Spasm and flexion-relaxation phenomenon response to large lifting load during the performance of a trunk flexion-extension exercise.

Background: The flexion relaxation phenomenon (FRP) has been widely investigated. Nevertheless, no study has been reported on the FRP as well as spasm response to large lifting load. The aim of this study was to evaluate the effect of large lifting load on the FRP response and spasm during execution of a flexion-extension exercise.

Muscular Activation Pattern of Bilateral Extensors Response to Asymmetric Hand Lifting During Trunk Flexion-extension Performance.

The authors' purpose was to test the effect of asymmetric hand lifting on muscular activation patterns of 3 bilateral extensors. Eighteen male university students without back pain were volunteered. Each performed flexion-extension randomly with conditions of right lifting, left lifting, and nonlifting.

Effect of posterior cruciate ligament creep on muscular co-activation around knee: a pilot study.

The effect of posterior cruciate ligament (PCL) on muscle co-activation (MCO) is not known though MCO has been extensively studied. The purpose of the study was to investigate the effect of PCL creep on MCO and on joint moment around the knee. Twelve males and twelve females volunteered for this study.

The effects of stance width and foot posture on lumbar muscle flexion-relaxation phenomenon.

Background: Characterizing the lumbar muscle flexion-relaxation phenomenon is a clinically relevant approach in understanding the neuromuscular alternations of low back pain patients. Previous studies have indicated that changes in stance posture could directly influence trunk kinematics and potentially change the lumbar tissue synergy. In this study, the effects of stance width and foot posture on the lumbar muscle relaxation responses during trunk flexion were investigated.

Effect of leg support on muscle cross-correlation of bilateral erector spinae during trunk flexion-extension performance.

Investigations corresponding to the affected factors of the cross-correlation of pair muscles are limited though muscle activation patterns of bilateral erector spinae (ES) during trunk flexion-extension performance in standing have been utilized as an indicator in the evaluation of low back pain condition. The purpose of the study is to evaluate the effect of leg support on the cross-correlation of bilateral ES, and to test if the average of bilateral ES could weaken this effect. Twenty male university students volunteered for this study.

Low back pain development response to sustained trunk axial twisting.

Purpose: To investigate if there is an effect of sustained trunk axial twisting on the development of low back pain.

Methods: Sixteen male pain-free university students volunteered for this study. The trunk axial twisting was created by a torsion moment of 50 Nm for 10-min duration.

Flexion relaxation of erector spinae response to spinal shrinkage.

The purpose of the study was to investigate the effect of spinal shrinkage on the characteristic of flexion relaxation phenomenon in erector spinae muscle. Twelve male university students volunteered for this study. The spinal shrinkage was created with a load of 20% body weight on shoulder in 10 min.