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JACC. Advances Nov 2023
PubMed: 38938703
DOI: 10.1016/j.jacadv.2023.100652 -
Translational Sports Medicine 2024The purpose of this study was to examine kinematic, kinetic, and muscle activation metrics during countermovement jumps (CMJs) with varying countermovement depths. The...
The purpose of this study was to examine kinematic, kinetic, and muscle activation metrics during countermovement jumps (CMJs) with varying countermovement depths. The hypothesis was that a shallow countermovement depth would compromise jump height by disrupting neuromechanical control. Ten healthy men (age 26 ± 8 yr, height 1.81 ± 0.08 m, mass 83.5 ± 9.0 kg) performed maximal CMJs at self-selected countermovement depth (self-selected CMJ), at reduced countermovement depth (shallow CMJ), and at increased countermovement depth (deep CMJ). Three jumps were performed in each condition on force plates with ankle, knee, and hip motion recorded and electromyograms (EMG) recorded from the gluteus maximus (GM), vastus lateralis (VL), and medial gastrocnemius (MG) muscles. During CMJs, the knee flexion angle was recorded with an electrogoniometer. Jumpers were instructed to flex at least 15% less (shallow CMJ) and at least 15% more (deep CMJ) than the self-selected CMJs. Kinematic, kinetic, and EMG metrics were compared between the different CMJ depths using repeated measures ANOVA. Compared with self-selected CMJs, shallow CMJs had 26% less countermovement depth ( < 0.001, effect size 1.74) and the deep CMJs had 28% greater countermovement depth ( < 0.001, effect size 1.56). Jump height was 8% less for the shallow vs. self-selected CMJs ( = 0.007, effect size 1.09) but not different between self-selected and deep CMJs ( = 0.254). Shallow CMJs differed from self-selected CMJs at the initiation of the countermovement (unweighting). For self-selected CMJs, force dropped to 43% of body weight during unweighting but only to 58% for shallow CMJs ( = 0.015, effect size 0.95). During unweighting, VL EMG averaged 5.5% of MVC during self-selected CMJs versus 8.1% for shallow CMJs ( = 0.014, effect size 0.97). Percent decline in jump height with shallow versus self-selected CMJs was correlated with the difference in VL EMG during unweighting between shallow and self-selected CMJs ( = 0.651, = 0.041). A deep countermovement prolonged the time to execute the jump by 38% ( < 0.010, effect size 1.04) but did not impair CMJ force metrics. In conclusion, self-selected countermovement depth represents a tradeoff between dropping the center of mass sufficiently far and executing the jump quickly. Unweighting at the initiation of a CMJ appears to be a critical element in the neuromechanics of the CMJ.
PubMed: 38938526
DOI: 10.1155/2024/7113900 -
Open Veterinary Journal May 2024During electrochemotherapy (ECT), a chemotherapeutic drug is injected into the tumor and then an electroporation is provided. In horses, ear manipulation may be very...
BACKGROUND
During electrochemotherapy (ECT), a chemotherapeutic drug is injected into the tumor and then an electroporation is provided. In horses, ear manipulation may be very painful, and combining a loco-regional technique with sedation might be a good option to avoid anesthesia-related risks. A two-injection-point block of the internal and external pinna and acoustic meatus was described in horse cadavers, and it permitted complete stain of all three branches of the great auricular nerve (GAN), internal auricular nerve branch (IAB), lateral auricular branch (LAB), and caudal auricular nerve (CAN), suggesting a lower risk of intra-parotid injection during the IAB and LAB block.
CASE DESCRIPTION
An 8-year-old Italian jumping gelding presented for ECT to treat a fibroblastic sarcoid in the left medial pinna. After intravenous sedation with acepromazine, romifidine, and butorphanol, a two-injection-point block was provided as previously described. The block of the GAN was blind, whereas an electrical nerve locator was used for the IAB, LAB, and CAN. A total of 12 ml of 0.5% ropivacaine was injected. The ECT was safely performed without any difficulties. The horse well tolerated the procedure and completely recovered 75 minutes after sedation. No complications were detected.
CONCLUSION
The described approach seems feasible and suitable for the blockade of the sensory innervation of the equine ear in the case of ECT.
