Physiological adaptations of active postmenopausal women and matched men to the multi-day Sardinia Selvaggio Blu wild trek: a gender-comparative pilot study.

PURPOSE: To evaluate the effects of wild trekking by examining, in postmenopausal women, the physiological adaptations to an intensive 5-day wild trek and comparing their responses to those displayed by a group of men of comparable age, training status and mountaineering skills. METHODS: Six healthy, active postmenopausal women in their sixth decade of life participated in the study. Six men of comparable age and training status were also enrolled for gender-based comparisons. The participants traversed the Selvaggio Blu wild trek (Sardinia, Italy) completing a total of 56 km, for an overall height differential of 14,301 m. During all 5-day trek, subjects were supervised by two alpine guides. Changes in body composition, cardiorespiratory fitness, and metabolic patterns of energy expenditure were evaluated before and after the intervention. RESULTS: Total energy expenditure during the trek was significantly higher (p = 0.03) in women (12.88 ± 3.37 kcal/h/kg) than men (9.27 ± 0.89 kcal/h/kg). Extracellular (ECW) and intracellular water (ICW) increased significantly following the trek only in women (ECW: - 3.8%; p = 0.01; ICW: + 3.4%; p = 0.01). The same applied to fat-free mass (+ 5.6%; p = 0.006), fat mass (- 20.4%; p = 0.006), skeletal muscle mass (+ 9.5%; p = 0.007), and appendicular muscle mass (+ 7.3%; p = 0.002). Peak VO2/kg (+ 9.4%; p = 0.05) and fat oxidation (at 80 W: + 26.96%; p = 0.04; at 100 W: + 40.95%; p = 0.02; at 120 W: + 83.02%; p = 0.01) were found increased only in women, although no concurrent changes in partial pressure of end-tidal CO2 (PETCO2) was observed. CONCLUSIONS: In postmenopausal women, a 5-day, intensive and physically/technically demanding outdoor trekking activity led to significant and potentially relevant changes in body composition, energy balance and metabolism that are generally attained following quite longer periods of training.

A Novel Paired Somatosensory-Cerebellar Stimulation Induces Plasticity on Cerebellar-Brain Connectivity.

The cerebellum receives and integrates a large amount of sensory information that is important for motor coordination and learning. The aim of the present work was to investigate whether peripheral nerve and cerebellum paired associative stimulation (cPAS) could induce plasticity in both the cerebellum and the cortex. In a cross-over design, we delivered right median nerve electrical stimulation 25 or 10 ms before applying transcranial magnetic stimulation over the cerebellum. We assessed changes in motor evoked potentials (MEP), somatosensory evoked potentials (SEP), short-afferent inhibition (SAI), and cerebellum-brain inhibition (CBI) immediately, and 30 min after cPAS. Our results showed a significant reduction in CBI 30 minutes after cPAS, with no discernible changes in MEP, SEP, and SAI. Notably, cPAS10 did not produce any modulatory effects on these parameters. In summary, cPAS25 demonstrated the capacity to induce plasticity effects in the cerebellar cortex, leading to a reduction in CBI. This novel intervention may be used to modulate plasticity mechanisms and motor learning in healthy individuals and patients with neurological conditions.

Short-term transcutaneous trigeminal nerve stimulation does not affect visual oddball task and paired-click paradigm ERP responses in healthy volunteers.

Recent research suggests that transcutaneous trigeminal nerve stimulation (TNS) may positively affect cognitive function. However, no clear-cut evidence is available yet, since the majority of it derives from clinical studies, and the few data on healthy subjects show inconsistent results. In this study, we report the effects of short-term TNS on event-related potentials (ERP) recorded during the administration of a simple visual oddball task and a paired-click paradigm, both considered useful for studying brain information processing functions. Thirty-two healthy subjects underwent EEG recording before and after 20 min of sham- or real-TNS, delivered bilaterally to the infraorbital nerve. The amplitude and latency of P200 and P300 waves in the simple visual oddball task and P50, N100 and P200 waves in the paired-click paradigm were measured before and after treatment. Our results show that short-term TNS did not alter any of the ERP parameters measured, suggesting that in healthy subjects, short-term TNS may not affect brain processes involved in cognitive functions such as pre-attentional processes, early allocation of attention and immediate memory. The perspective of having an effective, non-pharmacological, non-invasive, and safe treatment option for cognitive decline is particularly appealing; therefore, more research on the positive effects on cognition of TNS is definitely needed.

