Importance of heat therapy in the treatment of pain in the daily clinical practice.

BACKGROUND: Musculoskeletal (MSK) pain includes a wide variety of causes and conditions. Despite the heterogeneity of MSK pain, it is possible to identify some common clinical features and treatments. Heat therapy (HT) is one of the most common and could be a suitable non-pharmacological approach. OBJECTIVE: To obtain a European overview on the use of non-pharmacological approaches and the role of heat therapy in the treatment of MSK pain. METHODS: Through a two-cycle Delphi-like method, an international board of experts reached a consensus on 13 questions for a survey to healthcare professionals who provide direct patient care. Between November 2021 and January 2022, the resulting web survey was distributed to professionals with the collaboration of ten European scientific societies and associations. Univariate and bivariate analyses were performed on collected data. RESULTS: Two hundred eighty-two answers were validated. Most of the respondents had extensive professional experience. Participants were widely distributed throughout Europe. HT is administered to about 50% of patients, with a higher percentage administered to those affected by low back pain (92%) and neck pain (84%). The choice of exogenous HT is based on both personal clinical experience and scientific evidence. HT is primarily chosen due to its relaxation effect, high safety profile and enhancement of tissue perfusion. The use of HT is recommended by 86.5% of respondents. CONCLUSION: Experts indicate that exogenous HT represents a valid therapeutic choice and is widely used in Europe. Patients should be informed about the use of heat therapy as a valuable self-management therapy option.

Pathogenesis and Diagnosis of Proximal Hamstring Tendinopathies.

The proximal hamstring complex is a highly vulnerable area that is especially prone to injury. Proximal hamstring tendinopathies (PHTs) remain challenging in diagnosis, treatment, rehabilitation, and prevention due to a large variety of different injuries, slow healing response, persistent symptoms, and functional impairments. PHTs are often misdiagnosed or underdiagnosed, leading to delayed treatment and therapy failure. In addition, many athletes are at a high risk of PHT recurrence, a leading cause of prolonged rehabilitation and impaired individual performance. Until now, there have been no clear criteria for the diagnosis and classification of PHT. Tendinopathies can be graded based on their symptoms and onset. Additionally, radiological characteristics exist that describe the severity of tendinopathies. The diagnosis usually includes a battery of pain provocation tests, functional tests, and imaging to ensure a proper classification. Understanding the specific tasks in the pathogenesis and diagnostic process of PHT requires knowledge of functional anatomy, injury pattern and pathophysiological mechanisms as well as examination and imaging techniques. This work provides a structured overview of the pathogenesis and diagnostic work-up of PHT, emphasizing structured examination and imaging to enable a reliable diagnosis and rapid treatment decisions.

Suitability of Slaughterhouse-Acquired Pig Eyes as Model Systems for Refractive Ultraviolet and Infrared Femtosecond Laser Research.

PURPOSE: To elucidate whether it is feasible to use porcine eyes from scalded, abattoir-acquired animals for refractive femtosecond laser research. METHODS: An infrared laser (FS 200) and an ultraviolet laser (prototype version) were tested for their applicability on scalded pig eyes. Fifty porcine eyes were divided into two equally-sized groups and assigned to either the infrared or the ultraviolet laser. Both laser groups were comprised of five subgroups of n = 5 eyes each. Group A: non-scalded eyes (negative control); group B: eyes taken from tunnel-scalded animals; group C1: eyes taken from tank-scalded animals without opaque corneal lesion; group C2: eyes taken from animals with opaque corneal lesion; group D: eyes scalded in toto in the laboratory (positive control). In each group the lasers were employed to create a stromal flap. The quality of the laser cuts and the resulting flap beds, as well as of the porcine corneas themselves, was examined by anterior segment optical coherence tomography and scanning electron microscopy. RESULTS: All scalded specimens exhibited substantial corneal swelling, most pronounced in group C2. After ultraviolet laser application, the tank- and tunnel-scalded samples displayed marked irregularities and an increased degree of surface roughness in the flap beds. After infrared laser application, this was only the case in the tank-scalded specimens. CONCLUSION: It is not recommended to use eyes taken from scalded pigs for ultraviolet femtosecond laser experiments. For infrared femtosecond lasers, eyes taken from tunnel-scalded animals may represent an acceptable alternative, if non-scalded eyes are not available.

