber fractions (WFs) through three psychophysical experiments in healthy adults to elucidate the perceptual resolution and mechanisms for frequency-based sensory encoding. First, we quantify the JNDs and WFs at 25-, 50-, 75-, and 100-Hz reference points and provide quantitative data supporting prior work that suggested intensity discrimination is worse at higher pulse frequencies. Second, we demonstrate that perceptual learning is frequency dependent; intensity discrimination at 50 Hz improved with greater exposure through additional JND experiments, whereas no improvement was observed with repeated exposure at 100 Hz. Third, by isolating frequency discrimination from intensity cues using pseudo-randomized pulse amplitudes, we show that temporal discrimination is impossible at higher frequencies. This suggests that temporal cues present at lower EC pulse frequencies contribute to enhanced perceptual sensitivity at lower frequencies. These findings serve as a quantitative benchmark for intensity discrimination across the working range of EC pulse frequencies, and provide new evidence that enhanced perceptual sensitivity at lower frequencies is likely due to the learnability of supplemental temporal cues. These findings highlight the importance of documenting the experience level of participants when reporting discriminability and may be used to optimize EC haptic feedback systems.

Objective To evaluate the outcomes of pre-participation cardiovascular screening among National Collegiate Athletic Association (NCAA) athletes and quantify the added value of history and physical exam (H&P) when combined with a screening ECG. Design Systematic review and meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data sources MEDLINE (1946–present), EMBASE (1947–present), PubMed (1966–present) and Cochrane Library (1991–present). Eligibility criteria for selecting studies Peer-reviewed research articles published in English reporting original findings on pre-participation cardiovascular screening outcomes in NCAA athletes. Results 18 studies, representing 27 891 NCAA athletes (44.2% female), were included. A total of 66 (0.24%) athletes were diagnosed with a cardiovascular condition associated with serious morbidity or sudden cardiac arrest/death (SCA/D). Wolff-Parkinson-White was the most common diagnosis (n=39, 59.1%), followed by hypertrophic cardiomyopathy (n=11, 16.7%). Among the eight studies (16 609 athletes) for which the screening performance of ECG and H&P could be extracted separately, ECG screening resulted in a 3.5-fold higher detection rate of true positive cases (number needed to screen (NNS) =475) compared with H&P alone (NNS=1661). The false positive rate for H&P was 17% versus 5% for ECG (pConclusion ECG screening significantly increases the detection of conditions associated with serious morbidity or SCA/D compared with H&P alone, with H&P providing minimal added value in athletes with a normal ECG. Our findings support the utility of ECG in preparticipation screening for NCAA athletes. PROSPERO registration number CRD42020188308.

Background : Little is known about physical activity and barriers to exercise in transgender and gender diverse (TGD) adults. We examined the impact of gender-affirming hormone therapy (GAHT) on exercise comfort and perceived barriers to physical activity. Methods : An online survey was distributed to TGD adults initiating or continuing GAHT at a primary care clinic. Comfort with exercise and agreement with statements describing potential barriers to physical activity were assessed using Likert scales. Pre- and post-GAHT comfort levels were compared using Wilcoxon signed-rank tests, and association with psychosocial variables was examined using Spearman correlations. Results : Among 111 participants, comfort exercising at home increased significantly after GAHT (58%–88%, P < .001), while discomfort in sports leagues increased (68%–85%). Fear of harassment or bullying was significantly associated with greater declines in comfort in public gyms ( ρ = −.295, P = .006) and sports leagues ( ρ = −.397, P < .001). In gender-stratified analyses, all groups reported increased comfort at home, but transgender women uniquely experienced declines in public gym ( P = .002) and sports league comfort ( P < .001). Conclusions : TGD respondents reported increased comfort exercising at home and decreased comfort exercising in sports leagues post-GAHT. Barriers included fear of acceptance, harassment, and body discomfort. Post-GAHT changes in exercise comfort appear strongly influenced by psychosocial factors and setting-specific concerns, particularly for transgender women. These findings highlight the need for safer, affirming exercise environments and targeted strategies to reduce harassment and enhance access to physical activity for TGD adults.

