scholarly journals Reference Values for Isometric, Dynamic, and Asymmetry Leg Extension Strength in Patients with Multiple Sclerosis

2020 ◽  
Vol 17 (21) ◽  
pp. 8083
Author(s):  
Kora Portilla-Cueto ◽  
Carlos Medina-Pérez ◽  
Ena Monserrat Romero-Pérez ◽  
José Aldo Hernández-Murúa ◽  
Claudia Eliza Patrocinio de Oliveira ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Reference Values ◽  
Knee Extension ◽  
Knee Extensors ◽  
Neurological Disability ◽  
Maximal Voluntary Isometric Contraction ◽  
Leg Extension ◽  
Relapsing Remitting ◽  
Degree Of Disability ◽  
Strength Asymmetry

Having recognized the value of resistance training in patients with multiple sclerosis (PwMS), there are a lack of lower limb normative reference values for one repetition maximum (1RM) and maximal voluntary isometric contraction (MVIC) in this population. Hence, the purposes of this study were to provide reference values for 1RM and MVIC of knee extensors in PwMS across the disability spectrum and to examine knee extension strength asymmetry. Three hundred and ninety PwMS participated in the study, performing MVIC and 1RM tests of bilateral (both legs together at once) and unilateral (each leg singly) knee extensors. There was no difference in 1RM according to the disease course of MS, but there was according to the degree of neurological disability, being more preserved in those with a lower degree of disability. MVIC tends to be higher in patients with relapsing–remitting MS respect those with progressive MS, and in patients with lower levels of neurological disability. Asymmetry above the values considered normal in 1RM was present in 20–60% of patients and 56–79% in the MVIC test, depending on the type of MS and tended to be lower in those with less disability. Reference values are given by quartiles for 1RM, MVIC, and asymmetry.

scholarly journals Beneficial effects of combined rTMS and physical rehabilitation for spasticity in multiple sclerosis

2021 ◽  
Author(s):  
Frederico Arriaga Criscuoli de Farias ◽  
Carolina Matté Dagostini ◽  
Carolina Dalla Santa Dal Moro ◽  
Carolina Odorizzi Magno Nunes ◽  
Mariana Moreira Rizzolli ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Physical Therapy ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Knee Extension ◽  
Modified Ashworth Scale ◽  
Relapsing Remitting ◽  
Limb Spasticity ◽  
Lower Limb Spasticity ◽  
Partial Weight

Background: spasticity affects up to 90% of multiple sclerosis (MS) patients, being a major cause of disability. Repetitive transcranial magnetic stimulation (rTMS) appears to be a potential treatment, but literature is scarce. Objectives: to evaluate the effects of combined rTMS and physical therapy for spasticity in MS patients. Methods: relapsing-remitting MS patients suffering from lower limb spasticity were included. The rTMS protocol consisted of 20 sessions of 18 trains of 50 stimuli at 5Hz and at 100% of rest potential threshold, with 10 seconds per train and 40 second pauses, amounting for 900 pulses (15 minutes) with a Neurosoft- MS/D double coil. Optimal coil positioning was determined by motor responses in the contralateral soleus muscle. The physical therapy protocol included active exercising – stationary bicycle, step climbing with partial weight suspension – followed by mild gradual resistance exercising for knee extension and hip and foot flexion, proprioceptive exercises and active stretching. The primary outcome was improvement on the Modified Ashworth Scale (MAS) score at baseline and 4 weeks after treatment. Results: five female patients were recruited. At the 4-week follow-up, 4 out the 5 patients had a significant improvement regarding spasticity. There was a reduction in mean MAS score from 2.30 to 1.42. Patient 1 had a MAS score reduction from 2 to 1 (50%). Patient 2 from 3 to 1 (66%), patient 3 from 4 to 3 (25%) and patient 4 from 0.5 to 0.125 (75%). Conclusion: combined rTMS and physical therapy protocols presents as a beneficial treatment modality for MS spasticity.

scholarly journals Cortical thickness and surface area relate to specific symptoms in early relapsing–remitting multiple sclerosis

2014 ◽  
Vol 21 (4) ◽  
pp. 402-414 ◽  
Author(s):  
Gro O Nygaard ◽  
Kristine B Walhovd ◽  
Piotr Sowa ◽  
Joy-Loi Chepkoech ◽  
Atle Bjørnerud ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Surface Area ◽  
Cortical Thickness ◽  
Clinical Symptoms ◽  
Cortical Surface ◽  
Healthy Controls ◽  
Neurological Disability ◽  
Cortical Surface Area ◽  
Relapsing Remitting ◽  
Relapsing Remitting Multiple Sclerosis

Background: Cortical atrophy is common in early relapsing–remitting multiple sclerosis (RRMS). Whether this atrophy is caused by changes in cortical thickness or cortical surface area is not known, nor is their separate contributions to clinical symptoms. Objectives: To investigate the difference in cortical surface area, thickness and volume between early RRMS patients and healthy controls; and the relationship between these measures and neurological disability, cognitive decline, fatigue and depression. Methods: RRMS patients ( n = 61) underwent magnetic resonance imaging (MRI), neurological and neuropsychological examinations. We estimated cortical surface area, thickness and volume and compared them with matched healthy controls ( n = 61). We estimated the correlations between clinical symptoms and cortical measures within the patient group. Results: We found no differences in cortical surface area, but widespread differences in cortical thickness and volume between the groups. Neurological disability was related to regionally smaller cortical thickness and volume. Better verbal memory was related to regionally larger surface area; and better visuo-spatial memory, to regionally larger cortical volume. Higher depression scores and fatigue were associated with regionally smaller cortical surface area and volume. Conclusions: We found that cortical thickness, but not cortical surface area, is affected in early RRMS. We identified specific structural correlates to the main clinical symptoms in early RRMS.

scholarly journals Does ischemic preconditioning really improve performance or it is just a placebo effect?

