Steffen T. Rubin RK. Baramki HG. Antoniou J. Marchesi D. Aebi M. A new technique for measuring lumbar segmental motion in vivo. Method, accuracy, and preliminary results. Spine. 22(2):156-66, 1997 Jan 15 Cholewicki J. Crisco JJ 3rd. Oxland TR. Yamamoto I. Panjabi MM. Effects of posture and structure on three-dimensional coupled rotations in | the lumbar spine. A biomechanical analysis. Spine. 21(21):2421-8, 1996 Nov 1. Kaigle AM. Holm SH. Hansson TH. Experimental instability in the lumbar spine. Spine. 20(4):421-30, 1995 Feb 15. Nowinski GP. Visarius H. Nolte LP. Herkowitz HN. A biomechanical comparison of cervical laminaplasty and cervical laminectomy with progressive facetectomy. Spine. 18(14):1995-2004, 1993 Oct 15. Roozmon P. Gracovetsky SA. Gouw GJ. Newman N. Examining motion in the cervical spine. II: Characterization of coupled joint motion using an opto-electronic device to track skin markers. Journal of Biomedical Engineering. 15(1):13-22, 1993 Jan. Haas M. Nyiendo J. Peterson C. Thiel H. Sellers T. Dal Mas E. Kirton | C. Cassidy D. Lumbar motion trends and correlation with low back pain. Part I. A roentgenological evaluation of coupled lumbar motion in lateral bending Journal of Manipulative & Physiological Therapeutics. 15(3):145-58, 1992 + Mar-Apr. Oxland TR. Crisco JJ 3d. Panjabi MM. Yamamoto I. The effect of injury on rotational coupling at the lumbosacral joint. A biomechanical investigation. Spine. 17(1):74-80, 1992 Jan. Panjabi M. Yamamoto I. Oxland T. Crisco J. How does posture affect coupling in the lumbar spine?. Spine. 14(9):1002-11, 1989 Sep. Panjabi MM. Brand RA Jr. White AA 3d. Mechanical properties of the human thoracic spine as shown by three-dimensional load-displacement curves. Journal of Bone & Joint Surgery - American Volume. 58(5):642-52, 1976 Ferguson SA. Marras WS. Crowell RR. Dynamic low back functional motion capacity evaluation. Journal of Occupational Rehabilitation. 6(4):203-14, 1996 Dec. (31 ref) Brown L. Treatment and examination of the spine by combined movements... part 2. Physiotherapy. 76(2):66-74, 1990 Feb. (25 ref) Oxland TR. Crisco JJ 3d. Panjabi MM. Yamamoto I. The effect of injury on rotational coupling at the lumbosacral joint. A biomechanical investigation. Spine.17(1):74-80, 1992 Jan. Department of Orthopaedics and Rehabilitation, Yale University School ofMedicine, New Haven, Connecticut. The lumbosacral joint is frequently indicated as a source of low-back pain, a cause of which may be abnormal patterns of vertebral motions. The goal of this study was to describe the influence of injury on the coupled motions of the L5-S1 joint in a human cadaveric model. Nine whole lumbosacral spine specimens were studied under the application of flexion, extension, left/right axial torque and right/left lateral bending pure moments. Injuries to the posterior ligaments, intervertebral disc, and articular facets at L5-S1 were produced, and the motion at L5-S1 was determined after each sequential injury. No significant coupled rotations were observed under flexion or extension moments. Under axial torque, lateral rotation at L5-S1 occurred to the same side as the applied torque and increased significantly only after injury to the intervertebral disc. Also coupled to axial torque was flexion rotation in the intact specimen,which became extension rotation after facetectomy. Under lateral bending moments, coupled axial rotation was to the opposite side of the applied moment and increased significantly only after removal of the facets of L5. Based on these results, it was concluded that intervertebral disc most resisted the coupled motion of lateral rotation under the application of axial torque, whereas the articular facets most resisted the coupled axial rotation under the application of lateral bending at the lumbosacraljoint. Also, the facets were the structures that produced the flexion rotation of L5 on S1 under axial torque loading. Haher TR. O'Brien M. Felmly WT. Welin D. Perrier G. Choueka J. Devlin V. Vassiliou A. Chow G. Instantaneous axis of rotation as a function of the three columns of the spine. Spine 17(6 Suppl):S149-54, 1992 Jun. Department of Orthopaedics and Rehabilitation Medicine, SUNY-HSC,Brooklyn. A knowledge of the rotatory motion of the vertebral bodies is needed to understand the normal biomechanical behavior of the spine. The aims of this investigation were 1) to define the instantaneous axis of rotation of the lumbar spine in rotation; and 2) to study the effect of the loss of the anulus, facet joints, and ligamentous structures on the location of the instantaneous axis of rotation. The instantaneous axis of rotation was found in 10 human cadaver thoracolumbar spines by the method of Reuleaux from superimposed serial photographs. Long-segment specimens were tested to minimize the effect of the imposed axis of the testing device. The instantaneous axis of rotation was consistently posterior to the anulus in the intact spine. With isolated destruction of the columns of the spine,the instantaneous axis of rotation migrated to the remaining intact structures. Anterior releases enhance derotation by removing the primary rotatory stabilizer. Ultimate control of a rotatory deformity or instability lies in the recognition that the anterior structures have a mechanical advantage in resisting torsion. Smith TJ. Fernie GR. Functional biomechanics of the spine. Spine. 