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The primary aims of this study were to determine acute and longitudinal relationships between static flexibility measures and running economy (RE). Seventy-one healthy recreational runners (34 males/37 females, age: 36.4 [12.4] y, body mass index: 23.3 [3.1] kg/m²) completed an aerobic fitness assessment (VO₂max) based on self-selected half-marathon race pace (RP) and flexibility testing (standing toe-touch test and weight-bearing lunge test) at baseline and 2 to 3 weeks prior to an endurance running or multisport race (70 [21] d apart). Participants resumed self-selected training and physical activity between laboratory visits. Hierarchical linear regressions were used to assess relationships between flexibility and RE across timepoints, and pre–post changes in flexibility and RE. Interactions between age and flexibility, and experience and flexibility were also investigated. No significant differences (P > .05) were found between flexibility measurements and RE at RP from visit 1 to visit 2, nor were there any significant associations between RE at RP and scores on the weight-bearing lunge test or standing toe-touch test. However, there was a significant interaction between age and the weight-bearing lunge test on RE at RP (ß = −0.0270, P = .018) such that older runners with less flexibility and younger runners with greater flexibility were less economical at RP at baseline. Our findings suggest that reduced flexibility may decrease the energetic cost of running for older runners to a greater extent than it does for younger runners. When prescribing run training intensity and mileage, coaches and clinicians working with masters runners should be cognizant of the potential performance benefits of decreased ankle joint flexibility as well as the overall greater risk of calf injury in this population. Future research should consider the underlying mechanism by which age enhances the beneficial effects of decreased flexibility on RE.

Context: Anterior cruciate ligament reconstruction (ACLR) is a known risk factor for knee osteoarthritis (OA). Since no disease-modifying treatments for OA exist, it is critical to understand joint responses to physical activity following an ACLR. Understanding knee cartilage deformation through ultrasound may provide a better understanding of how knee cartilage responds to running, and how this may contribute to OA pathophysiology and risk. Objective: To compare medial femoral cartilage deformation, outcomes, and forces during running in females with and without a unilateral ACLR knee. Design: Cross-sectional laboratory study. Methods: Sixteen females (8 ACLR history, 8 controls) participated. ACLR participants had an average age of 20.75 (1.83) years, height of 165.07 (7.43) cm, mass of 65.97 (8.55) kg, and were 36.13 (18.74) months postsurgery; controls had an average age of 20.62 (1.84) years, height of 166.00 (5.76) cm, and mass of 63.18 (4.94) kg. Independent variables were group and limb, with dependent variables including patient reported outcomes Knee Injury and Osteoarthritis Outcome Score (KOOS), medial femoral cartilage thickness changes, and indirect measures of stance-averaged vertical ground reaction forces and vertical rate of loading normalized to body weight during treadmill running. Data were analyzed using nonparametric statistics with significance defined as P ≤ .05. Results: All participants exhibited cartilage thickness reduction after 30 minutes of running (P < .001), with no significant group or limb differences in cartilage deformation, vertical ground reaction forces, or vertical rate of loading. ACLR participants reported significantly poorer patient reported outcome scores across all KOOS subscales. Moderate negative correlations were found between involved cartilage percent change and KOOS Symptoms (P = .025) and Sport/Rec (P = .043). Conclusions: Cartilage thickness significantly decreased in all participants after running, with no group or limb differences observed despite lower patient-reported outcomes in the ACLR group. Exploring the relationship between KOOS scores and cartilage response to activity may inform future research and strategies to mitigate OA risk.

Neck pain ranks among the most prevalent musculoskeletal conditions and is commonly accompanied by altered physical function. With 10.8% of sports-related injuries affecting the head and neck, evaluating neck strength is vital for detecting muscle weakness and monitoring rehabilitation progress. The purpose of this study was to determine the intrasession and intersession reliability of a strain gauge for measuring neck retraction strength in healthy adult men. Ten male participants (age, 22.7 [2.6] y; body mass, 90.8 [13.3] kg; height, 184.2 [7.1] cm) completed a neck retraction isometric test across 3 testing occasions separated by 7 days. Contraction duration, peak and mean force, impulse, and peak rate of force development were quantified within and between sessions. Contraction duration, peak force, and impulse demonstrated moderate to excellent intra- (intraclass correlation coefficient [ICC] [3,1] = .72–.98, coefficient of variation [CV] = 2.7%–2.1%) and intersession reliability (ICC [3,k] = .66–.89, CV = 4.8%–7.1%); however, only acceptable intrasession reliability was found for peak rate of force development and mean force (ICC = .71–.99, CV = 3.4%–22.7%). It appears that a portable fixed strain gauge can be used to reliably measure neck retraction strength in a healthy male population.