Moderate evidence exists for four microRNAs as potential biomarkers for tendinopathies and degenerative tendon ruptures at the upper extremity in elderly patients: conclusion of a systematic review with best-evidence synthesis.

PURPOSE: The aim of this systematic review was to investigate tendon-specific microRNAs (miRNAs) as biomarkers for the detection of tendinopathies or degenerative tendon ruptures. Also, their regulatory mechanisms within the tendon pathophysiology were summarized. METHODS: A systematic literature research was performed using the PRISMA guidelines. The search was conducted in the Pubmed database. The SIGN checklist was used to assess the study quality of the included original studies. To determine the evidence and direction of the miRNA expression rates, a best-evidence synthesis was carried out, whereby only studies with at least a borderline methodological quality were considered for validity purposes. RESULTS: Three thousand three hundred seventy studies were reviewed from which 22 fulfilled the inclusion criteria. Moderate evidence was found for miR-140-3p and miR-425-5p as potential biomarkers for tendinopathies as well as for miR-25-3p, miR-29a-3p, miR-140-3p, and miR-425-5p for the detection of degenerative tendon ruptures. This evidence applies to tendons at the upper extremity in elderly patients. All miRNAs were associated with inflammatory cytokines as interleukin-6 or interleukin-1ß and tumor necrosis factor alpha. CONCLUSIONS: Moderate evidence exists for four miRNAs as potential biomarkers for tendinopathies and degenerative tendon ruptures at the upper extremity in elderly patients. The identified miRNAs are associated with inflammatory processes.

What makes an orthopaedic paper highly citable? A bibliometric analysis of top orthopeadic journals with 10-year follow up.

PURPOSE: To examine a series of papers from top ranked orthopaedic journals with respect to the number of citations over a 10-year observation period to identify factors that lead to high citation rates. METHODS: The Web of Science database was consulted to identify all published papers from the first-year term of 2010 (January-May) from four top orthopaedic journals: AJSM, Arthroscopy, JBJS Am and KSSTA. The database was used to analyze and compare the papers with respect to their characteristics and citations up to 2019. Basic information for each paper was collected including the author, country, study type and average citations per year (ACY). The most (Top20%) and least (Bottom20%) frequently cited papers were identified and differences were extracted. RESULTS: Five hundred sixteen papers were included with a total of 19,261 citations. Most of the published papers were from the United States (n = 245). On average, a paper received 37.3 citations over the 10-year observation period. The most cited paper was cited 322 times. The most cited study type was randomized controlled trial (RCT) (Ø80.8). The Top20% papers were cited 37 times more often than the Bottom20%. Among the Top20%, the largest group was cohort study (n = 20) followed by case series (n = 19). Among others, the number of authors, the number of keywords and the number of references significantly correlated with the number of citations (p < 0.001). CONCLUSIONS: Factors influencing citation frequency were identified.

Effects of exercise and cold-water exposure on microvascular muscle perfusion.

PURPOSE: Microvascular blood flow (MBF) and its intramuscular regulation are of importance for physiological responsiveness and adaptation. The quantifiable in-vivo monitoring of MBF after cycling or systemic cold-water exposure may reveal new insights into capillary regulatory mechanisms. This study aimed to assess the role of exercise and cold therapy on MBF by using contrast-enhanced ultrasound (CEUS). METHODS: Twenty healthy athletes were recruited and randomly assigned to an intervention (IG) or a control group (CG). MBF was quantified in superficial (rectus femoris, RF) and deep muscle layers (vastus intermedius, VI). Representative perfusion parameters (peak enhancement (PE) and wash-in area under the curve (WiAUC)) were measured after a standardized measurement protocol for both groups at resting conditions (t0) and after cycling (20 min., 70% Watt max, t1) for both groups, after cold-water immersion exposure for IG (15 min., 12°C) or after precisely 15 minutes of rest for CG (t2) and for both groups after 60 minutes of follow-up (t3). RESULTS: At t1, MBF in VI increased significantly compared to resting conditions in both groups in VI (p= 0.02). After the cold-water exposure (t2), there were no statistically significant changes in perfusion parameters as well as after 60 minutes of follow-up (t3) (p = 0.14). CONCLUSION: Cycling leads to an upregulation of MBF. However, cold exposure does not change the MBF. The implementation of CEUS during different physiological demands may provide deeper insight into intramuscular perfusion regulation and regenerative processes.