A Thematic Survey on the Reporting Quality of Randomized Controlled Trials in Rehabilitation: The Case of Multiple Sclerosis.

BACKGROUND AND PURPOSE: Optimal reporting is a critical element of scholarly communications. Several initiatives, such as the EQUATOR checklists, have raised authors' awareness about the importance of adequate research reports. On these premises, we aimed at appraising the reporting quality of published randomized controlled trials (RCTs) dealing with rehabilitation interventions. Given the breadth of such literature, we focused on rehabilitation for multiple sclerosis (MS), which was taken as a model of a challenging condition for all the rehabilitation professionals.A thematic methodological survey was performed to critically examine rehabilitative RCTs published in the last 2 decades in MS populations according to 3 main reporting themes: (1) basic methodological and statistical aspects; (2) reproducibility and responsiveness of measurements; and (3) clinical meaningfulness of the change. SUMMARY OF KEY POINTS: Of the initial 526 RCTs retrieved, 370 satisfied the inclusion criteria and were included in the analysis. The survey revealed several sources of weakness affecting all the predefined themes: among these, 25.7% of the studies complemented the P values with the confidence interval of the change; 46.8% reported the effect size of the observed differences; 40.0% conducted power analyses to establish the sample size; 4.3% performed retest procedures to determine the outcomes' reproducibility and responsiveness; and 5.9% appraised the observed differences against thresholds for clinically meaningful change, for example, the minimal important change. RECOMMENDATIONS FOR CLINICAL PRACTICE: The RCTs dealing with MS rehabilitation still suffer from incomplete reporting. Adherence to evidence-based checklists and attention to measurement issues and their impact on data interpretation can improve study design and reporting in order to truly advance the field of rehabilitation in people with MS.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1 available at: http://links.lww.com/JNPT/A424 ).

Base of Support, Step Length and Stride Width Estimation during Walking Using an Inertial and Infrared Wearable System.

The analysis of the stability of human gait may be effectively performed when estimates of the base of support are available. The base of support area is defined by the relative position of the feet when they are in contact with the ground and it is closely related to additional parameters such as step length and stride width. These parameters may be determined in the laboratory using either a stereophotogrammetric system or an instrumented mat. Unfortunately, their estimation in the real world is still an unaccomplished goal. This study aims at proposing a novel, compact wearable system, including a magneto-inertial measurement unit and two time-of-flight proximity sensors, suitable for the estimation of the base of support parameters. The wearable system was tested and validated on thirteen healthy adults walking at three self-selected speeds (slow, comfortable, and fast). Results were compared with the concurrent stereophotogrammetric data, used as the gold standard. The root mean square errors for the step length, stride width and base of support area varied from slow to high speed between 10-46 mm, 14-18 mm, and 39-52 cm2, respectively. The mean overlap of the base of support area as obtained with the wearable system and with the stereophotogrammetric system ranged between 70% and 89%. Thus, this study suggested that the proposed wearable solution is a valid tool for the estimation of the base of support parameters out of the laboratory.

Is it possible to compare inhibitory and excitatory intracortical circuits in face and hand primary motor cortex?