16(10):1197-203, 1991 Oct. Orthopaedic Biomechanics Laboratory, F.P. Dewar Spinal Unit, Max BellResearch Centre, Toronto General Hospital, Ontario, Canada. The exact nature of the mechanisms at work during movement of the human spine are not well understood, nor well defined. The spine supports the torso against loads and allows freedom of motion, within physiologic limits, at the same time. A great deal of information characterizing various attributes of the spine is available. Research has provided values for flexural stiffness, axial compliance, range of motion under various loading modalities, and considerably more. This study will focus not on isolated topics, but rather serve as a broad introduction to the behavior of the spine as a whole. Yamamoto I. Panjabi MM. Oxland TR. Crisco JJ. The role of the iliolumbar ligament in the lumbosacral junction. Spine. 15(11):1138-41, 1990 Nov. Department of Orthopaedic Surgery, Hokkaido University, School of Medicine, Sapporo, Japan. The biomechanical function of the iliolumbar ligament in the human lumbosacral junction was investigated by analyzing the three-dimensional movements of the whole lumbar and lumbo-sacral-ilium specimens. The experiment was repeated in the following three conditions: 1) intact iliolumbar ligament, 2) right iliolumbar ligament transected, and 3) bilateral iliolumbar ligaments transected. The representative values of the increased motions, compared with intact, after transection of the bilateral iliolumbar ligaments were 1.7 degrees (23%) in flexion, 1.1 degrees (20%) in extension, 0.3 degrees (18%) in axial rotation, and 1.2 degrees (29%) in lateral bending. The most restricted motion governed by the iliolumbar ligament in the lumbosacral junction was lateral bending. The bilateral iliolumbar ligament specimen could restrict flexion and extension of the lumbosacral junction, but the unilateral iliolumbar ligament preparation alone could not restrict these motions. The iliolumbar ligament also had the function of restricting the rotational movement of the lumbosacral junction. Panjabi M. Yamamoto I. Oxland T. Crisco J. How does posture affect coupling in the lumbar spine?. Spine 14(9):1002-11, 1989 Sep. Department of Orthopaedics and Rehabilitation, Yale University, School of Medicine, New Haven, Connecticut. There is evidence to suggest that abnormal coupling patterns in the lumbar spine may be an indicator of low-back problems. To quantify the normal coupling patterns, fresh cadaveric human lumbar spine specimens (L1-S1) were used. A pure axial torque or lateral bending moment of 10 N-m (in five equal steps) was applied to the specimen, in five spinal postures, and three-dimensional motions were measured at the five vertebral levels. The results indicated that the coupling patterns changed significantly with the intervertebral level. For example, in neutral posture, the left axial torque produced coupled lateral bending, which varied from approximately 2 degrees right lateral bending at L1-2, to approximately 0 degrees at L3-4, and to approximately 2.5 degrees left lateral bending at L5-S1. Additionally, there was coupled flexion of approximately 1 degrees to 2 degrees at all levels. Application of left lateral bending moment resulted in approximately 1.7 degrees of coupled right axial rotation at all levels, except at L1-L2, where it was 0 degrees. Additionally, there was coupled flexion of 0.7 degrees to 2 degrees at all levels. For example, at the L2-3 level, the left axial torque produced coupled right lateral bending that ranged from approximately 0.5 degrees at full extension to approximately 2.5 degrees at full flexion. There was also accompanying coupled flexion of approximately 0.4 degrees to 1.7 degrees. Application of left lateral bending moment at the L2-3 level produced axial rotation of approximately 2.5 degrees, which did not vary with the posture, while the other coupled motion varied from approximately 1.7 degrees flexion at full extension posture to approximately 0.8 degrees extension at full flexion posture. Panjabi M. Abumi K. Duranceau J. Oxland T. Spinal stability and intersegmental muscle forces. A biomechanical model. Spine 14(2):194-200, 1989 Feb. Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut. The human spinal column, devoid of musculature, is incapable of carrying normal physiologic loads. In an in vitro experiment, the effect of simulated intersegmental muscle forces on spinal instability was investigated. Intact and sequentially injured fresh lumbar functional spinal units were subjected to three-dimensional biomechanical tests with increasing muscle forces. With the application of muscle forces, range of motion (ROM) increased and neutral zone (NZ) decreased in flexion loading, while both ROM and NZ decreased in extension loading. In lateral bending, ROM and NZ were unaffected by the application of the muscle forces. In axial rotation, ROM decreased significantly, while NZ decrease was statistically insignificant. It was concluded that the action of the intersegmental muscle forces is to maintain or decrease intervertebral motions after injury, with the exception of the flexion ROM, which increased with the application of muscle forces. In addition, the study suggested that Neutral Zone is a better indicator of spinal instability than Range of Motion. MacKinnon CD, Winter DA. Control of whole body balance in the frontal plane during human walking. Journal of Biomechanics. 1993; 26(6):633-44. A whole-body inverted pendulum model was used to investigate the control of balance and posture in the frontal plane during human walking. The model assessed the effects of net joint moments, joint accelerations and gravitational forces acting about the supporting foot and hip. Three video cameras and two force platforms were used to collect kinematic and kinetic data from repeat trials on four subjects during natural walking. An inverse solution was used to calculate net joint moments and powers. Whole body balance was ensured by the centre of mass (CM) passing medial to the supporting foot, thus creating a continual state of dynamic imbalance towards the centerline of the plane of progression. The medial acceleration of the CM was primarily generated by a gravitational moment about the supporting foot, whose magnitude was established at initial contact by the lateral placement of the new supporting foot relative to the horizontal location of the CM. Balance of the trunk and swing leg about the supporting hip was maintained by an active hip abduction moment, which recognized the contribution of the passive accelerational moment, and countered a large destabilizing gravitational moment. Posture of the upper trunk was regulated by the spinal lateral flexors. Interactions between the supporting foot and hip musculature to permit variability in strategies used to maintain balance were identified. Possible control strategies and muscle activation synergies are discussed. (Faculty of Medicine, Department of Rehabilitation Medicine, University of Toronto, Ontario, Canada.) Unique Identifier 91173803 Nudelman W. Reis ND. Anatomy of the extrinsic spinal muscles related to the deformities of scoliosis. Acta Anatomica. [JC:09a] 139(3):220-5, 1990. The spatial displacement of vertebrae in idiopathic scoliosis is not explicable by forces created by the muscles which act upon the spine only (intrinsic muscles). The trapezius and latissimus muscles are attached to the spinous processes and the upper limb. In keeping with Newton's third law, these muscles act on the spine as well as upon the upper extremity. The peculiarity of the vertebral anatomy, together with the direction of pull of these muscles, permits an explanation of the biomechanics of the development of 'idiopathic' scoliosis. Unique Identifier 90105015 Kalimo H. Rantanen J. Viljanen T. Einola S. Lumbar muscles: structure and function. Annals of Medicine. [JC:amd] 21(5):353-9, 1989 Oct. We review new data derived from careful dissection studies on the macroscopic anatomy, innervation and function of the lumbar muscles, as well as information on the fibres in these muscles. The new findings correct previous misconceptions of the functional anatomy of the lumbar muscles. The innervation and function of the erector spinae and multifidus muscles are so different that they cannot be classified as a single unit. The new interpretation of the innervation of multifidus muscle is of importance, for example, for the neurophysiological examination of the lumbar muscles. The relative number of the slow and fast type of muscle fibres in lumbar muscles varies considerably, and selective atrophy of the fast fibres seems to ensue from inactivity, not only in patients with back pain but also in sedentary controls. The atrophy may be corrected by adequate exercise. Both the fibre type composition and degree of atrophy may well influence a person's susceptibility to low back pain arising from the muscles. Unique Identifier 88271496 Ashton-Miller JA. Schultz AB. Biomechanics of the human spine and trunk. Exercise & Sport Sciences Reviews. [JC:enz] 16:169-204, 1988. This chapter has reviewed the past 30 years of experimental biomechanical studies of the spine and trunk. In the last 10 years, computers have allowed the development of simulation techniques and models to predict spine and muscle loading in most static and quasi-static activities. Some problems remain, however, particularly with activities involving bending and twisting and those that entail maximal efforts. Current research is focused on trying to validate models for the analysis of dynamic activities involving simple planar motions. Although the body segment kinematics