Investigating prismatic adaptation effects in handgrip strength and in plantar pressure in healthy subjects

Acute effects of prismatic adaptation on penalty kick accuracy and postural control in young soccer players: A pilot study

Background

Prismatic adaptation (PA) is a visuomotor technique using prismatic glasses that are capable of moving the visual field and to affect the excitability of certain brain areas. The aim of this pilot study was to explore potential acute effects of PA on penalty kick accuracy and postural control in youth soccer players.

Methods

In this randomized crossover study, seven young male soccer players performed three PA sessions (rightward PA, r-PA; leftward PA, l-PA; sham PA, s-PA) with a washout period of 1-week between them. Immediately before and after each PA session, penalty kick accuracy and postural control were assessed.

Results

We detected an increase in penalty kick accuracy following PA, regardless of the deviation side of the prismatic glasses (F1,5 = 52.15; p = 0.08; ηp2 = 0.981). In detail, our results showed an increase in the penalty kick accuracy toward the right target of the football goal following r-PA and toward the left target of the football goal following l-PA. We detected a significant effect on the sway path length (F2,12 = 10.42; p = 0.002; ηp2 = 0.635) and the sway average speed (F2,12 = 9.17; p = 0.004; ηp2 = 0.605) parameters in the stabilometric test with open eyes following PA, regardless of the deviation side of the prismatic glasses. In detail, our results showed a significant difference in both the stabilometric parameters (p = 0.016 and p = 0.009, respectively) only following l-PA.

Conclusion

The findings of this pilot study indicate that PA could positively affect penalty kick accuracy and postural control suggesting that PA could be used as a visual training technique in athletes.

Gross motor proficiency deficits among children and adolescents post posterior fossa brain tumor removal vs. traumatic brain injury in the chronic phase of recovery: a cross-sectional study

Introduction

Acquired brain injury (ABI) is a prevalent diagnosis in pediatric rehabilitation. Gross motor skills are often affected by ABI and limit the ability to participate in various physical activities. However, as ABI injury location is diverse, children and adolescents (youth) with localized ABI, such as ABI in the posterior fossa (ABI-PF) may present unique and different motor disabilities than youth with ABI on account of traumatic brain injury (TBI).

Aims

The aims of the study were: (1) to compare gross motor deficits in youth with TBI vs. ABI-PF; and (2) to compare two methods on scoring BOT2 to determine which is better for identifying motor deficits.

Methods

Participated in this study youth with TBI (N = 50) and ABI-PF (N = 30). Participants were tested on Bruininks-Oseretsky Test of Motor Proficiency-2nd Edition (BOT2) Upper-Limb Coordination, Balance, Strength, Running Speed and Agility, and Bilateral-Coordination subtests. Motor performance deficits were established using two-standard deviations (2SD) and age-equivalent methods. Between-group differences were assessed via independent t-tests and receiver operating characteristic curves (ROC).

Results

According to the 2SD method, motor deficits in the ABI-PF group ranged from 20% to 66.66%, whereas in the TBI group 8%-16%. According to the age-equivalent method, in the TBI and ABI-PF groups 40%-66.0% and 46.66%-76.66% of the youth presented motor deficits, respectively. Moreover, ROC analysis showed that motor performance deficits of both groups in all sub-scales except for Bilateral Coordination differed enough to result in medium area under the curve.

Conclusions

Motor deficits post-pediatric ABI are prevalent. In comparison to the TBI group, deficits are greater in the ABI-PF group. Moreover, compared to the 2SD method, the extent of motor deficiency is greater in the age-equivalent method. Therefore, using the later might provide a more valid classification of deficits in gross motor proficiency for youth post-ABI.

