Relationship between intended force and actual force: comparison between athletes and non-athletes.

This cross-sectional study aimed to investigate whether athletes (ATHL) and non-athletes (NON-ATHL) individuals had similar accuracy in matching intended to actual force during ballistic (BAL) and tonic (TON) isometric contractions. In this cross-sectional study, the subjects were divided into ATHL (n = 20; 22.4 ± 2.3 yrs; 73.2 ± 15.7 kg; 1.76 ± 0.08 m) and NON-ATHL (n = 20; 24.6 ± 2.4 yrs; 68.2 ± 15.0 kg; 1.73 ± 0.1 m) groups. The isometric quadriceps strength was measured with a load cell applied to a custom-built chair. For each condition, subjects performed at first three maximal voluntary isometric contractions (MVIC) as reference. Then, subjects had to match three intended force intensities expressed in percentage of the MVIC (i.e., 25%, 50%, and 75%) without any external feedback. Subjects performed three trials for each force intensity. The accuracy (AC) was calculated as the absolute difference in percentage between the intended and the actual force. A Likert scale was administered for each trial to assess the subjective matching between the intended and the actual force. Statistical analysis showed that the ATHL group was more accurate (p < 0.001) than the NON-ATHL group. In contrast, the AC (p < 0.001) was lower when the force intensities increased independently from the group. Moreover, significantly higher AC (p < 0.001) and lower aggregate Likert scores (p < 0.001) were found in BAL than TON conditions. These results suggest that (i) sports practice could enhance muscle recruitment strategies by increasing the AC in the isometric task; (ii) differences between intended and actual force appeared to be intensity-dependent with lower AC at high force intensities; (iii) different control systems act in modulating BAL and TON contractions.

Sport-specific balance tests account for youth alpine skiers' ranking.

Objective: Alpine skiing requires complex motor skills and fine adjustments to maintain balance in dynamic and challenging conditions. This study aimed to understand whether the balance ability in unspecific (UST) and sport-specific (SST) tasks could depend on the skiers' ranking level. The balance performance of the dominant and non-dominant limbs in the SST was also investigated. Methods: Twenty-five skiers (14.96 ± 1.61 yrs; 1.69 ± 0.69 m; 59.9 ± 9.52 kg) were divided into high-ranking (position < 50) and low-ranking (position > 50) groups. Subjects performed three balance conditions: static (ST), dynamic UST, and dynamic SST. Subjects stood on an unstable board over a force platform during UST. During SST, subjects wore ski boots, grasped ski poles, and each foot was clipped to an unstable board over two force plates. From the center-of-pressure (CoP) trajectory the area of the 95th percentile ellipse and the CoP mean velocity were calculated. Angular displacements were recorded by a 12-camera system, to calculate the full balance (FB), fine (FiB), and gross (GB) balance in UST and SST. Results: Balance control was higher (p < 0.01) in high-ranking than low-ranking skiers only in the SST. Kinematic parameters (i.e., FB, FiB, and GB) showed a higher (p < 0.001) balance performance in SST than UST independently from the group. Dominant and non-dominant limbs motion was similar (Pearson correlation, r = 0.97) in SST independently from the skiers' ranking. Conclusion: High-ranking skiers showed better balance control and performance than low-ranking skiers only when the task was sport-specific. Therefore, we suggest testing balance under sport-specific conditions to discriminate the youth skiers' abilities.

Center of Pressure Behavior in Response to Unexpected Base of Support Shifting: A New Objective Tool for Dynamic Balance Assessment.

The translation of the base of support represents a promising approach for the objective assessment of dynamic balance control. Therefore, this study aimed to present a servo-controlled, electrically driven movable plate and a new set of parameters based on the center-of-pressure (CoP) trajectory. Twenty subjects were assessed on a force platform screwed over a movable plate that could combine the following settings: direction (forward (FW) and backward (BW)), displacement (25 mm, 50 mm, and 100 mm), and ramp rate (100 mm/s and 200 mm/s). The subjects underwent two sets of 12 trials randomly combining the plate settings. From the CoP trajectory of the 2.5 s time window after the perturbation, the 95% confidence-interval ellipse (Area95) and the CoP mean velocity (Unit Path) were calculated. Within the same time window, the first peak (FP), the maximal oscillations (ΔCoPMax), and the standard deviation (PPV) of the CoP anterior-posterior trajectory were calculated. The plate direction (p < 0.01), ramp rate (p < 0.001), and displacement (p < 0.01) affected the Area95, FP, and ΔCoPMax, while the Unit Path and PPV were influenced only by the ramp rate (p < 0.001) and displacement (p < 0.001). The servo-controlled, electrically driven movable plate and the CoP-related parameters presented in this study represent a new promising objective tool for dynamic balance assessment.

