Evaluating Intraocular Pressure Alterations during Large Muscle Group Isometric Exercises with Varying Head and Body Positions.

Performing physical exercise affects intraocular pressure, and its elevation and fluctuations are the main risk factors for glaucoma development or progression. The aim of this study was to examine the acute alterations in intraocular pressure (IOP) during four unweighted isometric exercises and to determine whether the different head and body positions taken during exercise additionally affect IOP. Twelve healthy volunteers between the ages of 25 and 33 performed four isometric exercises: wall sit in neutral head and body position, elbow plank in prone head and body position, reverse plank in supine head and body position for 1 min, and right-side plank in lateral head and body position for 30 s. Intraocular pressure was measured by applanation portable tonometry, before performing the exercise, immediately after exercise completion, and after five minutes of rest. A significant acute increase in intraocular pressure was found as a response to the performance of the elbow plank (p < 0.01), the reverse plank (p < 0.001), and the right-side plank (p < 0.001). The wall sit exercise did not reveal a statistically significant IOP elevation (p = 0.232). Different head and body positions had no significant additional influence on IOP (F (3,33) = 0.611; p = 0.613), even though the alteration in IOP was found to be greater in exercises with a lower head and body position. Our data revealed that IOP elevation seems to be affected by the performance of the elbow plank, the reverse plank, and the right-side plank; and not by the wall sit exercise. More different isometric exercises should be examined to find ones that are safe to perform for glaucoma patients.

Thyroid Stimulating Hormone as a Possible Additional COVID-19 Outcome Marker.

Background and Objectives: The interaction between thyroid and SARS-CoV-2 is complex and not yet fully understood. This study aimed to identify a predictive value of serum TSH levels on the short-term and middle-term outcomes of patients hospitalized for COVID-19. Materials and Methods: We retrospectively analyzed electronic records (ERs) data for hospitalized COVID-19 patients between March 2020 and June 2021 and their ERs during outpatient visits, 6-8 weeks post-discharge, in cases of known serum TSH levels and no previous thyroid disorder. The short-term (length of hospital stay, MSCT findings of lung involvement, required level of oxygen supplementation, admission to the ICU, and death) and middle-term outcomes after 6 to 8 weeks post-discharge (MSCT findings of lung involvement) were analyzed. Results: There were 580 patients included: 302 males and 278 females, average age of 66.39 ± 13.31 years, with no known thyroid disease (TSH mean 1.16 ± 1.8; median 0.80; no value higher than 6.0 mIU/L were included). Higher TSH was observed in patients with less severe outcomes and was associated with significantly higher SpO2 during hospitalization. Patients who required overall more oxygen supplementation or HFOT, mechanical ventilation, and patients who were more frequently admitted to the ICU or were more often treated with corticosteroids had lower TSH than those who did not show these indicators of disease severity. Lower TSH was also present in non-survivors when compared to survivors (all p < 0.01). Patients with low TSH during hospitalization more often had persistent lung involvement during the post-COVID-19 period (p = 0.028). In the post-COVID-19 period, there was an overall, statistically significant increase in the TSH levels when compared to TSH during hospitalization (p < 0.001). Conclusions: Low/suppressed serum TSH levels during acute COVID-19 may be an additional laboratory test that should be included in the prediction of unfavorable short- and middle-term outcomes.

The Influence of Protective Headgear on the Visual Field of Recreational-Level Skiers.

The benefit of protective headgear for recreational skiers is an ongoing debate in the snow sports industry, and there are a lot of opposing opinions. Due to the dynamic conditions in which winter sports are performed, athletes demand rapid and constant processing of visual information. A sufficient level of anticipation helps athletes to properly position themselves to reduce the forces transferred to the head or even move to avoid a collision. To objectively identify the impact of protective headgear on the visual field when skiing, it is necessary to conduct suitable measurements. The sample consisted of 43 recreational-level skiers (27 M, 16 F; age 31.6 ± 8.23 years). A predefined testing protocol on an ortoreter was used to assess the visual field for three conditions of wearing protective headgear. Differences in perceived visual stimuli between the three conditions were evaluated by repeated measures analysis of variance (ANOVA). Based on the observed results, it can be concluded that the combination of wearing a ski helmet and ski goggles significantly negatively influences visual performance in a way that the visual field is narrowed, for both helmet users and non-users, only when comparing the tested conditions. When comparing helmet users and non-users, there are no differences in the amount of visual impairment; therefore, the habit of wearing a helmet does not influence the ability of perceiving visual stimuli.