Young basketball players have better manual dexterity performance than sportsmen and non-sportsmen of the same age: a cross-sectional study

Manual dexterity is a key skill in motor development. There are conflicting studies on the influence of sports practice on this skill and on which type of sport trains this ability the most in youth. Manual dexterity is usually assessed with expensive and time-consuming tools not easily available to facilities such as schools or sports clubs. The aim of this study was to assess differences in manual dexterity performance between young basketball players, sportsmen, and non-sportsmen. A further aim was to analyze whether the coin rotation task was a reliable tool for assessing manual dexterity. Based on the characteristics of the sport, we hypothesized that basketball players had better manual dexterity performances. Seventy-eight participants were included in the study and categorized into "basketball", "sports", and "non-sports" groups. Manual dexterity was assessed with the grooved pegboard, the coin rotation task, and the handgrip tests. The basketball group showed better performance in all tests. Significant differences were found between the basketball group and sports group and between the basketball group and non-sport group in the grooved pegboard (p < 0.05) and in the handgrip (p < 0.05) tests. Test-retest reliability of the coin rotation task scores was moderate in the basketball group (ICC2,1 0.63-0.6). Basketball practice could positively influence manual dexterity. The coin rotation task showed an acceptable construct of validity.

Prism adaptation during balance standing enhances the transfer after-effect on standing postural displacement

Prism adaptation (PA) is a sensorimotor adaptation paradigm that induces after-effects of adapted tasks and transfer after-effects of non-adapted tasks. Previous studies showed inconsistent results of transfer after-effects of adaptation to a leftward prismatic shift on the center-of-pressure (COP) displacement during eyes-closed standing. Challenging balance during PA increases the generalization of the internal model to untrained movements, resulting in increased transfer after-effects. The present study aimed to investigate the transfer after-effects of PA with challenging balance on standing postural displacement. Thirty healthy young adults were grouped into floor standing and balance-disc standing groups during leftward PA and pointed to targets while adapting to a leftward visual shift (30 diopters) for 20 min. After leftward PA, both groups had a significant rightward displacement of straight-ahead pointing with eyes closed. However, the COP position during eyes-closed standing with feet-closed was significantly displaced rightward only in the balance-disc standing group after leftward PA. These results show that challenging balance might increase the somatosensory and proprioceptive information for standing postural control, resulting in increased transfer after-effects of leftward PA on rightward standing postural displacement.

Bilateral transfer of motor performance as a function of motor imagery training: a systematic review and meta-analysis

Objective

The objective of this review was to evaluate the efficacy of mental imagery training (MIT) in promoting bilateral transfer (BT) of motor performance for healthy subjects.

Data sources

We searched 6 online-databases (Jul-Dec 2022) using terms: "mental practice," "motor imagery training," "motor imagery practice," "mental training," "movement imagery," "cognitive training," "bilateral transfer," "interlimb transfer," "cross education," "motor learning," "strength," "force" and "motor performance."

Study selection and data extraction

We selected randomized-controlled studies that examined the effect of MIT on BT. Two reviewers independently determined if each study met the inclusion criteria for the review. Disagreements were resolved through discussion and, if necessary, by a third reviewer. A total of 9 articles out of 728 initially identified studies were chosen for the meta-analysis.

Data synthesis

The meta-analysis included 14 studies for the comparison between MIT and no-exercise control (CTR) and 15 studies for the comparison between MIT and physical training (PT).

Results

MIT showed significant benefit in inducing BT compared to CTR (ES = 0.78, 95% CI = 0.57-0.98). The effect of MIT on BT was similar to that of PT (ES = -0.02, 95% CI = -0.15-0.17). Subgroup analyses showed that internal MIT (IMIT) was more effective (ES = 2.17, 95% CI = 1.57-2.76) than external MIT (EMIT) (ES = 0.95, 95% CI = 0.74-1.17), and mixed-task (ES = 1.68, 95% CI = 1.26-2.11) was more effective than mirror-task (ES = 0.46, 95% CI = 0.14-0.78) and normal-task (ES = 0.56, 95% CI = 0.23-0.90). No significant difference was found between transfer from dominant limb (DL) to non-dominant limb (NDL) (ES = 0.67, 95% CI = 0.37-0.97) and NDL to DL (ES = 0.87, 95% CI = 0.59-1.15).

