scholarly journals Local and Contralateral Effects after the Application of Neuromuscular Electrostimulation in Lower Limbs

2020 ◽  
Vol 17 (23) ◽  
pp. 9028
Author(s):  
Elisa Benito-Martínez ◽  
Diego Senovilla-Herguedas ◽  
Julio César de la Torre-Montero ◽  
María Jesús Martínez-Beltrán ◽  
María Mercedes Reguera-García ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Local Level ◽  
Lower Limbs ◽  
Anterior Region ◽  
Measurement Tool ◽  
Cross Education ◽  
Education Effects ◽  
Neuromuscular Electrostimulation ◽  
Dominant Side ◽  
Contralateral Effects

Neuromuscular electrostimulation (NMES) has been used mainly as a method to promote muscle strength, but its effects on improving blood flow are less well known. The aim of this study is to deepen the knowledge about the local and contralateral effects of the application of symmetric biphasic square currents on skin temperature (Tsk). An experimental pilot study was developed with a single study group consisting of 45 healthy subjects. Thermographic evaluations were recorded following the application of NMES to the anterior region of the thigh. The results showed an increase in the maximal Tsk of 0.67% in the anterior region of the thigh where the NMES was applied (p < 0.001) and an increase of 0.54% (p < 0.01) due to cross-education effects, which was higher when the NMES was applied on the dominant side (0.79%; p < 0.01). The duration of the effect was 20 min in the dominant leg and 10 min in the nondominant one. The application of a symmetrical biphasic current (8 Hz and 400 μs) creates an increase in the maximal Tsk at the local level. A temperature cross-education effect is produced, which is greater when the NMES is applied on the dominant side. This could be a useful noninvasive measurement tool in NMES treatments.

Contralateral effects of unilateral training: sparing of muscle strength and size after immobilization

2018 ◽  
Vol 43 (11) ◽  
pp. 1131-1139 ◽  
Author(s):  
Justin W. Andrushko ◽  
Layla A. Gould ◽  
Jonathan P. Farthing
Keyword(s):  
Strength Training ◽  
Potential Interaction ◽  
Muscle Size ◽  
Clinical Settings ◽  
Cross Sectional ◽  
Published Evidence ◽  
Cross Education ◽  
New Research ◽  
Education Effects ◽  
Contralateral Effects

The contralateral effects of unilateral strength training, known as cross-education of strength, date back well over a century. In the last decade, a limited number of studies have emerged demonstrating the preservation or “sparing” effects of cross-education during immobilization. Recently published evidence reveals that the sparing effects of cross-education show muscle site specificity and involve preservation of muscle cross-sectional area. The new research also demonstrates utility of training with eccentric contractions as a potent stimulus to preserve immobilized limb strength across multiple modes of contraction. The cumulative data in nonclinical settings suggest that cross-education can completely abolish expected declines in strength and muscle size in the range of ∼13% and ∼4%, respectively, after 3–4 weeks of immobilization of a healthy arm. The evidence hints towards the possibility that unique mechanisms may be involved in preservation effects of cross-education, as compared with those that lead to functional improvements under normal conditions. Cross-education effects after strength training appear to be larger in clinical settings, but there is still only 1 randomized clinical trial demonstrating the potential utility of cross-education in addition to standard treatment. More work is necessary in both controlled and clinical settings to understand the potential interaction of neural and muscle adaptations involved in the observed sparing effects, but there is growing evidence to advocate for the clinical utility of cross-education.

scholarly journals Biomechanical analysis of an unpowered hip flexion orthosis on individuals with and without multiple sclerosis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Ross M. Neuman ◽  
Staci M. Shearin ◽  
Karen J. McCain ◽  
Nicholas P. Fey
Keyword(s):  
Multiple Sclerosis ◽  
Muscle Activity ◽  
Healthy Subjects ◽  
Muscle Activation ◽  
Assistive Technologies ◽  
Lower Limbs ◽  
Biomechanical Analysis ◽  
Foot Drop ◽  
Plantar Flexors ◽  
Hip Flexion