Effectiveness and therapeutic compliance of digital therapy in shoulder rehabilitation: a randomized controlled trial.

BACKGROUND: Interactive videogames, virtual reality, and robotics represent a new opportunity for multimodal treatments in many rehabilitation contexts. However, several commercial videogames are designed for leisure and are not oriented toward definite rehabilitation goals. Among the many, Playball® (Playwork, Alon 10, Ness Ziona, Israel) is a therapeutic ball that measures both movement and pressure applied on it while performing rehabilitation games. This study aimed: (i) to evaluate whether the use of this novel digital therapy gaming system was clinically effective during shoulder rehabilitation; (ii) to understand whether this gaming rehabilitation program was effective in improving patients' engagement (perceived enjoyment and self-efficacy during therapy; attitude and intention to train at home) in comparison to a control non-gaming rehabilitation program. METHODS: A randomized controlled experimental design was outlined. Twenty-two adults with shoulder pathologies were recruited for a rehabilitation program of ten consecutive sessions. A control (CTRL; N = 11; age: 62.0 ± 10.9 yrs) and an intervention group (PG; N = 11; age: 59.9 ± 10.2 yrs) followed a non-digital and a digital therapy, respectively. The day before (T0) and after (T1) the rehabilitation program, pain, strength, and mobility assessments were performed, together with six questionnaires: PENN shoulder Score, PACES-short, Self-efficacy, Attitudes to train at home, Intention to train at home, and System usability scale (SUS). RESULTS: MANOVA analysis showed significant improvements in pain (p < 0.01), strength (p < 0.05), and PENN Shoulder Score (p < 0.001) in both groups. Similarly, patients' engagement improved, with significant increments in Self-efficacy (p < 0.05) and attitude (p < 0.05) scores in both groups after the rehabilitation. Pearson correlation showed significant correlations of the Δ scores (T1 - T0) between PACES and Self-efficacy (r = 0.623; p = 0.041) and between PACES and Intention to train at home (r = 0.674; p = 0.023) only in the PG. SUS score after the rehabilitation (74.54 ± 15.60) overcame the cut-off value of 68, representative of good usability of a device. CONCLUSIONS: The investigated digital therapy resulted as effective as an equivalent non-digital therapy in shoulder rehabilitation. The reported positive relationship between the subject's enjoyment during digital therapy and intention to train at home suggests promising results in possible patient's exercise engagement at home after the rehabilitation in the medical center. RETROSPECTIVELY REGISTERED: NCT05230056.

Different neuromuscular control mechanisms regulate static and dynamic balance: A center-of-pressure analysis in young adults.

The analysis of the center of pressure (CoP) trajectory, derived from force platforms, is a widely accepted measure to investigate postural balance control. The CoP trajectory could be analyzed as a physiological time-series through a general stochastic modeling framework (i.e., Stabilogram Diffusion Analysis (SDA)). Critical point divides short-term from long-term regions and diffusion coefficients reflect the level of stochastic activity of the CoP. Sample Entropy (SampEn) allows quantifying the CoP complexity in terms of regularity. Thus, this study aimed to understand whether SDA and SampEn could discriminate the neuromuscular control mechanisms underpinning static and dynamic postural tasks. Static balance control and its relationship with dynamic balance control were investigated through the CoP velocity (Mean Velocity) and the area of the 95th percentile ellipse (Area95). Balance was assessed in 15 subjects (age: 23.13 ± 0.99 years; M = 9) over a force platform under two conditions: static (ST) and dynamic, both in anterior-posterior (DAP) and medio-lateral (DML) directions. During the DAP and DML, subjects stood on an unstable board positioned over a force platform. Short-term SDA diffusion coefficients and critical points were lower in ST than in DAP and DML (p < 0.05). SampEn values resulted greater in ST than in DAP and DML (p < 0.001). As expected, lower values of Area95 (p < 0.001) and Mean Velocity (p < 0.001) were detected in the easiest condition, the ST, compared to DAP and DML. No significant correlations between static and dynamic balance performances were detected. Moreover, differences in the diffusion coefficients were detected comparing DAP and DML (p < 0.05). In the anterior-posterior direction, the critical point occurred at relatively small intervals in DML compared to DAP (p < 0.001) and ST (p < 0.001). In the medio-lateral direction, the critical point differed only between DAP and DML (p < 0.05). Overall, SDA analysis pointed out a less tightly regulated neuromuscular control system in the dynamic tasks, with closed-loop corrective feedback mechanisms called into play at different time intervals in the three conditions. SampEn results reflected more attention and, thus, less automatic control mechanisms in the dynamic conditions, particularly in the medio-lateral task. The different neuromuscular control mechanisms that emerged in the static and dynamic balance tasks encourage using both static and dynamic tests for a more comprehensive balance performance assessment.