Topics: Horses; Animals; Horse Diseases; Male; Electrochemotherapy; Pain; Ropivacaine; Anesthetics, Local; Nerve Block
PubMed: 38938434
DOI: 10.5455/OVJ.2024.v14.i5.26 -
NeuroImage Jun 2024The extended practice of meditation may reduce the influence of state fatigue by changing neurocognitive processing. However, little is known about the preventive...
INTRODUCTION
The extended practice of meditation may reduce the influence of state fatigue by changing neurocognitive processing. However, little is known about the preventive effects of one-session brief focused attention meditation (FAM) on state fatigue in healthy participants or its potential neural mechanisms. This study examined the preventive effects of one-session brief FAM on state fatigue and its neural correlates using resting-state functional MRI (rsfMRI) measurements.
METHODS
We randomly divided 56 meditation-naïve participants into FAM and control groups. After the first rsfMRI scan, each group performed a 10-minute each condition while wearing a functional near-infrared spectroscopy (fNIRS) device for assessing brain activity. Subsequently, following a second rsfMRI scan, the participants completed a fatigue-inducing task (a Go/NoGo task) for 60 min. We evaluated the temporal changes in the Go/NoGo task performance of participants as an indicator of state fatigue. We then calculated changes in the resting-state functional connectivity (rsFC) of the rsfMRI from before to after each condition and compared them between groups. We also evaluated neural correlates between the changes in rsFC and state fatigue.
RESULTS AND DISCUSSION
The fNIRS measurements indicated differences in brain activity during each condition between the FAM and control groups, showing decreased medial prefrontal cortex activity and decreased functional connectivity between the medial prefrontal cortex and middle frontal gyrus. The control group exhibited a decrement in Go/NoGo task performance over time, whereas the FAM group did not. These results, thus, suggested that FAM could prevent state fatigue. Compared with the control group, the rsFC analysis revealed a significant increase in the connectivity between the left dorsomedial prefrontal cortex and right superior parietal lobule in the FAM group, suggesting a modification of attention regulation by cognitive effort. In the control group, increased connectivity was observed between the bilateral posterior cingulate cortex and left inferior occipital gyrus, which might be associated with poor attention regulation and reduced higher-order cognitive function. Additionally, the change in the rsFC of the control group was related to state fatigue.
CONCLUSION
Our findings suggested that one session of 10-minute FAM could prevent behavioral state fatigue by employing cognitive effort to modify attention regulation as well as suppressing poor attention regulation and reduced higher-order cognitive function.
PubMed: 38936650
DOI: 10.1016/j.neuroimage.2024.120709 -
NeuroImage Jun 2024Time and space form an integral part of every human experience, and for the neuronal representation of these perceptual dimensions, previous studies point to the...
Time and space form an integral part of every human experience, and for the neuronal representation of these perceptual dimensions, previous studies point to the involvement of the right-hemispheric intraparietal sulcus and structures in the medial temporal lobe. Here we used multi-voxel pattern analysis (MVPA) to investigate long-term memory traces for temporal and spatial stimulus features in those areas. Participants were trained on four images associated with short versus long durations and with left versus right locations. Our results demonstrate stable representations of both temporal and spatial information in the right posterior intraparietal sulcus. Building upon previous findings of stable neuronal codes for directly perceived durations and locations, these results show that the reactivation of long-term memory traces for temporal and spatial features can be decoded from neuronal activation patterns in the right parietal cortex.
PubMed: 38936649
DOI: 10.1016/j.neuroimage.2024.120706 -
Behavioural Brain Research Jun 2024Object-location memory (OLM) is a type of declarative memory for spatial information and consists of the individual's ability to establish accurate associations between...
Object-location memory (OLM) is a type of declarative memory for spatial information and consists of the individual's ability to establish accurate associations between objects and their spatial locations. Long-COVID describes the long-term effects of the COVID-19 disease. Long-COVID patients show medial temporal lobe dysfunction and neuropsychological alterations affecting memory. This study aimed to assess OLM in a group of Long-COVID patients, n=66, and a Control group of healthy individuals with similar age and sex composition, n=21, using an immersive virtual reality (iVR)-based OLM task. We also explored associations between the performance in the iVR-based OLM task and general cognitive function (MoCA), and both verbal (VSTM) and visuospatial (SSTM) span. The Long-COVID group showed fewer correct responses, made more task attempts, and invested more time in the iVR-based OLM task than the Control group. Delayed memory was more severely altered than immediate memory in Long-COVID participants. Better MoCA scores of the Long-COVID group were strongly associated with shorter times to complete the immediate recall of the iVR-based OLM task. Besides, the months elapsed since the COVID-19 infection were slightly associated with fewer correct responses in the immediate and 24-hour recalls. These results corroborate previous findings of memory alterations in the Long-COVID syndrome using an iVR-based OLM task, adding new evidence on spatial memory and long-term memory in this population. Implementing spatial iVR tasks to clinical research may improve our understanding of neuropsychological disorders.