Abstract Background Gait impairment is a common complication of multiple sclerosis (MS). Gait limitations such as limited hip flexion, foot drop, and knee hyperextension often require external devices like crutches, canes, and orthoses. The effects of mobility-assistive technologies (MATs) prescribed to people with MS are not well understood, and current devices do not cater to the specific needs of these individuals. To address this, a passive unilateral hip flexion-assisting orthosis (HFO) was developed that uses resistance bands spanning the hip joint to redirect energy in the gait cycle. The purpose of this study was to investigate the short-term effects of the HFO on gait mechanics and muscle activation for people with and without MS. We hypothesized that (1) hip flexion would increase in the limb wearing the device, and (2) that muscle activity would increase in hip extensors, and decrease in hip flexors and plantar flexors. Methods Five healthy subjects and five subjects with MS walked for minute-long sessions with the device using three different levels of band stiffness. We analyzed peak hip flexion and extension angles, lower limb joint work, and muscle activity in eight muscles on the lower limbs and trunk. Single-subjects analysis was used due to inter-subject variability. Results For subjects with MS, the HFO caused an increase in peak hip flexion angle and a decrease in peak hip extension angle, confirming our first hypothesis. Healthy subjects showed less pronounced kinematic changes when using the device. Power generated at the hip was increased in most subjects while using the HFO. The second hypothesis was not confirmed, as muscle activity showed inconsistent results, however several subjects demonstrated increased hip extensor and trunk muscle activity with the HFO. Conclusions This exploratory study showed that the HFO was well-tolerated by healthy subjects and subjects with MS, and that it promoted more normative kinematics at the hip for those with MS. Future studies with longer exposure to the HFO and personalized assistance parameters are needed to understand the efficacy of the HFO for mobility assistance and rehabilitation for people with MS.

scholarly journals Assessment of an Assistive Control Approach Applied in an Active Knee Orthosis Plus Walker for Post-Stroke Gait Rehabilitation

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2452
Author(s):  
Ana Cecilia Villa-Parra ◽  
Jessica Lima ◽  
Denis Delisle-Rodriguez ◽  
Laura Vargas-Valencia ◽  
Anselmo Frizera-Neto ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Muscle Activation ◽  
Inertial Sensors ◽  
Lower Limbs ◽  
Trunk Muscles ◽  
Control Group ◽  
Gait Rehabilitation ◽  
Control Approach ◽  
Post Stroke ◽  
Knee Orthosis

The goal of this study is the assessment of an assistive control approach applied to an active knee orthosis plus a walker for gait rehabilitation. The study evaluates post-stroke patients and healthy subjects (control group) in terms of kinematics, kinetics, and muscle activity. Muscle and gait information of interest were acquired from their lower limbs and trunk, and a comparison was conducted between patients and control group. Signals from plantar pressure, gait phase, and knee angle and torque were acquired during gait, which allowed us to verify that the stance control strategy proposed here was efficient at improving the patients’ gaits (comparing their results to the control group), without the necessity of imposing a fixed knee trajectory. An innovative evaluation of trunk muscles related to the maintenance of dynamic postural equilibrium during gait assisted by our active knee orthosis plus walker was also conducted through inertial sensors. An increase in gait cycle (stance phase) was also observed when comparing the results of this study to our previous work. Regarding the kinematics, the maximum knee torque was lower for patients when compared to the control group, which implies that our orthosis did not demand from the patients a knee torque greater than that for healthy subjects. Through surface electromyography (sEMG) analysis, a significant reduction in trunk muscle activation and fatigability, before and during the use of our orthosis by patients, was also observed. This suggest that our orthosis, together with the assistive control approach proposed here, is promising and could be considered to complement post-stroke patient gait rehabilitation.

The Effects of Uni- and Bilateral Fatigue on Postural and Power Tasks

2013 ◽  
Vol 29 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Paulo H. Marchetti ◽  
Maria I.V. Orselli ◽  
Marcos Duarte
Keyword(s):  
Lower Limb ◽  
Healthy Subjects ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Lower Limbs ◽  
Quiet Standing ◽  
Ground Reaction Forces ◽  
Before And After ◽  
Reaction Forces ◽  
The Mean