DIFFERENCE IN PATIENT QUALITY OF LIFE AFTER HIP ARTHROPLASTY WITH A MINIMALLY INVASIVE APPROACH OR CLASSIC APPROACH.

The increasing rate of orthopedic procedures, hip arthroplasty in particular, requires improvement of surgical techniques, as well as of the respective rehabilitation protocols. The aim of the study was to assess differences in the quality of life and incidence of limping eight years after total hip arthroplasty performed with a minimally invasive or classic approach. This cross-sectional study included 68 patients, i.e. 32 operated with classic approach and 36 with minimally invasive approach during 2011. The following parameters were observed: anthropometric measurements, history of comorbidity, subjective assessment of limping, and SF-36 questionnaire (Short Form Survey Instrument). SF-36 testing, which consists of 8 domains, showed that 5 domains of the quality of life were statistically significantly better in the minimally invasive group (level of significance p<0.05). These domains were role of limitation due to physical health (p=0.01), energy (p=0.02), social functioning (p=0.02), pain (p=0.02) and general health (p=0.00). The minimally invasive group had a statistically significantly lower incidence of limping (p=0.032). Quality of life after hip replacement could be a decisive factor when choosing the type of orthopedic procedure. The higher number of limping patients in the classic approach group may have contributed to differences in the quality of life. In conclusion, the minimally invasive approach enables higher long-term quality of life and functional recovery.

Women in sports: the applicability of common national reference intervals for inflammatory and coagulation biomarkers (HemSter Study).

INTRODUCTION: Intensive physical activity causes functional and metabolic changes in the athlete's organism. The study aimed to verify the common national available reference intervals (RIs) for common inflammatory and screening coagulation tests in a population of healthy young female athletes. MATERIALS AND METHODS: One hundred and twenty-one female athletes (age range: 16-34), from various sports disciplines (water polo, handball, volleyball, football, basketball), were included in the study. All participants completed the international physical activity short-form questionnaire. Blood samples were collected between 8-10 am, after an overnight fast, before any physical activity. Reference intervals were determined according to Clinical & Laboratory Standards Institute EP28-A3C Guidelines. RESULTS: Calculated RIs for white blood cell count (WBC), prothrombin time (PT), and activated partial thromboplastin time (APTT) ratio were in accordance with the common national RIs. Calculated RI for C-reactive protein (CRP) was lower (< 2.9 mg/L) than the proposed cut-off for a healthy population (< 5.0 mg/L). Reference interval for fibrinogen was higher (1.9-4.4 g/L), than the available RIs (1.8-3.5 g/L). D-dimer cut-off value was set at 852 µg/L fibrinogen equivalent units (FEU), higher than the proposed 500 µg/L FEU for venous thromboembolism (VTE) exclusion. CONCLUSIONS: The applicability of the available RIs for WBC count, PT, and APTT-ratio was confirmed. However, RIs for CRP and fibrinogen differed significantly than the available common national RIs for the healthy non-athletes' population. A higher cut-off for D-dimers should be extensively verified before implementation for VTE diagnosis exclusion in a group of healthy young female athletes.

Women in sports: The applicability of reference intervals for 6 commercially available testosterone immunoassays (HemSter Study).

BACKGROUND: Testosterone levels in female athletes are increased due to their physical activity and correlate with their exercise volume. We therefore hypothesized that the reference intervals (RIs) derived from the general population are not applicable for female athletes. The aim of this study was to evaluate the applicability of the given RIs for 6 commercially available testosterone immunoassays in a group of female athletes. METHODS: Our study included 121 female athletes from various sporting disciplines (water polo, handball, volleyball, football, and basketball). The physical activity score was assessed by the Short Form of the International Physical Activity Questionnaire. Total testosterone was measured in serum samples by the reference LC-MS/MS method and six different immunoassays (Abbott Architect 2nd Generation Testosterone, Beckman Coulter Access Testosterone, Roche Elecsys Testosterone II, Siemens Atellica® IM Testosterone II (TSTII), Siemens IMMULITE 2000 Total Testosterone, and Snibe MAGLUMI™ Testosterone). RESULTS: There were statistically significant differences in age (P = 0.042), weight (P = 0.001), height (P < 0.001), and BMI (P < 0.001) between athletes across different sports. Their quantitative measurements of physical activity and testosterone concentration did not differ significantly between subgroups of various sports, P = 0.167 and P = 0.181, respectively. All immunoassays had a positive absolute and relative bias, in comparison with the LC-MS/MS. The manufacturer's RI was not verified for Abbott Architect, Beckman Coulter Access, and Roche Elecsys Testosterone methods, with the highest percentage of athletes above RI for Beckman Coulter (30%). CONCLUSIONS: We demonstrated that the upper reference limit provided was too low for some young female athletes. Clinical laboratories should consider implementation of the new proposed RIs.

