Analysis of linear electrode array EMG for assessment of hemiparetic biceps brachii muscles

Yao, Bo; Zhang, Xu; Li, Sheng; Li, Xiaoyan; Chen, Xiang; Klein, Cliff S.; Zhou, Ping

doi:10.3389/fnhum.2015.00569

Cited by 34 publications

(27 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reduction in MPF or MF on the paretic side has been report previously (16, 17). The decrease in MPF values of the paretic muscles could be due to the loss of muscle fibers and impairments in the motor unit following stroke.…”

Section: Discussionsupporting

confidence: 82%

Alterations of Muscle Activation Pattern in Stroke Survivors during Obstacle Crossing

Chen

Mao

et al. 2017

Front. Neurol.

View full text Add to dashboard Cite

ObjectiveThis study investigates changes in the neuromuscular activation pattern of the lower limb muscles in stroke survivors when crossing obstacles of three different heights.MethodsEight stroke survivors and eight age-, height-, and gender-matched healthy controls were recruited and instructed to cross over obstacles with heights of 10, 20, and 30% leg length. Surface electromyography (EMG) signals were recorded from the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (MG) of both limbs. Muscle activation signals were normalized to maximum voluntary contraction. Differences between groups and heights were compared using the root mean square of EMG, the cocontraction index of agonist and antagonist muscles, and power spectral analysis based on the mean power frequency (MPF). The correlations between the calculated variables and clinical scales such as Berg Balance Scale and Fugl-Meyer assessment (FMA) were also examined.ResultsDuring the leading limb swing phase, the activation levels of all four muscles were greater in the stroke group than the healthy controls (p < 0.05), and the TA showed increased activation level with increasing obstacle height in both groups (p < 0.05). Cocontraction between the TA and MG was higher in the stroke group during the swing phase of the leading limb and between the RF and BF during the stance phase (p < 0.05). Similarly, for the trailing limb, increased cocontractions between the two pairs of agonist and antagonist muscles were found during the stance phase in the stroke group (p < 0.05). During the crossing stride, the frequency analysis showed significantly smaller MPF values in all four lower limb muscles in the leading limb of stroke survivors compared with healthy controls (p < 0.05). Moreover, significant correlations were found between the FMA scores and the BF and TA activations in the leading limb during the swing phase (p < 0.05).ConclusionGreater activation levels of the lower limb muscles resulted in higher muscular demands for stroke survivors, which might lead to greater difficulty in maintaining balance. The increased cocontraction during obstacle crossing might be compensation for the affected stability and enable safe crossing for stroke survivors. The reduced MPF in the affected limb of the stroke group might be due to impairments in motor units or other complex neuromuscular alterations.

show abstract

Section: Discussionsupporting

confidence: 82%

Alterations of Muscle Activation Pattern in Stroke Survivors during Obstacle Crossing

Chen

Mao

et al. 2017

Front. Neurol.

View full text Add to dashboard Cite

show abstract

“…This finding correspond with EMG studies assessing hemiparetic biceps brachii muscles which attribute reduction in MFCV to altered motor unit and muscle fiber after stroke 36 . The measured shift may indicate an increase in the proportion of active type I fibers to type II fibers, which could result from motor unit dysfunction, preferential atrophy of type II fibers and/or a denervation-reinnervation of fibers occurring over time.…”

Section: Discussionsupporting

confidence: 87%

Analysis of muscle fiber conduction velocity during finger flexion and extension after stroke