Context: Subtalar dislocation is a rare but severe condition that usually requires emergency attention and could be associated with secondary injuries. Most of the research about this injury is case reports focused on the medical management, so there are no guidelines for rehabilitation and return to sport (RTS). This case report describes the rehabilitation and RTS in an amateur basketball player with an isolated medial subtalar dislocation on his right foot. Case Presentation: A 20-year-old amateur basketball player suffered a forced foot inversion after landing on an opponent’s foot. The patient was taken to the emergency department for a closed reduction under anesthesia, followed by 2 weeks in a cast and 3 weeks in a walker boot. Management and Outcomes: Rehabilitation started after the immobilization period with the main objective of returning to the same level of competition. It was organized through a 4 phase continuum with a stepwise approach. After 16 weeks since injury, the patient returned to team training. Conclusions: To our knowledge, this is the first report to inform on rehabilitation and RTS of medial subtalar dislocation. The 4 phases continuum model could be useful for clinicians for safe progression in this rare condition.

Context: Short daily surveys are common in elite sports to capture psychological outcomes, but there is no information on the surveys convergent validity and test–retest reliability. Therefore, the purpose of this study is to determine the validity and test–retest reliability of daily athlete health surveys in collegiate athletes. Design: Descriptive study. Methods: Participants (n = 193, 74 males and 119 females; age = 20.3 [1.4] y) responded daily to sliding scale questions regarding readiness (scored from 0 to 100), fatigue, stress, and sleep quality (−5 [indicating low or poor scores] to +5 [indicating high or “good” scores]). At pre- and midseason times, participants completed the Perceived Stress Scale, Pittsburgh Sleep Quality Index, Athlete Sleep Screening Questionnaire, Overuse Injury Scale, and the Acute Recovery and Stress Scale. To assess validity, Spearman rho (ρ) correlation coefficients were used to assess the relationship between each athlete health variable and the corresponding validated survey. Reliability and precision were assessed with the intraclass correlation coefficient and the standard error of measurement, respectively. Results: Daily stress was correlated with the Perceived Stress Scale (ρ = −.40, P < .001); daily sleep quality was associated with the Pittsburgh Sleep Quality Index (ρ = −.44, P < .001) and the Athlete Sleep Screening Questionnaire (ρ = −0.46, P < .001), and daily readiness was associated with the Overuse Injury Scale (ρ = −.21, P = .003). Daily fatigue was associated with the recovery (ρ = .37, P < .001) and stress dimensions (ρ = −.36, P < .001) of the Acute Recovery and Stress Scale. All daily athlete health variables demonstrated either good or excellent reliability (intraclass correlation coefficient = .85–.94; standard error of measurement = 0.87–4.94). Conclusions: All daily health variables demonstrated acceptable reliability and precision. Sleep quality and stress were most strongly correlated with the outcome scores of their validated surveys. Fatigue was related to the Acute Recovery and Stress Scale, and readiness demonstrated a weak correlation to the Overuse Injury Scale. Clinicians should feel comfortable using these single-question daily health surveys in clinical care but exert caution when using readiness, and fatigue.