High-intensity interval training changes the expression of muscle RING-finger protein-1 and muscle atrophy F-box proteins and proteins involved in the mechanistic target of rapamycin pathway and autophagy in rat skeletal muscle.

NEW FINDINGS: What is the central question of this study? What are the adaptations of protein synthesis and degradation that occur in skeletal muscle in response to high-intensity interval training (HIIT), and what are the magnitudes of the changes in response to HIIT, compared to moderate-intensity continuous training (MICT), and the mechanisms underlying these changes? What is the main finding and its importance? HIIT is more effective than MICT in altering the expression of muscle RING-finger protein-1 and muscle atrophy F-box, and enhancing the autophagic flux in rat soleus muscle. In addition, HIIT could activate the mechanistic target of rapamycin pathway. These findings suggest that HIIT might be an effective exercise strategy for health promotion in skeletal muscle. ABSTRACT: This study aimed to investigate the impact of high-intensity interval training (HIIT) on the proteins involved in protein synthesis, the ubiquitin-proteasome system (UPS) and autophagy in skeletal muscle of middle-aged rats. Nine-month-old male Wistar rats (n = 56) were randomly divided into three groups: a control (C) group, a moderate-intensity continuous training (MICT) group and a HIIT group. Rats in the training groups ran on treadmills 5 days per week for 8 weeks. The MICT group ran for 50 min at 60% V̇O2max , while the HIIT group ran for 3 min at 80% of V̇O2max six times separated by 3-min periods at 40% V̇O2max . Aerobic endurance, number of autophagosomes and expression of proteins involved in protein synthesis and degradation in the soleus muscle were measured at three time points: before training, after 4 weeks and after 8 weeks of training. Compared to the C group, HIIT and MICT increased the expression of phosphorylated mechanistic target of rapamycin (mTOR) after 8 weeks (P < 0.05 and P < 0.01, respectively). HIIT increased the expression of muscle RING-finger protein-1 (MuRF-1) after 4 weeks (P < 0.01), and decreased its expression after 8 weeks (P < 0.01). Both HIIT and MICT decreased the expression of muscle atrophy F-box (MAFbx) after 4 weeks (P < 0.05). HIIT improved the expression of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II (P < 0.05), and decreased the P62 content (P < 0.01) after 4 weeks. The LC3II/LC3I ratio was increased after 8 weeks (P < 0.01). This study demonstrated that HIIT could activate the mTOR pathway, alter the expression of MuRF-1 and MAFbx proteins, and enhance autophagic flux in soleus muscle of middle-aged rats.

Sport Courage, Worry and Fear in Relation to Success of Alpine Ski Learning.

(1) Background: Individuals' psychological traits can influence not just success in sport but also the ability to learn new motor skills. We investigated whether sport courage, worry and fear differ between alpine ski-naive and basic level skiers and how they affect ski learning. (2): A total of 337 students (249 ski-naive and 88 basic level) participated in research consisting of a four-part questionnaire and structured skiing program. (3) Results: For beginners, lower fear (r = -0.30, p < 0.01) and higher Self-efficiency (r = 0.28, p < 0.05) and mastery (r = 0.20, p < 0.01) were associated with better performance; reducing fear and increasing self-efficiency and worry increased performance. Experienced skiers were better in determination, mastery, and self-efficiency (all p < 0.05). In case of lower score in worry (r = -0.28, p < 0.01) and higher in self-efficiency (r = 0.22, p < 0.05) performance was better. Males scored higher in sport courage scale-31 (all p < 0.05). In particular, self-efficiency was associated with better (r = 0.39, p < 0.01), and higher fear with poorer performance (r = -0.33, p < 0.01). Moreover, self-efficiency was a predictor of ski success (p < 0.001). On the other hand, females like ski beginners scored higher in fear (p < 0.001). In females, determination, mastery and self-efficiency had a positive correlation with skiing (r = 0.21, p < 0.05, r = 0.28, p < 0.01, and r = 0.33, p < 0.01, respectively), while association between Fear and skiing (r = -0.46, p < 0.01) was negative, and fear (p < 0.001) was inversely related to success. (4): Conclusions: Psychological factors and gender differences need to be considered during learning phases of alpine skiing. There is a positive association between self-efficiency and performance of male ski beginners, and negative association between fear and achieved results in basic alpine ski school in case of female ski beginners.