and external support forces in complex motions can be measured fairly easily with modern motion analysis equipment, models that correctly predict the internal trunk forces have yet to be fully developed and validated. These models will be useful in studying how, why, and where failure of the soft and bony tissues is most likely to occur in a given activity, and whether it is related to work or athletics. The challenge for the future is to develop models that adequately reflect the anatomical sophistication of the spine and trunk. Thus the stress and strain distributions in any trunk musculoskeletal component, whether the posterior wall of the annulus, a muscle slip of the semi-spinalis group, or the lumbosacral endplate, will be able to be found. These results can then be combined with models of cumulative trauma response to successfully identify potential failure sites. Oxland TR. Crisco JJ 3d. Panjabi MM. Yamamoto I. The effect of injury on rotational coupling at the lumbosacral joint. A biomechanical investigation. Spine.17(1):74-80, 1992 Jan. Department of Orthopaedics and Rehabilitation, Yale University School ofMedicine, New Haven, Connecticut. The lumbosacral joint is frequently indicated as a source of low-back pain, a cause of which may be abnormal patterns of vertebral motions. The goal of this study was to describe the influence of injury on the coupled motions of the L5-S1 joint in a human cadaveric model. Nine whole lumbosacral spine specimens were studied under the application of flexion, extension, left/right axial torque and right/left lateral bending pure moments. Injuries to the posterior ligaments, intervertebral disc, and articular facets at L5-S1 were produced, and the motion at L5-S1 was determined after each sequential injury. No significant coupled rotations were observed under flexion or extension moments. Under axial torque, lateral rotation at L5-S1 occurred to the same side as the applied torque and increased significantly only after injury to the intervertebral disc. Also coupled to axial torque was flexion rotation in the intact specimen,which became extension rotation after facetectomy. Under lateral bending moments, coupled axial rotation was to the opposite side of the applied moment and increased significantly only after removal of the facets of L5. Based on these results, it was concluded that intervertebral disc most resisted the coupled motion of lateral rotation under the application of axial torque, whereas the articular facets most resisted the coupled axial rotation under the application of lateral bending at the lumbosacraljoint. Also, the facets were the structures that produced the flexion rotation of L5 on S1 under axial torque loading. Panjabi M. Yamamoto I. Oxland T. Crisco J. How does posture affect coupling in the lumbar spine?. Spine 14(9):1002-11, 1989 Sep. Department of Orthopaedics and Rehabilitation, Yale University, School of Medicine, New Haven, Connecticut. There is evidence to suggest that abnormal coupling patterns in the lumbar spine may be an indicator of low-back problems. To quantify the normal coupling patterns, fresh cadaveric human lumbar spine specimens (L1-S1) were used. A pure axial torque or lateral bending moment of 10 N-m (in five equal steps) was applied to the specimen, in five spinal postures, and three-dimensional motions were measured at the five vertebral levels. The results indicated that the coupling patterns changed significantly with the intervertebral level. For example, in neutral posture, the left axial torque produced coupled lateral bending, which varied from approximately 2 degrees right lateral bending at L1-2, to approximately 0 degrees at L3-4, and to approximately 2.5 degrees left lateral bending at L5-S1. Additionally, there was coupled flexion of approximately 1 degrees to 2 degrees at all levels. Application of left lateral bending moment resulted in approximately 1.7 degrees of coupled right axial rotation at all levels, except at L1-L2, where it was 0 degrees. Additionally, there was coupled flexion of 0.7 degrees to 2 degrees at all levels. For example, at the L2-3 level, the left axial torque produced coupled right lateral bending that ranged from approximately 0.5 degrees at full extension to approximately 2.5 degrees at full flexion. There was also accompanying coupled flexion of approximately 0.4 degrees to 1.7 degrees. Application of left lateral bending moment at the L2-3 level produced axial rotation of approximately 2.5 degrees, which did not vary with the posture, while the other coupled motion varied from approximately 1.7 degrees flexion at full extension posture to approximately 0.8 degrees extension at full flexion posture. Yamamoto I. Panjabi MM. Oxland TR. Crisco JJ. The role of the iliolumbar ligament in the lumbosacral junction. Spine. 