Regional neuromuscular regulation within human rectus femoris muscle during gait

Abstract

The spatial distribution pattern of neuromuscular activation within the human rectus femoris (RF) muscle was investigated during gait by multi-channel surface electromyography (surface EMG). Eleven healthy men walked on a treadmill with three gait speeds (4, 5, and 6 km/h) and gradients (0°, 12.5°, and 25°). The spatial distribution of surface EMG was tested by central locus activation (CLA), which is calculated from 2-D multi-channel surface EMG with 46 surface electrodes. For all conditions, CLA was around the middle regions during the swing-to-stance transition and moved in a proximal direction during the stance phase and stance-to-swing transition (p<0.05). CLA during the stance-to-swing transition and early swing phase significantly moved to proximal site with increasing gait speed (p<0.05). During the early stance and swing phases, with increasing grade, CLA significantly moved distally (p<0.05). These results suggest that the RF muscle is regionally activated during a gait cycle and is non-uniformly regulated longitudinally.

Spatial variability of muscle activity during human walking: The effects of different EMG normalization approaches

“…walking (Watanabe et al, 2014). In all three of the examined conditions in the present study, LG activity was spatially distributed, and was greater in the distal and lateral regions during walking and MVCs.…”

“…To date, this method has been used in dynamic conditions including cycling (Schmitz et al, 2012), as well as to study quadriceps function in walking (Watanabe et al, 2014). However, spatial distribution of muscle activity has not been studied in the functionally important triceps surae muscles during walking.…”

Effect of aging on region‐specific functional role and muscle geometry along human rectus femoris muscle

“…Our recent studies tested this possibility and demonstrated that the proximal region is selectively activated for hip flexion joint moment while the distal and/or all regions are activated for knee extension joint moment during isometric contractions at various hip and knee joint angles . This region‐specific functional role along the RF muscle was also found in actual human movements, namely walking and pedaling . On the other hand, we also reported in an earlier study that the elderly exhibit different regional activation along the RF muscle during walking .…”

Non-uniform recruitment along human rectus femoris muscle during transcutaneous electrical nerve stimulation

“…We demonstrated that the proximal regions mainly contribute to hip flexion joint moment, while most parts of the muscle contribute to knee extension joint moments (Watanabe et al 2012). For example, during walking, the proximal regions are selectively activated for swing movement (Watanabe et al 2014b). This regional neuromuscular control (Watanabe et al 2012(Watanabe et al , 2014b) may be important for smooth leg movement of human walking.…”

“…For example, during walking, the proximal regions are selectively activated for swing movement (Watanabe et al 2014b). This regional neuromuscular control (Watanabe et al 2012(Watanabe et al , 2014b) may be important for smooth leg movement of human walking. In functional electrical stimulation for a paralyzed muscle in a patient with spinal cord injury, accurate reproduction of human movements would be necessary.…”