International Journal of Sports Physical Therapy最新文献

Background/purpose: Monitoring intensity during elastic resistance training in velocity-based training (VBT) is challenging in clinical and field settings due to the lack of validated, practical tools. This study aimed to determine whether the OMNI-Resistance Exercise Scale for elastic bands (OMNI-RES EB) is an appropriate tool for monitoring exercise intensity during squats performed at maximal intended velocity and with a 10% velocity loss during elastic resistance training within a VBT framework.

Study type: Quasi-experimental cohort study.

Methods: Twenty-four physically active individuals (8 women, 16 men; 23.54±3.18 years; 23.47±2.37 kg/m²; body fat %: 14.11±5.29%; 1RM: 102.73±26.16 kg) completed two sessions of four sets of squats (40%, 55%, 70%, 85%, 100% 1RM, random order) using EB. Participants were specifically instructed to perform each repetition at their maximum intended velocity. Sets were stopped at 10% velocity loss. Mean propulsive velocity (MPV) was measured during the first and last repetitions using a linear velocity transducer. Rating of perceived exertion (RPE) obtained from the OMNI-RES EB was recorded immediately after the first and last repetitions. Load, heart rate, and repetitions were recorded at each set's end. Outcome measures were analyzed by sex, physical activity level, and relative strength. Effect sizes were calculated, and internal consistency was also explored.

Results: All concurrent variables, including RPE, varied significantly among %1RM. Physical activity and sex did not influence RPE. Significant differences in first-repetition RPE were found at 55%, 85%, and 100% 1RM between normal and high relative strength participants. Internal consistency analysis showed good to excellent relative reliability and acceptable absolute reliability. The MPV-RPE correlation was r = -0.76.

Conclusion: First-repetition RPE using the OMNI-RES EB is a reliable, cost-effective method for monitoring velocity-based training with EB, comparable to linear velocity transducers.

Level of evidence: 3b.

Background: Injuries often result from an interaction between load and intrinsic risk factors, with female handball players demonstrating higher prevalence of shoulder problems compared to males. While shoulder rotation strength deficits are recognized as risk factors, the influence of lower body strength (LBS), trunk rotation power (TRP), and the relative importance of internal versus external load on shoulder problems in female handball players remains unknown.

Purpose: To assess whether pre-season LBS, TRP, and shoulder strength were associated with shoulder problems in female handball players, and whether pre-season strength and power influenced the association between load and shoulder problems.

Study design: Prospective observational cohort study.

Methods: Pre-season LBS (Isometric Mid-thigh Pull), TRP (measured while seated) and isometric external (ER) and internal rotation (IR) shoulder strength were measured (31 female handball players). Prevalence, substantial prevalence, and severity of shoulder problems were documented weekly through one season (29 weeks) via the Oslo Sports Trauma Research Center Overuse Questionnaire. Participation-related (internal) shoulder load (PSL) was documented weekly with the modified Borg rate of perceived exertion and the number of shots taken during the season documented to reflect external load. Data was analyzed using the Spearman´s correlation coefficient and a mixed model ANOVA (separate mixed model ANOVAs were constructed for each pre-season variable).

Results: Thirty-one players (mean age 23.5 +/- 4.6 years) participated. For all mixed model ANOVAs, higher PSL was associated with higher severity score (F range: 31.1-39.9, p<0.001). Significant positive interactions were found between PSL and pre-season TRP (p=0.001), LBS (p<0.001), and ER strength (p=0.01) in terms of their influence on the severity score. High pre-season LBS and ER strength were correlated with prevalence of substantial shoulder problems (r_s=0.40, r_s=0.38, respectively).

Conclusions: The positive association between pre-season strength and power, and shoulder problems, highlights the complexity of shoulder problems in female handball players.

Level of evidence: 3.

Background: The single-leg wall squat (SLWS) has the potential to be used as a functional test to assess lower extremity muscular endurance. While previous research has explored its muscular activation patterns, its relationship with isolated muscle strength and potential sex-specific responses remains under-investigated.

Purpose: This study aimed to examine the descriptive statistics of the SLWS and the correlation between handheld dynamometry (HHD) measures of hip and knee strength and SLWS test performance. Secondary aims included the investigation of potential sex differences in SLWS test performance and associated physiological responses.

Study design: Observational cohort.

