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.

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.

Early functional and morphological changes of calf muscles in delayed onset muscle soreness (DOMS) assessed with 7T MRI

BACKGROUND

To assess morphological and functional alterations of the skeletal muscle in exercise-induced delayed onset muscle soreness (DOMS) using 7 Tesla (T) magnetic resonance imaging (MRI).

METHODS

DOMS was induced in 16 volunteers performing an eccentric exercise protocol of the calf muscles of one randomized leg. 7 T MRI including T1w- (0.18×0.18×1mm3), T2w-images (0.2×0.2×2mm3), T2-maps (0.5×0.5×5mm3), and susceptibility weighted imaging (SWI, 0.7×0.7×0.7 mm3) were acquired at baseline, directly (t1) and 60 hours (t2) after the exercise. T2 signal intensity (SI), T2 values [ms], T1 SI and SWI were assessed in the medial (MG) and lateral gastrocnemius muscle (LG) and in the soleus muscle (SM). In addition, the serum creatine kinase (CK) activity, range of motion (ROM) of the ankle, calf circumference, and muscle soreness were assessed at each time point.

RESULTS

Directly after exercise (t1), T2 SI (p=0.04) and T2 values (p=0.03) increased significantly in the LG. No changes of SI and T2 values for MG and SM were present at t1. At t2, T2 SI and T2 values of LG (p=0.001, p=0.02) and MG (p=0.04, p=0.03) increased significantly compared to baseline. T1 SI did not change in any muscle at any time point. In SWI, no signs of intramuscular signal drop could be detected. Clinical parameters confirmed the induction of DOMS, with a significant increase of CK (p=0.03), muscle soreness (p<0.001), calf circumference (p=0.001), and respective a decrease of ROM (p=0.04).

CONCLUSIONS

7 T MRI has the potential to visualize microstructural muscle damage immediately after an exercise that induces DOMS. No changes in susceptibility which could, for example, reflect micro-hemorrhage, could be detected with SWI immediately after exercise or in DOMS. Ultra-high field MRI may potentially be used in sports medicine to monitor intramuscular structural changes, allowing for modification of training intensity or to implement appropriate therapeutic strategies.

Effects of foam rolling on vastus intermedius and lateralis microvascular blood flow

INTRODUCTION

Foam Rolling (FR) as a technique of self-massage has become a widely used intervention in clinical and sports practice. It is assumed that FR leads to an increased intramuscular microvascular blood flow (MBF), and therefore is commonly recommended as a warm-up or regeneration method. However, no data validate the effects of FR on MBF. This study aimed to assess whether FR increases intramuscular MBF using contrast-enhanced ultrasound (CEUS).

METHODS

Ten healthy athletes performed a standardized FR intervention applied to the lateral thigh (3 sets: 45 s FR, 20 s rest). Intramuscular perfusion was determined by CEUS under resting conditions (t0), immediately (t1), and 30 min (t2) after the intervention. Peak enhancement (PE), wash-in rate (WiR), and wash-in perfusion index (WiPI) were evaluated as quantitative perfusion parameters in vastus lateralis (VL) and intermedius (VI) muscle separately via regions of interest mapping.

RESULTS

Immediately after the intervention (t1), perfusion parameters showed a non-significant decrease in VL (p = 0.3; PE: -32.1%, WiPI: -29.6%, WiR: -50.4%) and VI (p = 0.4; PE: -10.3%, WiPI: -6.4%, WiR: -35.6%). A non-significant decrease was found at t2 in VL (p = 0.2; PE: -34%, WiPI -33.9%, WiR -61.2%) and VI (p = 0.2; PE -17.6%, WiPI -13.8%, WiR -43.2%).

CONCLUSIONS

The common assumption of intramuscular MBF improvement due to FR could not be confirmed for up to 30 min after the intervention. If an increase in intramuscular metabolism or MBF is intended, we recommend that alternative methods (i.e., traditional warm-up) should be preferred.

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]

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]

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 B‑mode ultrasound and ¹H‑MRI, 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 X‑nuclei into clinical routine, additional studies are needed to validate these techniques further.

CONCLUSION

B‑mode 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.

Back and neck problems as well as disadvantageous ergonomic behavior patterns in university students: Concomitants of the pandemic?

Background

As a part of the coronavirus disease 2019 (COVID-19) lockdown measures, universities converted courses to digital formats, leading to remote studying. It is unclear how these measures affect university students in terms of musculoskeletal problems (i.e., neck and back pain), e.g., by non-ergonomically equipped home offices or reduced physical activity.

Material and methods

Students from Osnabrück University weresurveyed via fully standardized online questionnaires from early March to mid-April 2022 (6 weeks) about neck and back problems, movement behavior in home offices, and personal information.

Results

Of 447 students who clicked on the link, 378 students (80.4% female, mean age: 24.1 ± 4.2 years) answered the questionnaire (response rate: 84.6%). 299 (79.1%) students suffered from neck pain and 294 (77.8%) from back pain during the pandemic. 206 (54.4%) students generally used ergonomic furniture, 83 (22.0%) used ergonomic sitting furniture, 57 (15.1%) used a standing desk, and 212 (56.1%) used aids for a more comfortable use of laptops in home office. 203 (53.7%) students took movement breaks in home office, 207 (54.8%) worked out regularly, and 65 (17.2%) moved regularly in the fresh air.

Conclusions

The present study found a high rate of neck and back pain amongst university students. Measures are needed to prevent neck and back pain in this group, considering that increased physical activity and enhanced home office equipment might be beneficial.