[Groin pain in sports games: a systematic review]. / Risikofaktoren für Leistenschmerzen in den Sportspielen: Eine systematische Literaturrecherche.

BACKGROUND: In sports games, epidemiological data show that groin pain is relatively common and can lead to repeated loss of time. Consequently, it is essential to be aware of the evidence-based prevention strategies. The aim of this systematic review was to examine risk factors and prevention strategies for groin pain and to rank them based on their evidence in sports games. METHODS: The review was conducted according to the PRISMA guidelines, using a PICO-scheme in the PubMed, Web of Science and SPOLIT databases. We included all available intervention and observational studies on the influence of risk factors and prevention strategies on groin pain in sports games. The methodological quality and level of evidence was assessed using the PEDro-Scale and OCEBM model, respectively. Finally, the quantity, quality and level of evidence was used to rank each risk factor for its grade. RESULTS: Moderate evidence was found for four risk factors that significantly influence the risk of groin pain: male sex, previous groin pain, hip adductor strength and not participating in the FIFA 11+ Kids. Moreover, moderate evidence was found for the following non-significant risk factors: older age, body height and weight, higher BMI, body fat percentage, playing position, leg dominance, training exposure, reduced hip abduction, adduction, extension, flexion, and internal rotation-ROM, hip flexor strength, hip abductor, adductor, flexor and core strengthening with balance exercises, clinical hip mobility tests and physical capacities. CONCLUSION: The identified risk factors can be considered when developing prevention strategies to reduce the risk of groin pain in sports games. Thereby, not only the significant, but also the non-significant risk factors should be considered for prioritisation.

[Imaging of muscle injuries in sports medicine]. / Bildgebung von Muskelverletzungen im Sport.

BACKGROUND: Early diagnosis of muscle injuries is indispensable in order to initiate appropriate treatment and to facilitate optimal healing. PURPOSE: The aim of this review is to provide an update on imaging of muscle injuries in sports medicine with a focus on ultrasound and magnetic resonance imaging (MRI) and to present experimental approaches in addition to routine diagnostic procedures. MATERIALS AND METHODS: A PubMed literature search for the years 2012-2022 using the following keywords was performed: muscle, muscle injury, muscle imaging, muscle injury classification, delayed onset muscle soreness, ultrasound, MRI, sodium MRI, potassium MRI, ultra-high-field MRI, injuries of athletes. RESULTS: Imaging is crucial to confirm and assess the extent of sports-related muscle injuries and may help establishing treatment decisions, which directly affect the prognosis. This is of importance when the diagnosis or grade of injury is unclear, when recovery is taking longer than expected, and when interventional or surgical management may be necessary. In addition to established methods such as B­mode ultrasound and 1H­MRI, individual studies show promising approaches to further improve the imaging of muscle injuries in the future. Prior to the integration of contrast-enhanced ultrasound and X­nuclei into clinical routine, additional studies are needed to validate these techniques further. CONCLUSION: B­mode ultrasound represents an easily available, cost-effective modality for the initial diagnosis of muscle injuries. MRI is still considered the reference standard and enables an accurate morphological assessment of the extent of the injury. There are still no imaging approaches available for the objective determination of the optimal point of return to play.