Validity and reliability of an unstable board for dynamic balance assessment in young adults.

Scientific literature is giving greater importance to dynamic balance in fall prevention. Recently, the validity and reliability of the most employed functional tests for dynamic balance assessment has been investigated. Although these functional tests are practical and require minimal equipment, they are inherently subjective, as most do not use instrumented measurement data in the scoring process. Therefore, this study aimed to assess the validity and reliability of an instrumented unstable board for dynamic balance objective assessment in young adults through double-leg standing trials. A test-retest design was outlined with the unstable board positioned over a force platform to collect objective Center of Pressure (CoP) related and kinematic parameters. Fifteen young adults participated in two evaluation sessions (7-day apart) that comprised ten trials per two dynamic conditions (anterior-posterior and medio-lateral oscillations) aiming to maintain the board parallel to the ground. Pearson's correlation coefficient (r) was employed to assess the validity of the kinematic parameters with those derived from the CoP. The test-retest reliability was investigated through Intraclass Correlation Coefficient (ICC), Standard Error of the measurement, Minimal Detectable Change, and Bland-Altman plots. Statistically significant correlations between the CoP and kinematic parameters were found, with r values ranging from 0.66 to 0.95. Good to excellent intrasession (0.89≤ICCs≤0.95) and intersession (0.66≤ICCs≤0.95) ICCs were found for the kinematics parameters. The Bland-Altman plots showed no significant systematic bias. The kinematics parameters derived from the unstable board resulted valid and reliable. The small size of the board makes it a suitable tool for the on-site dynamic balance assessment and a complement of computerized dynamic posturography.

Concurrent activation potentiation improves lower-limb maximal strength but not dynamic balance control in rugby players.

Concurrent activation potentiation (CAP) increases athletic performance by activating muscles not involved in the performed activity. Among the CAP strategies, jaw clenching is the most practical to implement in sports contexts. Muscle strength and balance control are essential among rugby players to cope tackles. Besides combat sports, mouthguard has become mandatory also in rugby. Therefore, this study aimed to understand whether mouthguard jaw-clenching could improve rugby players' dynamic balance and quadriceps isometric strength. Thirteen rugby players were tested under maximal-bite (MB) and no-bite (NB) conditions. During standing balance tests, an electro-actuated platform with a force plate screwed on it allowed for the perturbation of the support base of the rugby players. A verbal signal warned the subject that the perturbation was coming, mentally recalling an in-field expected collision. In the first 2.5 s window after the perturbation, the center of pressure (CoP) displacement and mean velocity were measured. The first peak, the maximal oscillations, and the standard deviation of the anterior-posterior CoP trajectory were calculated within the same time window. In the isometric leg-extension test, a custom-built chair instrumented with a uni-axial load cell allowed to collect the maximal strength and rate of force development (RFD). Mouthguard jaw-clenching did not affect CoP-related parameters but increased maximal strength (p < 0.05) and RFD (0-50 ms: p < 0.01; 50-100 ms: p < 0.001; 100-150 ms: p < 0.05) in the isometric leg-extension test. Mouthguard jaw-clenching alone could be useful to increase lower-limb maximal isometric strength and RFD but did not improve dynamic balance performance in a sport-oriented postural balance test.

Non-exercise activity thermogenesis in the workplace: The office is on fire.

From the second half of the previous century, there has been a shift toward occupations largely composed of desk-based behaviors. This, inevitably, has led to a workload reduction and a consequent lower energy expenditure. On this point, small increments of the non-exercise activity thermogenesis (NEAT) could be the rationale to reach health benefits over a prolonged period. Different published researches suggest solutions to reverse sitting time and new alternative workstations have been thought to increase total physical activity. Therefore, the purpose of this narrative review is to summarize the current state of the research regarding the "NEAT approach" to weight-gain prevention in work environments. This review analyzes the main evidence regarding new alternative workstations such as standing, walking workstations, seated pedal, and gymnastic balls to replace a standard office chair.