PubMed: 38936427
DOI: 10.1016/j.bbr.2024.115127 -
American Journal of Veterinary Research Jun 2024Evaluate whether total elbow replacement (TER) through a lateral approach is accurate and stable.
OBJECTIVE
Evaluate whether total elbow replacement (TER) through a lateral approach is accurate and stable.
ANIMALS
12 skeletally mature large-breed dog cadavers were used.
METHODS
Limb alignment, elbow joint motion, and collateral ligament laxity were evaluated preoperatively. The order of surgery (left or right) and the approach (lateral or medial) were randomly selected for TER in each dog. The other approach was used in the contralateral elbow. Intraoperative technical difficulties, duration of surgery, and anatomic complications were recorded. Limb alignment, elbow joint motion, collateral ligament laxity, and prosthetic component alignment were evaluated after surgery. Data were collected from June 11 to 15, 2023.
RESULTS
The duration of surgery using a lateral or medial approach did not differ (P = .499). Anatomic complications were not observed. The lateral approach resulted in 8° more elbow extension (P = .003), 1.58° less lateral collateral ligament constraint (P = .033), 2.80° less medial collateral ligament constraint (P = .002), 4.38° less frontal plane constraint (P = .004), 8° greater humeral component inclination (P = .033), and 5.6° greater radioulnar component varus (P = .001) than the medial approach. Varus of the radius, mechanical axis deviation, limb supination, elbow flexion, mediolateral humeral component and craniocaudal radioulnar component orientation did not differ among joints operated using a lateral or medial approach. In normal cadaveric elbows, a lateral approach for TER appears feasible, producing equivalent limb alignment, joint laxity, and joint motion to normal elbows and to TER placed using a medial approach.
CLINICAL RELEVANCE
In dogs, TER can be performed using a lateral surgical approach.
PubMed: 38936406
DOI: 10.2460/ajvr.24.04.0100 -
Frontiers in Aging Neuroscience 2024Changes in everyday functioning constitute a clinically meaningful outcome, even in the early stages of Alzheimer's disease. Performance-based assessments of everyday...
Amyloid and tau burden relate to longitudinal changes in the performance of complex everyday activities among cognitively unimpaired older adults: results from the performance-based Harvard Automated Phone Task.
BACKGROUND
Changes in everyday functioning constitute a clinically meaningful outcome, even in the early stages of Alzheimer's disease. Performance-based assessments of everyday functioning might help uncover these early changes. We aimed to investigate how changes over time in everyday functioning relate to tau and amyloid in cognitively unimpaired older adults.
METHODS
Seventy-six cognitively unimpaired participants (72 ± 6 years old, 61% female) completed multiple Harvard Automated Phone Task (APT) assessments over 2.0 ± 0.9 years. The Harvard APT consists of three tasks, performed through an automated phone system, in which participants refill a prescription (APT-Script), select a new primary care physician (APT-PCP), and transfer money to pay a bill (APT-Bank). Participants underwent Pittsburgh compound-B and flortaucipir positron emission tomography scans at baseline. We computed distribution volume ratios for a cortical amyloid aggregate and standardized uptake volume ratios for medial temporal and neocortical tau regions. In separate linear mixed models, baseline amyloid by time and tau by time interactions were used to predict longitudinal changes in performance on the Harvard APT tasks. Three-way amyloid by tau by time interactions were also investigated. Lastly, we examined associations between tau and change in Harvard APT scores in exploratory voxel-wise whole-brain analyses. All models were adjusted for age, sex, and education.