Sodium and quantitative hydrogen parameter changes in muscle tissue after eccentric exercise and in delayed-onset muscle soreness assessed with magnetic resonance imaging.

The objective of the current study was to assess sodium (23 Na) and quantitative proton (1 H) parameter changes in muscle tissue with magnetic resonance imaging (MRI) after eccentric exercise and in delayed-onset muscle soreness (DOMS). Fourteen participants (mean age: 25 ± 4 years) underwent 23 Na/1 H MRI of the calf muscle on a 3-T MRI system before exercise (t0), directly after eccentric exercise (t1), and 48 h postintervention (t2). In addition to tissue sodium concentration (TSC), intracellular-weighted sodium (ICwS) signal was acquired using a three-dimensional density-adapted radial projection readout with an additional inversion recovery preparation module. Phantoms containing saline solution served as references to quantify sodium concentrations. The 1 H MRI protocol consisted of a T1 -weighted turbo spin echo sequence, a T2 -weighted turbo inversion recovery, as well as water T2 mapping and water T1 mapping. Additionally, blood serum creatine kinase (CK) levels were assessed at baseline and 48 h after exercise. The TSC and ICwS of exercised muscles increased significantly from t0 to t1 and decreased significantly from t1 to t2. In the soleus muscle (SM), ICwS decreased below baseline values at t2. In the tibialis anterior muscle (TA), TSC and ICwS remained at baseline levels at each measurement point. However, high-CK participants (i.e., participants with a more than 10-fold CK increase, n = 3) displayed different behavior, with 2- to 4-fold increases in TSC values in the medial gastrocnemius muscle (MGM) at t2. 1 H water T1 relaxation times increased significantly after 48 h in the MGM and SM. 1 H water T2 relaxation times and muscle volume increased in the MGM at t2. Sodium MRI parameters and water relaxation times peaked at different points. Whereas water relaxation times were highest at t2, sodium MRI parameters had already returned to baseline values (or even below baseline values, for low-CK participants) by this point. The observed changes in ion concentrations and water relaxation time parameters could enable a better understanding of the physiological processes during DOMS and muscle regeneration. In the future, this might help to optimize training and to reduce associated sports injuries.

Effects of Different Orthoses on Neuromuscular Activity of Superficial and Deep Shoulder Muscles during Activities of Daily Living and Physiotherapeutic Exercises in Healthy Participants.

BACKGROUND: This study aimed to investigate the effects of different shoulder orthoses on the neuromuscular activity of superficial and deep shoulder muscles during activities of daily living (ADL) and physiotherapeutic exercises. METHODS: Ten participants with healthy shoulders (31 ± 3 years, 23.1 ± 3.8 kg/m2) were randomized to receive a "shoulder sling", an "abduction pillow" and a "variably adjustable orthosis" on the dominant side. With each orthosis, they completed seven ADL with and four physiotherapeutic exercises without wearing the orthoses. An electromyographic system was used to record the neuromuscular activity of three superficial (trapezius, deltoid, pectoralis major) and two deep shoulder muscles (infraspinatus, supraspinatus) using surface and intramuscular fine-wire electrodes. RESULTS: The neuromuscular activity differs between the orthoses during ADL (p ≤ 0.045), whereby the "variably adjustable orthosis" mostly showed the highest activation levels associated with the worst subjective wearing comfort rated on a visual analog scale. In addition, differences exist between the physiotherapeutic exercises (p ≤ 0.006) demonstrating the highest activations of the infra- and supraspinatus muscles for assistive elevation and wipe across a table, middle for pendulum and lowest for continuous passive motion exercises. CONCLUSIONS: The neuromuscular activity of superficial and deep shoulder muscles differs between the orthoses during ADL and also between the physiotherapeutic exercises.

Muscle perfusion and the effect of compression garments in delayed-onset muscle soreness assessed with arterial spin labeling magnetic resonance imaging.

