one of the most common diseases associated with musculo-skeletal ailment is low back pain which is epidemic among general public. if manual tasks are performed inappropriately by workers at workplaces, it may cause back pain in the lumbar spine. in recent years, a variety of assistive devices has been presented and used to utilize a passive force generator which has been effective in decreasing...

STUDY DESIGN Biomechanical experiment. OBJECTIVE The aims of the present study were to test the effect of fascial tension on lumbar segmental axial rotation and lateral flexion and the effect of the angle of fascial attachment. SUMMARY OF BACKGROUND DATA Tension in the middle layer of lumbar fascia has been demonstrated to affect mechanical properties of lumbar segmental flexion and extensi...

The load-displacement behavior of 35 fresh adult cervical spine motion segments was measured in compression, shear, flexion, extension, lateral bending and axial torsion tests. Motion segments were tested both intact and with posterior elements removed. Applied forces ranged to 73.6 N in compression and to 39 N in shear, while applied moments ranged to 2.16 Nm. For each mode of loading, princip...

A biomechanical model for studying lumbar muscle load sharing for a class of physical tasks that involve gravitational loading (holding weights) of the upper body in an erect posture is presented. The model assumes that the lumbar muscles balance the externally applied flexion and lateral bending moments. The concept of a 'loading plane' whose axes are the two bending moments is introduced. Any...

BACKGROUND There is a wide range of mechanical properties of spinal ligaments documented in literature. Due to the fact that ligaments contribute in stabilizing the spine by limiting excessive intersegmental motion, those properties are of particular interest for the implementation in musculoskeletal models. The aim of this study was to investigate the effect of varying ligament stiffness on th...

Study design: An in vitro biomechanical flexibility and fatigue test comparing two different lumbar interbody fusion cages using mono segmental lumbar spine specimens. Objective: To investigate and compare the stabilizing effect of a transforaminal lumbar interbody fusion (TLIF) cage against an expandable posterior lumbar interbody fusion (PLIF) cage. Method: Six intact human lumbar spine segme...

OBJECTIVE To determine if five days of practice on a novel dynamic, multi-joint pulling task resulted in lower magnitudes of lumbar loading or a more consistent relationship between pulling force and lumbar loading. DESIGN A repeated measures design compared how practice influenced the magnitude of lumbar torque and the correlations between lumbar torque and pulling force. BACKGROUND Previo...

The aim of this study was to introduce a Newton-Euler inverse dynamics model that included reaction force and moment estimation at the lumbo-sacral (L5-S1) and thoraco-lumbar (T12-L1) joints. Data were collected while participants ran over ground at 3.8 m x s(-1) at three different stride lengths: preferred stride length, 20% greater than preferred, and 20% less than preferred. Inputs to the mo...

AIM To determine whether transforaminal lumbar interbody fusion aggravate adjacent segmental degeneration more adversely than anterior lumbar interbody fusion. MATERIAL AND METHODS A normal finite element model, an anterior lumbar interbody fusion model and a transforaminal lumbar interbody fusion model of L3-5 were developed. 800 N compressive loading plus 10 Nm moments simulating flexion, e...

OBJECTIVE Assess the effect of different controlled lumbar back support tightness levels on trunk muscle activity. DESIGN Two-way repeated measure design assessing lumbar back support tension and submaximal trunk extension moments on trunk muscle electromyographic activity. BACKGROUND Biomechanical studies on lumbar back supports often use electromyography (EMG) to assess the affect on trun...