International Journal of Sports Physical Therapy最新文献

Background: The kinematic sequencing of overhead throwing demonstrates a series of joint motions to generate the throwing force. The biomechanics of the overhead throw have been heavily researched in baseball players; however, more research is needed on the biomechanics of passing in football quarterbacks.

Purpose: The purpose of this pilot descriptive study was to identify the kinematic sequencing of a football quarterback's pass using wireless inertial motion technology.

Study design: Pilot descriptive cross-sectional study.

Methods: Eight young, healthy, right-handed, pain-free quarterbacks (four high school, four collegiate) performed three drop back passes each at three increasing distances (9 total passes at 10, 20 and 30 yards) while wearing Ultium wireless IMUs (Noraxon, Scottsdale AZ) as part of their pre-season assessment. Kinematic data of each pass were identified and marked at four points of interest: foot contact, maximal external rotation, ball release, and maximal internal rotation. Data were analyzed with Noraxon MyoMotion 3.18 using a customized kinematic sequence algorithm to provide mean angles at specific points of interest over the nine throws of each quarterback.

Results: Subjects were male, mean age 16.4 +/- 1.8 years (range 14-20). Kinematic sequencing of the extremities revealed shoulder abduction and external rotation peaked respectively at an average of 112° and 134° at the beginning of the acceleration phase, as did elbow flexion (100°). Stride knee flexion remained relatively consistent, increasing from 29° to 46° after maximal shoulder external rotation. The trunk remained relatively upright; however, quarterbacks experienced an average of 23° of lumbar extension at maximal shoulder external rotation. The trunk initiated rotation with an average of 40° to the right at foot contact, which reversed during the acceleration phase to a maximum of 21° to the left. Hip-shoulder separation remained about 20°, initially favoring right trunk rotation in the cocking phase, but quickly reversed to 20° favoring left trunk rotation in the follow-through. Minimal hip-shoulder separation (11°) occurred at ball release.

Conclusion: In the kinematic sequence from lower to upper extremity, stride knee flexion remains relatively unchanged, while trunk movement tends to shift away from the throwing side, converging toward a near-neutral position in all three planes just before ball release. This pilot study provided insight into the kinematic sequencing of football quarterbacks. Further research is warranted in evaluating the quarterback pass with inertial motion units.

Level of evidence: 3.

Background: Downhill and uphill running alter running kinematics, changing force distributions and muscle activities. While changes in the lower limbs have received more attention, research on the back and pelvis remains scarce. Understanding grade-specific changes in the trunk is crucial for developing injury prevention strategies and return-to-activity protocols after back injuries.

Purpose: This study examined how running on six different gradients (ranging from -15% downhill to +15% uphill) affects back and pelvic posture, as well as muscle activity in trunk and lower limb muscles.

Methods: Twelve healthy recreational runners (6 women, 6 men) participated in a descriptive laboratory study. Kinematic variables (lumbar lordosis, hip drop, pelvic tilt, and trunk inclination) were assessed via 3D motion capture. Surface electromyography recorded muscle activity, normalized to maximum voluntary isometric contraction (MVIC), in selected trunk and lower limb muscles, including the medial gastrocnemius, semitendinosus, biceps femoris, gluteus maximus, gluteus medius, vastus lateralis, rectus abdominis, external oblique, and erector spinae. A linear mixed-effects model with random intercepts was used to compare each gradient to level running. Cohen's d was calculated to quantify effect sizes.

Results: Compared to level running lumbar lordosis was increased at -15% (mean difference [MD]: 1.2 ± 4.9 degrees, Cohen's d = 0.73, p-value = 0.007) and decreased at +15% (MD: -1 ± 3.6 degrees, d = 0.39, p = 0.290). Total hip drop decreased at -15% (MD: 14.2 ± 11 mm, d = 1.93, p < 0.001). Muscular activity of certain lower limb muscles was higher at steep downhill and uphill gradients. While the abdominals showed no consistent changes across gradients, activity of erector spinae was reduced at -10% and -5%.

Conclusion: Downhill running increases lumbar lordosis, potentially elevating the risk of lumbar spine overload. When attempting to prevent and rehabilitate lower back injuries, a progression starting with uphill, followed by level and lastly by downhill running, may be advisable. Gradient-specific training should be considered due to the distinct neuromuscular demands across inclines.

Level of evidence: 3b.