Background: There is limited information about perfusion in exercise-induced muscle injuries such as delayed-onset muscle soreness (DOMS) and the effect of compression garments as a therapeutic strategy during the regeneration phase. The purpose of this prospective, explorative study was to evaluate muscle perfusion in DOMS and to assess the effect of compression garments at resting conditions and during DOMS by magnetic resonance (MR) arterial spin labeling (ASL). Methods: DOMS was induced from 03/2021 to 04/2021 using an eccentric and plyometric exercises targeting the calf muscles in 14 volunteers. A compression garment (21-22 mmHg) was worn during and for 6 h after exercise on one randomized leg. Magnetic resonance imaging (MRI) including ASL of both lower legs was performed before and directly after the exercise as well as after 6 h, and 48 h using a 3 Tesla MRI system. Perfusion analyses of the gastrocnemius muscle (GM) and the tibialis anterior muscle (TA) were performed and results were compared to baseline measurements. T2-weighted images and creatine kinase levels were acquired at baseline and after 48 h. Results: All volunteers presented a successful induction of DOMS in the GM after 48 h. Arterial muscle perfusion in the GM increased from baseline to measurements taken directly after the exercise (4.97±5.59 mL/100 g/min, P<0.001). No significant alteration in perfusion compared to baseline was observed at 6 h (P=0.16) and 48 h (P=1.0) after the induction of DOMS. Compression garments did not elicit a significant alteration in ASL parameters in the GM (P=0.65) or the TA (P=0.05) at any time point. No adverse events occurred during the study. Conclusions: After an initial exercise-associated increase in arterial muscle perfusion, a normalization of blood supply was observed at 6 and 48 h after the exercise intervention inducing DOMS. Wearing a compression garment (21-22 mmHg) during and after the induction of DOMS did not affect muscle perfusion at rest, nor did it have any significant effect on muscle perfusion during the regeneration phase. The results can help to better understand the pathophysiological properties of DOMS and may have implications for diagnostic and therapeutic strategies.

Multi-Parametric Analysis of Below-Knee Compression Garments on Delayed-Onset Muscle Soreness.

To investigate below-knee compression garments during exercise and a post-exercise period of 6 h on clinical, functional, and morphological outcomes in delayed-onset muscle soreness (DOMS). Eighteen volunteers (age: 24.1 ± 3.6, BMI 22.7 ± 2.7 kg/m2) were enrolled. Measures were acquired at baseline, 6 h, and 48 h after eccentric and plyometric exercise, with wearing a compression garment (21-22 mmHg) on a calf during and for the first 6 h after exercise. 3T MRI was performed for quantification of intramuscular edema (T2 signal intensity (SI), T2 time, and manual volume segmentation); jump height, calf circumference, ankle dorsiflexion (DF), creatine kinase (CK), and muscle soreness were assessed. DOMS was confirmed in all participants after 48 h, with an increase in soreness (p < 0.001) and CK (p = 0.001), decrease in jump height (p < 0.01), and the presence of intramuscular edema (p < 0.01) in both the compressed and non-compressed limbs. No differences between the compressed and non-compressed limbs were observed for muscle soreness and jump height. MRI T2 SI, T2 time, soreness, and manual segmentation revealed no effect of the compression treatment. The assessment of calf circumference and DF showed no changes in either the compression or non-compression limb (p = 1.0). Wearing compression garments during combined eccentric and plyometric exercise and for 6 h post-exercise has no effect on clinical signs of DOMS, jump performance, or the development of intramuscular edema.

Effect of compression garments on muscle perfusion in delayed-onset muscle soreness: A quantitative analysis using intravoxel incoherent motion MR perfusion imaging.