Reliability and Validity of the Inline Skating Skill Test.

This study aimed to examine the reliability and validity of the inline skating skill test. Based on previous skating experience forty-two skaters (26 female and 16 male) were randomized into two groups (competitive level vs. recreational level). They performed the test four times, with a recovery time of 45 minutes between sessions. Prior to testing, the participants rated their skating skill using a scale from 1 to 10. The protocol included performance time measurement through a course, combining different skating techniques. Trivial changes in performance time between the repeated sessions were determined in both competitive females/males and recreational females/males (-1.7% [95% CI: -5.8-2.6%] - 2.2% [95% CI: 0.0-4.5%]). In all four subgroups, the skill test had a low mean within-individual variation (1.6% [95% CI: 1.2-2.4%] - 2.7% [95% CI: 2.1-4.0%]) and high mean inter-session correlation (ICC = 0.97 [95% CI: 0.92-0.99] - 0.99 [95% CI: 0.98-1.00]). The comparison of detected typical errors and smallest worthwhile changes (calculated as standard deviations × 0.2) revealed that the skill test was able to track changes in skaters' performances. Competitive-level skaters needed shorter time (24.4-26.4%, all p < 0.01) to complete the test in comparison to recreational-level skaters. Moreover, moderate correlation (ρ = 0.80-0.82; all p < 0.01) was observed between the participant's self-rating and achieved performance times. In conclusion, the proposed test is a reliable and valid method to evaluate inline skating skills in amateur competitive and recreational level skaters. Further studies are needed to evaluate the reproducibility of this skill test in different populations including elite inline skaters.

Reliability and Discriminative Ability of a New Method for Soccer Kicking Evaluation.

The study aimed to evaluate the test-retest reliability of a newly developed 356 Soccer Shooting Test (356-SST), and the discriminative ability of this test with respect to the soccer players' proficiency level and leg dominance. Sixty-six male soccer players, divided into three groups based on their proficiency level (amateur, n = 24; novice semi-professional, n = 18; and experienced semi-professional players, n = 24), performed 10 kicks following a two-step run up. Forty-eight of them repeated the test on a separate day. The following shooting variables were derived: ball velocity (BV; measured via radar gun), shooting accuracy (SA; average distance from the ball-entry point to the goal centre), and shooting quality (SQ; shooting accuracy divided by the time elapsed from hitting the ball to the point of entry). No systematic bias was evident in the selected shooting variables (SA: 1.98±0.65 vs. 2.00±0.63 m; BV: 24.6±2.3 vs. 24.5±1.9 m s-1; SQ: 2.92±1.0 vs. 2.93±1.0 m s-1; all p>0.05). The intra-class correlation coefficients were high (ICC = 0.70-0.88), and the coefficients of variation were low (CV = 5.3-5.4%). Finally, all three 356-SST variables identify, with adequate sensitivity, differences in soccer shooting ability with respect to the players' proficiency and leg dominance. The results suggest that the 356-SST is a reliable and sensitive test of specific shooting ability in men's soccer. Future studies should test the validity of these findings in a fatigued state, as well as in other populations.

Functional recovery after muscle sparing total hip arthroplasty in comparison to classic lateral approach - A three years follow-up study.

