scholarly journals Does the Score on the MRC Strength Scale Reflect Instrumented Measures of Maximal Torque and Muscle Activity in Post-Stroke Survivors?

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8175
Author(s):  
Pawel Kiper ◽  
Daniele Rimini ◽  
Deborah Falla ◽  
Alfonc Baba ◽  
Sebastian Rutkowski ◽  
...  

It remains unknown whether variation of scores on the Medical Research Council (MRC) scale for muscle strength is associated with operator-independent techniques: dynamometry and surface electromyography (sEMG). This study aimed to evaluate whether the scores of the MRC strength scale are associated with instrumented measures of torque and muscle activity in post-stroke survivors with severe hemiparesis both before and after an intervention. Patients affected by a first ischemic or hemorrhagic stroke within 6 months before enrollment and with complete paresis were included in the study. The pre- and post-treatment assessments included the MRC strength scale, sEMG, and dynamometry assessment of the triceps brachii (TB) and biceps brachii (BB) as measures of maximal elbow extension and flexion torque, respectively. Proprioceptive-based training was used as a treatment model, which consisted of multidirectional exercises with verbal feedback. Each treatment session lasted 1 h/day, 5 days a week for a total 15 sessions. Nineteen individuals with stroke participated in the study. A significant correlation between outcome measures for the BB (MRC and sEMG p = 0.0177, ρ = 0.601; MRC and torque p = 0.0001, ρ = 0.867) and TB (MRC and sEMG p = 0.0026, ρ = 0.717; MRC and torque p = 0.0001, ρ = 0.873) were observed post intervention. Regression models revealed a relationship between the MRC score and sEMG and torque measures for both the TB and BB. The results confirmed that variation on the MRC strength scale is associated with variation in sEMG and torque measures, especially post intervention. The regression model showed a causal relationship between MRC scale scores, sEMG, and torque assessments.

2017 ◽  
Vol 57 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Atle Hole Saeterbakken ◽  
Dag-André Mo ◽  
Suzanne Scott ◽  
Vidar Andersen

AbstractThe aim of the study was to compare the EMG activity performing 6RM competition style bench press (flat bench-wide grip) with 1) medium and narrow grip widths on a flat bench and 1) inclined and declined bench positions with a wide grip. Twelve bench press athletes competing at national and international level participated in the study. EMG activity was measured in the pectoralis major, anterior and posterior deltoid, biceps brachii, triceps brachii and latissimus dorsi. Non-significant differences in activation were observed between the three bench positions with the exception of 58.5-62.6% lower triceps brachii activation, but 48.3-68.7% greater biceps brachii activation in the inclined bench compared with the flat and declined bench position. Comparing the three grip widths, non-significant differences in activations were observed, with the exception of 25.9-30.5% lower EMG activity in the biceps brachii using a narrow grip, compared to the medium and wide grip conditions. The 6-RM loads were 5.8-11.1% greater using a medium and wide grip compared to narrow grip width and 18.5-21.5% lower in the inclined bench position compared with flat and declined. Comparing the EMG activity during the competition bench press style with either the inclined and declined bench position (wide grip) or using a narrow and medium grip (flat bench), only resulted in different EMG activity in the biceps- and triceps brachii. The 6RM loads varied with each bench press variation and we recommend the use of a wide grip on a flat bench during high load hypertrophy training to bench press athletes.


Author(s):  
Nahid Norouzi-Gheidari ◽  
Alejandro Hernandez ◽  
Philippe S. Archambault ◽  
Johanne Higgins ◽  
Lise Poissant ◽  
...  