The aim of this prospective cohort study was to evaluate the effect of compression garments under resting conditions and after the induction of delayed-onset muscle soreness (DOMS) by MR perfusion imaging using intravoxel incoherent motion (IVIM). Magnetic resonance imaging of both lower legs of 16 volunteers was performed before and after standardized eccentric exercises that induced DOMS. A compression garment (21-22 mmHg) was worn during and for 6 h after exercise on one randomly selected leg. IVIM MR imaging, represented as total muscle perfusion D*f, perfusion fraction f and tissue diffusivity D, were compared between baseline and directly, 30 min, 6 h and 48 h after exhausting exercise with and without compression. Creatine kinase levels and T2-weighted images were acquired at baseline and after 48 h. DOMS was induced in the medial head of the gastrocnemius muscle (MGM) in all volunteers. Compression garments did not show any significant effect on IVIM perfusion parameters at any time point in the MGM or the tibialis anterior muscle (p > 0.05). Microvascular perfusion in the MGM increased significantly in both the compressed and noncompressed leg between baseline measurements and those taken directly after and 30 min after the exercise: the relative median f increased by 31.5% and 24.7% in the compressed and noncompressed leg, respectively, directly after the exercise compared with the baseline value. No significant change in tissue perfusion occurred 48 h after the induction of DOMS compared with baseline. It was concluded that compression garments (21-22 mmHg) do not alter microvascular muscle perfusion at rest, nor do they have any significant effect during the regeneration phase of DOMS. In DOMS, only a short-term effect of increased muscle perfusion (30 min after exercise) was observed, with normalization occurring during regeneration after 6-48 h. The normalization of perfusion independently of compression after 6 h may have implications for diagnostic and therapeutic strategies and for the better understanding of pathophysiological pathways in DOMS.

Quantifiable Contrast-Enhanced Ultrasound Explores the Role of Protection, Rest, Ice (Cryotherapy), Compression and Elevation (PRICE) Therapy on Microvascular Blood Flow.

The aim of this randomized controlled laboratory study was to evaluate the role of standardized protection, rest, ice (cryotherapy), compression and elevation (PRICE) therapy on microvascular blood flow in human skeletal muscle. Quantifiable contrast-enhanced ultrasound was used to analyze intramuscular tissue perfusion (ITP) of the rectus femoris (RF) and vastus intermedius (VI) muscles in 20 healthy athletes who were randomly assigned to PRICE or control groups. Baseline perfusion measurements (resting conditions, T0) were compared with cycling exercise (T1), intervention (PRICE or control, T2) and follow-up at 60 min post-intervention (T3). The 20 min PRICE intervention included rest, cryotherapy (3°C), compression (35 mm Hg) and elevation. After intervention, PRICE demonstrated a decrease of ITP in VI (-47%, p = 0.01) and RF (-50%, p = 0.037) muscles. At T3, an ongoing decreased ITP for the RF (p = 0.003) and no significant changes for the VI were observed. In contrast, the control group showed an increased ITP at T2 and no significant differences at T3. PRICE applied after exercise led to a down-regulation of ITP, and the termination of PRICE does not appear to be associated with a reactive hyperemia for at least 60 min after treatment.

Assessing Foot Loads in Continuous Passive Motion (CPM) and Active Knee Joint Motion Devices.

BACKGROUND: Continuous passive motion (CPM) and active knee joint motion devices are commonly applied after various surgical procedures. Despite the growing use of active motion devices, there is a paucity of data comparing plantar loads between the different mobilization techniques. The aim of this study was to investigate foot loads during knee joint mobilization in continuous passive and active knee joint motion devices and to compare this data to the physiological load of full weight-bearing. PATIENTS/MATERIAL AND METHODS: Fifteen healthy participants (7 women and 8 men, 25 ±â€Š3 years, 66 ±â€Š6 kg, 175 ±â€Š10 cm, BMI 21.9 ±â€Š2) were recruited. Plantar loads were measured via dynamic pedobarography using a continuous passive motion device (ARTROMOT-K1, ORMED GmbH, Freiburg, Germany) and an active motion device (CAMOped, OPED AG, Cham, Switzerland), each with a restricted range of motion of 0-0-90° (ex/flex) and free ROM for the knee joint. For the active motion device, cycles were performed at four different resistance levels (0-III). Data were assessed using the pedar® X system (Novel Inc., Munich, Germany), which monitors loads from the foot-sole interface. Force values were compared between motion devices and normal gait, which served as the reference for conditions of full weight-bearing. P-values of < 0.05 were considered statistically significant. RESULTS: Normal gait revealed peak forces of 694 ±â€Š96 N, defined as 100 %. The CPM device produced plantar forces of less than 1.5 N. Using the active motion device in the setting of 0-0-90° produced foot loads of < 1.5 N (resistance 0-II) and 3.4 ±â€Š9.3 N with a resistance of III (p < 0.001). Conditions of free ROM resulted in foot loads of 4.5 ±â€Š4.5 N (resistance 0), 7.7 ± 10.7 N (resistance I), 6.7 ±â€Š10.4 (resistance II) and 6.7 ±â€Š6.9 N with a resistance of III (p < 0.001), corresponding to 0.6 %, 1.1 %, 1.0 % and 1.0 % of full weight-bearing, respectively. CONCLUSION: Motion exercises of the knee joint can be performed both with passive and active devices in accordance with strict weight-bearing restrictions, which are often recommended by surgeons. Also, active motion devices can be used when the ankle joint or foot have to be offloaded. Further studies assessing intraarticular joint load conditions have to be performed to confirm the findings obtained in this study.