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

Methods

Results

Conclusions

Influence of physical activity on well-being at times of the COVID-19 pandemic: a review

Background

Physical activity (PA) has been shown to be advantageous to one's health. Coronavirus disease 2019 (COVID-19) lockdown measures have reportedly led to substantial decrease of PA and to drastic reduction of well-being (WB). In light of this, the purpose of this review was to assess the impact of PA on WB during the COVID-19 pandemic.

Material and Methods

In May 2021, Literature search was conducted in Pubmed/Medline. The eligible publication period was one year from the search date.

Results

Synthesis of results from eight publications reporting on data from around 100 countries showed that PA positively influences diverse dimensions of the multivariate construct of WB, all of them relating to mental health. Young adults and women showed lowest PA concomitant with lowest self-reported WB.

Conclusions

Reduced PA levels resulted in lower WB levels, which might have a negative impact on mental health. Forthcoming, initiatives will be needed to facilitate PA – ideally whilst promoting joy of moving – in consideration of pandemic circumstances. By this means it will be possible to effectively promote WB and to prevent arising mental health issues. The current findings are fundamental to develop suitable approaches to improve PA in pandemic situations.

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.

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.

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 T_3, 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.

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 (T<inf>0</inf>) and twice after standardized ankle flossing (T<inf>1</inf>: 0 min., T<inf>2</inf>: 60 min. postintervention).

RESULTS

The connective tissue stiffness decreased significantly after ankle flossing compared to baseline (T<inf>1</inf>, AC: -12%, P=0.009, ATFL: -12%, P=0.003; T<inf>2</inf>, AC: -8%, P=0.002, ATFL: -9%, P=0.015). The PBM stiffness decreased by 3% (T<inf>1</inf>, P=0.304) and 4% (T<inf>2</inf>, P=0.029). The perfusion measures significantly increased by 30% at T<inf>1</inf> compared to baseline (P=0.001); no significant changes were observed at T<inf>2</inf> (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.

Effects of Pre- and Post-Exercise Cold-Water Immersion Therapy on Passive Muscle Stiffness

BACKGROUND

 Cold-water immersion (CWI) has become a popular preventive, regenerative and performance-enhancing intervention in various sports. However, its effects on soft tissue, including changes of intramuscular stiffness, are poorly understood. The purpose of this study was to investigate the effect of CWI on muscle stiffness.

PATIENTS/MATERIAL AND METHODS

 Thirty healthy participants were included and divided into the three following groups (n = 10): 1) post-ESU group: exercise and CWI (post-exercise set-up); 2) control group: exercise without CWI (control condition); 3) pre-ESU group: CWI alone (pre-exercise set-up). Acoustic radiation force impulse (ARFI) elastography was conducted to assess tissue stiffness (shear wave velocity, SWV). Values obtained at resting conditions (baseline, t0) were compared to values post-exercise (t1, for post-ESU group and control group), post-CWI (t2, for post-ESU group and pre-ESU group; rest for control group) and to 60-min follow-up time (t3, for all groups). Data were assessed in superficial and deep muscle tissue (rectus femoris muscle, RF; vastus intermedius muscle, VI).

RESULTS

 For the post-ESU group (CWI post-exercise), there was no significant difference between the time points of measurements: exercise (t1: RF: 1.63 m/s; VI: 1.54 m/s), CWI (t2: RF: 1.63 m/s; VI: 1.53 m/s) and at 60-min follow-up (t3: RF: 1.72 m/s; VI: 1.61 m/s). In the control group, a significant decrease of SWV was found between baseline conditions at t0 and post-exercise (t1) at VI (VI: 1.37 m/s; p = 0.004; RF: 1.59 m/s; p = 0.084). For t2 and t3, no further significant changes were detected. Regarding the pre-exercise set-up (pre-ESU group), a significant decrease in SWV from baseline to t2 in VI (1.60 m/s to 1.49 m/s; VI: p = 0.027) was found.

CONCLUSION

 This study shows varying influences of CWI on muscle stiffness. Overall, we did not detect any significant effects of CWI on muscle stiffness post-exercise. Muscle stiffness-related effects of CWI differ in the context of a pre- or post-exercise condition and have to be considered in the implementation of CWI to ensure its potential preventive and regenerative benefits.

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.

Prevalence of MRI-Detected Ankle Injuries in Athletes in the Rio de Janeiro 2016 Summer Olympics

OBJECTIVE

To describe the prevalence, severity, and location of ankle injuries as assessed on magnetic resonance imaging (MRI) in athletes participating in the Rio de Janeiro 2016 Summer Olympic Games.

METHODS

We analyzed all ankle MRIs that were acquired for suspected injury as reported by the National Olympic Committee medical teams and the Organizing Committee medical staff during the Rio 2016 Summer Olympics. Diagnostic imaging was performed through the Olympic Village Polyclinic. Images were interpreted retrospectively according to standardized criteria.

RESULTS

A total of 11,274 athletes participated in the Games, of which 89 (8.8%) were referred for an ankle MRI. Eighty-eight of the 89 (99%) had at least 1 abnormal finding, and some had as many as 27, for an average of 6.2 abnormalities per examination. Around one-fifth of all abnormal findings were considered pre-existing (21%) and 79% were assumed to be the result of an acute or subacute injury. The highest proportion of acute/subacute injuries per athlete occurred in ball sports (7.0 injuries per examination) and in the age group >30. Most pre-existing findings per athlete were identified in the group of others (no track and field or ball sports athletes) with 2.5 findings per examination and respectively in the age group >30 (1.7).

