Characteristics of Standing Up Motion with the Thoracolumbar Spine Flexed Investigated in Healthy Adults

Abstract

[Purpose] The purpose of this study was to clarify the muscle activities and joint angles of standing up motion with thoracolumbar spine flexed, reproducing the humpback posture of the elderly.[Subjects] The subjects were ten healthy adult males.[Methods] Electromyography (EMG) and joint angles of the lower leg, captured by a video camera, were studied during standing up motion from the sitting position under the conditions of: normal posture, thoracolumbar flexion of 20˚, and thoracolumbar flexion of 40˚. We calculated the average amplitude of the relative EMG value and noted the order of EMG activities in the lower leg, as well as the forward tilt angle of the trunk and lower leg. [Results] Compared to normal posture, the average amplitude of the relative EMG value of the tibialis anterior muscle (TA), and the forward tilt angle of both the trunk and lower leg during standing with thoracolumbar flexion of 40˚ were significantly increased. In addition, TA activity started significantly earlier than in the other muscles.[Conclusion] The results suggest thoracolumbar flexion influences the muscle activity of TA and the forward tilt angle of the lower leg.

Evaluation of standing‐sitting support system with passive rotational seat mechanism in standing motion

“…As can be seen from Table , in case of round back posture, Δ θ T tends to increase, while tends to decrease as compared to health persons, regardless of the use of the system; this agrees with previous research results . One can assume that with Senior Pose, hip joint extension is restricted, and the effect of trunk extension‐flexion is inhibited; thus, T R due to static body centroid motion is utilized.…”

Evaluation of Standing-Sitting Support System with Passive Rotational Seat Mechanism in Standing Motion

“…As can be seen from Table 2, in case of round back posture, Δ T tends to increase, whilėtends to decrease as compared to health persons, regardless of the use of the system; this agrees with previous research results. [20][21][22] One can assume that with Senior Pose, hip joint extension is restricted, and the effect of trunk extension-flexion is inhibited; thus, T R due to static body centroid motion is utilized. Now consider the two subjects that did not show significant difference.…”