A study on trunk muscle activation patterns according to tilt angle during whole body tilts

Abstract

Abstract. BACKGROUND:Lower back pain has a lifetime prevalence of 80% for people in a modern society, and in recent years, spinal stabilization movement has been highlighted as a method to treat lower back pain and an unbalanced position. OBJECTIVE: The objectives of this study were to assess the trunk muscle activities in accordance with the tilt angles (10• , 20• , 30• , 40• ) during trunk tilt exercises with a 3D dynamic exercise device. METHODS: Active tilt mode (a self-generated active movement in the angle and direction steered by the user) was used in this study. The rotation capability enabled the investigation of the anterior (A), anterior right (AR), right (R), posterior right (PR), posterior (P), posterior left (PL), left (L), and anterior left (AL) tilt directions. EMG signals of the trunk (3 global muscles: rectus abdominis, RA, external obliques, EO, latissimus dorsi, LD, and 1 local muscle: multifidus, MF) muscles were obtained. RESULTS: The MF muscle activity was higher while the anterior tilt was maintained, and the abdominal muscle activity was higher while the posterior tilt was maintained. Also, as the tilt angle increased, the activity of the muscles opposite the tilt direction increased. CONCLUSIONS:The results indicate that to maintain equilibrium through posture stabilization during whole body tilting, the human body maintains a proper interaction among the body segments as well as between the body and the execution environment. Moreover, stability is maintained through the co-contraction of antagonistic and agonistic muscles. In future studies, it will be important to conduct research on improving imbalance in the trunk muscles.

Changes in morphology of the lateral abdominal wall muscles during sagittal tilting in young healthy subjects

“…in the literature, congruent studies analysing the morphology of the lateral abdominal wall muscles in similar groups during low-degree body tilts in the sagittal plane were not found. it has been confirmed so far that changing the body position and its relation to the gravitational force induces muscular response [34][35][36][37], which is enabled by the information flow between effectors and numerous receptor organs, such as the vestibular system, eyes and also receptors within the soles [38][39][40]. The available reports mainly concern changes in the muscles during body movements and tilts at large degrees.…”

“…They also support many vital functions and safety reflexes [33]. So far, their ability to automatically activate has been demonstrated, especially in perturbation conditions, and when the support plane is being reduced to maintain equilibrium through body posture and increased stability is required [30,34]. The contraction of the transverse muscle accompanying movements of limbs precedes the movement, which makes it possible to create a firm base within the body centre for the mobility of peripheral elements [1].…”

“…The analysis is often limited to the measurement of the electrical potential of the superficial muscles [35,37]. Shin et al [34] reported that a backward inclination in the range of 10-40 degrees increases the activation of the rectus abdominis muscle and oblique muscles. Forbes et al [38] reported that balance disturbances and head roll initiates a balance response of the vestibular system and stabilising reflexes.…”

Analysis of body imbalance in various writing sitting postures using sitting pressure measurement

“…Therefore, all 3 imbalanced postures can cause spinal imbalances. An increased tilt angle can also activate the muscles opposite the tilt direction 13 ) , so that imbalanced postures can cause pathological symptoms such as pelvic asymmetry. Pelvic asymmetry and idiopathic scoliosis can lead to postural asymmetry, unequal weight distribution, and muscular imbalance 14 ) , or even cause more serious physical imbalances.…”