CONCLUSION

Our study demonstrated a high prevalence of acute and subacute, but also pre-existing injuries in Olympic athletes undergoing ankle MRI. Tendon injuries were the most common acute injuries, found mainly in ball sports athletes. Most pre-existing ankle injuries were identified at the ligaments.

Evaluation of Rock Climbing Related Injuries in Older Athletes

INTRODUCTION

With the growing enthusiasm from people of all ages about rock climbing and bouldering, adaptions and medical conditions of the older athlete have become increasingly important. We aimed to analyze injury demographics, distribution, and severity for the older rock-climbing athlete.

METHODS

During a 3-y period, we performed a single-center injury surveillance in athletes ≥35 y of age presenting with rock climbing-related injuries or complaints. A standard questionnaire and examination protocol were conducted.

RESULTS

A total of 198 patients (age 44.2±7.1 [35-77] y) (mean±SD, with range) with 275 independent injuries were recorded. Ninety percent of all injuries affected the upper extremity, 6% the lower extremity, and 4% other body regions. The Union Internationale des Associations d'Alpinisme injury scores were 2.0±0.3 (1-4), and no fatalities occurred. Acute injuries were observed in 32% and overuse injuries in 68% of all injuries. Among the overuse injuries, 47% were classified as degenerative overuse conditions. Athlete age did not significantly correlate with the development of overuse injuries and UIAA injury score, but subgroup analysis showed a weak correlation of the climber age with the development of degenerative conditions (P<0.05). The leading diagnosis of degenerative conditions was subacromial impingement syndrome of the shoulder.

CONCLUSIONS

Compared to younger athletes, older rock climbers demonstrate a higher proportion of overuse injuries, especially degenerative conditions. Profound knowledge of climbing injuries patterns and conditions in older rock climbers is crucial to prevent injuries among all age groups and to decrease the number of degenerative injuries.

Trefoil Factor 3 (TFF3) Is Involved in Cell Migration for Skeletal Repair

The aim of the study was to explore the possible role of Trefoil Factor Family peptide 3 (TFF3) for skeletal repair. The expression of TFF3 was analyzed in human joint tissues as well as in a murine bone fracture model. Serum levels of TFF3 following a defined skeletal trauma in humans were determined by ELISA. The mRNA expression of TFF3 was analyzed under normoxia and hypoxia. Expression analysis after stimulation of human mesenchymal progenitor cells (MPCs) with TFF3 was performed by RT² Profiler PCR Array. The effect of recombinant human (rh)TFF3 on MPCs was analysed by different migration and chemotaxis assays. The effect on cell motility was also visualized by fluorescence staining of F-Actin. TFF3 was absent in human articular cartilage, but strongly expressed in the subchondral bone and periosteum of adult joints. Strong TFF3 immunoreactivity was also detected in murine fracture callus. Serum levels of TFF3 were significantly increased after skeletal trauma in humans. Expression analysis demonstrated that rhTFF3 significantly decreased mRNA of ROCK1. Wound healing assays showed increased cell migration of MPCs by rhTFF3. The F-Actin cytoskeleton was markedly influenced by rhTFF3. Cell proliferation was not increased by rhTFF3. The data demonstrate elevated expression of TFF3 after skeletal trauma. The stimulatory effects on cell motility and migration of MPCs suggest a role of TFF3 in skeletal repair.

[Effectiveness of Upper Body Compression Garments Under Competitive Conditions: A Randomised Crossover Study with Elite Canoeists with an Additional Case Study]

This study aimed to investigate the effects of upper body compression garments on performance changes in elite canoeists. A total of 23 elite athletes from the German Canoe Federation (6 women and 17 men) were recruited. On a regatta lake, the athletes completed a 1650-m test track with their competition or training boats and paddles. The athletes were randomised into two groups and performed the test track with and without upper body compression garments. Besides split and end times, capillary blood lactate concentrations were assessed. For statistical analysis, an effect-based approach ("Magnitude-Based Inferences") and an additional case study were conducted. For this purpose, the mean and individual effects were examined in relation to the smallest worthwhile changes. On average, the effect-based approach shows that upper body compression garments do not lead to clear changes in performance. The changes in lactate concentrations were clear, but were considered trivial. In contrast to the average statistical analysis, the results of the case study demonstrate that upper body compression garments lead to an improved performance in 13.0 % and a worsened performance in 4.4 % of athletes. Additionally, a decreased lactate concentration was found in 4.4 % and an increased lactate concentration in 17.4 % of athletes. Our study shows that, on average, upper body compression garments have no effects on the performance and lactate concentration of highly trained elite canoeists. In individual cases, however, there are beneficial as well as harmful effects that may have practical relevant consequences for elite athletes.

Radial extracorporeal shock wave therapy in flexor tendon pathology of the hand: A feasibility study

BACKGROUND

Radial extracorporeal shock wave therapy (rESWT) is an effective and safe non-invasive therapeutic option for various musculoskeletal pathologies. However, data on possible application of radial extracorporeal shock waves (rESWs) on soft tissue components of fingers is still scarce.

OBJECTIVE

We now aimed to analyze the feasibility of applying rESWs to human fingers ex vivo.