(1) Background: Increasing the amount of therapy time has been shown to improve motor function in stroke survivors. However, it is often not possible to increase the amount of therapy time provided in the current one-on-one therapy models. Rehabilitation-based virtual reality exergame systems, such as Jintronix, can be offered to stroke survivors as an adjunct to traditional therapy. The goal of this study was to examine the safety and feasibility of providing additional therapy using an exergame system and assess its preliminary clinical efficacy. (2) Methods: Stroke survivors receiving outpatient rehabilitation services participated in this pilot randomized control trial in which the intervention group received 4 weeks of exergaming sessions in addition to traditional therapy sessions. (3) Results: Nine subjects in the intervention and nine subjects in the control group completed the study. The intervention group had at least two extra sessions per week, with an average duration of 44 min per session and no serious adverse events (falls, dizziness, or pain). The efficacy measures showed statistically meaningful improvements in the activities of daily living measures (i.e., MAL-QOM (motor activity log-quality of movement) and both mobility and physical domains of the SIS (stroke impact scale) with mean difference of 1.0%, 5.5%, and 6.7% between the intervention and control group, respectively) at post-intervention. (4) Conclusion: Using virtual reality exergaming technology as an adjunct to traditional therapy is feasible and safe in post-stroke rehabilitation and may be beneficial to upper extremity functional recovery.


2004 ◽  
Vol 20 (2) ◽  
pp. 129-143 ◽  
Author(s):  
Eadric Bressel ◽  
Gary D. Heise

The purpose of this study was to compare muscle activity, kinematic, and oxygen consumption characteristics between forward and reverse arm cranking. Twenty able-bodied men performed 5-min exercise bouts of forward and reverse arm cranking while electromyographic (EMG), kinematic, and oxygen consumption data were collected. EMG activity of biceps brachii, triceps brachii, deltoid, and infraspinatus muscles were recorded and analyzed to reflect on-time durations and amplitudes for each half-cycle (first 180° and second 180° of crank cycle). Kinematic data were quantified from digitization of video images, and oxygen consumption was calculated from expired gases. Dependent measures were analyzed with a MANOVA and follow-up univariate procedures; alpha was set at .01. The biceps brachii, deltoid, and infraspinatus muscles displayed greater on-time durations and amplitudes for select half-cycles of reverse arm cranking compared to forward arm cranking (p< 0.01). Peak wrist flexion was 9% less in reverse arm cranking (p< 0.01), and oxygen consumption values did not differ between conditions (p= 0.25). Although there were no differences in oxygen consumption and only minor differences kinematically, reverse arm cranking requires greater muscle activity from the biceps brachii, deltoid, and infraspinatus muscles. These results may allow clinicians to more effectively choose an arm cranking direction that either minimizes or maximizes upper extremity muscle activity depending on the treatment objectives.


Sports ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 224
Author(s):  
Andrea Melani ◽  
Giuliana Gobbi ◽  
Daniela Galli ◽  
Cecilia Carubbi ◽  
Elena Masselli ◽  
...  

Background: The bench press exercise (BP) is commonly practiced in both recreational and professional training. The weight is lowered from a position where the elbows are at a 90° angle at the start and <90° at the end of eccentric phase, and then returned to the elbows extended position. In order to focus the exercise more on the triceps brachii (TB) rather than the pectoralis major (PM), the inter-handle distance (IHD) is decreased diminishing the involvement of the PM in favor of the TB. Purpose: To improve performance of the exercise by reducing force dissociation and transmitting 100% of the external load to the muscle tissue we propose a prototype of the barbell with a bar on which two sleeves are capable of sliding. The dynamic modifications of the IHD keep the elbow flexion angle constant at 90°. Results: Analysis of the inter-handle distance (IHD) signals of the upper body muscles showed a marked increase in muscle activity using the experimental barbell for the PM (19.5%) and for the biceps brachii (173%). Conclusions: The experimental barbell increased the muscle activity typical of the bench press exercise, obtaining the same training induction with a lower load and consequently preventing articular stress.


Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 492
Author(s):  
Yen-Ting Chen ◽  
Chuan Zhang ◽  
Yang Liu ◽  
Elaine Magat ◽  
Monica Verduzco-Gutierrez ◽  
...  