Methods: Thirty healthy university students (13 female, 17 male) aged 18-30 years participated. Maximal isometric strength of the dominant leg's hip extensors, abductors, and knee extensors was measured using HHD. Participants then performed a SLWS test on the dominant leg to volitional failure, with repetitions counted and perceived exertion (RPE) assessed. Heart rate was monitored and reasons for test termination were recorded. Descriptive statistics were calculated for all measures. Pearson correlations assessed relationships between isometric strength and single-leg wall squat repetitions, while independent samples t-tests compared measures between sexes.

Results: Average SLWS test performance was 76.2 ± 35.2 repetitions. Average heart rate and RPE post-SLWS were 146.3 ± 17.1 bpm and 8.3 ± 1.2 out of 10, respectively. SLWS test performance was not significantly correlated with HHD measures. No significant sex differences were observed in SLWS performance, although they were observed for HHD measures and RPE. Gluteus maximus fatigue was the most commonly reported reason for test termination (41.4%).

Conclusion: The SLWS test demonstrated potential as a functional endurance assessment, eliciting moderate-to-high physiological strain. However, performance did not correlate with isolated muscle strength, suggesting the test captures a complex interplay of factors beyond isolated muscle function. No sex differences were observed in SLWS performance. Further research is needed to explore the test's validity and sensitivity to changes in lower extremity function.

Level of evidence: 3.

Background: Running offers numerous health benefits, yet the prevalence of running-related injuries remains perfect. Evaluating running biomechanics through kinematic variables has gained attention due to their association with injuries. Currently, 3D video analysis is considered the gold standard, however, its complexity and cost limit widespread use. Consequently, 2D kinematic analysis using standard cameras has become popular, although research on its reliability is lacking. Hypothesis/Purpose: The purpose of this study was to evaluate the reliability of the main kinematic variables of running, assessed categorically using 2D video analysis, in amateur runners aged 18 to 55 years.

Study design: A cross-sectional analytical observational study.

Methods: Thirty-three amateur runners aged 18-55 underwent evaluation. Reflective markers were placed on key anatomical landmarks of the dominant lower limb to enhance motion tracking in 2D video recordings from sagittal and posterior frontal planes. The videos were analyzed by three independent raters: a consensus group (four persons), a separate physical therapist, and an athletic trainer. Pairwise inter-rater agreement was assessed among all three raters using the Kappa coefficient. Nine categorical kinematic variables related to running biomechanics were assessed.

Results: The variables that presented the greater concordance were the foot progression angle (K 0.847, 0.654, 0.792), heel whip (K 0.780, 0.847, 0.835), knee window (K 0.847, 0.847, 0.835) and overstriding (K 0.920, 0.780, 0.857). The variables with the lowest concordance were pelvic drop (K 0.257, 0.047, 0.597) and hindfoot eversion (K 0.604, 0.236, 0.604). Perfect concordance was obtained in seven of the nine variables between the consensus group and the physical therapist.

Conclusion: 2D kinematic analysis exhibited promising reliability for specific running variables, suggesting its potential in clinical settings. However, its effectiveness depends on both the evaluated variables and the expertise of the evaluators.

Level of evidence: Level 3.

Introduction: Although the stretch-shortening cycle (SSC) influence is well determined on jump performance in adult professional volleyball, the influence of this mechanism on jump in volleyball players in the development phase is unknown. The aim of this study was to evaluate anthropometric profile, jump performance, stiffness and pre-stretch augmentation percentage (PSAP) in Brazilian under-19 volleyball team athletes.

Methods: Twenty-nine male volleyball athletes who were members of the Brazilian under-19 volleyball team were recruited. Squat jump (SJ) and countermovement jump (CMJ) were assessed followed the protocol suggested by Bosco et al. on a contact mat, along with the determination of lower limb stiffness and PSAP. The data were evaluated using descriptive statistics.

Results: The subjects were 18.2±0.5 years (Body mass: 87.59±10.93 kg, height: 195.75±9.21 cm.) The mean results included stiffness 0.43±0.15 N.m-1.kg-1, CMJ height 39.9±5.21 cm, SJ height 41.99±5.7 cm, and PSAP 5.22±3.18 %.

Discussion: The anthropometric profile results highlight the inclusion of athletes of large stature for volleyball, and that SJ and CMJ values are still below those found in adult athletes.