The aim of this study was to investigate the effects of unilateral and bilateral fatigue on both postural and power bipedal tasks. Ten healthy subjects performed two tasks: bipedal quiet standing and a maximal bipedal counter-movement jumping before and after unilateral (with either the dominant or nondominant lower limb) and bilateral (with both lower limbs) fatigue. We employed two force plates (one under each lower limb) to measure the ground reaction forces and center of pressure produced by subjects during the tasks. To quantify the postural sway during quiet standing, we calculated the resultant center of pressure (COP) speed and COP area of sway, as well as the mean weight distribution between lower limbs. To quantify the performance during the countermovement jumping, we calculated the jump height and the peak force of each lower limb. We observed that both unilateral and bilateral fatigue affected the performance of maximal voluntary jumping and standing tasks and that the effects of unilateral and bilateral fatigue were stronger in the dominant limb than in the nondominant limb during bipedal tasks. We conclude that unilateral neuromuscular fatigue affects both postural and power tasks negatively.

scholarly journals Are the mediolateral joint forces in the lower limbs different between scoliotic and healthy subjects during gait?

Scoliosis ◽  
2015 ◽  
Vol 10 (S2) ◽  
Author(s):  
Mouna Yazji ◽  
Maxime Raison ◽  
Carl-Éric Aubin ◽  
Hubert Labelle ◽  
Christine Detrembleur ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Lower Limbs ◽  
Joint Forces

scholarly journals Neuromuscular Mechanosensitivity in Subjects with Chronic Ankle Sprain: A Cross-Sectional Study

Pain Medicine ◽  
2019 ◽  
Vol 21 (9) ◽  
pp. 1991-1998 ◽  
Author(s):  
Cristina Lorenzo-Sánchez-Aguilera ◽  
David Rodríguez-Sanz ◽  
Tomás Gallego-Izquierdo ◽  
Irene Lázaro-Navas ◽  
Josue Plaza-Rodríguez ◽  
...  
Keyword(s):  
Ankle Sprain ◽  
Healthy Subjects ◽  
Ankle Instability ◽  
Pressure Pain Threshold ◽  
Neuromuscular Control ◽  
Lower Limbs ◽  
Control Group ◽  
Case Group ◽  
Strong Positive Correlation ◽  
Cross Sectional

Abstract Background Ankle sprain is one of the most common musculoskeletal injuries in sports, at work, and at home. Subjects who suffer from this injury may develop ankle instability. Functional instability has been associated with a high rate of resprain and impaired neuromuscular control in patients with ankle instability. Objective Measurement of neural and muscular mechanosensitivity after ankle sprain injury and establishment of the relationship between these variables. Methods A cross-sectional case-control study was performed with a sample of 58 students from Alcalá de Henares University (21 males and 37 females, mean age ± SD = 21 ± 3.7 years). Subjects were divided into two groups: a case group (N = 29, subjects with unstable ankle) and a control group (N = 29, healthy subjects). The pressure pain threshold (PPT) of the tibialis anterior, peroneus longus, and peroneus brevis muscles and mechanosensitivity of the common peroneus and tibial nerves were evaluated in all subjects through a manual mechanical algometer. Results Neuromuscular PPTs showed significant differences (P &lt; 0.05) between both groups, such that, compared with the control group, the case group exhibited significantly lower PPT levels. In the case group, a strong positive correlation was observed between neural and muscular homolateral mechanosensitivity in both lower limbs. Conclusions Participants with chronic ankle instability showed higher neuromuscular mechanosensitivity in muscles and nerves surrounding the ankle joint than healthy subjects. These findings indicate that low PPT values may be associated with symptoms that characterize this disease.

scholarly journals Patterns of lower limb muscular activity and joint moments during directional efforts using a static dynamometer

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Mathieu Lalumiere ◽  
Cloé Villeneuve ◽  
Cassandra Bellavance ◽  
Michel Goyette ◽  
Daniel Bourbonnais
Keyword(s):  
Lower Limb ◽  
Healthy Subjects ◽  
Inverse Dynamics ◽  
Pearson Correlation ◽  
Activity Patterns ◽  
Correlation Coefficients ◽  
Muscular Activity ◽  
Lower Limbs ◽  
Joint Moments ◽  
Muscle Groups