Age and training intensity differently affect male runners' endocrine and sexual parameters.

Physical activity is widely recognized to improve health and its inclusion in daily life at all ages is highly recommended. Gonadal hormones are known to be affected by physical activity. The exercise-induced effects on male runners of different ages were investigated by dividing 31 runners by age (Young, Y, 30-55 years; Old, O, 56-70 years) and amount of training (Light, L, <50 km/week; Heavy, H, 50 or more km/week). To test the somatic, sexual, and psychological health aspects, the Aging Male's Symptoms Scale (AMS) and the International Index of Erectile Function-6 (IIEF-6) questionnaires were administered and blood samples were drawn for adrenocorticotropic hormone, testosterone (Total-TT), free testosterone (Free-T), cortisol (C), dihydrotestosterone (DHT), estradiol, and sex hormone-binding globulin determinations. Clinical evaluations and questionnaire results showed the presence in all groups of some subclinical symptoms and "Light" dysfunctions. TT in the old-heavy (OH) group was significantly lower than in the OL group (2.38 ± 0.18 ng/mL vs. 3.36 ± 0.44 ng/ml, P = 0.05). The TT/DHT ratio was significantly higher in YH than in OH (3.64 ± 0.16 vs. 2.92 ± 0.23, P < 0.05). TT was positively correlated with AMS sexual subscale and negatively correlated with IIEF-6. Physical activity can significantly affect andrological health and testosterone levels in runners at all ages. Thus, due to the important testosterone-mediated vital functions in men, the evaluation of these parameters would be indicated in old as well as in young subjects.

Are Static and Dynamic Postural Balance Assessments Two Sides of the Same Coin? A Cross-Sectional Study in the Older Adults.

The aim of this study was to investigate if the combination of static and dynamic postural balance assessments gives more accurate indications on balance performance among healthy older adults. We also aimed at studying the effect of a dual-task condition on static and dynamic postural balance control. Fifty-seven healthy older adults (age = 73.2 ± 5.0 year, height = 1.66 ± 0.08 m, and body mass = 72.8 ± 13.8 kg) completed the study. Static and dynamic balance were assessed both in single-task and dual-task conditions through a force plate and an oscillating platform. The dominant handgrip strength was also measured with a dynamometer. Pearson's correlation revealed non-statistically significant correlations between static and dynamic balance performance. The dual-task worsened the balance performance more in the dynamic (+147.8%) than in the static (+25.10%, +43.45%, and +72.93% for ellipse area, sway path, and AP oscillations, respectively) condition (p < 0.001). A weak correlation was found between dynamic balance performance and handgrip strength both in the single (p < 0.05; r = -0.264) and dual (p < 0.05; r = -0.302) task condition. The absence of correlations between static and dynamic balance performance suggests including both static and dynamic balance tests in the assessment of postural balance alterations among older adults. Since cognitive-interference tasks exacerbated the degradation of the postural control performance, dual-task condition should also be considered in the postural balance assessment.

Hyperbaric Oxygen Therapy Improves the Osteogenic and Vasculogenic Properties of Mesenchymal Stem Cells in the Presence of Inflammation In Vitro.

Hyperbaric oxygen (HBO) therapy has been reported to be beneficial for treating many conditions of inflammation-associated bone loss. The aim of this work was to in vitro investigate the effect of HBO in the course of osteogenesis of human Mesenchymal Stem Cells (MSCs) grown in a simulated pro-inflammatory environment. Cells were cultured with osteogenic differentiation factors in the presence or not of the pro-inflammatory cytokine Tumor Necrosis Factor-α (TNF-α), and simultaneously exposed daily for 60 min, and up to 21 days, at 2,4 atmosphere absolute (ATA) and 100% O2. To elucidate osteogenic differentiation-dependent effects, cells were additionally pre-committed prior to treatments. Cell metabolic activity was evaluated by means of the MTT assay and DNA content quantification, whereas osteogenic and vasculogenic differentiation was assessed by quantification of extracellular calcium deposition and gene expression analysis. Metabolic activity and osteogenic properties of cells did not differ between HBO, high pressure (HB) alone, or high oxygen (HO) alone and control if cells were pre-differentiated to the osteogenic lineage. In contrast, when treatments started contextually to the osteogenic differentiation of the cells, a significant reduction in cell metabolic activity first, and in mineral deposition at later time points, were observed in the HBO-treated group. Interestingly, TNF-α supplementation determined a significant improvement in the osteogenic capacity of cells subjected to HBO, which was not observed in TNF-α-treated cells exposed to HB or HO alone. This study suggests that exposure of osteogenic-differentiating MSCs to HBO under in vitro simulated inflammatory conditions enhances differentiation towards the osteogenic phenotype, providing evidence of the potential application of HBO in all those processes requiring bone regeneration.