Conclusion

This review concludes that MIT can serve as a valuable alternative or supplement to PT in facilitating BT effects. Notably, IMIT is preferable to EMIT, and interventions incorporating tasks that have access to both intrinsic and extrinsic coordinates (mixed-task) are preferred over those that involve only one of the two coordinates (mirror-task or normal-task). These findings have implications for rehabilitation of patients such as stroke survivors.

Saddle Pressures Factors in Road and Off-Road Cyclists of Both Genders: A Narrative Review

The contact point of the pelvis with the saddle of the bicycle could generate abnormal pressure, which could lead to injuries to the perineum in cyclists. The aim of this review was to summarize in a narrative way the current literature on the saddle pressures and to present the factors that influence saddle pressures in order to prevent injury risk in road and off-road cyclists of both genders. We searched the PubMed database to identify English-language sources, using the following terms: "saddle pressures", "pressure mapping", "saddle design" AND "cycling". We also searched the bibliographies of the retrieved articles. Saddle pressures are influenced by factors such as sitting time on the bike, pedaling intensity, pedaling frequency, trunk and hand position, handlebars position, saddle design, saddle height, padded shorts, and gender. The jolts of the perineum on the saddle, especially on mountain bikes, generate intermittent pressures, which represent a risk factor for various pathologies of the urogenital system. This review highlights the importance of considering these factors that influence saddle pressures in order to prevent urogenital system injuries in cyclists.

Prism adaptation in patients with unilateral lesion of the parietal or cerebellar cortex: A pilot study on two single cases using a concurrent exposure procedure

Neuroimaging studies showed that prism adaptation (PA), a widely used tool for the rehabilitation of neglect, involves a wide network of brain regions including the parietal cortex and the cerebellum. In particular, the parietal cortex has been suggested to mediate the initial stage of PA through conscious compensatory mechanisms as a reaction to the deviation induced by PA. The cerebellum, on the other side, intervenes in sensory errors prediction to update internal models in later stages. It has been suggested that two mechanisms may underlie PA effects: recalibration, a strategic cognitive process occurring in the initial stages of PA, and realignment, a fully automatic reorganization of spatial maps emerging later and more slowly in time. The parietal lobe has been proposed to be involved mainly in the recalibration whereas the realignment would be carried over by the cerebellum. Previous studies have investigated the effects of a lesion involving either the cerebellum or the parietal lobe in PA taking into account both realignment and recalibration processes. Conversely, no studies have compared the performance of a patient with a cerebellar lesion to that of a patient with a parietal lesion. In the present study, we used a recently developed technique for digital PA to test differences in visuomotor learning after a single session of PA in a patient with parietal and a patient with cerebellar lesions, respectively. The PA procedure, in this case, includes a digital pointing task based on a concurrent exposure technique, which allows patients to fully see their arm during the pointing task. This procedure has been shown to be as effective as the terminal exposure condition in neglect rehabilitation albeit different processes take place during concurrent exposure condition compared to the most used terminal exposure (allowing to see only the final part of the movement). Patients' performances were compared to that of a control group. A single session of PA was administered to 1) a patient (BC) with left parieto-occipital lesion involving SPL and IPL, 2) a patient (TGM) with a stroke in the territory sub-served by the SCA in the cerebellum, and 3) 14 healthy controls (HC). The task included three conditions: before wearing prismatic goggles (pre-exposure), while wearing prisms (exposure) and after removing the goggles (post-exposure). Mean deviations were calculated for the following phases: pre-exposure, early-exposure, late-exposure, post-exposure. The presence of after-effect was calculated as the difference between pre-exposure and post-exposure conditions. For each of these conditions, patients' performance was compared to that of the control group by using a modified Crawford t-test. We found that the patient with the parietal lesion had a significantly different performance in the late-exposure and in the post-exposure compared to both HC and the patient with the cerebellar lesion. Conversely, no differences were observed between TGM and HC across all the conditions. Our results show an increase in the magnitude of the adaptation during the late stage of PA in the patient with the parietal lesion whereas no differences in the performance between the cerebellar patient and the controls were found. These results confirm previous studies suggesting that the parietal cortex is an important node of a wider network involved in PA effect. Furthermore, results in the cerebellar patient suggest that visuomotor learning is not affected by lesions of the SCA territory when a concurrent exposure is used as, in such case, it less relies on sensory errors prediction to update internal models. Results are discussed considering the novelty of the applied PA technique.