Abstract Background Strength and coordination of lower muscle groups typically identified in healthy subjects are two prerequisites to performing functional activities. These physical qualities can be impaired following a neurological insult. A static dynamometer apparatus that measures lower limb joint moments during directional efforts at the foot was developed to recruit different patterns of muscular activity. The objectives of the present study were to 1) validate joint moments estimated by the apparatus, and 2) to characterize lower limb joint moments and muscular activity patterns of healthy subjects during progressive static efforts. Subjects were seated in a semi-reclined position with one foot attached to a force platform interfaced with a laboratory computer. Forces and moments exerted under the foot were computed using inverse dynamics, allowing for the estimation of lower limb joint moments. To achieve the study’s first objective, joint moments were validated by comparing moments of various magnitudes of force applied by turnbuckles on an instrumented leg equipped with strain gauges with those estimated by the apparatus. Concurrent validity and agreement were assessed using Pearson correlation coefficients and Bland and Altman analysis, respectively. For the second objective, joint moments and muscular activity were characterized for five healthy subjects while exerting progressive effort in eight sagittal directions. Lower limb joint moments were estimated during directional efforts using inverse dynamics. Muscular activity of eight muscles of the lower limb was recorded using surface electrodes and further analyzed using normalized root mean square data. Results The joint moments estimated with the instrumented leg were correlated (r > 0.999) with those measured by the dynamometer. Limits of agreement ranged between 8.5 and 19.2% of the average joint moment calculated by both devices. During progressive efforts on the apparatus, joint moments and patterns of muscular activity were specific to the direction of effort. Patterns of muscular activity in four directions were similar to activation patterns reported in the literature for specific portions of gait cycle. Conclusion This apparatus provides valid joint moments exerted at the lower limbs. It is suggested that this methodology be used to recruit muscular activity patterns impaired in neurological populations.

Cross-education: effects of age on rapid and maximal voluntary contractile characteristics in males

2019 ◽  
Vol 119 (6) ◽  
pp. 1313-1322 ◽  
Author(s):  
Garrett M. Hester ◽  
Mitchel A. Magrini ◽  
Ryan J. Colquhoun ◽  
Alejandra Barrera-Curiel ◽  
Carlos A. Estrada ◽  
...  
Keyword(s):  
Cross Education ◽  
Education Effects ◽  
Contractile Characteristics

Inflation of antishock trousers increases bronchial response to methacholine in healthy subjects

1990 ◽  
Vol 68 (4) ◽  
pp. 1528-1533 ◽  
Author(s):  
J. Regnard ◽  
P. Baudrillard ◽  
B. Salah ◽  
A. T. Dinh Xuan ◽  
L. Cabanes ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Vital Capacity ◽  
Alternative Explanation ◽  
Venous Occlusion ◽  
Forced Expiratory Volume ◽  
Lower Limbs ◽  
Base Line ◽  
Lung Volumes ◽  
Residual Capacity ◽  
Lung Vessels

We studied changes in lung volumes and in bronchial response to methacholine chloride (MC) challenge when antishock trousers (AST) were inflated at venous occlusion pressure in healthy subjects in the standing posture, a maneuver known to shift blood toward lung vessels. On inflation of bladders isolated to lower limbs, lung volumes did not change but bronchial response to MC increased, as evidenced by a greater fall in the forced expiratory volume in 1 s (FEV1) at the highest dose of MC used compared with control without AST inflation (delta FEV1 = 0.94 +/- 0.40 vs. 0.66 +/- 0.46 liter, P less than 0.001). Full inflation of AST, i.e., lower limb and abdominal bladder inflated, significantly reduced vital capacity (P less than 0.001), functional residual capacity (P less than 0.01), and FEV1 (P less than 0.01) and enhanced the bronchial response to MC challenge compared with partial AST inflation (delta FEV1 = 1.28 +/- 0.47 liter, P less than 0.05). Because there was no significant reduction of lung volumes on partial AST inflation, the enhanced bronchial response to MC cannot be explained solely by changes in base-line lung volumes. An alternative explanation might be a congestion and/or edema of the airway wall on AST inflation. Therefore, to investigate further the mechanism of the increased bronchial response to MC, we pretreated the subjects with the inhaled alpha 1-adrenergic agonist methoxamine, which has both direct bronchoconstrictor and bronchial vasoconstrictor effects.(ABSTRACT TRUNCATED AT 250 WORDS)

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