Effects of passive, active, and mixed playing strategies on external and internal loads in female tennis players.

This study aimed to investigate the effects of different playing strategies on external and internal loads in female tennis players during match play. Also, the underlying effects on the technical-tactical actions and activity profiles were examined. Twelve well-trained female players (age: 25±5 years; maximum oxygen uptake: 40.9±4.3 ml/kg/min) played points against an opponent of similar ability outdoors on red-clay courts. The players played points over five playing conditions. Before each condition, the players were instructed to apply either a passive, an active, or their own playing strategy (free play) to succeed. The five conditions were played in a randomized order, whereas the condition with the own strategy was always played first and served as control. During play, the external and internal loads were investigated by 10 Hz global positioning system, 100 Hz inertial measurement unit, short-range telemetry, capillary blood, and visual analog scale procedures. A 25 Hz video camera was used to examine the technical-tactical actions and activity profiles. Compared to the control condition, the passive, active, and mixed playing strategy conditions induce up to large effects on the external loads (running distances with high acceleration and deceleration), up to moderate effects on the internal loads (energy expenditures spent with high metabolic power, lactate concentration, and rating of effort), and up to very large effects on the technical-tactical actions (number of ground strokes and errors) and activity profiles (strokes per rally, rally duration, work to rest ratio, and effective playing time). Our study shows that passive, active, and mixed playing strategies have an impact on the external and internal loads, technical-tactical actions, and activity profiles of female tennis players during match play. This finding should be considered for practical purposes like match analyses and training procedures in the tennis environment.

Ankle flossing alters periarticular stiffness and arterial blood flow in asymptomatic athletes.

BACKGROUND: Tissue flossing has been introduced to increase impaired range of motion (ROM) and flexibility, to enhance prevention and rehabilitation, as well as to improve athletic performance; however, limited evidence exists for its efficacy. The aim of the present study was to evaluate the effects of ankle flossing on periarticular stiffness and perfusion via Acoustic Radiation Force Impulse (ARFI) elastography and Power Doppler Sonography (PDS). METHODS: Twenty-one healthy students (age: 24±2 years, BMI: 22±3 kg/m2) were recruited as participants. ARFI was performed to evaluate periarticular ankle stiffness involving the anterior ankle capsule (AC), the anterior talofibular ligament (ATFL) and the peroneus brevis muscle (PBM). Arterial blood flow was assessed in the dorsal pedal artery. Measurements were taken under resting conditions (T0) and twice after standardized ankle flossing (T1: 0 min., T2: 60 min. postintervention). RESULTS: The connective tissue stiffness decreased significantly after ankle flossing compared to baseline (T1, AC: -12%, P=0.009, ATFL: -12%, P=0.003; T2, AC: -8%, P=0.002, ATFL: -9%, P=0.015). The PBM stiffness decreased by 3% (T1, P=0.304) and 4% (T2, P=0.029). The perfusion measures significantly increased by 30% at T1 compared to baseline (P=0.001); no significant changes were observed at T2 (P=0.492). CONCLUSIONS: This is the first study demonstrating decreased AC and ATFL stiffness and reactive hyperemia to be key mechanisms of ankle flossing. Additional studies must be conducted to determine whether changes in biomechanical properties influence dynamic ankle stability.

