scholarly journals Alterations in Leg Muscle Glucose Uptake and Inter-Limb Asymmetry after a Single Session of tDCS in Four People with Multiple Sclerosis

2021 ◽  
Vol 11 (10) ◽  
pp. 1363
Author(s):  
Alexandra C. Fietsam ◽  
Justin R. Deters ◽  
Craig D. Workman ◽  
Laura L. Boles Ponto ◽  
Thorsten Rudroff
Keyword(s):  
Multiple Sclerosis ◽  
Glucose Uptake ◽  
Lower Limb ◽  
Muscle Activation ◽  
Treadmill Walking ◽  
Whole Body ◽  
Walking Ability ◽  
Neural Drive ◽  
Limb Weakness ◽  
Positron Emission

Asymmetrical lower limb weakness is an early symptom and significant contributor to the progressive worsening of walking ability in people with multiple sclerosis (PwMS). Transcranial direct current stimulation (tDCS) may effectively increase neural drive to the more-affected lower limb and, therefore, increase symmetrical activation. Four PwMS (1 female, age range: 27–57) underwent one session each of 3 mA or SHAM tDCS over the motor cortex corresponding to their more-affected limb followed by 20 min of treadmill walking at a self-selected speed. Two min into the treadmill task, the subjects were injected with the glucose analog [18F]fluorodeoxyglucose (FDG). Immediately after treadmill walking, the subjects underwent whole-body positron emission tomography (PET) imaging. Glucose uptake (GU) values were compared between the legs, the spatial distribution of FDG was assessed to estimate glucose uptake heterogeneity (GUh), and GU asymmetry indices (AIs) were calculated. After tDCS, GU was altered, and GUh was decreased in various muscle groups in each subject. Additionally, AIs went from asymmetric to symmetric after tDCS in the subjects that demonstrated asymmetrical glucose uptake during SHAM. These results indicate that tDCS improved GU asymmetries, potentially from an increased neural drive and a more efficient muscle activation strategy of the lower limb in PwMS.

Evaluation of individual skeletal muscle activity by glucose uptake during pedaling exercise at different workloads using positron emission tomography

2009 ◽  
Vol 107 (2) ◽  
pp. 599-604 ◽  
Author(s):  
Yuichi Gondoh ◽  
Manabu Tashiro ◽  
Masatoshi Itoh ◽  
Mohammad M. Masud ◽  
Hiroomi Sensui ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Positron Emission Tomography ◽  
Glucose Uptake ◽  
Muscle Activity ◽  
Rectus Femoris ◽  
Emission Tomography ◽  
Whole Body ◽  
Control Subjects ◽  
Positron Emission ◽  
Iliacus Muscle

Skeletal muscle glucose uptake closely reflects muscle activity at exercise intensity levels <55% of maximal oxygen consumption (V̇o2max). Our purpose was to evaluate individual skeletal muscle activity from glucose uptake in humans during pedaling exercise at different workloads by using [18F]fluorodeoxyglucose (FDG) and positron emission tomography (PET). Twenty healthy male subjects were divided into two groups (7 exercise subjects and 13 control subjects). Exercise subjects were studied during 35 min of pedaling exercise at 40 and 55% V̇o2max exercise intensities. FDG was injected 10 min after the start of exercise or after 20 min of rest. PET scanning of the whole body was conducted after completion of the exercise or rest period. In exercise subjects, mean FDG uptake [standardized uptake ratio (SUR)] of the iliacus muscle and muscles of the anterior part of the thigh was significantly greater than uptake in muscles of control subjects. At 55% V̇o2max exercise, SURs of the iliacus muscle and thigh muscles, except for the rectus femoris, increased significantly compared with SURs at 40% V̇o2max exercise. Our results are the first to clarify that the iliacus muscle, as well as the muscles of the anterior thigh, is the prime muscle used during pedaling exercise. In addition, the iliacus muscle and all muscles in the thigh, except for the rectus femoris, contribute when the workload of the pedaling exercise increases from 40 to 55% V̇o2max.

