We aimed to investigate the impact of time on fine-wire (fw) electromyography (EMG) signal amplitude, and to determine whether any attenuation is confounded by task type. Twenty healthy participants were instrumented with fw and surface (s) EMG electrodes at the biceps brachii bilaterally. Participants held a weight statically with one arm and with the other arm either repeated the same task following a maximum voluntary contraction (MVC) or repeated dynamic elbow flexion/extension contractions. Each task was repeated for 30 s every five minutes over two hours. EMG amplitude was smoothed and normalized to time = 0. Stable median power frequency of the s-EMG ruled out the confounding influence of fatigue. Repeated-measures ANCOVAs determined the effect of electrode type and time (covariate) on EMG amplitude and the confounding impact of task type. During the isometric protocol, fw-EMG amplitude reduced over time (p = 0.002), while s-EMG amplitude (p = 0.895) and MPF (p > 0.05) did not change. Fw-EMG amplitude attenuated faster during the dynamic than the isometric protocol (p = 0.008) and there was evidence that the MVC preceding the isometric protocol impacted the rate of decline (p = 0.001). We conclude that systematic signal attenuation of fw-EMG occurs over time and is more pronounced during dynamic tasks.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jelekin.2021.102566DOI Listing

Publication Analysis

Top Keywords

emg amplitude
12
isometric protocol
12
voluntary contraction
8
task type
8
fw-emg amplitude
8
amplitude
7
emg
5
influence contraction
4
type
4
contraction type
4

Similar Publications

BACKGROUND Swallowing is a complex behavior involving the musculoskeletal system and higher-order brain functions. We investigated the effects of different modalities of repetitive transcranial magnetic stimulation (rTMS) on the unaffected hemisphere and observed correlation between suprahyoid muscle activity and cortical activation in unilateral stroke patients when swallowing saliva, based on functional near-infrared spectroscopy (fNIRS). MATERIAL AND METHODS From November 2022 to March 2023, twenty-five patients with unilateral stroke were screened using computed tomography or magnetic resonance imaging and identified via a video fluoroscopic swallow study.

View Article and Find Full Text PDF

Background: The dosage and intensity of physical therapy are crucial factors influencing the motor recovery of the hemiplegic lower limb in patients with subacute stroke. Biofeedback using wearable sensors may provide opportunities for patients with stroke to effectively guide self-exercises with monitoring of muscular activities in hemiplegic lower limbs. This study aims to explore the feasibility and safety of in-bed self-exercises based on electromyography sensor feedback in patients with subacute stroke.

View Article and Find Full Text PDF

This study investigated muscle activation, shocks, and vibrations of the upper extremities during tennis serves between junior and adult tennis players. Thirty-five well-trained tennis players (15 juniors and 20 adults) performed 10 maximal successful tennis serves. Two triaxial accelerometers recorded the shock and vibration on the racket and the hand on the dominant side.

View Article and Find Full Text PDF

: Amyloidosis is a disorder characterized by the abnormal folding of proteins, forming insoluble fibrils that accumulate in tissues and organs. This accumulation disrupts normal tissue architecture and organ function, often with serious consequences, including death if left untreated. Light-chain amyloidosis (AL) and hereditary transthyretin-type amyloidosis (hATTR) are two of the most common types.

View Article and Find Full Text PDF

Analyzing How Skinfold Thickness Affects Log-Transformed EMG Amplitude-Power Output Metrics.

Bioengineering (Basel)

December 2024

Physical Therapy Program, Department of Health Care Sciences, Wayne State University, College of Pharmacy and Health Sciences, Detroit, MI 48201, USA.

Background: The purpose of this study was to determine whether accounting for skinfold thickness would reduce the variability observed on a subject-by-subject basis for the -intercept and slope terms derived from the log-transformed EMG amplitude-power output relationship. We hypothesized that using skinfold thickness as a covariate would reduce the subject-by-subject variability in the -intercept and slope terms and, therefore, indicate potential mean differences between muscle groups.

Methods: Subjects had the skinfold from their three superficial quadriceps femoris muscles measured and then EMG electrodes placed over the three muscles.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!