Electromyographic analysis of pedaling: A review

Abstract

Although pedaling is constrained by the circular trajectory of the pedals, it is not a simple movement. This review attempts to provide an overview of the pedaling technique using an electromyographic (EMG) approach. Literature concerning the electromyographic analysis of pedaling is reviewed in an effort to make a synthesis of the available information, and to point out its relevance for researchers, clinicians and/or cycling/triathlon trainers. The first part of the review depicts methodological aspects of the EMG signal recording and processing. We show how the pattern of muscle activation during pedaling can be analyzed in terms of muscle activity level and muscle activation timing. Muscle activity level is generally quantified with root mean square or integrated EMG values. Muscle activation timing is studied by defining EMG signal onset and offset times that identify the duration of EMG bursts and, more recently, by the determination of a lag time maximizing the cross-correlation coefficient. In the second part of the review, we describe whether the patterns of the lower limb muscles activity are influenced by numerous factors affecting pedaling such as power output, pedaling rate, body position, shoe-pedal interface, training status and fatigue. Some research perspectives linked to pedaling performance are discussed throughout the manuscript and in the conclusion.

Effects of Saddle Height on Performance and Muscular Activity During the Wingate Test

“…Hug and Dorel 31 reported that the vastus lateralis is a muscle that exclusively participates in the propulsive phase of the pedaling cycle (0°-180°) and its main function is to produce power since it is a single joint muscle 32 . On the other hand, the rectus femoris acts in the propulsive and recovery (180°-360°) phases 31 , and its main function is to transfer muscle power since it is a biarticular muscle. Thus, as expected small adjustments in saddle height (±2.5%) were sufficient to change muscle activation pattern and percentage of participation of the muscles responsible for the propulsive phase of the pedaling cycle (i.e., vastus lateralis and rectus femoris).…”

Coherence and Phase Locking Disruption in Electromyograms of Patients with Amyotrophic Lateral Sclerosis

“…EMG signals can be acquired by surface electrodes attached to the skin over the target muscle -interferential process -or by needle electrodes inserted invasively into the muscles tissues -intramuscular process. Surface EMG (sEMG) measures action potentials along the entire recorded area underneath the electrodes, while needle electrodes measure action potentials from a small number of fibres and may not be representative of the entire muscle mass involved [1,22]. sEMG appears to be more practical but it is easily contaminated by volume conduction between muscles.…”

“…In this work, sEMG is used in order to estimate the number of activated motor units and their discharge rate on superficial muscles [22]. sEMG is more frequently used since it is a non-invasive procedure, painless and risk-free for the patient whose signal is being required, does not require specialized medical doctors and is more directly correlated with the mechanical outcome [22].…”

“…sEMG is more frequently used since it is a non-invasive procedure, painless and risk-free for the patient whose signal is being required, does not require specialized medical doctors and is more directly correlated with the mechanical outcome [22]. Two electrodes are placed on the skin over the muscle region to be analysed and the difference of potential between them is acquired and amplified [1].…”

Keep on rolling: functional evaluation of power-assisted wheelchair use

“…[79] Mean power of the EMG signal was determined by the root mean square (RMS) of the signal based on previous studies on cyclic movements. [75,80,81] A 10 Hz fourth order, zero phase-shift Butterworth filter was used to smooth the signal. RMS was calculated as the mean RMS of the 10 selected propulsion cycles.…”