scholarly journals Indices of callosal axonal density and radius from diffusion MRI relate to upper and lower limb motor performance

NeuroImage ◽  
2021 ◽  
pp. 118433
Author(s):  
J. Gooijers ◽  
A. De Luca ◽  
H. Zivari Adab ◽  
A. Leemans ◽  
A. Roebroeck ◽  
...  
Keyword(s):  
Lower Limb ◽  
Motor Performance ◽  
Diffusion Mri ◽  
Axonal Density

scholarly journals Relationship Between 3 Single-Leg Functional Performance Tests for Netball Noncontact Knee Injury Prevention Screening in Uninjured Female Adult Players

2021 ◽  
pp. 1-7
Author(s):  
Nicholas C. Clark ◽  
Elaine M. Mullally
Keyword(s):  
Injury Prevention ◽  
Lower Limb ◽  
Motor Performance ◽  
Knee Injury ◽  
Local Community ◽  
Functional Performance ◽  
Lower Limbs ◽  
Coefficient Of Determination ◽  
Performance Tests ◽  
Knee Injury Prevention

Context: Single- versus double-leg landing events occur the majority of the time in a netball match. Landings are involved in large proportions of netball noncontact knee injury events. Of all landing-induced anterior cruciate ligament injuries, most occur during single-leg landings. Knowledge of whether different single-leg functional performance tests capture the same or different aspects of lower-limb motor performance will therefore inform clinicians’ reasoning processes and assist in netball noncontact knee injury prevention screening. Objective: To determine the correlation between the triple hop for distance (THD), single hop for distance (SHD), and vertical hop (VH) for the right and left lower limbs in adult female netball players. Design: Cross-sectional. Setting: Local community netball club. Participants: A total of 23 players (age 28.7 [6.2] y; height 171.6 [7.0] cm; mass 68.2 [9.8] kg). Interventions: There were 3 measured trials (right and left) for THD, SHD, and VH, respectively. Main Outcome Measures: Mean hop distance (percentage of leg length [%LL]), Pearson intertest correlation (r), and coefficient of determination (r2). Results: Values (right and left; mean [SD]) were as follows: THD, 508.5 (71.8) %LL and 510.9 (56.7) %LL; SHD, 183.4 (24.6) %LL and 183.0 (21.5) %LL; and VH, 21.3 (5.2) %LL and 20.6 (5.0) %LL. All correlations were significant (P ≤ .05), r/r2 values (right and left) were THD–SHD, .91/.83 and .87/.76; THD–VH, .59/.35 and .51/.26; and SHD–VH, .50/.25 and .37/.17. A very large proportion of variance (76%–83%) was shared between the THD and SHD. A small proportion of variance was shared between the THD and VH (25%–35%) and SHD and VH (17%–25%). Conclusion: The THD and SHD capture highly similar aspects of lower-limb motor performance. In contrast, the VH captures aspects of lower-limb motor performance different to the THD or SHD. Either the THD or the SHD can be chosen for use within netball knee injury prevention screening protocols according to which is reasoned as most appropriate at a specific point in time. The VH, however, should be employed consistently alongside rather than in place of the THD or SHD.

Modulation of Stretch-Shortening-Cycle Behavior With Eccentric Loading of Triceps Surae: A Possible Therapeutic Mechanism

2017 ◽  
Vol 26 (2) ◽  
pp. 151-158 ◽  
Author(s):  
James R. Debenham ◽  
William I. Gibson ◽  
Mervyn J. Travers ◽  
Amity C. Campbell ◽  
Garry T. Allison
Keyword(s):  
Outcome Measures ◽  
Lower Limb ◽  
Motor Performance ◽  
Plantar Flexion ◽  
Triceps Surae ◽  
Temporal Muscle ◽  
Ankle Kinematics ◽  
Limb Stiffness ◽  
Stretch Shortening Cycle ◽  
Lower Limb Stiffness