Face muscles are important in a variety of different functions, such as feeding, speech and communication of non-verbal affective states, which require quite different patterns of activity from those of a typical hand muscle. We ask whether there are differences in their neurophysiological control that might reflect this. Fifteen healthy individuals were studied. Standard single- and paired-pulse transcranial magnetic stimulation (TMS) methods were used to compare intracortical inhibitory (short interval intracortical inhibition (SICI); cortical silent period (CSP)) and excitatory circuitries (short interval intracortical facilitation (SICF)) in two typical muscles, the depressor anguli oris (DAO), a face muscle, and the first dorsal interosseous (FDI), a hand muscle. TMS threshold was higher in DAO than in FDI. Over a range of intensities, resting SICF was not different between DAO and FDI, while during muscle activation SICF was stronger in FDI than in DAO (P = 0.012). At rest, SICI was stronger in FDI than in DAO (P = 0.038) but during muscle contraction, SICI was weaker in FDI than in DAO (P = 0.034). We argue that although many of the difference in response to the TMS protocols could result from the difference in thresholds, some, such as the reduction of resting SICI in DAO, may reflect fundamental differences in the physiology of the two muscle groups. KEY POINTS: Transcranial magnetic stimulation (TMS) single- and paired-pulse protocols were used to investigate and compare the activity of facilitatory and inhibitory intracortical circuits in a face (depressor anguli oris; DAO) and hand (first dorsal interosseous; FDI) muscles. Several TMS intensities and interstimulus intervals were tested with the target muscles at rest and when voluntarily activated. At rest, intracortical inhibitory activity was stronger in FDI than in DAO. In contrast, during muscle contraction inhibitory activity was stronger in DAO than in FDI. As many previous reports have found, the motor evoked potential threshold was higher in DAO than in FDI. Although many of the differences in response to the TMS protocols could result from the difference in thresholds, some, such as the reduction of resting short interval intracortical inhibition in DAO, may reflect fundamental differences in the physiology of the two muscle groups.

Analysis of sex-based differences in energy substrate utilization during moderate-intensity aerobic exercise.

PURPOSE: To explore sex-based differences in energy substrate utilization during moderate-intensity aerobic exercise; to identify the underpinning candidate physiological mechanisms. METHODS: Three databases were searched from inception to August 2020. Pertinent studies quantifying the utilization of substrates during moderate aerobic exercise in healthy men and reproductive-age women were considered. Studies conducted on sedentary/recreationally active and athletic populations were included and analyzed separately. RESULTS: Thirty-five studies entered the meta-analysis (21 in sedentary/recreationally active, 14 in athletic populations). Compared to women, the respiratory exchange ratio was significantly higher both in sedentary (mean difference, MD: + 0.03; p < 0.00001) and athletic men (MD: + 0.02; p < 0.0001). Greater carbohydrate oxidation was observed both in sedentary (standardized MD, SMD: 0.53; p = 0.006) and athletic men (SMD: 1.24; p < 0.00001). Regarding lipid substrates, sedentary men oxidized less fat than women (SMD:  - 0.77; p = 0.0002), while no sex-based differences in fat oxidation were observed in athletes (SMD: 0.06; p = 0.77). Paucity of data prevented robust meta-analyses for protein sources. Sex hormones and different adrenergic activation were the most cited mechanisms to discuss sex-based differences. CONCLUSIONS: Meta-analyses confirmed that men display greater reliance on carbohydrates while women rely more on lipids to sustain moderate aerobic exercise. The latter finding was not confirmed in athletes, a novel aspect of the present study. Mechanistically driven research is needed to further dissect the physiological underpinnings of sex differences in substrate utilization during aerobic exercise, especially for proteins, which are still less investigated than other substrates.

Healthy Women and Men Do Not Show Differences in Tongue Strength and Regular Effort Saliva Swallows as Assessed by Piezo-Resistive Sensors: Results from a Reproducibility Study.

The aim of this study was to establish the reproducibility of tongue strength measurements in healthy women and men during maximum anterior isometric pressure (MAIP) and regular effort saliva swallows (RESS). In this cross-sectional study, 30 healthy young adults were required to push with the tip of the tongue on a piezo-resistive sensor glued to the hard palate, immediately above the central incisor line. Tongue pressures exerted on the sensor during MAIP and spontaneous RESS were recorded. Participants underwent a retest procedure within the same session to verify the reproducibility of measurements, as determined by intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimum detectable change (MDC). Complete data were obtained from 30 subjects (15 women, 15 men; mean age 31.4 ± 7.8 years; mean weight 61.3 ± 9.4 kg). Compared to women, men showed a trend for generating larger MAIP (p = 0.06; d = 0.71) and RESS (p = 0.07; d = 0.69). After normalizing to body weight, height, and body mass index (BMI), such trends disappeared. At retest, MAIP and RESS proved stable and highly reliable (all ICCs ≥ 0.93) in men and women but associated to moderate variability as for SEM and MDC, with MAIP estimates associated to smaller SEM and MDC (SEM ranging 7.4-14.2%; MDC 18.6-20.9%) than RESS (SEM ranging 20.4-38.5%; MDC 52.5-55.6%). Piezo-resistive pressure sensors allow clinicians and researchers to perform reproducible measurements of tongue muscle performance. However, if therapeutic interventions are administered, measurement variability in tongue performance should be considered when appraising their clinical efficacy, especially for those populations who display impaired performance and may not be capable to generate high and stable forces. No gender-based differences emerged in the motor tasks tested.