The Concussion in Sport Group (CISG) developed the 6th Consensus Statement on Concussion in Sport following the international conference held in Amsterdam in 2022. Their published statement provides recommendations and an updated Return to Sport (RTS) Strategy that can be adapted for different sports/disciplines. # Description Given the unique demands of figure skating-such as high-speed spins, jumps, inversions, and overhead lifts-this clinical commentary offers sport-specific guidance for healthcare practitioners (HCPs) managing elite figure skaters recovering from sports-related concussions (SRC). This adaptation focuses on reintroduction timing of vertical, rotational, and inversion elements. Further considerations regarding elite athletes and factors impacting recovery are also provided. While scientific evidence of SRCs continues to evolve, these recommendations were derived from the current and available research. # Clinical Relevance Given the complexity of figure skating and variability amongst multiple disciplines, the purpose of this clinical commentary is to provide recommendations and examples of how to apply the current RTS strategy to elite figure skaters following a SRC. # Level of Evidence 5.

The anterior upper arm is composed of the biceps brachii, the coracobrachialis and the brachialis muscles. Collectively, these 3 muscles flex the elbow. The brachialis is known as the workhorse of the elbow as it functions the same despite rotation of the forearm due to its distal attachment on the ulna. The brachialis sits anatomically directly dorsal to the biceps brachii. Although brachialis muscle injuries are rare, they can occur from either contusions or from repetitive overuse. Diagnostic musculoskeletal (MSK) ultrasound offers a portable, real-time, and cost-effective alternative that is gaining traction in rehabilitation and sports medicine settings. MSK ultrasound has emerged as a valuable, non-invasive imaging modality for evaluating brachialis injuries including tissue hypertrophy or structural changes and damage in the upper and anterior forearm. MSK ultrasound is adept at detecting changes in tendon tissue composition and integrity. Furthermore, this manuscript will review the utility of MSK ultrasound in evaluating the brachialis muscle including its anatomy, common injury patterns, sonographic techniques, and clinical implications for professional rehabilitation. By integrating MSK ultrasound into clinical practice, providers can improve the accuracy of diagnosis, enhance diagnostic confidence, monitor healing progression, and guide rehabilitation strategies to optimal patient outcomes.

Background: Endurance athletes (EA) with lung disease and allergic inflammation have worse performance.

Purpose: To examine whether pharmacological treatment can reduce airway disorders such as exercise-induced bronchoconstriction (EIB) and allergic inflammatory response (AIR) in EA.

Study design: Prospective, controlled clinical trial.

Methods: EA who were marathon runners underwent eucapnic voluntary hyperventilation (EVH) for screening assessment. EA who fulfilled the criteria for an EIB+ after an EVH were included in the treatment group (EIB+; n=13), and those who did not were included in the control group (CON; n=18). The athletes were assessed before and 30 days after the intervention. Outcomes included cardiopulmonary exercise testing, lung function, allergic symptoms (allergic questionnaire for athletes [AQUA©]), AIR (T helper [Th]-1, Th2, and Th17 lymphocytes in cell cultures), inflammatory mediator expression, salivary immunoglobulin (Ig)A, blood cortisol, blood IgE levels, and airway inflammation (fraction exhaled nitric oxide [FeNO]). Both groups were advised to keep the same training routine, and only the EIB+ received pharmacological treatment with inhaled corticosteroids (400-800 mcg/day) and long-acting bronchodilators (12 mcg/day). The CON and EIB+ groups underwent the same assessments after the intervention and were compared pre- and post-intervention, and effect sizes were calculated.

Results: EIB+ (males, age 28.1±7.4 years, BMI 20.3±1.0 kg/m2) CON (males, age 29.8±6.5 years, BMI 20.5±1.6 kg/m2) participated. At baseline, the O2 peak, lung function, allergic symptoms, IgE, IgA, FeNO levels, and AIR were not significancly different between groups (p>0.05). After pharmacological treatment, only the EIB+ group showed a decrease in EIB (p<0.001) and an increase in VO2peak compared to baseline (p<0.05). However, no difference was observed in the expression of inflammatory mediators (p>0.05).

Conclusion: Pharmacological treatment reduces EIB and increases the aerobic perforance/fitness in endurance athletes. These benefits occur without modification of the AIR.

Level of evidence: Level II- Prospective Comparative Study.

Background: Markerless motion capture has the potential to repeatedly collect biomechanical data during activities associated with injuries. Few studies have assessed the reliability of this technology during single-leg tasks.