Context:Eccentric exercises are increasingly being used to treat lower-limb musculoskeletal conditions such as Achilles tendinopathy. Despite widespread clinical application and documented efficacy, mechanisms underpinning clinical benefit remain unclear. Positive adaptations in motor performance are a potential mechanism.Objective:To investigate how an eccentric loading intervention influences measures of stretch-shortening-cycle (SSC) behavior during a hopping task.Design:Within-subjects repeated-measures observational study.Setting:University motion-analysis laboratory.Participants:Healthy adults.Interventions:A single intervention of 5 sets of 10 eccentric plantar-flexion contractions at 6 repetitions maximum using a commercial seated calf-raise machine.Main Outcome Measures:Lower-limb stiffness, sagittal-plane ankle kinematics, and temporal muscle activity of the agonist (soleus) and antagonist (tibialis anterior) muscles, measured during submaximal hopping on a custom-built sledge-jump system.Results:Eccentric loading altered ankle kinematics during submaximal hopping; peak angle shifted to a less dorsiflexed position by 2.9° and ankle angle precontact shifted by 4.4° (P < .001). Lower-limb stiffness increased from 5.9 to 6.8 N/m (P < .001), while surface EMG measures of soleus occurred 14–44% earlier (P < .001) after the loading intervention.Conclusions:These findings suggest that eccentric loading alters SSC behavior in a manner reflective of improved motor performance. Decreased ankle excursion, increased lower-limb stiffness, and alterations in motor control may represent a positive adaptive response to eccentric loading. These findings support the theory that mechanisms underpinning eccentric loading for tendinopathy may in part be due to improved “buffering” of the tendon by the neuromuscular system.

scholarly journals FTO POLYMORPHISM AND PHYSICAL FITNESS IN OBESE SCHOOLCHILDREN AFTER AN INTERVENTION PROGRAM

2018 ◽  
Vol 24 (1) ◽  
pp. 13-16
Author(s):  
Greice Graziela Moraes ◽  
Cézane Priscila Reuter ◽  
Elisa Inês Klinger ◽  
Daniel Prá ◽  
Andréia Rosane de Moura Valim ◽  
...  
Keyword(s):  
Gene Polymorphism ◽  
Physical Fitness ◽  
Lower Limb ◽  
Motor Performance ◽  
Intervention Program ◽  
Fto Gene ◽  
Level Of Evidence ◽  
Lower Limb Strength ◽  
Experimental Group ◽  
Abdominal Strength

ABSTRACT Introduction: Recent studies have shown that the association of FTO rs9939609 gene polymorphism with obesity depends on the level of the individual’s physical activity. However, there are some studies that evaluated physical fitness, health, and motor performance in relation to the rs9939609 FTO gene polymorphism. Objective: To evaluate how the rs9939609 FTO gene polymorphism affects the results of physical fitness tests related to health and athletic performance in schoolchildren after 4 months of intervention of physical exercise. Method: The rs9939609 FTO gene polymorphism was genotyped in a total of 36 schoolchildren from southern Brazil, aged 8 to 16 years. Body mass index (BMI), health-related physical fitness (cardiorespiratory fitness, abdominal strength/endurance, and flexibility) and motor performance (upper and lower limb strength, agility, and speed) were evaluated. The intervention included exercise strategies based on Physical Education, healthy eating, and oral and postural care. Results: In the experimental group, after the intervention, significant differences were noted in individuals with the TT genotype. These individuals showed improvements in abdominal strength (p=0.025), lower limb strength (p=0.037) and agility (p=0.021). For individuals with the AA/AT genotype, improvements in flexibility (p=0.026), abdominal strength (p=0.002), upper limb strength (p=0.008) and lower limb strength (p=0.001) were observed. However, these differences were not statistically significant when comparing the TT and AT/AA genotypes. Conclusions: The experimental group showed improvements in abdominal strength, lower limb strength, and speed. Yet, individuals with different genotypes (AA/AT and TT) for polymorphism rs9939609 exhibited similar values for indicators of physical fitness, health, and motor performance. Level of Evidence II; Lesser quality RCT.

scholarly journals Multi-tract multi-symptom relationships in pediatric concussions

2021 ◽  
Author(s):  
Guido I. Guberman ◽  
Sonja Stojanovski ◽  
Eman Nishat ◽  
Alain Ptito ◽  
Danilo Bzdok ◽  
...  
Keyword(s):  
Diffusion Mri ◽  
Pattern Learning ◽  
Group Comparison ◽  
White Matter Damage ◽  
Concussion Management ◽  
History Of ◽  
Psychiatric Outcomes ◽  
Axonal Density ◽  
Univariate Analyses ◽  
Informative Indices