Faces emotional expressions: from perceptive to motor areas in aged and young subjects.

The role of age in perception and production of facial expressions is still unclear. Therefore, this work compared, in aged and young subjects, the effects of passive viewing of faces expressing different emotions on perceptive brain regions, such as occipital and temporal cortical areas and on the primary motor cortex (M1) innervating lower face muscles. Seventeen young (24.41 ± 0.71 yr) and seventeen aged (63.82 ± 0.99 yr) subjects underwent recording of event-related potentials (ERP), of motor potentials evoked by transcranial magnetic stimulation of face M1 in the depressor anguli oris muscle and reaction time assessment. In both groups, the P100 and N170 waves, as well as short-latency intracortical inhibition (SICI) and intracortical facilitation (ICF) were probed in face M1 after 300 ms from the presentation of images reporting faces expressing happy, sad, and neutral emotions. ERP data evidenced a major involvement of the right hemisphere in perceptual processing of faces, regardless of age. Compared with young subjects, the aged group showed a delayed N170 wave and a smaller P100 wave following the view of sad but not happy or neutral expressions, along with less accuracy and longer reaction times for recognition of the emotion expressed by faces. Aged subjects presented less SICI than young subjects, but facial expressions of happiness increased the excitability of face M1 with no differences between groups. In conclusion, data suggest that encoding of sad face expressions is impaired in the aged compared with the young group, whereas perception of happiness and its excitatory effects on face M1 remains preserved.NEW & NOTEWORTHY This study shows that aged subjects have less visual attention and impaired perception for sad, but not for happy, face expressions. Conversely, the view of happy, but not sad, faces increases excitability in face M1 bilaterally, regardless of age. The impaired attention for sad expressions, the preserved perception of faces expressing happiness, along with the enhancing effects of the latter on face M1 excitability, likely makes the aged subjects more motivated in approaching positive emotions.

Energy Expenditure and Oxygen Consumption During Activities of Daily Living in People With Multiple Sclerosis and Healthy Subjects: An Ecological Approach to Estimate Real-Life Fatigue and Fatigability.

OBJECTIVE: To compare oxygen consumption and energy expenditure (EE) of the activities of daily living (ADL) in people with multiple sclerosis (PwMS) and healthy subjects. DESIGN: Cross-sectional observational study. SETTING: Outpatient care facilities. PARTICIPANTS: Twenty-four moderately impaired PwMS and 21 healthy controls (N=45). INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Oxygen consumption, EE rate, and total EE assessed by portable open-circuit spirometry during the accomplishment of a comprehensive set of 14 ADL. Body composition was also assessed with bioelectrical impedance analysis. Body cell mass was used to normalize metabolic rates between groups. RESULTS: PwMS exhibited significantly higher oxygen consumption than controls in transfer and mobility tasks (walking with stairs: +10.4%, P=.04; without stairs: +15.2%, P=.002; driving: +10.4%, P=.04) and higher EE rates for walking (+13.6%, P=.01). ADL completion took significantly longer in PwMS. Consequently, when total EE to complete each ADL was considered, PwMS used significantly more energy in 10 of the 14 ADL. Of these, "climb stairs" and walking with or without stairs showed the largest differences (+100%, +99.5%, +79.3%, respectively; all P values<.0005), followed by "dressing" (+48.8%; P=.002), "laundry" (+41.7%; P=.007), and "shopping" (+40.1%; P=.003). CONCLUSIONS: Moderately disabled PwMS display oxygen consumption and EE rates during ADL that are comparable to those of matched healthy subjects, except for the activities that involve walking. Although metabolic rates were not different for the majority of ADL, PwMS showed higher total EE to complete the same activities at a comparable work intensity, which may contribute to the burden of "real-life" tiredness and fatigue typically described in this population. Importantly, the subjective Modified Fatigue Impact Scale score significantly correlated to EE and oxygen consumption of selected ADL, such as "make a bed," "driving," "clean surfaces," and "climb stairs." The joint employment of open-circuit spirometry during ADL and body composition analysis allows an accurate metabolic characterization of PwMS, who frequently complain of fatigue.