Arterial blood gases in divers at surface after prolonged breath-hold.

PURPOSE: Adaptations during voluntary breath-hold diving have been increasingly investigated since these athletes are exposed to critical hypoxia during the ascent. However, only a limited amount of literature explored the pathophysiological mechanisms underlying this phenomenon. This is the first study to measure arterial blood gases immediately before the end of a breath-hold in real conditions. METHODS: Six well-trained breath-hold divers were enrolled for the experiment held at the "Y-40 THE DEEP JOY" pool (Montegrotto Terme, Padova, Italy). Before the experiment, an arterial cannula was inserted in the radial artery of the non-dominant limb. All divers performed: a breath-hold while moving at the surface using a sea-bob; a sled-assisted breath-hold dive to 42 m; and a breath-hold dive to 42 m with fins. Arterial blood samples were obtained in four conditions: one at rest before submersion and one at the end of each breath-hold. RESULTS: No diving-related complications were observed. The arterial partial pressure of oxygen (96.2 ± 7.0 mmHg at rest, mean ± SD) decreased, particularly after the sled-assisted dive (39.8 ± 8.7 mmHg), and especially after the dive with fins (31.6 ± 17.0 mmHg). The arterial partial pressure of CO2 varied somewhat but after each study was close to normal (38.2 ± 3.0 mmHg at rest; 31.4 ± 3.7 mmHg after the sled-assisted dive; 36.1 ± 5.3 after the dive with fins). CONCLUSION: We confirmed that the arterial partial pressure of oxygen reaches hazardously low values at the end of breath-hold, especially after the dive performed with voluntary effort. Critical hypoxia can occur in breath-hold divers even without symptoms.

Clinical and morphological effects of hyperbaric oxygen therapy in patients with interstitial cystitis associated with fibromyalgia.

BACKGROUND: Interstitial Cystitis (IC) is a debilitating disorder of the bladder, with a multifactorial and poorly understood origin dealing with microcirculation repeated damages. Also Fibromyalgia (FM) is a persistent disorder whose etiology is not completely explained, and its theorized alteration of pain processing can compromise the quality of life. Both these conditions have a high incidence of conventional therapeutic failure, but recent literature suggests a significant beneficial response to Hyperbaric Oxygen Therapy (HBOT). With this study, this study we evaluated the effects of HBOT on quality of life, symptoms, urodynamic parameters, and cystoscopic examination of patients suffering from both IC and FM. METHODS: We structured an observational clinical trial design with repeated measures (questionnaires, urodynamic test, and cystoscopy) conducted before and 6 months after a therapeutic protocol with hyperbaric oxygen for the treatment of patients suffering from both IC and FM. Patients were exposed to breathing 100% oxygen at 2 atm absolute (ATA) in a multiplace pressure chamber for 90 min using an oro-nasal mask. Patients undertook a cycle of 20 sessions for 5 days per week, and a second cycle of 20 sessions after 1 week of suspension. RESULTS: Twelve patients completed the protocol. Changes after HBOT were not significant, except for hydrodistension tolerance (mean pre-treatment: 409.2 ml; mean post-treatment: 489.2 ml; p < 0.05). A regression of petechiae and Hunner's ulcers was also noted 6 months after the completion of HBOT. CONCLUSIONS: Our study showed no improvement of symptoms, quality of life, and urodynamic parameters, except for hydrodistension, and a slight improvement in cystoscopic pattern. However, to date, we could not demonstrate the significance of overall results to justify the use of HBOT alone in patients with IC and FM. This observation suggests that additional studies are needed to better understand if HBOT could treat this subset of patients. TRIAL REGISTRATION: NCT03693001 ; October 2, 2018. Retrospectively registered.

