Does the relative muscle activation of the vastus medialis, rectus femoris, and vastus lateralis, during the various activities, change in relation to the quadriceps angle?

Abstract

[Purpose] The purpose of this study was to examine the correlation between the quadriceps angle and muscle-activation ratios for the vastus medialis, rectus femoris, and vastus lateralis during various activities. [Subjects and Methods] Seventeen heathy females were recruited. The quadriceps angles were measured with long-arm goniometers. The muscle activity of the vastus medialis, rectus femoris, and vastus lateralis were measured using electromyography under four different activity settings: walking, squatting, step-up, and sit-to-stand. The muscle activation ratios were calculated and their correlations with the quadriceps angles were analyzed. [Results] The activation ratio of the rectus femoris to the vastus medialis (and, although less significant, of the vastus lateralis to the vastus medialis) was positively correlated with the quadriceps angle during the step-up and sit-to-stand. A similar tendency was also seen during squatting. The activation ratio of the vastus lateralis to the rectus femoris was negatively correlated with the quadriceps angle during walking. [Conclusion] The relative muscle activity among the muscles composing the quadriceps was correlated with the quadriceps angle. During activities involving deeper knee flexion like the step-up, sit-to-stand, and squatting, the relative activity of the lateral muscles tended to increase as the quadriceps angle increased. Meanwhile, during walking the activity of the medial muscles seemed to increase with a larger quadriceps angle.

Physiology of sedentary behavior

“…This could suggest that the squats interruptions resulted in the stimulation of translation initiation and myofibrillar protein synthesis. In contrast, walking had no effect on any anabolic signaling protein targets, which may be related to a lower activation of the vastus lateralis during walking compared to squatting (268). It is not clear whether type, intensity, and frequency of interruptions to sitting differentially affect markers of protein metabolism.…”

The Effect of Motorized vs Non-Motorized Treadmills on Exercise Economy during Acute Sub-maximal Bouts in Collegiate Cross-Country Female Athletes

“…When exercising on a NMT or MT, different gait patterns occur even at the same given speed, creating different tasks in movement (S. M. C. Lee et al, 2008), while changes of speed and gait have been shown to effect muscle activation (Cappellini, Ivanenko, Poppele, & Lacquaniti, 2006). Recent studies have found correlations between a greater hip-knee-ankle (HKA) angle and an increase in medial muscle activation (Kim, Bae, Lee, & Lee, 2016;N. Lee, 2018), however in our study there was a significant difference only in the VL during the walking condition.…”