Patisiran Enhances Muscle Mass after Nine Months of Treatment in ATTRv Amyloidosis: A Study with Bioelectrical Impedance Analysis and Handgrip Strength

BACKGROUND AND AIMS

Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv) is caused by mutations in the TTR gene, leading to misfolded monomers that aggregate generating amyloid fibrils. The clinical phenotype is heterogeneous, characterized by a multisystemic disease affecting the sensorimotor, autonomic functions along with other organs. Patisiran is a small interfering RNA acting as a TTR silencer approved for the treatment of ATTRv. Punctual and detailed instrumental biomarkers are on demand for ATTRv to measure the severity of the disease and monitor progression and response to treatment.

METHODS

Fifteen patients affected by ATTRv amyloidosis (66.4 ± 7.8 years, six males) were evaluated before the start of therapy with patisiran and after 9-months of follow-up. The clinical and instrumental evaluation included body weight and height; Coutinho stage; Neuropathy Impairment Score (NIS); Karnofsky performance status (KPS); Norfolk QOL Questionnaire; Six-minute walking test (6 MWT); nerve conduction studies; handgrip strength (HGS); and bioimpedance analysis (BIA).

RESULTS

Body composition significantly changed following the 9-months pharmacological treatment. In particular, the patients exhibited an increase in fat free mass, body cell mass, and body weight with a decrease in fat mass. A significant increase after 9 months of treatment was observed for the 6 MWT. Coutinho stage, KPS, NIS, NIS-W, nerve conduction studies, Norfolk, COMPASS-31 scale, and HGS remained unchanged.

CONCLUSIONS

BIA might represent a useful tool to assess the effects of multiorgan damage in ATTRv and to monitor disease progression and response to treatments. More evidence is still needed for HGS. Patisiran stabilizes polyneuropathy and preserves motor strength by increasing muscle mass after 9 months of treatment.

Recovery of the physiological status in professional basketball players using NESA neuromodulation treatment during different types of microcycles in season: A preliminary randomized clinical trial

The purpose of the study was to describe and compare recovery status after official basketball competition in players who underwent NESA neuromodulation treatment (NNT) in weeks with one or two matches. The recovery parameters of 12 professional male basketball players (mean ± SD, age: 20.6 ± 2.7 yr; height: 197.8 ± 11.7 cm; and body mass: 89.0 ± 21.2 kg) that competed in the LEB Plata (Spanish third division) were monitored 2 days after match-play over 6 weeks, and included: 1) the Hooper Test, which combines four subjective variables (sleep, stress, fatigue and soreness); 2) common biochemical markers (e.g., testosterone, cortisol and ratio T:C); and 3) lowest heart rate [HR], average HR, HR variability, sleep duration, awake time during night and onset latency before asleep). Players that completed NNT presented differences compared to the control group in sleep data. For instance, the lowest HR (p < 0.001), average HR (p < 0.001) and total awake time (p = 0.04) were significantly reduced in the NNT group. On the contrary, the control group presented greater values than the NNT group in the subjective Hooper Test, although only stress presented significant differences (Control 2.5 ± 1.2 vs. NNT cost or 3.2 ± 0.9; p = 0.01). Additionally, there were no significant differences in recovery parameters between weeks with one or two matches. In conclusion, the results suggest that players that underwent NNT tended to improve their sleep quality. Nevertheless, player's values in the biochemical markers and wellness status remained similar in both groups. The fact that no significant differences were found between weeks with one or two matches could help basketball professionals to determine that a congested schedule does not seem to negatively alter recovery status. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT04939181?term=NCT04939181, NCT04939181.