Conclusion: Brazilian athletes from the under-19 national team show potential for improvement in the efficiency of the stretch-shortening cycle (SSC), as indicated by the PSAP values.

Level of evidence: 3b.

Background and purpose: Understanding how strength profiles of footballers effect the extent or location of injury sustained is limited. The purpose of this study was to investigate the effect of eccentric hamstrings strength (EHS), on the resultant injury sustained, graded utilizing the British Athletic Muscle Injury Classification, diagnosed via MRI.

Methods: EHS of 95 professional footballers were assessed on match-day minus two (MD-2) and plus two (MD+2). Participants completed three maximal repetitions of the bilateral Nordic hamstring exercises. Metrics included Peak Force (PF), Peak Torque (PkT), Average Force (AvF), Average Torque (AvT), Maximum Impulse (MI), Impulse Symmetry (IS), PF symmetry (PFS), PkT symmetry (PkTS) and relative strength (RS). Profiles were identified in relation to the date the injury was sustained.

Results: EHS across all metrics with the exemption of PkT, had no effect on injury grade, site or playing level. Tendon injuries were the most frequently occurring injury location, specifically grade 3c. Athlete strength had no effect on whether an injury was sustained or grade of injury.

Conclusion: The occurrence of tendon related injury is high within this study population and may be a result of the physical strength of the muscle tissue, combined with game play demands, exposing the tendon to greater forces, thus heightening the extent of injury sustained. Level of Evidence - 3.

Background: While the clinical effects of localized percussive therapy (PT) are well-documented, studies investigating the underlying physiological mechanisms remain scarce. # Purpose The aim of this study was to investigate the changes and time course of local skin temperature (Tskin), deep tissue perfusion (erythrocyte flow velocity [speed] and deep tissue blood flow [flux]), and muscle oxygenation (SmO2) after a standardized 4-minute treatment with a TheragunTM of the vastus medialis muscle of healthy women. # Study design Descriptive Laboratory Study. # Methods Tskin, speed, flux and SmO2 were measured in the treated area in 26 healthy female participants at baseline and following a 4-minute TheragunTM application, with recordings taken at 5-minute intervals for up to 50 minutes post-application. Additionally, Tskin was also measured on the control leg. A repeated measures ANOVA was performed to assess temporal changes and differences between the treated and control conditions. # Results Following the Theragun™ treatment, significant increases were observed in the treated area at all time points for Tskin (p < 0.001), speed (p < 0.001), flux (p < 0.001), and SmO2 (p < 0.05) compared to baseline. Tskin (mean change of 3.76 °C) and SmO2 (mean change of 5.78%) reached their highest values at five minutes post-treatment (t5), whereas speed (mean change of 23.79 arbitrary units [AU]) and flux (mean change of 115.66 AU) peaked immediately (t0) after the application. Tskin on the control leg also differed significantly across all time intervals compared to baseline (p < 0.05), peaking at t30 (mean change 0.64°C). # Conclusion A 4-minute localized Theragun™ application enhances physiological responses in cutaneous, subcutaneous, and muscle tissues. It increases skin temperature and improves deep tissue blood flow, red blood cell movement, and muscle oxygenation. These findings highlight the impact of TheragunTM on deep tissue layers, offering valuable insights into the physiological mechanisms of PT. The results support the potential for its use in optimising athletic performance and recovery through enhanced blood flow and muscle oxygenation.

Level of evidence: 2b.

Background: Neuromuscular fatigue (NMF) has been defined as the exercise-induced performance decrease associated with muscular activity. # Purpose The primary aim was to identify the available evidence regarding the testing tasks used to assess NMF in the lower limbs and to determine the most commonly used test in specific sports. The secondary aim was to group the tests found according to the type of sport. # Study Design Scoping review. # Methods A literature search was conducted in PubMed, ScienceDirect, SportDiscus, and Web of Science databases. Search terms were "neuromuscular fatigue" and ("test" or "tests" or "testing task" or "task"). Studies that analyzed healthy humans, voluntary contractions, and participants under 50 years old were included. Studies in which the main focus was not NMF, the lower limbs were not analyzed, the knee joint was not involved, the pre-post analysis of fatigue was not used, or there was no sport fatigue protocol between tests were excluded. The PRISMA-ScR guidelines were followed. # Results A total of 97 studies were included. Most of these included males (68.0%) and professional athletes in their samples (46.4%) . The data most commonly studied for NMF were athletes from team sports (74.2%), specifically soccer (32.0%) and rugby (18.6%). Matches and trainings sessions were the fatiguing protocols (59.8%), whereas vertical jumps (82.5%), measured by force platforms (77.5%), was the test most commonly used. The most commonly evaluated parameters were jump height (75.0%) and peak power (41.3%). Tests varied different according to the sport, and vertical jumps (77.8%), and sprints (15.3%) were the tests most commonly used for the athletes in team sports. For athletes in individual sports, vertical jumps (72.0%) and isometric knee extension/knee flexion (24.0%) were most utilized. # Conclusions Different fatigue protocols, test tasks, materials, and variables are used to assess NMF. Veritcal jump is the most commonly utilized test task for athletes of both team and individual sports. It appears necessary to choose the most appropriate test tasks according to each type of sport.

