Comparison of electromyographic responses for the superficial quadriceps muscles: Cycle versus knee‐extensor ergometry

Abstract

The purpose of this study was to compare the electromyographic (EMG) amplitude and mean power frequency (MPF) versus power output relationships for the three superficial quadriceps muscles during incremental cycle (CE) and knee-extensor (KE) ergometry in the same subjects. Eight men performed incremental CE and KE tests to exhaustion. Surface EMG signals were recorded simultaneously from the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM). Polynomial regression analyses on a subject-by-subject basis indicated that the relationship between EMG amplitude versus power output was best-fit with either a linear, quadratic, or cubic model for CE, whereas the relationship was best-fit with a linear model for all subjects for the KE test. No consistent relationship was found for EMG MPF within subjects and between muscle groups for CE or KE. Compared with CE, however, the EMG amplitude during KE exercise was, on average, approximately 87% and 30% higher for the RF and VM muscles, respectively. These results suggest that KE exercise may be a better mode of examining EMG amplitude in the quadriceps muscle during incremental exercise than traditional CE.

Comparison of mechanomyographic amplitude and mean power frequency for the rectus femoris muscle: Cycle versus knee-extensor ergometry

“…The single-leg KE exercise paradigm has been described previously (Richardson et al, 1995(Richardson et al, , 1998, but it was modified for two-legged exercise (Koga et al, 2005;Malek et al, 2009) for the present study (Fig. 1).…”

“…For KE, however, the patterns of responses for EMG amplitude versus power output were best-fit with a linear model for the composite data as well as for each subject for all three muscles. In addition, Malek et al (2009) reported that the EMG amplitude was higher (p < 0.05) for both the rectus femoris and vastus medialis muscles during KE incremental exercise when compared to CE. The investigators (Malek et al, 2009), therefore, concluded that KE exercise was a more optimal measure and better representation of quadriceps muscle activity than CE exercise.…”

“…Furthermore, this small mass-specific exercise allows the investigator to study the quadriceps without circulatory limitations such as cardiac output (Andersen et al, 1985;Richardson et al, 1995). Recently, Malek et al (2009) examined the EMG response to incremental exercise for CE and KE in the same subjects. Using polynomial regression analyses on a subject-by-subject basis, the investigators (Malek et al, 2009) reported that the patterns of responses for EMG amplitude versus power output were best-fit with either linear, quadratic, or cubic models for each of the three superficial quadriceps muscles (i.e., rectus femoris, vastus medialis, and vastus lateralis) for CE exercise.…”

“…Recently, Malek et al (2009) examined the EMG response to incremental exercise for CE and KE in the same subjects. Using polynomial regression analyses on a subject-by-subject basis, the investigators (Malek et al, 2009) reported that the patterns of responses for EMG amplitude versus power output were best-fit with either linear, quadratic, or cubic models for each of the three superficial quadriceps muscles (i.e., rectus femoris, vastus medialis, and vastus lateralis) for CE exercise. For KE, however, the patterns of responses for EMG amplitude versus power output were best-fit with a linear model for the composite data as well as for each subject for all three muscles.…”

“…Therefore, the purpose of this study was to examine the MMG amplitude and MPF versus power output relationships for the rectus femoris muscle during CE and KE incremental exercise in the same subject. The rectus femoris muscle was selected because both Malek et al (2009) and Richardson et al (1998) reported higher muscular activity in this superficial quadriceps muscle when compared to the vastus lateralis or vastus medialis. Based on the findings of Malek et al (2009) for the EMG response for CE and KE, we hypothesized that the patterns of responses for MMG amplitude versus power output would vary between subjects for CE, but that they would be linear for KE.…”