BACKGROUND: The muscle sparing total hip arthroplasty had generated a distinguishable interest, in both the patients and the surgeons, but its benefits are still often questioned. The main idea of this study was to compare the functional clinical outcome of the patients operated by the anterolateral approach with a muscle-sparing technique (modified Watson-Jones approach), and the patients operated by modified direct lateral approach without the muscle-sparing technique (Bauer/Hardinge approach). METHODS: The patients (N = 130) were divided into two groups: 68 in a standard method group (STAND) and 62 patients in a muscle sparing surgery group (MSS). The hip flexibility, mobility, the strength of the hip abduction, the pain scale, Harris hip scores, the duration of the hospital stay and the overall satisfaction were measured seven days, three months, one year and three years (in 80 patients) after the surgery. There were no differences in any of the parameters between the groups prior to the procedure. RESULTS: The statistically significant differences in first three follow-ups (up to one year) were determined between the groups in passive and active hip flexion ability but the hip abduction strength, which is a crucial parameter for functional recovery, and 50 m walk test remained better in MSS group even after three years. Patients, who underwent MSS suffered also less pain, stayed in hospital shorter and were more satisfied with the operation outcome. CONCLUSIONS: The functional recovery in patients treated with muscle sparing method was faster than in patients operated with conventional lateral approach. Based on the results, we could recommend anterolateral muscle sparing approach for a total hip replacement for its faster and fuller functional recovery.

The acute effects of graded physiological strain on soccer kicking performance: a randomized, controlled cross-over study.

PURPOSE: The aim of the present study was to examine the acute effects of graded physiological strain on soccer kicking performance. METHODS: Twenty-eight semi-professional soccer players completed both experimental and control procedure. The experimental protocol incorporated repeated shooting trials combined with a progressive discontinuous maximal shuttle-run intervention. The initial running velocity was 8 km/h and increasing for 1 km/h every 3 min until exhaustion. The control protocol comprised only eight subsequent shooting trials. The soccer-specific kicking accuracy (KA; average distance from the ball-entry point to the goal center), kicking velocity (KV), and kicking quality (KQ; kicking accuracy divided by the time elapsed from hitting the ball to the point of entry) were evaluated via reproducible and valid test over five individually determined exercise intensity zones. RESULTS: Compared with baseline or exercise at intensities below the second lactate threshold (LT2), physiological exertion above the LT2 (blood lactate > 4 mmol/L) resulted in meaningful decrease in KA (11-13%; p < 0.05), KV (3-4%; p < 0.05), and overall KQ (13-15%; p < 0.01). The light and moderate-intensity exercise below the LT2 had no significant effect on soccer kicking performance. CONCLUSIONS: The results suggest that high-intensity physiological exertion above the player's LT2 impairs soccer kicking performance. In contrast, light to moderate physiological stress appears to be neither harmful nor beneficial for kicking performance.

The influence of ski helmets on sound perception and sound localisation on the ski slope.

OBJECTIVES: The aim of the study was to investigate whether a ski helmet interferes with the sound localization and the time of sound perception in the frontal plane. MATERIAL AND METHODS: Twenty-three participants (age 30.7±10.2) were tested on the slope in 2 conditions, with and without wearing the ski helmet, by 6 different spatially distributed sound stimuli per each condition. Each of the subjects had to react when hearing the sound as soon as possible and to signalize the correct side of the sound arrival. RESULTS: The results showed a significant difference in the ability to localize the specific ski sounds; 72.5±15.6% of correct answers without a helmet vs. 61.3±16.2% with a helmet (p < 0.01). However, the performance on this test did not depend on whether they were used to wearing a helmet (p = 0.89). In identifying the timing, at which the sound was firstly perceived, the results were also in favor of the subjects not wearing a helmet. The subjects reported hearing the ski sound clues at 73.4±5.56 m without a helmet vs. 60.29±6.34 m with a helmet (p < 0.001). In that case the results did depend on previously used helmets (p < 0.05), meaning that that regular usage of helmets might help to diminish the attenuation of the sound identification that occurs because of the helmets. CONCLUSIONS: Ski helmets might limit the ability of a skier to localize the direction of the sounds of danger and might interfere with the moment, in which the sound is firstly heard.

Acute physiological responses to recreational in-line skating in young adults.