Oxidative stress assessment in breath-hold diving.

PURPOSE: Breath-hold diving results in significant changes in blood gases' levels. Challenging variations in oxygen partial pressures may induce reactive oxygen species (ROS) production that exacerbate oxidative stress and, consequently, affect endothelial function. The aim of this study was to investigate the effects of breath-hold diving on oxidative stress damage, assessing ROS production. Nitric oxide metabolites, inducible nitric oxide synthase (iNOS), aminothiols, and renal function were evaluated too as markers of redox status and renal damage. METHODS: ROS production was assessed with electron paramagnetic resonance. Oxidative status values were measured at pre- and post-40 m dive in a deep swimming pool (Y-40) from six divers (mean age 46.6 ± 9.3 years; height 176 ± 4 cm; BMI 25 ± 2.9 kg/m2). RESULTS: Significant (p < 0.05) increases at post-dive of ROS production rate (0.158 ± 0.003 vs 0.195 ± 0.006 µmol min-1), lipid peroxidation (8-isoprostane: 375.67 ± 195.62 vs 420.49 ± 232.31 pg mg-1 creatinine), nitrate (27.91 ± 19.71 vs 30.80 ± 20.44 µM), iNOS (31.30 ± 4.52 vs 35.68 ± 6.72 IU mL-1) and neopterin concentration (96.20 ± 40.41 vs 118.76 ± 27.84 µmol mol-1 creatinine) were recorded. Conversely, the antioxidant capacity significantly decreased (3.423 ± 0.089 vs 3.015 ± 0.284 mM) after immersion. CONCLUSION: Overproduction of ROS and consequent oxidative damage to lipids of membrane and antioxidant capacity decreasing reflect also a hypoxic condition, which in the breath-hold diving typically occurs in the last few meters below the surface. iNOS produces NO in large quantities under the examined extreme conditions. Neopterin and creatinine concentration level increased, suggesting an "impairment of renal function" as a likely physiological response to PaO2 variations during dive activity.

Body Composition and Endocrine Adaptations to High-Altitude Trekking in the Himalayas.

Long-term exposure to high altitude causes adaptive changes in several blood biochemical markers along with a marked body mass reduction involving both the lean and fat components. The aim of this study was to evaluate the impact of extended physical strain, due to extensive trekking at high altitude, on body composition, selected biomarkers in the blood, and the protective role of a high-protein diet in muscle dysfunction. We found that physical strain at high altitude caused a significant reduction in body mass and body fat, with a concomitant increase in the cross-sectional area of thigh muscles and an unchanged total lean body mass. Further, we found reductions in plasma leptin and homocysteine, while myoglobin, insulin, and C-reactive protein significantly increased. Creatine kinase, lactate dehydrogenase, and leptin normalized per body fat were unchanged. These findings demonstrate that high-altitude hypoxia, involving extended physical effort, has an impact on muscle function and body composition, facilitating sarcopenia and affecting body mass and fat distribution. It also activates pro-inflammatory metabolic pathways in response to muscular distress. These changes can be mitigated by a provision of a high-protein diet.

Expertise level influences postural balance control in young gymnasts.

BACKGROUND: The specificity of postural balance control in sports as gymnastic where complex motor skills are involved is widely debated in the literature. The aim of this study was to investigate in young gymnasts whether the amount of training influenced postural balance control in a simple-task and in a sport-specific task. METHODS: Seven female basic-level gymnasts (BLG) and eight female advanced-level gymnasts (ALG) performed two tests on a dynamometric platform: bipedal standing (B) and single-leg back scale (BS) before and after a combination of two gymnastic elements (rondade + flic-flac). RESULTS: BLG showed a better postural balance control in the B position while ALG in the BS position. All parameters referred to the Centre of pressure (COP) increased after the execution of the rondade + flic-flac in both ALG and BLG. ALG showed in BS a better performance on balance time-dependent response after the rondade + flic-flac. CONCLUSIONS: Results underlined how expertise level did not affect postural balance control during the simple task (B). Conversely, the sport specific task (BS) revealed to be more selective in representing the young gymnasts' level of expertise. Thus, the application of sport-specific tasks is recommended among coaches and practitioners to increase balance assessment selectivity.

Short-Term Modifications of Postural Balance Control in Young Healthy Subjects After Moderate Aquatic and Land Treadmill Running.