AbstractThe heterogeneity of white matter damage and symptoms in concussions has been identified as a major obstacle to therapeutic innovation. In contrast, the vast majority of diffusion MRI studies on concussion have traditionally employed group-comparison approaches. Such studies do not consider heterogeneity of damage and symptoms in concussion. To parse concussion heterogeneity, the present study combines diffusion MRI (dMRI) and multivariate statistics to investigate multi-tract multi-symptom relationships. Using dMRI data from a sample of 306 children ages 9 and 10 with a history of concussion from the Adolescent Brain Cognitive Development Study (ABCD study), we built connectomes weighted by classical and emerging diffusion measures. These measures were combined into two informative indices, the first capturing a mixture of patterns suggestive of microstructural complexity, the second representing almost exclusively axonal density. We deployed pattern-learning algorithms to jointly decompose these connectivity features and 19 behavioural measures that capture well-known symptoms of concussions. We found idiosyncratic symptom-specific multi-tract connectivity features, which would not be captured in traditional univariate analyses. Multivariable connectome-symptom correspondences were stronger than all single-tract/single-symptom associations. Multi-tract connectivity features were also expressed equally across different sociodemographic strata and their expression was not accounted for by injury-related variables. In a replication dataset, the expression of multi-tract connectivity features predicted adverse psychiatric outcomes after accounting for other psychopathology-related variables. By defining cross-demographic multi-tract multi-symptom relationships to parse concussion heterogeneity, the present study can pave the way for the development of improved stratification strategies that may contribute to the success of future clinical trials and the improvement of concussion management.

scholarly journals Upper and Lower Limb Motor Function Correlates with Ipsilesional Corticospinal Tract and Red Nucleus Structural Integrity in Chronic Stroke: A Cross-Sectional, ROI-Based MRI Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Denise M. Peters ◽  
Julius Fridriksson ◽  
Jessica D. Richardson ◽  
Jill C. Stewart ◽  
Chris Rorden ◽  
...  
Keyword(s):  
Motor Function ◽  
Lower Limb ◽  
Gait Speed ◽  
Motor Performance ◽  
Corticospinal Tract ◽  
Structural Integrity ◽  
Red Nucleus ◽  
Chronic Stroke ◽  
Neural Basis ◽  
Motor Tracts

Background. Structural integrity of the ipsilesional corticospinal tract (CST) is important for upper limb motor recovery after stroke. However, additional neuromechanisms associated with motor function poststroke are less well understood, especially regarding the lower limb. Objective. To investigate the neural basis of upper/lower limb motor deficits poststroke by correlating measures of motor function with diffusion tensor imaging-derived indices of white matter integrity (fractional anisotropy (FA), mean diffusivity (MD)) in primary and secondary motor tracts/structures. Methods. Forty-three individuals with chronic stroke (time poststroke, 64.4 ± 58.8 months) underwent a comprehensive motor assessment and MRI scanning. Correlation and multiple regression analyses were performed to examine relationships between FA/MD in a priori motor tracts/structures and motor function. Results. FA in the ipsilesional CST and red nucleus (RN) was positively correlated with motor function of both the affected upper and lower limb ( r = 0.36 ‐ 0.55 , p ≤ 0.01 ), while only ipsilesional RN FA was associated with gait speed ( r = 0.50 ). Ipsilesional CST FA explained 37.3% of the variance in grip strength ( p < 0.001 ) and 31.5% of the variance in Arm Motricity Index ( p = 0.004 ). Measures of MD were not predictors of motor performance. Conclusions. Microstructural integrity of the ipsilesional CST is associated with both upper and lower limb motor function poststroke, but appears less important for gait speed. Integrity of the ipsilesional RN was also associated with motor performance, suggesting increased contributions from secondary motor areas may play a role in supporting chronic motor function and could become a target for interventions.

The chronically ischemic lower limb

JAMA ◽  
1966 ◽  
Vol 197 (11) ◽  
pp. 915-916
Author(s):  
I. J. Schatz
Keyword(s):  
Lower Limb
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