Effects of an experimental short-time high-intensity warm-up on explosive muscle strength performance in soccer players: A pilot study

Objective: This study aimed to evaluate the effects of an experimental short-time warm-up consisting of a small number of intermittent high-intensity sprints on explosive muscle strength performance in soccer players and to identify recovery times after performing the sprints. Furthermore, we evaluated the reliability of a smartphone app in jumping performance.

Methods: Twenty male soccer players were given the following tests: 1) the counter-movement jump (CMJ) test with the Microgate system, 2) the counter-movement jump (CMJ) test with the MyJump smartphone app, and 3) the handgrip strength test. The experimental short-time high-intensity warm-up was carried out 1 week after test administration. The warm-up consisted of three maximum sprints over 60 m with 120 s of recovery between sprints. Then, the tests were administered again: the vertical jump height (VJH) performances (five trials) were measured 90 s after the last sprint; the handgrip strength performances (three trials) were measured 120 s after the last vertical jump test.

Results: The maximum VJH was found in the third trial of the CMJ test, 330 s after the last sprint (p < 0.01), the result closest to the baseline. The lowest VJH was found in the first trial of the CMJ test, 90 s after the last sprint (p < 0.05). Pearson’s analysis between the CMJ test with the Microgate system and the CMJ test with MyJump showed a strong correlation (R = 0.96). Lin’s concordance correlation coefficient showed a substantial concordance (ρc = 0.959) between measures.

Conclusion: This experimental short-time warm-up of high-intensity intermittent sprints appears to be a simple, quick, and efficient activity to accelerate soccer players’ optimal performance.

The Refraction Assessment and the Electronic Trial Frame Measurement during Standing or Sitting Position Can Affect Postural Stability

Vision has been shown to influence body posture. The purpose of this study is to investigate the correlations between visual acuity and body postural control both in a standing and seated position. This cohort study included 37 patients examined using Adaptica’s (Italy) Kaleidos and VisionFit. Objective refraction was measured with Kaleidos both in a standing and seated position by the same operator and in the same environmental conditions. The parameters obtained with the device were binocular refraction, monocular refraction, pupil distance, pupil size, head tilt, gaze, phorias, and tropias. The results obtained were then subjectively tested using VisionFit: an electronic trial frame with phoropter functionalities. The study’s outcome revealed that the differences in the visual acuity parameters obtained in standing and seated positions were statistically significant; the Student’s t-test showed a p-value < 0.001 in all parameter averages. Automated refraction is widely being performed and postural control can affect the visual acuity parameters; therefore, it is relevant to consider the possibility of measuring in orthostatism. It might be appropriate to take into account the possibility of measuring in orthostatism and wearing trial frames in orthostatic conditions as well as walking freely around the room, looking outside of a window, sitting, and reading.

Transcranial Alternating Current Stimulation (tACS) Does Not Affect Sports People's Explosive Power: A Pilot Study

Purpose: This study is aimed to preliminary investigate whether transcranial alternating current stimulation (tACS) could affect explosive power considering genetic background in sport subjects. Methods: Seventeen healthy sports volunteers with at least 3 years of sports activities participated in the experiment. After 2 weeks of familiarization performed without any stimulation, each participant received either 50 Hz-tACS or sham-tACS. Before and after stimulation, subjects performed the following tests: (1) the squat jump with the hands on the hips (SJ); (2) countermovement jump with the hands on the hips (CMJ); (3) countermovement jump with arm swing (CMJ-AS); (4) 15-s Bosco's test; (5) seated backward overhead medicine ball throw (SBOMBT); (6) seated chest pass throw (SCPT) with a 3-kg rubber medicine ball; and (7) hand-grip test. Additionally, saliva samples were collected from each participant. Genotyping analysis was carried out by polymerase chain reaction (PCR). Results: No significant differences were found in sport performance of subjects after 50 Hz-tACS. Additionally, we did not find any influence of genetic background on tACS-related effect on physical performance. These results suggest that tACS at gamma frequency is not able to induce an after-effect modulating sport performance. Further investigations with larger sample size are needed in order to understand the potential role of non-invasive brain stimulation techniques (NIBS) in motor performances. Conclusions: Gamma-tACS applied before the physical performance fails to improve explosive power in sport subjects.