Role of cutaneous and proprioceptive inputs in sensorimotor integration and plasticity occurring in the facial primary motor cortex.

KEY POINTS: Previous studies investigating the effects of somatosensory afferent inputs on cortical excitability and neural plasticity often used transcranial magnetic stimulation (TMS) of hand motor cortex (M1) as a model, but in this model it is difficult to separate out the relative contribution of cutaneous and muscle afferent input to each effect. In the face, cutaneous and muscle afferents are segregated in the trigeminal and facial nerves, respectively. We studied their relative contribution to corticobulbar excitability and neural plasticity in the depressor anguli oris M1. Stimulation of trigeminal afferents induced short-latency (SAI) but not long-latency (LAI) afferent inhibition of face M1, while facial nerve stimulation evoked LAI but not SAI. Plasticity induction was observed only after a paired associative stimulation protocol using the facial nerve. Physiological differences in effects of cutaneous and muscle afferent inputs on face M1 excitability suggest they play separate functional roles in behaviour. ABSTRACT: The lack of conventional muscle spindles in face muscles raises the question of how sensory input from the face is used to control muscle activation. In 16 healthy volunteers, we probed sensorimotor interactions in face motor cortex (fM1) using short-afferent inhibition (SAI), long-afferent inhibition (LAI) and LTP-like plasticity following paired associative stimulation (PAS) in the depressor anguli oris muscle (DAO). Stimulation of low threshold afferents in the trigeminal nerve produced a clear SAI (P < 0.05) when the interval between trigeminal stimulation and transcranial magnetic stimulation (TMS) of fM1 was 15-30 ms. However, there was no evidence for LAI at longer intervals of 100-200 ms, nor was there any effect of PAS. In contrast, facial nerve stimulation produced significant LAI (P < 0.05) as well as significant facilitation 10-30 minutes after PAS (P < 0.05). Given that the facial nerve is a pure motor nerve, we presume that the afferent fibres responsible were those activated by the evoked muscle twitch. The F-wave in DAO was unaffected during both LAI and SAI, consistent with their presumed cortical origin. We hypothesize that, in fM1, SAI is evoked by activity in low threshold, presumably cutaneous afferents, whereas LAI and PAS require activity in (higher threshold) afferents activated by the muscle twitch evoked by electrical stimulation of the facial nerve. Cutaneous inputs may exert a paucisynaptic inhibitory effect on fM1, while proprioceptive information is likely to target inhibitory and excitatory polysynaptic circuits involved in LAI and PAS. Such information may be relevant to the physiopathology of several disorders involving the cranio-facial system.

The vestibulo-masseteric reflex and the acoustic-masseteric reflex: a reliability and responsiveness study in healthy subjects.

The vestibulo-masseteric reflex (VMR or p11 wave), the acoustic-masseteric reflex (AMR or p1/n21 wave) and the mixed vestibulo-cochlear p11/n21 potential are responses of masseter muscles to sound that can be employed to evaluate brainstem function. This study was aimed at establishing the test-retest reliability and responsiveness of these reflex parameters according to the type of electrode configuration. Twenty-two healthy volunteers (M:F = 11:11; mean age 25.3 ± 5.2 years) participated in two testing sessions separated by one week. Zygomatic and mandibular montages were compared following unilateral and bilateral stimulations. For reliability purposes, intraclass correlation coefficient (ICC), coefficient of variation of the method error (CVME) and standard error of measurement (SEM) were calculated. The minimal detectable difference (MDD) was also determined as a measure of responsiveness. Both VMR (p11 wave) and AMR could be consistently evoked from test to retest, although the frequency rate was significantly higher (all p values ≤ 0.009) with zygomatic (VMR: 97.7-100%; AMR: 86.9-97.6%) than mandibular montage (VMR: 84.7-89.8%; AMR: 65.0-67.8%), with no significant differences between unilateral and bilateral stimulations. Good-to-excellent reliability and responsiveness (high ICC, low CVME, SEM and MDD scores) were detected for corrected amplitudes and peak latencies for all reflex responses, whereas raw amplitudes were associated to poor reliability. The reliability of the zygomatic montage proved superior to the mandibular montage for all reflex responses. Given their high test-retest consistency and capability to study different features of the reflex arch, both peak latencies and corrected amplitudes should be reported and considered in the interpretation of reflex testing results.