METHODS

Fresh frozen human cadaveric fingers were exposed to rESWs of varying energy density. The penetration of the rESWs into the soft tissue was determined using pressure sensitive Fuji films that were placed underneath the flexor tendons and other soft tissue components at the proximal phalanx. Then, rESWs were applied and activation of the Fuji film was recorded. Software based image analysis was performed on all films treated with rESWT under ultrasound gel.

RESULTS

Penetration of the rESWs through the soft tissue was detected in all settings. Increasing energy density of the rESWs resulted in increasing film activation. Image analysis of films used under ultrasound showed a significant difference among the groups.

CONCLUSION

The results of this study demonstrate that rESWs can penetrate soft tissues including the flexor tendons of human cadaveric fingers. rESWT should be considered as a valuable potential therapeutic option of different finger pathologies. Further studies focusing on the clinical application of rESWT for finger pathologies are required.

Compartment Syndrome of the Foot: An Evidence-Based Review

Compartment syndrome of the foot (CSF) is a surgical emergency, with high risk of morbidity and poor outcome, including persistent neurologic deficits or amputation. Uncertainty remains regarding surgical approaches, pressure monitoring values, and the extent of surgical treatment. This review provides a summary of the current knowledge and reports evidence-based diagnostic and therapeutic management options for CSF. Articles describing CSF were identified from MEDLINE, PubMed, and Cochrane databases up until February 2018. Experimental and original articles, systematic and nonsystematic reviews, case reports, and book chapters, independent of their level of evidence, were included. Crush injuries are the leading cause of CSF, but CSF can present after fractures of the tarsal or metatarsal bones and dislocations of the Lisfranc or Chopart joints. CSF is often associated with persistent neurologic deficits, claw toes, amputations, and skin healing problems. Diagnosis is made after accurate clinical evaluation combined with intracompartmental pressure monitoring. A threshold value of <20 mmHg difference between the diastolic blood pressure and the intracompartmental pressure is considered diagnostic. Management consists of surgery, whereby 2 dorsal incisions are combined with a medioplantar incision to the calcaneal compartment. The calcaneal compartment can serve as an "indicator compartment," as the highest-pressure values can regularly be measured within this compartment. Appropriately powered studies of CSF are necessary to further evaluate and compare diagnostic and therapeutic options.

Accelerating Recovery from Exercise-Induced Muscle Injuries in Triathletes: Considerations for Olympic Distance Races

The triathlon is one of the fastest developing sports in the world due to expanding participation and media attention. The fundamental change in Olympic triathlon races from a single to a multistart event is highly demanding in terms of recovery from and prevention of exercise-induced muscle injures. In elite and competitive sports, ultrastructural muscle injuries, including delayed onset muscle soreness (DOMS), are responsible for impaired muscle performance capacities. Prevention and treatment of these conditions have become key in regaining muscular performance levels and to guarantee performance and economy of motion in swimming, cycling and running. The aim of this review is to provide an overview of the current findings on the pathophysiology, as well as treatment and prevention of, these conditions in compliance with clinical implications for elite triathletes. In the context of DOMS, the majority of recovery interventions have focused on different protocols of compression, cold or heat therapy, active regeneration, nutritional interventions, or sleep. The authors agree that there is a compelling need for further studies, including high-quality randomized trials, to completely evaluate the effectiveness of existing therapeutic approaches, particularly in triathletes. The given recommendations must be updated and adjusted, as further evidence emerges.

Effectiveness of Manual Therapy, Customised Foot Orthoses and Combined Therapy in the Management of Plantar Fasciitis-a RCT

Background: Plantar fasciitis (PF) is one of the most common causes of plantar heel pain. Objective: To evaluate the effectiveness of three different treatment approaches in the management of PF. Methods: Sixty-three patients (44 female, 19 men; 48.4 ± 9.8 years) were randomly assigned into a manual therapy (MT), customised foot orthosis (FO) and a combined therapy (combined) group. The primary outcomes of pain and function were evaluated using the American Orthopaedic Foot and Ankle Society-Ankle Hindfoot Scale (AOFAS-AHS) and the patient reported outcome measure (PROM) Foot Pain and Function Scale (FPFS). Data were evaluated at baseline (T0) and at follow-up sessions after 1 month, 2 months and 3 months (T1–T3). Results: All three treatments showed statistically significant (p < 0.01) improvements in both scales from T0 to T1. However, the MT group showed greater improvements than both other groups (p < 0.01). Conclusion: Manual therapy, customised foot orthoses and combined treatments of PF all reduced pain and function, with the greatest benefits shown by isolated manual therapy.

Cross-Sectional Investigation of Stress Fractures in German Elite Triathletes

Triathlon is a popular sport for both recreational and competitive athletes. This study investigated the rates and patterns of stress fractures in the German national triathlon squad. We developed a web-based retrospective questionnaire containing questions about the frequency of stress fractures, anatomic localisation and associated risk factors. The survey was conducted as an explorative cross-sectional study. Eighty-six athletes completed the questionnaire. Twenty athletes (23%) sustained at least one stress fracture. All documented stress fractures were located in the lower extremities. Factors associated with a higher risk for stress fractures were female gender, competitive sport prior to triathlon career, Vitamin D or iron deficiency, menstrual disturbances and a high number of annual training hours. Disseminating knowledge among athletes and their professional community in order to raise awareness about early symptoms and relevant risk factors could help to improve prevention and reduce the incidence of stress fractures.