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250572
Author(s):  
Hiago L. R. de Souza ◽  
Rhaí A. Arriel ◽  
Gustavo R. Mota ◽  
Rodrigo Hohl ◽  
Moacir Marocolo
Keyword(s):  
Ischemic Preconditioning ◽  
Placebo Effect ◽  
A Priori ◽  
Knee Extension ◽  
Fatigue Index ◽  
Maximal Voluntary Isometric Contraction ◽  
Leg Extension ◽  
Volume Load ◽  
Ergogenic Effects ◽  
Sham Intervention

This study examined the effects of a simultaneous ischemic preconditioning (IPC) and SHAM intervention to reduce the placebo effect due to a priori expectation on the performance of knee extension resistance exercise. Nine moderately trained men were tested in three different occasions. Following the baseline tests, subjects performed a first set of leg extension tests after the IPC (3 X 5 min 50 mmHg above systolic blood pressure) on right thigh and the SHAM (same as IPC, but 20 mmHg) on left thigh. After 48 hours, the subjects performed another set of tests with the opposite applications. Number of repetitions, maximal voluntary isometric contraction (MVIC) and perceptual indicators were analyzed. After IPC and SHAM intervention performed at the same time, similar results were observed for the number of repetitions, with no significant differences between conditions (baseline x IPC x SHAM) for either left (p = 0.274) or right thigh (p = 0.242). The fatigue index and volume load did not show significant effect size after IPC and SHAM maneuvers. In contrast, significant reduction on left tight MVIC was observed (p = 0.001) in SHAM and IPC compared to baseline, but not for right thigh (p = 0.106). Results from the current study may indicate that applying IPC prior to a set of leg extension does not result in ergogenic effects. The placebo effect seems to be related to this technique and its dissociation seems unlikely, therefore including a SHAM or placebo group in IPC studies is strongly recommended.

ELECTROMYOGRAPHIC ANALYSIS OF LEG EXTENSION EXERCISE DURING DIFFERENT ANKLE AND KNEE POSITIONS

2015 ◽  
Vol 15 (02) ◽  
pp. 1540037 ◽  
Author(s):  
GUIDO BELLI ◽  
LUCA VITALI ◽  
MATTEO BOTTEGHI ◽  
LEYDI NATALIA VITTORI ◽  
ELISABETTA PETRACCI ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Vastus Lateralis ◽  
Pain Syndrome ◽  
Knee Extension ◽  
Maximal Voluntary Isometric Contraction ◽  
Leg Extension ◽  
Isometric Knee Extension ◽  
Medial Rotation ◽  
Electromyographic Analysis ◽  
Main Factor

The imbalance between vastus medialis oblique (VMO) and vastus lateralis (VL) strength is one of the main factor for patellofemoral pain syndrome (PFPS) onset, related to improper alignment of the patella. The aim of this paper is to investigate the effects of knee flexion, knee rotation and ankle flexion attitudes on the activity of the VMO and VL muscles during unilateral maximal voluntary isometric contraction (MIVC) of the quadriceps femoris. Eighteen healthy subjects volunteered for the study. Five conditions for two different knee flexion angles (90°; 30°) were tested using leg extension machine: Neutral (N) condition, maximal knee medial rotation (MR), maximal knee lateral rotation (LR), maximal ankle plantarflexion (PF) and maximal ankle dorsiflexion (DF). Data were normalized in order to calculate the normalized VMO/VL ratio. The normalized VMO/VL ratio for all the conditions occurred at 90° of knee flexion was higher than the same conditions at 30° of knee flexion (p = 0.02). No statistical differences between conditions at the same knee angle and for angle x condition interaction were observed (p > 0.05). These findings suggest that knee flexion should be the first variable to be managed during isometric knee extension movement performed by leg extension machine, in order to increase VMO/VL ratio.

scholarly journals Acute effect of intra-set static stretching on antagonists versus passive interval on the performance of maximum repetitions of agonists in leg extension machine

2020 ◽  
Vol 22 ◽  
Author(s):  
Priscila Alves de Souza ◽  
Diego Rodrigues Teixeira ◽  
Jaime Della Corte ◽  
Camila Aparecida de Souza Batista ◽  
Humberto Lameira Miranda ◽  
...  
Keyword(s):  
Strength Training ◽  
Acute Effect ◽  
Knee Extension ◽  
Knee Extensors ◽  
Muscle Endurance ◽  
Static Stretching ◽  
Healthy Male ◽  
Leg Extension ◽  
Experimental Protocols ◽  
Knee Extension Exercise

Abstract The aim of this study was to investigate the acute effect of intra-set antagonist static stretching (hamstrings) on the performance of maximum repetitions of knee extensors adopting muscle endurance training zone. The sample consisted of 15 healthy male volunteers with experience in strength training (23.7 ± 4.3 years, 81.9 ± 15.0 kg, 1.8 ± 0.1 m). Two experimental protocols were conducted: protocol without static stretching (PT) and antagonist stretching protocol (PAA) in the knee extension exercise. The results showed that there was no difference between protocols or interactions between protocols and sets in maximum repetitions performance (PT, set1 – 21.3 ± 3.4; set2 – 16.1 ± 1.9; set3 – 13.5 ± 1.3 / PAA, set1 – 21.0 ± 2.0; set2 – 16.7 ± 2.6; set3 – 13.7 ± 2.2) (p ≤ 0.05) (p ≤ 0.05). Therefore, antagonist static stretching does not influence performance of maximum repetitions of knee extensors over multiple sets focused on muscle endurance.

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