Happy faces selectively increase the excitability of cortical neurons innervating frowning muscles of the mouth.

Although facial muscles are heavily involved in emotional expressions, there is still a lack of evidence about the role of face primary motor cortex (face M1) in the processing of facial recognition and expression. This work investigated the effects of the passive viewing of different facial expressions on face M1 and compared data with those obtained from the hand M1. Thirty healthy subjects were randomly assigned to two groups undergoing transcranial magnetic stimulation (TMS) of face or hand M1. In both groups, short-latency intracortical inhibition (SICI) and intracortical facilitation (ICF) were probed in the depressor anguli oris (DAO) and first dorsal interosseous (FDI) muscles 300 ms after presentation of a picture of a face that expressed happy, sad or neutral emotions. Statistical analysis of SICI showed a non-significant effect of muscle (F1,28 = 1.903, p = 0.179), but a significant effect of emotion (F2,56 = 6.860, p = 0.004) and a significant interaction between muscle and emotion (F2,56 = 5.072, p = 0.015). Post hoc analysis showed that there was a significant reduction of SICI in the DAO muscle after presentation of a face with a happy expression compared with a neutral face (p < 0.001). In the FDI, a significant difference was observed between neutral and sad expressions (p = 0.010) No clear differences in ICF were detected. The different responses of face and hand muscles to emotional stimuli may be due to their functional roles in emotional expression versus protection of the body.

Linearity and repeatability of postural responses in relation to peak force and impulse of manually delivered perturbations: a preliminary study.

PURPOSE: Postural reactions (PR) of standing subjects have been mostly investigated in response to platform displacements or body perturbations of fixed magnitude. The objective of this study was to investigate the relationship between PR and the peak force and impulse of the perturbation. METHODS: In ten healthy young men, standing balance was challenged by anteriorly directed perturbations (peak force: 20-60 N) delivered to the back, at the lumbar (L) or inter-scapular (IS) level, by means of a manual perturbator equipped with a force sensor. Postural reactions as expressed by the displacement of the center of pressure (CoP) were recorded using a force platform. Two sets of 20 randomly ordered perturbations (10 to each site) were delivered in two separate testing sessions. RESULTS: The magnitude of CoP response (∆CoP) was better correlated with the impulse (I) than with the peak force of the perturbation. The normalized response, ∆CoPn = ∆CoP/I, exhibited good reliability (ICCs of 0.93 for IS and 0.82 for L), was higher with IS than with L perturbations (p < 0.01), and was significantly correlated with the latency of CoP response: r = 0.69 and 0.71 for IS and L, respectively. CONCLUSION: These preliminary findings support the concept that manually delivered perturbations can be used to reliably assess individual PR and that ∆CoPn may effectively express a relevant aspect of postural control.

Listening to music while running alters ground reaction forces: a study of acute exposure to varying speed and loudness levels in young women and men.