Advances in Delayed-Onset Muscle Soreness (DOMS) – Part II: Treatment and Prevention

Delayed-onset muscle soreness (DOMS) describes an entity of ultrastructural muscle damage. The manifestation of DOMS is caused by eccentric muscle contractions or unaccustomed forms of exercise. Clinical signs include impaired muscular force capacities, painful restriction of movement, stiffness, swelling, and altered biomechanics in adjacent joints. Although DOMS is categorised as a mild type of muscle damage, it is one of the most common reasons for compromised sportive performance. In the last decade, many hypotheses have been developed to explain the aetiology of DOMS, and there are a wide range of different interventions aiming to prevent or alleviate the symptoms. Many studies have evaluated various types of cold or heat therapy, compression, massage, physical therapy or nutritional interventions. Treatment considerations focus on the primary prevention of ultrastructural lesions during exercise, the treatment of the inflammatory response that leads to DOMS, and recovery strategies for manifest DOMS. This narrative review aims to present an overview of the current treatment and preventive strategies in the field of DOMS.

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 ± 3 years, 66 ± 6 kg, 175 ± 10 cm, BMI 21.9 ± 2) 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 ± 96 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 ± 9.3 N with a resistance of III (p < 0.001). Conditions of free ROM resulted in foot loads of 4.5 ± 4.5 N (resistance 0), 7.7 ± 10.7 N (resistance I), 6.7 ± 10.4 (resistance II) and 6.7 ± 6.9 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.

Plantar pressure changes in hindfoot relief devices of different designs

BACKGROUND

It is frequently observed that overloading the foot can impair bone and soft tissue healing and can lead to harmful sequelae (i.e. ulcers, stress reactions) in context of pre-existing tissue disabilities. In terms of offloading, hindfoot relief devices are commonly applied as a non-operative treatment as well as after various surgical procedures for hindfoot disorders. Despite their common use, there is a paucity of data comparing different orthotic devices with respect to changes in plantar pressure distributions. The aim of this study was to investigate plantar loadings in hindfoot relief devices of different designs.

METHODS

Twenty-five healthy participants (13 women, 12 men; (mean ± SD) age 37 ± 14 years; BMI 23 ± 4 kg/m2) were recruited. Plantar pressure distributions were collected using i.) a neutral shoe, ii.) a hindfoot relief shoe (HRS) and iii.) a hindfoot relief orthosis (HRO). Peak pressure values were measured via dynamic pedobarography during walking and were analysed from four different plantar regions: the hindfoot, midfoot, metatarsal I-V and forefoot. As a reference standard, the normal walk using neutral shoes served as the condition for full weight-bearing.

RESULTS

Concerning the hindfoot, using the HRS as well as the HRO resulted in significant decreases in plantar pressures compared to baseline values that were obtained with the neutral shoe (- 52% for the HRS and - 52% for the HRO, p < 0.001). Significant increases in peak pressures were found in the midfoot region for both devices (HRS: 32%, p = 0.002; HRO: 47%, p < 0.001). For the metatarsal region, peak pressures were found to decrease significantly (HRS: - 52%, p < 0.001; HRO: -17%, p = 0.034). With respect to the forefoot, a significant reduction in peak pressures using the HRS (- 41%, p < 0.001) was detected, whereas the HRO did not lead to significant changes (- 4%, p = 0.691).

CONCLUSIONS

Both the HRO and HRS significantly reduced plantar hindfoot pressure, corresponding to a relative decrease of nearly 50% of the baseline. Nevertheless, the adjacent midfoot zone displayed a significant increase in plantar pressure values for both devices. Supported by these findings, physicians should cautiously consider a substantial increase in midfoot loading, especially in patients affected by additional midfoot injuries or accompanying impairments of tissue healing.

LEVEL OF EVIDENCE

IV, Case series.

Advances in Delayed-Onset Muscle Soreness (DOMS): Part I: Pathogenesis and Diagnostics

Delayed-onset muscle soreness (DOMS) is a type of ultrastructural muscle injury. The manifestation of DOMS is caused by eccentric or unfamiliar forms of exercise. Clinical signs include reduced force capacities, increased painful restriction of movement, stiffness, swelling, and dysfunction of adjacent joints. Although DOMS is considered a mild type of injury, it is one of the most common reasons for compromised sportive performance. In the past few decades, many hypotheses have been developed to explain the aetiology of DOMS. Although the exact pathophysiological pathway remains unknown, the primary mechanism is currently considered to be the ultrastructural damage of muscle cells due to unfamiliar sporting activities or eccentric exercise, which leads to further protein degradation, apoptosis and local inflammatory response. The development of clinical symptoms is typically delayed (peak soreness at 48 – 72 h post-exercise) as a result of complex sequences of local and systemic physiological responses. The following narrative review was conducted to present an overview of the current findings regarding the damaging mechanisms as well as the pathophysiology of DOMS and its diagnostic evaluation.

Acoustic radiation force impulse tissue characterization of the anterior talofibular ligament: a promising noninvasive approach in ankle imaging

OBJECTIVES

The anterior talofibular ligament (ATFL) is the most frequently injured ligament during inversion strains of the ankle. The purpose of this study was to evaluate the feasibility of acoustic radiation force impulse (ARFI) elastography and to determine the in vivo mechanical properties of the ATFL in healthy athletes.

METHODS

Sixty healthy athletes (32 female, 28 male; 28.9 ± 2.1 years) were recruited from the medical and sports faculty. ARFI values, represented as shear wave velocities (SWVs) as well as conventional ultrasound were obtained for the ATFL in neutral ankle position. A clinical assessment was performed in which the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Score and the functional ankle ability measure (FAAM) were collected. Interobserver and intraobserver reliability (repeated sessions and repeated days) were assessed using an intra class correlation coefficient (ICC) and typical error (TE) calculation in absolute (TE) and relative units as coefficient of the variation (CV).