The Effects of Stochastic Galvanic Vestibular Stimulation on Body Sway and Muscle Activity

Objective: This study aimed to investigate whether galvanic vestibular stimulation with stochastic noise (nGVS) modulates the body sway and muscle activity of the lower limbs, depending on visual and somatosensory information from the foot using rubber-foam.

Methods: Seventeen healthy young adults participated in the study. Each subject maintained an upright standing position on a force plate with/without rubber-foam, with their eyes open/closed, to measure the position of their foot center of pressure. Thirty minutes after baseline measurements under four possible conditions (eyes open/closed with/without rubber-foam) performed without nGVS (intensity: 1 mA, duration: 40 s), the stimulation trials (sham-nGVS/real-nGVS) were conducted under the same conditions in random order, which were then repeated a week or more later. The total center of pressure (COP) path length movement (COP-TL) and COP movement velocity in the mediolateral (Vel-ML) and anteroposterior (Vel-AP) directions were recorded for 30 s during nGVS. Furthermore, electromyography activity of the right tibial anterior muscle and soleus muscle was recorded for the same time and analyzed.

Results: Three-way analysis of variance and post-hoc multiple comparison revealed a significant increment in COP-related parameters by nGVS, and a significant increment in soleus muscle activity on rubber. There was no significant effect of eye condition on any parameter.

Conclusions: During nGVS (1 mA), body sway and muscle activity in the lower limb may be increased depending not on the visual condition, but on the foot somatosensory condition.

Immediate Effects of Anodal Transcranial Direct Current Stimulation on Postural Stability Using Computerized Dynamic Posturography in People With Chronic Post-stroke Hemiparesis

Postural stability is commonly decreased in individuals with chronic post-stroke hemiparesis due to multisystemic deficits. Transcranial direct current stimulation (tDCS) is a non-invasive method to modulate cortical excitability, inducing neuroplastic changes to the targeted cortical areas and has been suggested to potentially improve motor functions in individuals with neurological impairments. The purpose of this double-blinded, sham-controlled study was to examine the acute effects of anodal tDCS over the lesioned motor cortex leg area with concurrent limits of stability training on postural control in individuals with chronic post-stroke hemiparesis. Ten individuals with chronic post-stroke hemiparesis received either anodal or sham tDCS stimulation over the lesioned leg region of the motor cortex while undergoing 20 min of postural training. The type of stimulation to receive during the first session was pseudorandomized, and the two sessions were separated by 14 days. Before and immediately after 20 min of tDCS, the 10 m walk test, the Berg Balance Scale, and dynamic posturography assessments were performed. After a single session of anodal tDCS with concurrent postural training, we observed no changes in clinical measures of balance and walking, assessed using the Berg Balance Scale and 10 m walk test. For dynamic posturography assessments, participants demonstrated improvements in adaptation responses to toes-up and toes-down perturbations, regardless of the type of tDCS received. Additionally, improved performance in the shifting center of gravity was observed during anodal tDCS. Taken together, these preliminary findings suggest that tDCS can potentially be used as a feasible approach be incorporated into the rehabilitation of chronic post-stroke individuals with issues related to postural control and fear of falling, and that multiple sessions of tDCS stimulation may be needed to improve functional measures of postural control and walking.