PURPOSE: Music listening while running enhances physiological and psychological features, resulting in a more enjoyable experience. The possible influence of music on ground reaction forces (GRF) during running, however, is unknown. Considering the 'distracting' role of music on runner's attention, we hypothesized that music would cover foot impacts against the ground. This study verified such hypothesis by testing the effects of different music volumes while running at different velocities. METHODS: Fifty fit volunteers (F:M = 22:8; 23 ± 2 years) performed 2-min running stints over 3 random conditions (80-dB, 85-dB music; 'no music'), at 3 velocities (8, 10, 12 km/h). Participants ran on a sensorized treadmill that recorded GRF during all experiments. RESULTS: Listening to 85-dB music resulted in greater GRF at 8 (p = 0.0005) and 10 km/h (p = 0.04) but not 12 km/h (p = 0.35) and not with 80-dB volume. Gender-based analyses revealed significant Condition × gender interactions only for 85-dB music vs. 'no music'. Bonferroni-adjusted comparisons revealed significant music-induced increases in GRF only in men at 8 km/h (+ 4.1 kg/cm2, p < 0.0005; women: + 0.8 kg/cm2, p = 0.47) and 10 km/h (+ 3.3 kg/cm2, p = 0.004; women: + 0.8 kg/cm2, p = 0.51) but not at 12 km/h. CONCLUSION: In active men, listening to loud music while running results in increased GRF, whereas no effect was observed in women. The lack of music effect in women may be related to structural factors, such as larger hip width-to-femoral length ratio, possibly resulting in different loading patterns. The present preliminary findings introduce high-volume music listening as a new potential risk factor for injury in young runners.

Risk factors associated with low back pain in competitive female gymnasts: A meta-analytic approach.

The aim of this meta-analysis was to aggregate data from studies investigating the risk factors associated with low back pain (LBP) in competitive gymnasts.Four databases were searched and studies reporting demographics, anthropometrics, functional, psychosocial and gymnastics-practice variables in competitive gymnasts with and without LBP were included. For continuous data, the weighted mean difference (MD) and confidence interval (95% CI) were calculated, while odds or risk ratio (OR, RR) were calculated for dichotomous data.Meta-analysis of six cross-sectional studies involving 284 competitive female gymnasts revealed that artistic were more likely to report LBP compared to rhythmic gymnasts (RR 1.4, 95% CI 1.04-2.0, Z=2.2, p=0.03). Data pooling revealed that age (MD 1.5 years, 95% CI 0.4-2.5, p=0.005) and body weight (MD 3.5 kg, 95% CI 0.1-6.8, p=0.04) were significantly higher in gymnasts with LBP compared to those without. Subgroup-analyses confirmed these differences in artistic but not in rhythmic gymnasts. Moreover, artistic gymnasts with LBP tended to display longer gymnastics-practice history (p=0.09) compared to those without.Increased age, body weight and, to a lesser extent, longer gymnastics-practice appear to differentiate artistic gymnasts with LBP from those without; conversely, these potential risk factors seem less relevant for rhythmic gymnasts.

Enhancing research quality of studies on VEMPs in central neurological disorders: a scoping review.

Common pitfalls in vestibular-evoked myogenic potential (VEMP) recording methods have been extensively outlined by several reviews. Conversely, the robustness of research methodology employed for the design and conduct of VEMP studies has never been appraised. To fill this void, we conducted a scoping review to map and evaluate the overall quality of the existing literature on VEMPs in central neurological disorders. Five databases were searched from inception to October 2018 for case-control studies on multiple sclerosis (MS), cerebellar and/or brainstem strokes, Parkinson's disease (PD), migraine, and tumors of the cerebellopontine angle. Study quality was assessed using the Agency for Healthcare Research and Quality criteria (AHRQ). The 11-criteria AHRQ scoring system revealed that PD studies achieved a score of 5/11, migraine and cerebellar and/or brainstem stroke a score of 4/11, MS and tumors of the cerebellopontine angle a score of 3/11. Age was found to be one of the main sources of case-control imbalance: compared with controls, cases were significantly older with a 3.6-yr difference in MS studies, 6 yr in PD, up to 12 yr in stroke and tumors. Regardless of pathological condition, case-control groups were found unmatched also by gender. Post hoc power calculations revealed that 53% of the studies achieved the minimum statistical power of 80%. This scoping review revealed low research quality across the literature on VEMPs in central neurological disorders. Scoping lines are provided on actions to be undertaken in future studies to establish a common methodological platform and enhance the quality of research in this field.NEW & NOTEWORTHY Robust methodology is a prerequisite for any type of research, particularly for observational designs such as those employed in vestibular-evoked myogenic potential (VEMP) research. On these premises, this scoping review provides methodological guidelines to improve validity, accuracy and consistency of clinical outcomes from VEMP studies involving central nervous system disorders. In fact, the high risk for bias that is inherent to poor methodology threatens the validity of the findings of works that are technically sound but methodologically flawed.