Purpose: The primary aim was to examine the between-day reliability of trunk and lower limb kinematics during single-leg squat and single-leg landing tasks using markerless motion capture. The secondary aim was to examine the between-day reliability of the same protocol using marker-based motion capture.

Design: Reliability.

Methods: Nineteen recreational athletes performed all tasks in two sessions, one week apart. Joint angles of trunk, hip, knee, and ankle were processed using Theia3D. A separate study (10 different participants) evaluated the reliability of marker-based motion capture. In both technologies, full curve analysis was examined using root mean square difference (RMSD) and discrete point analysis (initial contact and peak knee flexion) using intraclass correlation coefficient (ICC) and standard error of measurement (SEM). Statistical parametric mapping (SPM) was also used for full curve analysis in markerless motion capture.

Results: For full curve analysis, markerless motion capture demonstrated low mean RMSD for all joints and planes in both SLS (3.6˚±1.3˚) and landing tasks (forward=3.2˚±1.3˚; medial=3.4˚±1.7˚). SPM showed statistical difference for bilateral hip flexion (full curve) and unilateral hip adduction, rotation, and knee flexion during a percentage of landing tasks. For discrete point analysis, ICC mean indicated moderate to good reliability (SLS= 0.77; forward landing= 0.83; medial landing= 0.80) with low mean SEM values (SLS=3.1°±1.3˚; forward landing=2.3˚±0.9°; medial landing=2.3˚±0.8˚). Marker-based motion capture showed slightly higher mean RMSD (SLS=4.2˚±1.8˚; forward landing=3.5˚±1.0˚; medial landing=3.3˚±0.9) and SEM values (SLS=4.1˚±2.2˚; forward landing=2.7˚±1.2°; medial landing=2.8˚±1.2˚). ICC mean showed good relative reliability (SLS=0.90; forward landing=0.88; medial landing=0.88). Hip flexion presented values >5° across tasks and technologies (RMSD and SEM= 5° to 8°).

Conclusions: Markerless motion capture using Theia3D can reliably measure single-leg tasks with measurement errors comparable to marker-based motion capture. The low measurement error provides confidence for the regular monitoring of athletes during single-leg tasks.

Level of evidence: 3.

Infraspinatus atrophy (IA) is a prevalent but often overlooked condition in elite tennis players, resulting from suprascapular nerve (SN) dysfunction due to repetitive traction or compression. While many athletes maintain normal biomechanics through compensatory mechanisms, these adaptations can lead to kinetic chain imbalances, increasing the risk of secondary injuries. Early detection is crucial to preventing long-term structural changes. Diagnosis involves visual inspection, palpation, and functional tests, though ultrasound imaging offers a more objective assessment of infraspinatus muscle thickness. Conservative treatment aims to restore mobility, strength, and neuromuscular control. Athletes should initially avoid aggravating movements before gradually reintroducing overhead activity. Preventing posterior capsule stiffness through targeted stretching reduces SN compression risk, while nerve gliding exercises enhance mobility. Strengthening programs should prioritize controlled eccentric loading of the infraspinatus and scapular control exercises to improve stability and reduce compensatory strain on surrounding muscles. Preventive strategies are similar to rehabilitation approaches and should be incorporated into training routines, particularly for young athletes. Structured progression in strength training and workload management is essential to prepare the shoulder for high-impact movements like serving. Further research is needed to investigate the relationship between IA and athletic performance, including serve speed and injury risk. This clinical commentary presents a practical approach to the diagnosis and management of IA in elite tennis players. # Level of Evidence 5.

Background and purpose: While indicators such as joint stability, range of motion, and muscle strength are critical for assessing readiness to return to sports, athletes may still face challenges even when these benchmarks are met. Therefore, this study aimed to examine the relationship between sports injury history or return-to-play status and central nervous system excitability during muscle output adjustments, and to investigate the characteristics of evoked EMG during torque maintenance as a potential indicator for assessing readiness to return to sport.

Design: Case control, observational study.

Methods: Twenty-one female university basketball players participated, including athletes with and without a history of surgery. Participants were eligible if they had no current injuries. Those with a history of surgery had completed rehabilitation and were cleared for return to play. Subjects were instructed to maintain 25% of maximum effort of voluntary isometric contraction of knee extension and the torque, long-latency reflexes (LLR) were recorded. Torque maintenance was assessed under two conditions: visual feedback and verbal instructions. Frequency of LLR appearance, and an average of latency, duration, amplitude ratio, and number of phases were calculated. Comparisons were made using Wilcoxon signed-rank tests between the dominant and non-dominant legs, and in participants with a history of injury, comparisons were also made between the injured and non-injured legs.