Postural balance control can be altered by land treadmill (LTM) running. This impairment seems to be related to a disturbance of vestibular and visual information. However, no studies are available on aquatic treadmill (ATM) running. The aim of the present study was to investigate the effect of running at moderate intensity over ATM and LTM on the postural balance control both with opened (OE) and closed (CE) eyes. Center of pressure (CoP) trajectory of 20 healthy subjects was collected on a dynamometric platform before and after a 20-min-long running on ATM and LTM at the same rate of perceived exertion (Borg's scale: 3/10). Heart rate (HR) was recorded every 30 s during running. Stabilogram diffusion analysis (SDA) and sample entropy (SampEn) were calculated to deepen motor control mechanisms. HR values were lower during ATM running with respect to LTM running (p < 0.01). A significant effect of the treadmill factor was detected in the OE condition for the sway path (p < 0.01; ηp 2 = 0.364; Power: 0.879), the sway area (p < 0.01; ηp 2 = 0.324; Power: 0.816), and the ML oscillations (p < 0.01; ηp 2 = 0.390; Power: 0.911) while an effect of the time factor was detected for the ellipse area (p < 0.05; ηp 2 = 0.213; Power: 0.576). However, the effect size for all the parameters ranged from 0.06 (trivial) to 0.48 (small). In the OE condition, the SDA highlighted a significant effect of the treadmill factor on all the short-term diffusion coefficients which negatively influenced the open loop motor control strategies. In the CE condition, SampEn analysis underlined a significant decrease of the CoP regularity after LTM running. Although slight modifications of the mechanisms involved in the postural balance control occurred, ATM and LTM moderate running did not seriously threaten postural balance performance. Therefore, the usage of ATM should be taken into account in all those situations where the well-known advantages of the aquatic environment are priorities.

Arterial Blood Gas Analysis in Breath-Hold Divers at Depth.

The present study aimed to evaluate the partial pressure of arterial blood gases in breath-hold divers performing a submersion at 40 m. Eight breath-hold divers were enrolled for the trials held at "Y-40 THE DEEP JOY" pool (Montegrotto Terme, Padova, Italy). Prior to submersion, an arterial cannula in the radial artery of the non-dominant limb was positioned. All divers performed a sled-assisted breath-hold dive to 40 m. Three blood samplings occurred: at 10 min prior to submersion, at 40 m depth, and within 2 min after diver's surfacing and after resuming normal ventilation. Blood samples were analyzed immediately on site. Six subjects completed the experiment, without diving-related problems. The theoretically predicted hyperoxia at the bottom was observed in 4 divers out of 6, while the other 2 experienced a reduction in the partial pressure of oxygen (paO2) at the bottom. There were no significant increases in arterial partial pressure of carbon dioxide (paCO2) at the end of descent in 4 of 6 divers, while in 2 divers paCO2 decreased. Arterial mean pH and mean bicarbonate ( HCO 3 - ) levels exhibited minor changes. There was a statistically significant increase in mean arterial lactate level after the exercise. Ours was the first attempt to verify real changes in blood gases at a depth of 40 m during a breath-hold descent in free-divers. We demonstrated that, at depth, relative hypoxemia can occur, presumably caused by lung compression. Also, hypercapnia exists at depth, to a lesser degree than would be expected from calculations, presumably because of pre-dive hyperventilation and carbon dioxide distribution in blood and tissues.

Hyperbaric oxygen therapy ameliorates osteonecrosis in patients by modulating inflammation and oxidative stress.

Early stages of avascular necrosis of the femoral head (AVNFH) can be conservatively treated with hyperbaric oxygen therapy (HBOT). This study investigated how HBOT modulates inflammatory markers and reactive oxygen species (ROS) in patients with AVNFH. Twenty-three male patients were treated with two cycles of HBOT, 30 sessions each with a 30 days break between cycles. Each session consisted of 90 minutes of 100% inspired oxygen at 2.5 absolute atmospheres of pressure. Plasma levels of tumor necrosis factor alfa (TNF-α), interleukin 6 (IL-6), interleukin 1 beta (IL-1ß) and ROS production were measured before treatment (T0), after 15 and 30 HBOT sessions (T1 and T2), after the 30-day break (T3), and after 60 sessions (T4). Results showed a significant reduction in TNF-α and IL-6 plasma levels over time. This decrease in inflammatory markers mirrored observed reductions in bone marrow edema and reductions in patient self-reported pain.