Adolescent athletes participating in sports involving sudden directional changes, pivoting, and jumping frequently sustain anterior cruciate ligament (ACL) ruptures. ACL reconstruction (ACLR) surgery is often required, followed by a lengthy rehabilitation period. This study aims to evaluate the effectiveness of combining BOth Sides Up (BOSU) ball exercises with conventional resistance training in the recovery of joint stability and function after ACLR in adolescent athletes. Thirty adolescent athletes (ages 14–18) who underwent ACLR were randomly allocated to either the control group receiving traditional postoperative rehabilitation (n = 15) or the intervention group combining BOSU ball training with resistance exercises (n = 15). Joint stability, proprioception, strength, and functional outcomes were assessed before the procedure, as well as 3, 6, and 12 months after the operation using the KT-1000 arthrometer, Y-balance test, isokinetic dynamometry, and the ACL-Return to Sport after Injury ACL-Return to Sport after Injury (ACL-RSI) scale. The intervention group demonstrated notably better anterior-posterior knee joint stability (P < .05) than the control group at the 6-month and 12-month follow-ups after the surgery, greater reach distances in the Star Excursion Balance Test (P < .05), higher quadriceps and hamstring strength ratios (P < .05), and superior ACL-RSI scores (P < .01). Incorporating BOSU ball training with resistance exercises appears to be more effective than traditional rehabilitation alone in enhancing joint stability and neuromuscular control after ACLR in adolescent athletes. These results provide evidence supporting the incorporation of unstable surfaces into a comprehensive rehabilitation program to optimize recovery and safe return to sports.

Introduction: Running overuse injuries are among the most common running-related musculoskeletal injuries. Modifying gait has been recognized as an effective strategy for preventing running overuse injuries. This study investigates whether gentle heel strike (GHS) running decreases the impact loading rate during 30-minute runs in healthy participants. Methods: In this prospective cohort interventional study, 20 male participants underwent gait modification in a controlled laboratory setting, with the goal of reducing heel impact through real-time visual feedback. Comprehensive measurements, including plantar contact, force, pressure, and detailed kinetic and kinematic analyses, were employed to assess changes in gait dynamics. Results: GHS significantly shifted plantar pressure, reducing heel forces and increasing forefoot load. Mean heel force decreased by 0.32 (0.1) body weight (BW) and heel pressure reduced by 0.1 kPa/BW. Although peak vertical ground reaction force and anterior–posterior ground reaction force did not change significantly across the entire stance phase, early stance vertical ground reaction force (7%–12% of the gait cycle) was reduced, leading to the disappearance of the vertical impact peak. Vertical impact peak dropped from 1.45 (0.23) to 1.27 (0.25) BW. Significant reductions were also seen in the vertical instantaneous loading rate, which decreased from 68.32 (14.20) to 46.77 (13.95) BW/s, and the vertical average loading rate, which fell from 54.96 (14.38) to 38.84 (12.62) BW/s (P < .001). Discussion: GHS has the potential to modify running mechanics by redistributing plantar pressure and diminishing heel impact force. This reduction in heel impact force could lead to a change in landing pattern anteriorly and a decrease in loading rates, potentially reducing the risk of running overuse injuries. Conclusion: Visual biofeedback-guided GHS is feasible in healthy participants, and it effectively reduces the loading rate during running for 30 minutes.

Context: Many healthcare professions incorporate foam rolling (FR) and static stretching (SS) to improve tissue extensibility. Currently, it is unknown if the order an individual performs FR and SS influences flexibility or whether flexibility is retained. This study aimed to determine if FR before, or, following SS influences passive hip flexion range of motion (ROM), and if changes are retained. Design: Between-group experimental design. Methods: Thirty-five participants with less than 90° of passive hip flexion ROM volunteered. Over 8 days, 6 days separated by 24 hours, and then 1 week (day 7) and 2 weeks (day 8) following the last treatment, ROM was measured before and following 1 of 5 treatments; FR/SS, SS/FR, SS, FR, or nothing (control). Participants laid supine on a table where a bubble inclinometer was placed on the tibia of the dominant leg with the hip passively flexed to establish pretreatment ROM. Participants then received the treatments. Passive hip flexion ROM was assessed from pretreatment on day 1 to posttreatment on day 6, day 7 (1 wk), and day 8 (2 wk). Results: Passive hip flexion ROM increased for those receiving FR/SS, SS/FR, FR, and SS. ROM with FR and SS/FR was retained at day 7 but not day 8. Hip flexion ROM for FR/SS and SS were not retained at day 7 nor 8. SS/FR resulted in greater ROM than FR on day 6. SS/FR, FR/SS, SS, and FR were greater than the control at day 6. SS/FR was also greater than the control on days 7 and 8. Conclusion: This study revealed that FR the hamstring muscles after SS produces the greatest gains in passive hip flexion and would be appropriate in noninjured patients with less than 90°.