RESULTS

SWV values of the ATFL had an average velocity of 1.79 ± 0.20 m/s for all participants, with an average of 1.72 ± 0.36 m/s for females and 1.85 ± 0.31 m/s for males. The interobserver and intraobserver reliability revealed an ICC of 0.902 and 0.933 (TE of 0.67 (CV: 5.2%) and 0.52 (CV: 3.84%)), respectively. FAAM and AOFAS revealed the best possible scores.

CONCLUSION

ARFI seems to be a valuable diagnostic modality and represents a promising imaging marker for the assessment and monitoring of ankle ligaments in the context of acute and chronic ankle instabilities; ARFI could also be used to investigate loading or sport dependent adaptions.

Effect of Compression Garments on the Development of Edema and Soreness in Delayed-Onset Muscle Soreness (DOMS)

Delayed-onset muscle soreness (DOMS), an ultrastructural muscle injury, is one of the most common reasons for impaired muscle performance. The purpose of this study was to investigate the influence of sport compression garments on the development of exercise-induced intramuscular edema in the context of DOMS. DOMS was induced in 15 healthy participants. The participants performed a standardized eccentric exercise of the calf muscles. Magnetic resonance imaging (MRI) was performed at baseline and 60h after exercise (T2-weighted signal intensity and T2 relaxation time was evaluated in each compartment and the intramuscular edema in the medial head of the gastrocnemius muscle was segmented). After the exercise, a conventional compression garment (18-21 mmHg) was placed on one randomized calf for 60h. The level of muscle soreness was evaluated using a visual analogue pain scale. T2-weighted signal intensity, T2 relaxation time and intramuscular edema showed a significant interaction for time with increased signal intensities/intramuscular edema in the medial head of the gastrocnemius muscle at follow-up compared to baseline. No significant main effect for compression or interaction between time and limb occurred. Further, no significant differences in the soleus muscle and the lateral head of the gastrocnemius muscle were noted between limbs or over time. After exercise, there was significantly increased muscle soreness in both lower legs in resting condition and when going downstairs and a decreased range of motion in the ankle joint. No significant difference was observed between the compressed and the non-compressed calf. Our results indicate that wearing conventional compression garments after DOMS has been induced has no significant effect on the development of muscle edema, muscle soreness, range of motion and calf circumference.

Nonoperative treatment of muscle injuries - recommendations from the GOTS expert meeting

BACKGROUND

Muscle injuries are some of the most common injuries in sports; they have a high recurrence rate and can result in the loss of ability to participate in training or competition. In clinical practice, a wide variety of treatment strategies are commonly applied. However, a limited amount of evidence-based data exists, and most therapeutic approaches are solely based on "best practice". Thus, there is a need for consensus to provide strategies and recommendations for the treatment of muscle injuries.

METHODS

The 2016 GOTS Expert Meeting, initiated by the German-Austrian-Swiss Society for Orthopaedic Traumatologic Sports Medicine (GOTS), focused on the topic of muscle and tendon injuries and was held in Spreewald/Berlin, Germany. The committee was composed of twenty-two medical specialists. Nine of them were delegated to a subcommittee focusing on the nonoperative treatment of muscle injuries. The recommendations and statements that were developed were reviewed by the entire consensus committee and voted on by the members.

RESULTS

The committee reached a consensus on the utility and effectiveness of the management of muscle injuries.

MAIN RESULTS

the "PRICE" principle to target the first inflammatory response is one of the most relevant steps in the treatment of muscle injuries. Haematoma aspiration may be considered in the early stages after injury. There is presently no clear evidence that intramuscular injections are of use in the treatment of muscle injuries. The ingestion of non-steroidal anti-inflammatory drugs (NSAIDs) should be regarded critically because there is currently no hard evidence to support their use, although they are appropriate in exceptional cases.

CONCLUSIONS

The present work provides a structured overview of the various nonoperative treatment strategies of muscle injuries and evaluates their effectiveness with respect to the existing scientific evidence and clinical expertise in the context of basic science on the healing process of muscle injuries. The committee agreed that there is a compelling need for further studies, including high-quality randomized investigations to completely evaluate the effectiveness of the existing therapeutic approaches. The given recommendations may be updated and adjusted as further evidence will be generated.

Cementless femoral components in bicondylar hybrid knee arthroplasty in patients with rheumatoid arthritis: A 10-year survivorship analysis

BACKGROUND

Total knee arthroplasty (TKA) has been established as a successful surgical treatment in the late stages of rheumatoid joint destruction. The purpose of this study was to review the clinical outcome and survivorship in rheumatoid arthritis (RA) patients undergoing TKA in hybrid technique with a cementless fixation of the femoral component.

METHODS

We analysed retrospectively 66 RA patients who underwent 72 TKAs (P.F.C. Sigma®). Mean follow-up time was 124 ± 41 months. To evaluate postoperative clinical outcome, knee injury and osteoarthritis outcome score (KOOS) and Oxford knee score (OKS) were assessed. Kaplan-Meier analysis was used to calculate survivorship. The primary outcome was revision for any reason.