We examined the physiological responses to in-line skating exercise at self-selected paces in recreationally trained adults. Seven men and 10 women performed in-line skating exercise during which oxygen uptake (VO2) and heart rate (HR) were recorded continuously. Ratings of perceived exertion (RPE) and blood lactate concentration were also obtained at the end of exercise. Furthermore, subjects' peak VO2, peak HR, RPE and gas-exchange thresholds were determined in laboratory settings. The average exercise intensity during in-line skating was 90% of peak HR, 67% of peak VO2, 84% of HR reserve and 64% of VO2 reserve. When expressed as RPE and as metabolic equivalents (METs), the average exercise intensity was 13.1 RPE and 9.4 METs. Overall, these indicators of exercise intensity categorise in-line skating at self-selected paces as a vigorous physical activity. Notably, at similar VO2 values, significantly higher HR (174 ± 16 vs. 156 ± 6 bpm; p<0.001) and RPE (13.1 ± 1.4 vs. 11.7 ± 1.4; p=0.019) were observed for in-line skating compared with treadmill running. We conclude that 1. recreational in-line skating induces physiological responses that are sufficient for improving and maintaining cardiovascular fitness in healthy adults, 2. HR- and RPE-based methods for quantifying the exercise intensity during in-line skating may overestimate the actual metabolic load and 3. the derivation of exercise prescriptions for in-line skating should be preferably based on specific (i.e. in-line skating) graded exhaustive exercise test.

Physiological load and posture control thresholds.

The aim of the study was to evaluate the influence of the physiological load on postural control. Special attention was directed toward the identifying the intensity level in which the major deterioration in balance abilities occurs. Thirty subjects randomly divided into two groups performed multistage all-out exertion protocol on cycle-ergometer with measurements of ventilatory-metabolic and subjective parameters of exertion. Each stage lasted three minutes and was followed with three minute breaks during which the subjects underwent the static (keeping the cursor in the center of the screen) and the dynamic balance testing (following the cursor clockwise or counter clock wise by body movements) on balance platform. In a control group, the protocol encompassed only balance testing procedures followed by 3 min rest. After the completion of the testing procedures, the five intensity zones were determined according to the ventilatory-metabolic parameters. The significant differences in both static and dynamic balance tests were found between the test stages in exercising group. The post hoc analyses revealed the significant negative effect of exercise on the static balance with three visible "balance thresholds". The first threshold was at the rest to work transition, the second at the anaerobic threshold and the third at the maximal exertion level. The dynamic balance was also negatively affected with exercise, however no "balance thresholds" were clearly identified. No significant changes in neither static nor dynamic balance abilities were observed in the control group so the changes in the experimental group could have been attributed to the exercise intensity.

Ultrasound-assisted calcaneoplasty.

PURPOSE: The endoscopic technique for resection of a postero-superior part of calcaneus served as a golden standard during the last 10 years, and it has mostly replaced the open techniques. In an effort to reduce the morbidity and the recovery time, we had introduced the ultrasound-assisted technique. METHODS: In the period of 1 year, 15 patients with the prominent postero-superior part of calcaneus and retrocalcaneal bursitis were operated through the single skin incision using the ultrasound-assisted technique. The prominent part of calcaneus was resected with a bone abrader under the ultrasound control to the point when there was no impingement between Achilles tendon and calcaneus in maximal dorsal flexion. The patients were evaluated preoperatively and postoperatively with the AOFAS score and Ogilvie-Harris score. The strength test of the muscle triceps surae, as well as the proprioceptive test, was also undertaken. RESULTS: Initially, the follow-up was meant to last 6 months, but there were no differences in results between 6 weeks and 3 months postoperatively, so it was concluded that the 3-month follow-up is sufficient and relevant. All 15 patients were available for follow-up. All measured variables significantly improved (AOFAS, Ogilvie-Harris), and all the patients were satisfied with the postoperative result. Only one minor complication occurred: superficial infection. CONCLUSION: The ultrasound-assisted calcaneoplasty enables a precise resection of the postero-superior part of calcaneus and removal of the retrocalcaneal impingement. This method could become clinically relevant as it enables effective treatment of Haglund deformity, and results of this study presented rapid functional recovery. LEVEL OF EVIDENCE: Case series with no comparison group, Level IV.

Validation of the Sensewear Armband during recreational in-line skating.