Rehabilitation following Anterior Cruciate Ligament Reconstruction (ACLR) is a complex process involving the restoration of muscular strength, movement patterns, and functional confidence. Clinical thresholds, defined target values tied to successful outcomes, are frequently used to guide rehabilitation and assess patient progress. While these thresholds may promote rehabilitation advancement and the establishment of structured goals, substantial variability exists in their values and how they are developed. Clinical thresholds are typically established by linking an independent variable (e.g., quadriceps strength) to a dichotomized outcome (e.g., return to running, return to sport, patient-reported function cutoff, etc.). Statistical tools like Receiver Operating Characteristic (ROC) curve analyses are used to determine a single strength value that best predicts a successful outcome, based on the sensitivity and specificity of predicting the outcome. Despite this standardized approach, existing thresholds differ significantly due to variations in outcome definitions, cohort characteristics, and strength testing protocols. This clinical commentary aims to (1) describe the methodology used to establish clinical thresholds, (2) discuss statistical considerations for interpreting these thresholds, and (3) examine the implications of variability in quadriceps strength targets for patient following ACLR. Level of Evidence: 5

Background: Musculoskeletal injections are a common clinical procedure, often intended to reduce joint or muscular pain in patients. Further identification is warranted to identify additional clinical variables that may lead to increased or decreased pain perception with musculoskeletal injections.Objective: To examine clinical, demographic, and injection‐related factors with patient‐perceived pain during musculoskeletal injections, which expands upon prior studies.Design: Cross‐sectional study.Setting: Retrospective study involving outpatient orthopedic clinics. Consecutive adult patients (age ≥ 18 years) undergoing musculoskeletal injections were reviewed.Patients: A total of 1371 injections from 935 patients were eligible for the analysis. Exclusion criteria included cognitive disability, non‐English‐speaking patients, and aphasia.Interventions: N/A.Main Outcome Measures: Patients reported their pre‐, intra‐, and postprocedural pain on a numerical scale from 0 to 10. Pain scores, demographics, and injection specifics were analyzed after retrospective chart review for their effect on intraprocedural pain.Results: A total of 1371 injections (62.4% female, mean age 58.6 ± 16.1 years, body mass index 29.6 ± 7.3 kg/m²) were included for analysis. The median intraprocedure pain score was 2. According to the multivariate linear regression model, female gender (B = 0.42; 95% confidence interval [CI] = 0.15–0.69; p < .01), ultrasound image guidance (B = 0.66; 95% CI = 0.22–1.10; p < .01), presence of a trainee (B = 0.44; 95% CI = 0.15–0.73 p < .01), and body mass index (B = 0.04; 95% CI = 0.01–0.06; p < .01) were significantly associated with greater intraprocedure pain score, whereas use of sodium bicarbonate (B = −0.68; 95% CI = −1.01 to −0.35; p < .01), age (B = −0.01; 95% CI = −0.02 to −0.01; p = .04), and injectate volume (B = −0.06; 95% CI = −0.13 to −0.01; p = .04) had significant, inverse associations with intraprocedure pain score. The logistic regression model showed the significant association of presence of trainee (odds ratio = 1.86; 95% CI = 1.23–2.83; p < .01) to intraprocedure pain score of ≥1 (vs. 0).Conclusions: This study identified clinical and demographic variables associated with worsened injection pain that may improve the counseling and expectations of patients and ideally lead to reduction in experienced procedural pain. Lower pain scores were associated with use of sodium bicarbonate, absence of a trainee, palpation guidance, and male gender of the patient.