RESULTS

Thirty-four patients (36 knees) died and two patients (2 knees) were lost to follow-up. Three patients (four knees) did not agree to participate. Twenty-seven patients (30 knees) were available for assessing clinical scores. The average scores were 85 ± 14 for KOOS and 34 ± 10 for OKS. In three patients (three knees), revision was necessary, including restricted range of motion ( n = 1), instability ( n = 1), and infection ( n = 1). There were no cases of loosening in this cohort study. The survival rates were 100% at 5 years, 97.1% at 10 years (95% CI 89.0-99.2%) and 95.6% at 15 years (95% CI 86.9-98.5%).

CONCLUSIONS

This study confirms that excellent clinical results and a good 10-year survivorship can be obtained with hybrid fixation technique in TKA in the unique population of RA patients.

Plantar pressures increase with raising body weight: A standardised approach with paired sample using neutral shoes

BACKGROUND

Plantar pressure leads to stress on plantar tissue and can be seen as risk factor for metatarsal stress fractures or plantar ulcers and is associated with prolonged and complicated recurrence of existing tissue damages. A clear demarcation of a systematic raise of body load regarding its effect on plantar pressure has not been described.

OBJECTIVE

Assessing plantar pressure patterns in different conditions of body weight, comparing data to initial body weight.

METHODS

Seventeen healthy volunteers were asked to participate. Peak pressure values were assessed during walking with dynamic pedobarography and analysed from three foot sections. Body weight was loaded up gradually with 10%, 20% and 30% of the individual initial weight by using a weighted vest.

RESULTS

We were able to detect a statistically significant increase of plantar pressure for all foot regions in case of loaded body weight of 20% and 30% comparing to initial weight (p< 0.05). The midfoot area displays a significant increase for peak pressure for the preferred foot even for 10% body load.

CONCLUSIONS

Peak plantar pressure increases with loaded body weight. The midfoot area seems to be a sensitive area in case of adapting increasing foot load. Considering the clinical relevance, loaded body weight has to be seen as risk factor for increasing plantar pressure patterns and should be considered in recurrence of plantar ulcers or stress fractures.

Intramuscular Perfusion Response in Delayed Onset Muscle Soreness (DOMS): A Quantitative Analysis with Contrast-Enhanced Ultrasound (CEUS)

The purpose of this study was to analyse intramuscular perfusion response in ultrastructural muscle lesions, by applying contrast-enhanced ultrasound (CEUS) to a delayed onset muscle soreness (DOMS) model. Results of this analysis were compared to high-resolution 3 Tesla MRI T2-weighted sequences. 14 healthy participants were recruited. Average perfusion parameters, represented as Peak enhancement (contrast agent inflow) and wash-in area under curve (WiAUC) of the gastrocnemius (GM) and soleus muscle (SM) were assessed before (baseline) and 60 h after inducing DOMS by eccentric exercise. Additionally, conventional ultrasound, high-resolution 3T MRI, creatine kinase level, range of motion (ROM) of the ankle joint, calf circumference and muscle soreness data were collected. Perfusion quantification revealed a statistically significant increase of intramuscular perfusion, corresponding to an increase in peak enhancement of 129.6% (p=0.0031) and in WiAUC of 115.2% (p=0.0107) in the gastrocnemius muscle at post-intervention. At follow-up, the MRI investigations showed intramuscular oedema for GM in all participants corresponding to a significant rise in T2 signal intensity (p=0.001) and in T2 time value (p=0.005). CEUS seems to be able to detect intramuscular perfusion changes and therefore may contribute to gaining deeper insight into the histopathology, inflammatory reactions and regeneration processes of ultrastructural muscle lesions.

Three-Dimensional Biomechanical Analysis of Rearfoot and Forefoot Running

Background:

In the running community, a forefoot strike (FFS) pattern is increasingly preferred compared with a rearfoot strike (RFS) pattern. However, it has not been fully understood which strike pattern may better reduce adverse joint forces within the different joints of the lower extremity.

Purpose:

To analyze the 3-dimensional (3D) stress pattern in the ankle, knee, and hip joint in runners with either a FFS or RFS pattern.

Study Design:

Descriptive laboratory study.

Methods:

In 22 runners (11 habitual rearfoot strikers, 11 habitual forefoot strikers), RFS and FFS patterns were compared at 3.0 m/s (6.7 mph) on a treadmill with integrated force plates and a 3D motion capture analysis system. This combined analysis allowed characterization of the 3D biomechanical forces differentiated for the ankle, knee, and hip joint. The maximum peak force (MPF) and maximum loading rate (LR) were determined in their 3 ordinal components: vertical, anterior-posterior (AP), and medial-lateral (ML).

Results:

For both strike patterns, the vertical components of the MPF and LR were significantly greater than their AP or ML components. In the vertical axis, FFS was generally associated with a greater MPF but significantly lower LR in all 3 joints. The AP components of MPF and LR were significantly lower for FFS in the knee joint but significantly greater in the ankle and hip joints. The ML components of MPF and LR tended to be greater for FFS but mostly did not reach a level of significance.

Conclusion:

FFS and RFS were associated with different 3D stress patterns in the ankle, knee, and hip joint, although there was no global advantage of one strike pattern over the other. The multimodal individual assessment for the different anatomic regions demonstrated that FFS seems favorable for patients with unstable knee joints in the AP axis and RFS may be recommended for runners with unstable ankle joints.

Clinical Relevance:

Different strike patterns show different 3D stress in joints of the lower extremity. Due to either rehabilitation after injuries or training in running sports, rearfoot or forefoot running should be preferred to prevent further damage or injuries caused by inadequate biomechanical load. Runners with a history of knee joint injuries may benefit from FFS whereas RFS may be favorable for runners with a history of ankle joint injuries.