Spastic muscles are weak muscles. It is known that muscle weakness is linked to poor motor performance. Botulinum neurotoxin (BoNT) injections are considered as the first-line treatment for focal spasticity. The purpose of this study was to quantitatively investigate the effects of BoNT injections on force control of spastic biceps brachii muscles in stroke survivors. Ten stroke survivors with spastic hemiplegia (51.7 ± 11.5 yrs; 5 men) who received 100 units of incobotulinumtoxinA or onabotulinumtoxinA to the biceps brachii muscles participated in this study. Spasticity assessment (Modified Ashworth Scale (MAS) and reflex torque) and muscle strength of elbow flexors, as well as motor performance assessment (force variability of submaximal elbow flexion) were performed within one week before (pre-injection) and 3~4 weeks (3-wk) after BoNT injections. As expected, BoNT injections reduced the MAS score and reflex torque, and elbow flexor strength on the spastic paretic side. However, motor performance remained within similar level before and after injections. There was no change in muscle strength or motor performance on the contralateral arm after BoNT injections. The results of this study provide evidence that BoNT injections can reduce spasticity and muscle strength, while motor performance of the weakened spastic muscle remains unchanged.


Author(s):  
Yong-Ku Kong ◽  
Chae-Won Park ◽  
Min-Uk Cho ◽  
Seoung-Yeon Kim ◽  
Min-Jung Kim ◽  
...  

The aim of this study was to evaluate the muscle activities and subjective discomfort according to the heights of tasks and the lower-limb exoskeleton CEX (Chairless EXoskeleton), which is a chair-type passive exoskeleton. Twenty healthy subjects (thirteen males and seven females) participated in this experiment. The independent variables were wearing of the exoskeleton (w/ CEX, w/o CEX), working height (6 levels: 40, 60, 80, 100, 120, and 140 cm), and muscle type (8 levels: upper trapezius (UT), erector spinae (ES), middle deltoid (MD), triceps brachii (TB), biceps brachii (BB), biceps femoris (BF), rectus femoris (RF), and tibialis anterior (TA)). The dependent variables were EMG activity (% MVC) and subjective discomfort rating. When wearing the CEX, the UT, ES, RF, and TA showed lower muscle activities at low working heights (40–80 cm) than not wearing the CEX, whereas those muscles showed higher muscle activities at high working heights (100–140 cm). Use of the CEX had a positive effect on subjective discomfort rating at lower working heights. Generally, lower discomfort was reported at working heights below 100 cm when using the CEX. At working heights of 100–140 cm, the muscle activity when wearing the CEX tended to be greater than when not wearing it. Thus, considering the results of this study, the use of the lower-limb exoskeleton (CEX) at a working height of 40–100 cm might reduce the muscle activity and discomfort of whole body and decrease the risk of related disorders.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam Viktorisson ◽  
Elisabeth M. Andersson ◽  
Erik Lundström ◽  
Katharina S. Sunnerhagen

AbstractRegular physical activity is widely recommended in the primary and secondary prevention of stroke. Physical activity may enhance cognitive performance after stroke, but cognitive impairments could also hinder a person to take part in physical activity. However, a majority of previous studies have not found any association between post-stroke cognitive impairments and a person’s subsequent level of activity. In this explorative, longitudinal study, we describe the intraindividual change in physical activity from before to 6 months after stroke, in relation to early screening of post-stroke cognitive impairments. Participants were recruited at 2 to 15 days after stroke, and screened for cognitive impairments using the Montreal Cognitive Assessment tool. Information on pre-stroke physical activity was retrospectively collected at hospital admittance by physiotherapists. Post-stroke physical activity was evaluated after 6 months. Of 49 participants included, 44 were followed up. The level of physical activity changed in more than half of all participants after stroke. Participants who were physically active 6 months after stroke presented with significantly less cognitive impairments. These results highlight that many stroke survivors experience a change in their physical activity level following stroke, and that unimpaired cognition may be important for a stroke survivors’ ability to be physically active.