Multi-sensor body monitors that combine accelerometry with other physiological data are designed to overcome drawbacks of accelerometers in assessing activities with little or no vertical movement. One of such devices is the Sensewear Armband (SWA) which has been extensively validated during various activities. However, very few of the validation studies included activities other than walking and running. The aim of this investigation was to assess the validity of the SWA during recreational in-line skating. Nineteen participants (11 females and 8 males), 28 (±6) years of age, performed in-line skating exercise on a circular track at a self-selected pace. Energy expenditure was measured with the SWA and the Cosmed K4b(2) breath-by-breath portable metabolic unit. The mean (SD) energy expenditure during in-line skating estimated by the SWA [25.5 (5.8) kJ/min] was significantly lower compared with indirect calorimetry [44.2 (9.7) kJ/min, P < 0.001]. Similarly, the mean (SD) MET values recorded by the SWA were also lower compared with IC [5.3 (1.0) METs vs. 9.1 (1.6) METs, P < 0.001]. The ratio limits of agreement suggest that in 95% of cases the SWA will underestimate the energy expenditure and MET values during in-line skating by as much as 24-56% compared with indirect calorimetry. In conclusion, the results of the present study indicate that the SWA is not able to overcome the drawbacks of accelerometry in assessing activities with limited vertical movement.

The "cello technique": a new technique for ultrasound-assisted calcaneoplasty.

The "cello technique" is a new calcaneoplasty technique for the treatment of Haglund disease. It is an ultrasound-assisted technique for resection of the posterosuperior part of the calcaneus. It is possible to resect the posterosuperior part of the calcaneus under direct ultrasound control with the patient in the prone position, with a dorsally positioned ultrasound probe, in line with the Achilles tendon fibers (sagittal line), and with the abrader in the posteromedial working portal. We describe in detail the technique for this new procedure in foot and ankle surgery. This innovative technique offers the possibility of expanding the indications for ultrasound-guided surgery in other fields of orthopaedic surgery.

Risk-taking behavior in skiing among helmet wearers and nonwearers.

OBJECTIVE: To examine differences in on-the-snow ski behavior between helmet wearers and nonwearers. METHODS: The data were collected using a survey. Several tourist agencies helped in administrating the survey to the skiers during the 2008-2009 and 2009-2010 seasons. The survey consisted of multiple-choice questions. The subjects were asked to choose answers most suitable for their skiing style and preferred skiing technique, volume of off-piste skiing, readiness to use time measuring systems on the slopes, and group-skiing preferences, such as leading the group, beside the group, away from the group, etc. The Risk Index was then calculated for each subject. RESULTS: The answers of 710 skiers (mean age 35.5, range 16-81 years) were analyzed. The predictive power for risk-taking behavior was tested for gender, age, educational level, level of skiing, years of skiing, and helmet usage. Younger age, male gender, higher skiing level, and helmet usage were used as independent predictors for the overall Risk Index (Power [1-ß err prob] = 0.942). Significantly higher risk was assessed for the male helmet wearers while the results were not significant for the female helmet wearers. The male occasional helmet wearers were found to be the most prone to risky behavior. In female nonhelmet wearers, there was a significant decrease in risk-taking behavior with age but this was not true for female helmet wearers. CONCLUSIONS: For males under 35 years of age, helmet use is one of the factors influencing risk-taking on the slopes. This is demonstrated for occasional helmet wearers in particular.

New "L value" parameter simplifies and enhances hip ultrasound interpretation in the detection of developmental dysplasia of the hip.

PURPOSE: The purpose of this study was to simplify and enhance the ultrasound (US) analysis of the infant's hip by introducing a novel parameter named "L value" into the widely used Graf method. METHODS: We analysed 508 ultrasonographic images of the hips in infants aged three months. The images were first evaluated using the Graf measurements. On the same images, two additional measurements were performed in order to define the new parameter that was named L value. The threshold values of the new L value were identified based on the highest specificity as well as sensitivity for discrimination between the Graf groups. Those values were then used in order to reclassify the hips into three simplified groups. Inter-observer agreement was estimated by Cohen's kappa coefficient. RESULTS: The threshold values for the L value between Graf groups Ia and Ib was 0.46, between Ib and IIb was 0.68 and between IIb and IIc was 0.92. Correlation analysis between Graf's classification and the values of the L value was performed and was proved to be statistically significant, r = 0.49; p < 0.001. After simplifying the classification into three newly defined groups of patients depending on the degree of hip development, the correlation coefficient was much higher, r = 0.94, r (2) = 0.88 for p < 0.001. Inter-observer agreement for the L value was substantial. CONCLUSIONS: The new L value parameter in Graf's ultrasound hip evaluation enables a faster, simpler, more reliable and more unbiased classification for developmental dysplasia of the hip as the L value changes proportionally with the hip maturity.