Acute Effects of Lateral Thigh Foam Rolling on Arterial Tissue Perfusion Determined by Spectral Doppler and Power Doppler Ultrasound

Hotfiel, T, Swoboda, B, Krinner, S, Grim, C, Engelhardt, M, Uder, M, and Heiss, R. Acute effects of lateral thigh foam rolling on arterial tissue perfusion determined by spectral Doppler and power Doppler ultrasound. J Strength Cond Res 31(4): 893-900, 2017-Foam rolling has been developed as a popular intervention in training and rehabilitation. However, evidence on its effects on the cellular and physiological level is lacking. The aim of this study was to assess the effect of foam rolling on arterial blood flow of the lateral thigh. Twenty-one healthy participants (age, 25 ± 2 years; height, 177 ± 9 cm; body weight, 74 ± 9 kg) were recruited from the medical and sports faculty. Arterial tissue perfusion was determined by spectral Doppler and power Doppler ultrasound, represented as peak flow (Vmax), time average velocity maximum (TAMx), time average velocity mean (TAMn), and resistive index (RI), and with semiquantitative grading that was assessed by 4 blindfolded investigators. Measurement values were assessed under resting conditions and twice after foam rolling exercises of the lateral thigh (0 and 30 minutes after intervention). The trochanteric region, mid portion, and distal tibial insertion of the lateral thigh were representative for data analysis. Arterial blood flow of the lateral thigh increased significantly after foam rolling exercises compared with baseline (p ≤ 0.05). We detected a relative increase in Vmax of 73.6% (0 minutes) and 52.7% (30 minutes) (p < 0.001), in TAMx of 53.2% (p < 0.001) and 38.3% (p = 0.002), and in TAMn of 84.4% (p < 0.001) and 68.2% (p < 0.001). Semiquantitative power Doppler scores at all portions revealed increased average grading of 1.96 after intervention and 2.04 after 30 minutes compared with 0.75 at baseline. Our results may contribute to the understanding of local physiological reactions to self-myofascial release.

[Sports Injuries and Illnesses of the German National Team during the 2016 Olympic Summer Games in Rio de Janeiro]

Background This article aims to survey and describe the injuries and illnesses of the German Team during the 2016 Olympic Games in Rio de Janeiro. Methods Through an electronic documentation system, injuries and illnesses requiring treatment were recorded and evaluated. An injury or illness was defined as any physical symptom that required medical attention and impaired participation in training and/or competition. The classification distinguished between type of injury (acute or overload), region and type of illness (infections, skin, allergy, etc.). Results A total of 808 treatments were performed on the German team during Rio 2016. Out of 283 musculoskeletal-related treatments, 160 were performed on the lower limb. 70 treatments addressed back problems. 164 treatments were performed due to upper respiratory tract infections. When extrapolated to 1000 athletes, 617 treatments were required due to illness while 672 treatments addressed musculoskeletal problems. The number of treatments for injuries and illness is almost identical. In addition to less severe problems, the following serious injuries occurred: lethal traumatic brain injury, acute thigh compartment syndrome, ACL tear with a medial meniscal lesion and antero-lateral instability, isolated ACL tear, stress fracture of the base of the third metatarsal bone, acute lateral ankle instability, AC joint dislocation, and infected bursa prepatellaris.

CONCLUSIONS

The documentation system is reliable for "injury and illness surveillance" at multi-sport events. Treatment numbers are consistent with the 2012 Summer Games in London, so a reliable strategy can be assumed. In addition to illnesses predominantly affecting the upper respiratory tract, the system also recorded serious musculoskeletal injuries, which implicates the need for an interdisciplinary setup of the medical team. The methods used for data collection currently do not allow for the identification of risk factors for injuries and illness and should therefore be extended in the future.

[Pigmented villonodular synovitis. A rare differential diagnosis of synovial joint swelling]

BACKGROUND

Pigmented villonodular synovitis (PVNS) describes a rare disease caused by an abnormal proliferation of the synovial membrane in large and small joints. In order to achieve an optimal result of treatment it is necessary to carry out specific diagnostics and a targeted therapy approach.

OBJECTIVE

This article gives a review of the epidemiology, etiopathogenesis and diagnostic management of PVNS as well as presenting the current therapy and treatment recommendations.

MATERIAL AND METHODS

A systematic search of the literature was performed in the databank of the National Center for Biotechnology Information ( http://www.ncbi.nlm.nih.gov/pubmed ). The search targeted randomized clinical and experimental studies, systematic and non-systematic review articles, expert opinions and case reports related to PVNS, independent of the level of evidence attained by each study.

RESULTS

The differential diagnosis of PVNS should be considered in cases of recurrent hemorrhagic joint effusions. The cause of the disease has not yet been exactly clarified. The final diagnosis can ultimately only be confirmed by histological investigations. In order to obtain representative histological tissue samples for the diagnosis, magnetic resonance imaging (MRI) with the appropriate heme sequences should be carried out prior to taking samples. The management of PVNS is often difficult due to the high risk of recurrence depending on the various forms. In view of the high rate of recurrence, therapy should include a complete synovectomy.

CONCLUSION

For the surgical approach arthroscopic and open procedures have been described, which are currently controversially discussed with respect to the complication and recurrence rates. Adjuvant interventional therapy forms, such as radiosynoviorthesis are recommended to reduce the recurrence rate.