2020 ◽  
Vol 13 (1) ◽  
pp. 129-136
Author(s):  
Amin Amini ◽  
Hossein Shirvani ◽  
Behzad Bazgir

Background: Good balance and muscle activity are essential to do daily activities. Recent studies have focused on the relations between balance and attention patterns. The study of the balance and muscle activity of people in different patterns of attention can clarify the nature of the effect of attention instructions. Purpose: The present study aims to evaluate the changes in different focus of attention instructions and quality of balance control and muscle activity in the elderly retired. Methods: Thirty elderly retired men [mean age: 51.6 ± 6.4 years] were recruited for this study. Subjects were selected through the berg balance test. Balance control ability [Biodex Balance System] and muscle activity [electromyography system] were assessed in two conditions, internal attention and external attention task. The data obtained were analyzed using repeated-measures ANOVA at a significant level of P<0.05. Results: Body sway and muscle activity parameters were correlated with different patterns of attention. During external focus condition, [1] Center of Pressure [CoP] total two-leg balance, CoP medio-lateral and CoP anterior-posterior for external-focus were lowered [P<0.05] and [2] Tibialis anterior and soleus for the leg, biceps brachii and triceps brachii for the arm, sternocleidomastoid and semispinalis capitis for external-focus were lowered [P<0.05]. Conclusion: Improved static balance responses and alterations in postural control were observed under external focus conditions. An external focus of attention may be the preferred method for facilitating balance control and muscle activation in an elderly retired man.


Author(s):  
Porakoch Sirisuwan ◽  
Chieko Narita ◽  
Tetsushi Koshino ◽  
Hisanori Yuminaga

The aim of study is to evaluate whether altering the bamboo moisture by immersed bamboo in water on 4-hour and 3 -day that would affect the muscle activity during separated bamboo by bending process. Moreover, thirteen muscles which bilateral side of Pectoralis major, Biceps brachii, Triceps brachii, Latissimus dorsi, Gluteus medius and only right side of Rectus abdominis, Extensor carpi radialis longus and Flexor carpi radialis were recorded. As a result, the bilateral side of Biceps brachii, right side of Extensor carpi radialis longus and Flexor carpi radialis, left side of Triceps brachii showed the difference quite clearly. When the craftsman was bending the bamboo he was necessary more effortful by these muscles activity on the 4-hour immersed bamboo in water than the 3-day. The scanning electron microscopy (SEM) photographs showed the fracture characteristic of 2 subjects that the adhesive of bamboo fiber decreased when increased moisture.


2020 ◽  
Vol 120 (11) ◽  
pp. 2517-2524
Author(s):  
Atle Hole Saeterbakken ◽  
Tom Erik J. Solstad ◽  
David G. Behm ◽  
Nicolay Stien ◽  
Matthew Peter Shaw ◽  
...  

Abstract Purpose To determine the effects of asymmetric loads on muscle activity with the bench press. Method Seventeen resistance-trained men performed one familiarization session including testing one repetition maximum (1RM) and three 5 repetition maximum (RM) lifts; using symmetric loads, 5% asymmetric loads, and 10% asymmetric loads. The asymmetric loading (i.e., reduced load on one side) was calculated as 5% and 10% of the subject`s 1RM load. In the experimental session, the three conditions of 5RM were conducted with electromyographic activity from the pectoralis major, triceps brachii, biceps brachii, anterior deltoid, posterior deltoid, and external oblique on both sides of the body. Results On the loaded side, asymmetric loads reduced triceps brachii activation compared to symmetric loads, whereas the other muscles demonstrated similar muscle activity between the three conditions. On the de-loaded side, 10% asymmetry in loading resulted in lower pectoralis major, anterior deltoid, and biceps brachii activation compared to 5% asymmetric and symmetric loading. On the de-loaded side, only pectoralis major demonstrated lower muscle activation than symmetric loads. Furthermore, asymmetric loads increased external oblique activation on both sides compared to symmetric loads. Conclusions Asymmetric bench press loads reduced chest and shoulder muscle activity on the de-loaded side while maintaining the muscle activity for the loaded side. The authors recommend resistance-trained participants struggling with strength imbalances between sides, or activities require asymmetric force generation (i.e., alpine skiing or martial arts), to implement asymmetric training as a supplement to the traditional resistance training.


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