Imbalances Of Trunk Muscle Activation During Treadmill Walking In Patients With Multiple Sclerosis

2015 ◽  
Vol 47 ◽  
pp. 219
Author(s):  
Nathaniel B. Ketelhut ◽  
John H. Kindred ◽  
Jeffrey R. Hebert ◽  
Thorsten Rudroff
Keyword(s):  
Multiple Sclerosis ◽  
Muscle Activation ◽  
Trunk Muscle ◽  
Treadmill Walking

scholarly journals Mechanism of anterior cruciate ligament loading during dynamic motor tasks

2020 ◽  
Author(s):  
Azadeh Nasseri ◽  
David G Lloyd ◽  
Adam L Bryant ◽  
Jonathon Headrick ◽  
Timothy Sayer ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Lower Limb ◽  
Muscle Activation ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Three Dimensional ◽  
Whole Body ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Anterior Cruciate

AbstractThis study determined anterior cruciate ligament (ACL) force and its contributors during a standardized drop-land-lateral jump task using a validated computational model. Healthy females (n=24) who were recreationally active performed drop-land-lateral jump and straight run tasks. Three-dimensional whole-body kinematics, ground reaction forces, and muscle activation patterns from eight lower limb muscles were collected concurrently during both tasks, but only the jump was analyzed computationally, with the run included for model calibration. External biomechanics, muscle-tendon unit kinematics, and muscle activation patterns were used to model lower limb muscle and ACL forces. Peak ACL force (2.3±0.5 BW) was observed at 13% of the stance phase during the drop-land-lateral jump task. The ACL force was primarily developed through the sagittal plane, and muscle was the dominant source of ACL loading. The gastrocnemii and quadriceps were main ACL antagonists (i.e., loaders), while hamstrings were the main ACL agonists (i.e., supporters).

scholarly journals Musculoskeletal Adaptation of Young and Older Adults in Response to Environmental, Physical, and Cognitive Conditions

2021 ◽  
Author(s):  
Amy E. Holcomb
Keyword(s):  
Older Adults ◽  
Knee Joint ◽  
Lower Limb ◽  
Accidental Falls ◽  
Muscle Activation ◽  
Adaptation Strategies ◽  
Whole Body ◽  
Joint Level ◽  
Body Function ◽  
Musculoskeletal Function

Accidental falls present a large functional and financial burden among people aged 65 years and older. Falls, injuries associated with falls, and the fear of falling decrease quality of life, physical function, and independence for older adults. To prevent falls, improve stability, and protect joints from damage or injury, the typical response to "challenging" conditions include cautious gait, increase muscle co-contraction, and decreased range of motion. These compensatory strategies are more pronounced in the older adult population with apprehensive "cautious" gait at slower speeds, decreased knee flexion, and increased muscle activation around the knee and ankle. The underlying mechanisms and driving forces behind accidental falls are not well investigated. Additionally, the effects of aging on the ability of the musculoskeletal system to adapt to changing and challenging conditions is poorly understood. There exists a gap in knowledge regarding the relationship between accidental fall risk factors, knee joint stability, adaptation mechanisms, and whole-body function. Establishing these relationships between stability and musculoskeletal adaptation may have far reaching implications on improving whole-body function through targeted joint- and muscle-level interventions. The purpose of this study was to compare neuromechanics (whole-body function) of young and older adults walking across various external challenging conditions, quantifying adaptation strategies for both cohorts. This was accomplished through two objectives. In the first objective, joint kinematics, ground reaction force loading and impulse, and lower-limb muscle activation strategies for ten young and ten older adults walking on normal, slick, and uneven surfaces were compared to assess how musculoskeletal adaptation strategies change with age. For the second objective, a pipeline to create subject-specific lower-limb finite element models was developed to investigate joint-level behavior across cohorts. Proof-of-concept for the model development and analysis process was demonstrated for an older and a young adult to implement a novel metric for functional stability and dynamic laxity of the knee joint during the stance phase of gait. Kinematic, force, and muscle activation analysis showed that an uneven surface reduced sagittal joint kinematics during the first 25% of stance, indicating a surface-specific compensatory strategy. Additionally, older adults tended to prepare for and step onto the uneven surfaces in a more conservative manner with joints more flexed or bent. This anticipatory or cautious musculoskeletal adaptation of older adults was also seen in reduced magnitude of initial vertical loading during the loading response of stance (0-25% stance). Results of this research study provide insight into the differences that exist in joint stiffening and other musculoskeletal adaption strategies for young and older adults during external challenging conditions. Specifically, understanding the relationships between joint-level stability and whole-body musculoskeletal function has the potential to inform targeted muscle training programs and joint-level interventions to improve whole-body musculoskeletal function and reduce risk of injuries.