Results: The visual feedback condition led to finer motor adjustments in uninjured knees compared to verbal feedback. For injured knees, the amplitude ratio of LLR was significantly higher with visual feedback, indicating increased central nervous system excitability. Athletes who had not returned to sports displayed greater torque fluctuation and lower LLR amplitudes, suggesting inadequate fine motor control.

Conclusion: These findings suggest that visual feedback enhances motor adjustments in athletes with previous injuries, indicating heightened reliance on central nervous functions.

Level of evidence: 3b.

Background: When treating runners with patellofemoral pain (PFP), clinicians aim to reduce patients' symptoms, such as pain and discomfort. Running retraining techniques (RRT) and neuromuscular exercises (NME) are key interventions to achieve these goals.

Purpose: This scoping review examined the use of RRT and NME, either combined or standalone, in runners with PFP.

Study design: Scoping review.

Methods: Databases searched included MEDLINE, ScienceDirect, and Google Scholar. Two researchers independently identified eligible studies and extracted data. The scoping review followed the PRISMA-SCR framework, using population, concept, and context criteria. The population included recreational to professional runners over 18 years with PFP, excluding those involved in any sport other than running., as well as those with prior knee surgeries, the history or presence of other knee pathologies, or pediatric populations. The review focused on studies utilizing NME or RRT for PFP treatment, adhering to ACSM guidelines and excluding studies only providing study protocols. Exercise reporting was assessed using the Consensus on Exercise Reporting Template. NME protocols were analyzed using the FITT framework (Frequency, Intensity, Time, Type). RRT protocols were evaluated by session frequency, start timing, clinician input, cadence, feedback, footwear use, speed changes, self-rehabilitation, and progression.

Results: Fifteen studies were reviewed. The timing and complementarity of RRT with NME were often absent or poorly defined. NME mainly focused on single-leg squats in seven protocols, with forward lunges, step-downs, and trunk-rotating squats in three studies each. These exercises emphasized trunk inclination and gluteal activation, with variations in feedback, sets, reps, and progression. RRT treatment ranged from a single 10-minute retraining session to 12 weekly sessions. Cadence increase was addressed in six studies, dynamic valgus in four, with most feedback being auditory/visual. Minimalist shoes were used in two studies, and three standardized running speed.

Conclusion: A notable variability exists in interventions for PFP in runners, especially in the timing and complementarity of RRT and NME. A standardized reporting system is needed to better analyze study protocol implementation.

Level of evidence: N/A.

Background: Maturity status varies among adolescents of the same age, making age an unreliable indicator. Although maturity status affects movement patterns, differences in landing force and jump performance among maturity groups remain unclear.

Hypothesis/purpose: This study compared landing force and jump performance during drop vertical jump in adolescent male soccer players based on classifications by maturity status and age. A hypothesis was formulated that landing force would be greater during the period of peak height velocity (PHV) and jump performance higher in the post-PHV group, showing clearer differences than age.

Study design: Cross-sectional study.

Methods: Forty-five male soccer players (13.5 ± 0.9 years) were grouped by maturity status (pre-, circa-, and post-PHV), and by age. Landing forces (peak vertical ground reaction force [PVGRF], time to PVGRF, and loading rate) and jump performance (jump height, contact time, reactive strength index [RSI], PVGRF, and power) were measured using a force plate. A one-way analysis of variance was performed to detect group differences.

Results: Landing forces showed no significant differences among maturity groups (PVGRF: p = 0.190; time to PVGRF: p = 0.122; and loading rate: p = 0.255). Jump height was greater in post-PHV (32.87 ± 4.18 cm) than in pre-PHV (25.17 ± 4.85 cm, p = 0.001). RSI was higher in post- (1.33 ± 0.31 m/s) than in pre- (1.00 ± 0.29 m/s, p = 0.024) and circa-PHV groups (1.02 ± 0.23 m/s, p = 0.021). Power was greater in post- (40.40 ± 6.31 W/kg) than in pre- (33.15 ± 7.78 W/kg, p = 0.045) and circa-PHV groups (33.59 ± 5.50 W/kg, p = 0.037). Age-related differences were found only in jump height (p < 0.001).

Conclusion: Maturity status classification detected significant group differences in jump height, RSI, and power, but age classification only detected a significant group difference in jump height.

Level of evidence: 3.