To date, no literature exists on mountain biking injuries in coaches. This study described cross-country mountain biking injuries among coaches in National Interscholastic Cycling Association (NICA) sanctioned leagues from 2018 to 2022. Data were collected using the NICA injury surveillance system (ISS), a web-based injury and exposure reporting system for youth mountain biking, and were analysed using descriptive and univariate inferential statistics. A total of 401 injury events, including 661 distinct time-loss injuries, were reported in 59,545 coach-years over five seasons, resulting in an injury event proportion of 0.67%. The median time-loss due to injury was about 31 days for all injured coaches. The most commonly injured body part was shoulder/clavicle (32.7% of all injury events), followed by head/concussion (18.0% of all injury events) and wrist/hand (17.7% of all injury events). Fracture was the most common diagnosis (27.1% of all non-head injuries). Male coaches sustained upper-limb injuries significantly more often than did female coaches (62.9% vs. 51.5%; p = 0.044), whereas the rate of lower-limb injuries was significantly higher among female coaches than male coaches (33.3% vs. 17.9%; p = 0.001). Fractures and concussions are the most common diagnoses. These findings could be used for designing future injury prevention programmes.

Objectives: Tendinopathy and fasciopathy are common conditions that can result in time-loss injury in athletes. This study aimed to determine if preseason sonographic abnormalities of the patellar tendon, Achilles tendon and plantar fascia are associated with future time-loss injuries in collegiate athletes.Methods: National Collegiate Athletic Association Division I athletes from three institutions participated in this 3-year prospective, observational study. Each athlete completed a questionnaire, self-reporting current and prior symptoms and underwent an ultrasound examination of bilateral patellar tendons, Achilles tendons and plantar fasciae during annual preseason examinations. Ultrasound evaluations assessed for tendon and fascia thickening, hypoechogenicity and neovascularisation. Athletes were monitored for time-loss injury over the subsequent year.Results: A total of 695 athletes across 18 sporting disciplines (61.1% female, age 20.0±1.6, body mass index 23.1±2.9 kg/m²) were analysed over 3 years. Sonographic abnormalities were identified in 36.6%, 7.5% and 2.8% of the patellar tendons, Achilles tendons and plantar fasciae, respectively. Injuries were reported in 3.3%, 1.6% and 0.7% of these structures with an adjusted relative risk of injury increased by 8.9 (95% CI 3.7, 21.4), 18.8 (95% CI 7.2, 48.8) and 21.0 (95% CI 6.4, 68.1) times in those with preseason ultrasound abnormalities (p<0.001). The presence of an ultrasound abnormality was more predictive of future injury than self-report of a prior injury or pain in the area at the time of the scan.Conclusion: Preseason sonographic abnormalities of the patellar tendon, Achilles tendon or plantar fascia are associated with a higher risk of developing time-loss injuries in collegiate athletes.

Purpose: To quantify and compare loads encountered in individual training sessions and games during noncongested and congested weeks in semiprofessional women basketball players. Methods: Using an observational, longitudinal design, 12 players from the same team had their external (PlayerLoad, relative PlayerLoad, and total and high-intensity inertial movement analysis variables) and internal load (session rating of perceived exertion [sRPE], sRPE-load, percentage of heart rate peak, and modified summated-heart-rate-zones load) monitored across a regular season. Training and game data were categorized into noncongested (0–1 game) and congested weeks (2–3 games). Linear mixed models and Cohen d effect sizes were used for analyses. Results: Comparisons between training sessions revealed higher (P < .05, d = 1.35–5.33) PlayerLoad, total inertial movement analysis, sRPE, and sRPE-load during training session 1 than training session 2 in congested weeks. Comparisons between training sessions and games revealed higher (P ≤ .001, d = 1.10–1.66) sRPE and sRPE-load during games than training sessions 1 and 2 in noncongested weeks, alongside higher (P ≤ .001, d = 1.87–3.55) sRPE during game 1 than training sessions 1 and 2 in congested weeks. Comparisons between games revealed higher (P < .05, d = 0.57–2.82) loads in game 3 during congested weeks compared with all other games. Conclusions: Training appeared to be tapered in congested weeks, likely to account for upcoming increases in game loading, but remained relatively consistent across sessions during noncongested weeks. Individual game loads remained relatively consistent but were noticeably increased when a third game was played in the week.