Conrad

Qiu

Hoffmann

et al. 2017

Topics in Stroke Rehabilitation

Self Cite

View full text Add to dashboard Cite

Background Stroke survivors experience greater strength deficits during finger extension than finger flexion. Prior research indicates relatively little observed weakness is directly attributable to muscle atrophy. Changes in other muscle properties, however, may contribute to strength deficits. Objectives This study measured muscle fiber conduction velocity in a finger flexor and extensor muscle to infer changes in muscle fiber type after stroke. Methods Conduction velocity was measured using a linear EMG surface electrode array for both extensor digitorum communis and flexor digitorum superficialis in 12 stroke survivors with chronic hand hemiparesis and 5 control subjects. Measurements were made in both hands for all subjects. Stroke survivors had either severe (n=5) or moderate (n=7) hand impairment. Results Absolute muscle fiber conduction velocity was significantly lower in the paretic hand of severely impaired stroke patients compared to moderately impaired patients and healthy control subjects. The relative conduction velocity between the two hands, however, was quite similar for flexor muscles across all subjects and for extensor muscles for the neurologically intact control subjects. However, muscle fiber conduction velocity for finger extensors was smaller in in the paretic as compared to the non-paretic hand for both groups of stroke survivors. Conclusions One explanation for reduced conduction velocity may be a type II to type I muscle fiber, especially in extrinsic extensors. Clinically, therapists may use this information to develop therapeutic exercises targeting loss of type II fiber in extensor muscles.

show abstract

“…Subjects with relatively longer MU action potential duration on the affected side tended to have higher MU MFRs on the affected side compared to the less-affected sides. Previous studies have reported slower muscle fiber conduction velocities in certain, but not all muscles ( Yao et al, 2015 ; Conrad et al, 2017 ), and longer MUAP durations on the affected side post-stroke using intramuscular EMG ( Lukács, 2005 ). Lower firing rates on the affected side have been reported when comparing firing rates recorded at the same absolute force on both sides, using intramuscular ( Gemperline et al, 1995 ; Chou et al, 2013 ) and surface EMG decomposition techniques ( Suresh et al, 2011 ; Hu et al, 2012 ; Li et al, 2015 ).…”

Section: Discussionmentioning

confidence: 93%

Motor Unit Activity during Fatiguing Isometric Muscle Contraction in Hemispheric Stroke Survivors

McManus

Rymer

et al. 2017

Front. Hum. Neurosci.

View full text Add to dashboard Cite

Enhanced muscle weakness is commonly experienced following stroke and may be accompanied by increased susceptibility to fatigue. To examine the contributions of central and peripheral factors to isometric muscle fatigue in stroke survivors, this study investigates changes in motor unit (MU) mean firing rate, and action potential duration during, and directly following, a sustained submaximal fatiguing contraction at 30% maximum voluntary contraction (MVC). A series of short contractions of the first dorsal interosseous muscle were performed pre- and post-fatigue at 20% MVC, and again following a 10-min recovery period, by 12 chronic stroke survivors. Individual MU firing times were extracted using surface EMG decomposition and used to obtain the spike-triggered average MU action potential waveforms. During the sustained fatiguing contraction, the mean rate of change in firing rate across all detected MUs was greater on the affected side (-0.02 ± 0.03 Hz/s) than on the less-affected side (-0.004 ± 0.003 Hz/s, p = 0.045). The change in firing rate immediately post-fatigue was also greater on the affected side than less-affected side (-13.5 ± 20 and 0.1 ± 19%, p = 0.04). Mean MU firing rates increased following the recovery period on the less-affected side when compared to the affected side (19.3 ± 17 and 0.5 ± 20%, respectively, p = 0.03). MU action potential duration increased post-fatigue on both sides (10.3 ± 1.2 to 11.2 ± 1.3 ms on the affected side and 9.9 ± 1.7 to 11.2 ± 1.9 ms on the less-affected side, p = 0.001 and p = 0.02, respectively), and changes in action potential duration tended to be smaller in subjects with greater impairment (p = 0.04). This study presents evidence of both central and peripheral fatigue at the MU level during isometric fatiguing contraction for the first time in stroke survivors. Together, these preliminary observations indicate that the response to an isometric fatiguing contraction differs between the affected and less-affected side post-stroke, and may suggest that central mechanisms observed here as changes in firing rate are the dominant processes leading to task failure on the affected side.

show abstract

Analysis of linear electrode array EMG for assessment of hemiparetic biceps brachii muscles

Cited by 34 publications

References 27 publications

Alterations of Muscle Activation Pattern in Stroke Survivors during Obstacle Crossing

Alterations of Muscle Activation Pattern in Stroke Survivors during Obstacle Crossing

Analysis of muscle fiber conduction velocity during finger flexion and extension after stroke

Motor Unit Activity during Fatiguing Isometric Muscle Contraction in Hemispheric Stroke Survivors

Contact Info

Product

Resources

About