Level of evidence: Level 2b.

Dance is a complex sport with a high prevalence of associated musculoskeletal injuries, especially among ballet dancers. Acute lower extremity (LE) fractures may occur in this population due to losses of balance and landing from high impact dance skills, but there is limited current evidence detailing the physical therapy rehabilitation of such injuries. The purpose of this case report is to describe the physical therapy management of a professional ballerina post-traumatic fracture of the proximal phalanx of the fourth toe. # Case Description The subject was a 27-year-old dancer employed by a professional ballet company. Ten months prior to her initial physical therapy evaluation, the subject landed from a leap on the lateral border of the left foot and flexed fourth and fifth toes. Plain film radiographic imaging revealed a nondisplaced fracture of the proximal phalanx of the fourth toe with a small section of avulsed bone. The avulsed bone was surgically resected eight months post-injury due to persistent pain with continued dance rehearsals. The subject was referred to outpatient physical therapy for post-operative rehabilitation and return to sport training. # Outcomes The subject attended 18 therapy visits over an eight-week period with documented improvements in ankle strength in all planes, fourth toe range of motion, and self-reported LE functional mobility with the Outpatient Physical Therapy Improvement in Movement Assessment Log (OPTIMAL). The subject improved by 14 points on the OPTIMAL, with additional improvements reported in her tolerance of en pointe and demi pointe ballet positions. Upon discharge, she was cleared for return to full training and performance en pointe using a novel return to sport protocol for body-region specific rehabilitation for ballet dancers. # Conclusion This case report outlines the successful rehabilitation of a high-level dance professional post-traumatic toe fracture. Additional research is needed to further examine return to sport protocol and testing with ballet professionals after an acute traumatic ankle or foot fracture. # Level of Evidence 4.

Background: Little is known about the injury risk associated with weighted ball use by professional baseball pitchers. The purpose of this study was to describe weighted ball training and injuries and compare injury rates between those professional pitchers using weighted ball training and those that did not use weighted ball training during the 2023 pre- and regular season.

Methods: This study, intended as a multi-year project, serves as an interim safety analysis after one year of follow up. Pitchers underwent routine physical examination and injury screening and were surveyed about their use of weighted baseball training. Throughout spring training and the Minor League Baseball (MiLB) season, all pitchers were monitored daily for athletic exposures and injuries. The outcome of interest was non-traumatic baseball injuries to any tendon, ligament, nerve, muscle, or bone that occurs during any baseball team sponsored activity or event that was confirmed by the team athletic trainer. Injury rates per 1000 game exposures (GE) was calculated by weighted ball use and grouped by body part.

Results: Eighty-eight pitchers were included (Weighted Ball: n = 46; No Weighted Ball: n = 42) A total of 28 injuries were reported ((Upper extremity=20 (Shoulder Injury:9; Elbow Injury 11); Trunk/Core=8; Lower Extremity=0). Pitchers that used weighted ball training suffered eight more injuries at a 1.1 greater injury rate per 1,000 athlete exposure days compared to pitchers that did not use weighted ball training. Weighted ball pitchers arm injury rate was 11.8 per 1000 GE, and no weighted ball arm injury rate was 7.5 per 1000 GE. Weighted ball pitcher trunk injury rate was 5.9 per 1000 GE, and no weighted ball trunk injury rate was 2.1 per 1000 GE.

Conclusions: In this interim safety analysis, professional pitchers that performed weighted ball training suffered from greater arm and core/trunk injuries compared to professional pitchers that did not perform weighted ball training.

Level of evidence: 3.