RESULTS
Amyloid [unstandardized partial regression coefficient estimate (β) = -0.007, 95% confidence interval (95% CI) = (-0.013, -0.001)], and medial temporal tau [β = -0.013, 95% CI = (-0.022, -0.004)] were associated with change over time in years on APT-PCP only, i.e., higher baseline amyloid and higher baseline tau were associated with steeper rate of decline of APT-PCP. Voxel-wise analyses showed widespread associations between tau and change in APT-PCP scores over time.
CONCLUSION
Even among cognitively unimpaired older adults, changes over time in the performance of cognitively complex everyday activities relate to cortical amyloid and widespread cerebral tau burden at baseline. These findings support the link between Alzheimer's disease pathology and function and highlight the importance of measuring everyday functioning in preclinical disease stages.
PubMed: 38934017
DOI: 10.3389/fnagi.2024.1420290 -
BMJ Open Sport & Exercise Medicine 2024The purpose of this study was to review the current literature regarding the non-operative treatment of isolated medial collateral ligament (MCL) injuries.
OBJECTIVE
The purpose of this study was to review the current literature regarding the non-operative treatment of isolated medial collateral ligament (MCL) injuries.
DESIGN
Systematic review, registered in the Open Science Framework (https://doi.org/10.17605/OSF.IO/E9CP4).
DATA SOURCES
The Embase, MEDLINE and PEDro databases were searched; last search was performed on December 2023.
ELIGIBILITY CRITERIA
Peer-reviewed original reports from studies that included information about individuals who sustained an isolated MCL injury with non-surgical treatment as an intervention, or reports comparing surgical with non-surgical treatment were eligible for inclusion. Included reports were synthesised qualitatively. Risk of bias was assessed with the Risk of Bias Assessment tool for Non-randomized Studies. Certainty of evidence was determined using the Grading of Recommendations Assessment Development and Evaluation.
RESULTS
A total of 26 reports (1912 patients) were included, of which 18 were published before the year 2000 and 8 after. No differences in non-operative treatment were reported between grade I and II injuries, where immediate weight bearing and ambulation were tolerated, and rehabilitation comprised different types of strengthening exercises with poorly reported details. Some reports used immobilisation with a brace as a treatment method, while others did not use any equipment. The use of a brace and duration of use was inconsistently reported.
CONCLUSION
There is substantial heterogeneity and lack of detail regarding the non-operative treatment of isolated MCL injuries. This should prompt researchers and clinicians to produce high-quality evidence studies on the promising non-operative treatment of isolated MCL injuries to aid in decision-making and guide rehabilitation after MCL injury.
LEVEL OF EVIDENCE
Level I, systematic review.
PubMed: 38933372
DOI: 10.1136/bmjsem-2023-001750 -
Sensors (Basel, Switzerland) Jun 2024After a stroke, antagonist muscle activation during agonist command impedes movement. This study compared measurements of antagonist muscle activation using surface...
After a stroke, antagonist muscle activation during agonist command impedes movement. This study compared measurements of antagonist muscle activation using surface bipolar EMG in the gastrocnemius medialis (GM) and high-density (HD) EMG in the GM and soleus (SO) during isometric submaximal and maximal dorsiflexion efforts, with knee flexed and extended, in 12 subjects with chronic hemiparesis. The coefficients of antagonist activation (CAN) of GM and SO were calculated according to the ratio of the RMS amplitude during dorsiflexion effort to the maximal agonist effort for the same muscle. Bipolar CAN (BipCAN) was compared to CAN from channel-specific (CsCAN) and overall (OvCAN) normalizations of HD-EMG. The location of the CAN centroid was explored in GM, and CAN was compared between the medial and lateral portions of SO. Between-EMG system differences in GM were observed in maximal efforts only, between BipCAN and CsCAN with lower values in BipCAN ( < 0.001), and between BipCAN and OvCAN with lower values in OvCAN ( < 0.05). The CAN centroid is located mid-height and medially in GM, while the CAN was similar in medial and lateral SO. In chronic hemiparesis, the estimates of GM hyperactivity differ between bipolar and HD-EMGs, with channel-specific and overall normalizations yielding, respectively, higher and lower CAN values than bipolar EMG. HD-EMG would be the way to develop personalized rehabilitation programs based on individual antagonist activations.
Topics: Humans; Electromyography; Paresis; Male; Female; Muscle, Skeletal; Middle Aged; Aged; Adult; Chronic Disease; Stroke
PubMed: 38931485
DOI: 10.3390/s24123701