A cross-sectional study on foot loading patterns in elite soccer players of different ages.

BACKGROUND: Alterations in plantar loading patterns are risk factors for stress injuries of the lower limb, particularly of the foot and ankle. Epidemiological studies have revealed a higher incidence of soccer-related stress fractures of the fifth metatarsal (MT V) in younger athletes than in their adult counterparts. OBJECTIVE: The aim of the present study was to assess the plantar pressure distributions of members of four high-level soccer teams of different age groups to identify age-related differences in loading patterns. METHODS: A total of 65 elite soccer players were included in the study. Data were computed with sensor-loaded insoles (pedar® X system, novel Inc., Munich, Germany) while the players ran in soccer shoes. Plantar pressures for nine defined regions on the preferred and nonpreferred foot were analyzed. RESULTS: The participants consisted of 17 elite male soccer professionals from the first national league (mean 23 years, height 184 cm, weight 81 kg), 14 players from the under-21 squad (U21, 20 years, 180 cm, 75 kg), 15 players from the U17 squad (16 years, 176 cm, 69 kg) and 19 players from the U16 squad (15 years, 179 cm, 70 kg). We detected statistically significantly elevated peak pressures on the lateral aspects of the nonpreferred foot compared with the preferred foot in the U16 and U17 players, corresponding to a relative increase by 29% (p= 0.044) in the lateral midfoot, a relative increase by 24% (p= 0.031) in MT heads 4-5 in the U16 players and a difference of 18% (p= 0.049) in the lateral midfoot in the U17 players. In contrast, the U21 and adult professional players displayed symmetric plantar pressure distributions in all foot regions. CONCLUSIONS: In contrast to adult elite soccer players, adolescents demonstrate asymmetric foot loading patterns with increased peak loads in the lateral aspects of the nonpreferred foot. Our results may provide some explanation for MT V stress fractures that occur in elite adolescents.

Mechanisms of Acute Knee Injuries in Bouldering and Rock Climbing Athletes.

BACKGROUND: There is limited insight into the mechanisms of knee injuries in rock climbing and bouldering in noncompetitive and competitive athletes. PURPOSE: To examine the traumatic mechanisms of injury, demographics, distribution, and severity of knee injuries in affected athletes. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: During a 4-year period, we performed a retrospective multicenter analysis of acute knee injuries in competitive and noncompetitive climbing athletes. Traumatic mechanisms were inquired and severity levels, therapies, and outcomes recorded with visual analog scale, Tegner, Lysholm, and climbing-specific outcome scores. RESULTS: Within the observation period, 71 patients (35% competitive athletes, 65% noncompetitive athletes) with 77 independent acute knee injuries were recorded. Four trauma mechanisms were identified: high step (20.8%), drop knee (16.9%), heel hook (40.3%), and (ground) fall (22.1%). The leading structural damage was a medial meniscal tear (28.6%), found significantly more often in the noncompetitive group. A specific climbing injury is iliotibial band strain during the heel hook position. Most injuries resulted from indoor bouldering (46.8%). Surgical procedures were predominantly necessary in noncompetitive climbers. One year after the injury, the Tegner score was 5.9 ± 0.8 (mean ± SD; range, 3-7); the Lysholm score was 97 ± 4.8 (range, 74-100); and the climbing-specific outcome score was 4.8 ± 0.6 (range, 2-5). CONCLUSION: Increased attention should be placed on the climber's knee, especially given the worldwide rise of indoor bouldering. Sport-specific awareness and training programs for noncompetitive and competitive climbing athletes to reduce knee injuries should be developed, and sports medical supervision is mandatory.