Meta-analytic and Scoping Study on Strength Training in People With Multiple Sclerosis.

Manca, A, Dvir, Z, and Deriu, F. Meta-analytic and scoping study on strength training in people with multiple sclerosis. J Strength Cond Res 33(3): 874-889, 2019-Aim of the study was to determine a pooled estimate of effect on muscle strength and functional capacity induced by strength training in people with multiple sclerosis (PwMS). Five databases and 2 public registries were searched from inception to May 2017. Indexing terms used were: "multiple sclerosis," "resistance training," and "strength training." After title/abstract screening, 2 independent reviewers evaluated the studies' eligibility, which were retained if PwMS were randomly assigned to strength training or to a no intervention group. Of the 1,467 items retrieved, 30 randomized controlled trials formed the initial database with 11 trials (426 subjects) entering the final meta-analysis. The quality of the included studies was assessed by the PEDro scale and the risk of bias using the Cochrane Risk-of-Bias tool. All meta-analyses were conducted using a random effects model. After interventions, PwMS increased strength by 23.1% (confidence interval [CI] 11.8-34.4; +12.1 N; CI 4.5-19.8; p = 0.002; n = 366 subjects) at a small-to-moderate effect size (0.37; CI 0.2-0.6). Walking speed increased by 16.3 ± 10.7% (p = 0.0002; effect size 0.54; n = 275 subjects), distance covered in the 2-minute walking test by 6.7 ± 6.4% (p = 0.04; effect size 0.50; n = 111 subjects). People with MS respond to resistance training with consistent strength gains. Methodological inconsistencies among studies and inadequate reporting of the findings limited a comprehensive determination of the impact of strength improvements on patient functioning, except for walking performance which seemed significantly improved. Methodological steps and scoping lines are provided to establish a common platform for future trials.

Effects of acute trigeminal nerve stimulation on rest EEG activity in healthy adults.

Trigeminal nerve stimulation (TNS) is a non-invasive neuromodulation method which is increasingly used for its beneficial effects on symptoms of several neuropsychiatric disorders such as drug-resistant epilepsy. Sites and mechanisms of its action are still unknown. The present study was aimed at investigating the physiological effects of acute TNS on rest electroencephalographic (EEG) activity. EEG was recorded with a 19-channel EEG system from 18 healthy adults who underwent 20 min of sham- and real-TNS (cycles of 30 s ON and 30 s OFF) in two separate sessions. EEG was continuously acquired in the 10-min preceding TNS, during TNS in the "OFF" period and throughout 10 min after TNS. Mean frequency, total power over the 0.5-48 Hz frequency range and absolute power for delta, theta, alpha, beta and gamma bands were analyzed by a discrete Fast Fourier Transform algorithm. Interhemispheric and intrahemispheric coherences were also analyzed for each band at different time points. Intra- and interhemispheric coherences were significantly reduced for the beta frequencies only during real-TNS (p = 0.002 and p = 0.006, respectively). No TNS effect on the power spectra of any band was detected. A trend of increase in the mean EEG frequency total power during real-TNS (p = 0.03) and of decrease in interhemispheric gamma coherence after real-TNS (p = 0.01) was observed. Acute TNS may induce a spatially diffuse desynchronization of fast EEG rhythms in healthy adults, this desynchronization may underpin the antiepileptic effect of TNS described by clinical studies.

Short-term trigeminal neuromodulation does not alter sleep latency in healthy subjects: a pilot study.

It has been reported that during and/or after acute trigeminal nerve stimulation (TNS) a state of sedation, decreased attention and vigilance, with a tendency to fall asleep, occurs. Whether these effects are due to a hypnotic action of TNS is yet to be demonstrated. This pilot study investigates whether acute TNS affects the latency of sleep using the Multiple Sleep Latency Test (MSLT) in healthy subjects. MSLT was performed in 14 healthy subjects after 20 min of real- and a sham-TNS, delivered in two different sessions. Mean latency of sleep across the five naps accorded and the latency of sleep for each nap was determined. All subjects reported a state of relaxation or drowsiness after the real-TNS session. Repeated-measures ANOVA showed no significant differences in sleep latency between the real and sham conditions. The sedative effects of acute TNS do not seem associated to a hypnotic effect.