Glucose uptake by individual skeletal muscles during running using whole-body positron emission tomography

2000 ◽  
Vol 83 (4-5) ◽  
pp. 297-302 ◽  
Author(s):  
Toshihiko Fujimoto ◽  
Masatoshi Itoh ◽  
Manabu Tashiro ◽  
Keiichiro Yamaguchi ◽  
Kazuo Kubota ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Glucose Uptake ◽  
Skeletal Muscles ◽  
Emission Tomography ◽  
Whole Body ◽  
Positron Emission

scholarly journals Different Effects of Transcranial Direct Current Stimulation on Leg Muscle Glucose Uptake Asymmetry in Two Women with Multiple Sclerosis

2020 ◽  
Vol 10 (8) ◽  
pp. 549
Author(s):  
Alexandra C. Fietsam ◽  
Craig D. Workman ◽  
Laura L. Boles Ponto ◽  
John Kamholz ◽  
Thorsten Rudroff
Keyword(s):  
Physical Activity ◽  
Multiple Sclerosis ◽  
Glucose Uptake ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Moderate Intensity ◽  
Plantar Flexors ◽  
Neural Drive ◽  
Direct Current Stimulation ◽  
Left And Right

Asymmetrical lower limb strength is a significant contributor to impaired walking abilities in people with multiple sclerosis (PwMS). Transcranial direct current stimulation (tDCS) may be an effective technique to enhance cortical excitability and increase neural drive to more-affected lower limbs. A sham-controlled, randomized, cross-over design was employed. Two women with MS underwent two 20 min sessions of either 3 mA tDCS or Sham before 20 min of treadmill walking at a self-selected speed. During walking, the participants were injected with the glucose analogue, [18F] fluorodeoxyglucose (FDG). Participants were then imaged to examine glucose metabolism and uptake asymmetries in the legs. Standardized uptake values (SUVs) were compared between the legs and asymmetry indices were calculated. Subject 2 was considered physically active (self-reported participating in at least 30 min of moderate-intensity physical activity on at least three days of the week for the last three months), while Subject 1 was physically inactive. In Subject 1, there was a decrease in SUVs at the left knee flexors, left upper leg, left and right plantar flexors, and left and right lower legs and SUVs in the knee extensors and dorsiflexors were considered symmetric after tDCS compared to Sham. Subject 2 showed an increase in SUVs at the left and right upper legs, right plantar flexors, and right lower leg with no muscle group changing asymmetry status. This study demonstrates that tDCS may increase neural drive to leg muscles and decrease glucose uptake during walking in PwMS with low physical activity levels.

scholarly journals Depot-specific regulation of glucose uptake and insulin sensitivity in HIV-lipodystrophy

2006 ◽  
Vol 290 (2) ◽  
pp. E289-E298 ◽  
Author(s):  
C. Hadigan ◽  
D. Kamin ◽  
J. Liebau ◽  
S. Mazza ◽  
S. Barrow ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Subcutaneous Fat ◽  
Fat Distribution ◽  
Whole Body ◽  
Glucose Disposal ◽  
Positron Emission ◽  
Specific Regulation ◽  
Hiv Lipodystrophy

Altered fat distribution is associated with insulin resistance in HIV, but little is known about regional glucose metabolism in fat and muscle depots in this patient population. The aim of the present study was to quantify regional fat, muscle, and whole body glucose disposal in HIV-infected men with lipoatrophy. Whole body glucose disposal was determined by hyperinsulinemic clamp technique (80 mU·m−2·min−1) in 6 HIV-infected men and 5 age/weight-matched healthy volunteers. Regional glucose uptake in muscle and subcutaneous (SAT) and visceral adipose tissue (VAT) was quantified in fasting and insulin-stimulated states using 2-deoxy-[18F]fluoro-d-glucose positron emission tomography. HIV-infected subjects with lipoatrophy had significantly increased glucose uptake into SAT (3.8 ± 0.4 vs. 2.3 ± 0.5 μmol·kg tissue−1·min−1, P < 0.05) in the fasted state. Glucose uptake into VAT did not differ between groups. VAT area was inversely related with whole body glucose disposal, insulin sensitivity, and muscle glucose uptake during insulin stimulation. VAT area was highly predictive of whole body glucose disposal ( r2 = 0.94, P < 0.0001). This may be mediated by adiponectin, which was significantly associated with VAT area ( r = −0.75, P = 0.008), and whole body glucose disposal ( r = 0.80, P = 0.003). This is the first study to directly demonstrate increased glucose uptake in subcutaneous fat of lipoatrophic patients, which may partially compensate for loss of SAT. Furthermore, we demonstrate a clear relationship between VAT and glucose metabolism in multiple fat and muscle depots, suggesting the critical importance of this depot in the regulation of glucose and highlighting the significant potential role of adiponectin in this process.

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