15(11):1138-41, 1990 Nov. Department of Orthopaedic Surgery, Hokkaido University, School of Medicine, Sapporo, Japan. The biomechanical function of the iliolumbar ligament in the human lumbosacral junction was investigated by analyzing the three-dimensional movements of the whole lumbar and lumbo-sacral-ilium specimens. The experiment was repeated in the following three conditions: 1) intact iliolumbar ligament, 2) right iliolumbar ligament transected, and 3) bilateral iliolumbar ligaments transected. The representative values of the increased motions, compared with intact, after transection of the bilateral iliolumbar ligaments were 1.7 degrees (23%) in flexion, 1.1 degrees (20%) in extension, 0.3 degrees (18%) in axial rotation, and 1.2 degrees (29%) in lateral bending. The most restricted motion governed by the iliolumbar ligament in the lumbosacral junction was lateral bending. The bilateral iliolumbar ligament specimen could restrict flexion and extension of the lumbosacral junction, but the unilateral iliolumbar ligament preparation alone could not restrict these motions. The iliolumbar ligament also had the function of restricting the rotational movement of the lumbosacral junction. Panjabi M. Abumi K. Duranceau J. Oxland T. Spinal stability and intersegmental muscle forces. A biomechanical model. Spine 14(2):194-200, 1989 Feb. Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut. The human spinal column, devoid of musculature, is incapable of carrying normal physiologic loads. In an in vitro experiment, the effect of simulated intersegmental muscle forces on spinal instability was investigated. Intact and sequentially injured fresh lumbar functional spinal units were subjected to three-dimensional biomechanical tests with increasing muscle forces. With the application of muscle forces, range of motion (ROM) increased and neutral zone (NZ) decreased in flexion loading, while both ROM and NZ decreased in extension loading. In lateral bending, ROM and NZ were unaffected by the application of the muscle forces. In axial rotation, ROM decreased significantly, while NZ decrease was statistically insignificant. It was concluded that the action of the intersegmental muscle forces is to maintain or decrease intervertebral motions after injury, with the exception of the flexion ROM, which increased with the application of muscle forces. In addition, the study suggested that Neutral Zone is a better indicator of spinal instability than Range of Motion. MacKinnon CD, Winter DA. Control of whole body balance in the frontal plane during human walking. Journal of Biomechanics. 1993; 26(6):633-44. A whole-body inverted pendulum model was used to investigate the control of balance and posture in the frontal plane during human walking. The model assessed the effects of net joint moments, joint accelerations and gravitational forces acting about the supporting foot and hip. Three video cameras and two force platforms were used to collect kinematic and kinetic data from repeat trials on four subjects during natural walking. An inverse solution was used to calculate net joint moments and powers. Whole body balance was ensured by the centre of mass (CM) passing medial to the supporting foot, thus creating a continual state of dynamic imbalance towards the centerline of the plane of progression. The medial acceleration of the CM was primarily generated by a gravitational moment about the supporting foot, whose magnitude was established at initial contact by the lateral placement of the new supporting foot relative to the horizontal location of the CM. Balance of the trunk and swing leg about the supporting hip was maintained by an active hip abduction moment, which recognized the contribution of the passive accelerational moment, and countered a large destabilizing gravitational moment. Posture of the upper trunk was regulated by the spinal lateral flexors. Interactions between the supporting foot and hip musculature to permit variability in strategies used to maintain balance were identified. Possible control strategies and muscle activation synergies are discussed. (Faculty of Medicine, Department of Rehabilitation Medicine, University of Toronto, Ontario, Canada.) Haher TR. O'Brien M. Felmly WT. Welin D. Perrier G. Choueka J. Devlin V. Vassiliou A. Chow G. Instantaneous axis of rotation as a function of the three columns of the spine. Spine 17(6 Suppl):S149-54, 1992 Jun. Department of Orthopaedics and Rehabilitation Medicine, SUNY-HSC,Brooklyn. A knowledge of the rotatory motion of the vertebral bodies is needed to understand the normal biomechanical behavior of the spine. The aims of this investigation were 1) to define the instantaneous axis of rotation of the lumbar spine in rotation; and 2) to study the effect of the loss of the anulus, facet joints, and ligamentous structures on the location of the instantaneous axis of rotation. The instantaneous axis of rotation was found in 10 human cadaver thoracolumbar spines by the method of Reuleaux from superimposed serial photographs. Long-segment specimens were tested to minimize the effect of the imposed axis of the testing device. The instantaneous axis of rotation was consistently posterior to the anulus in the intact spine. With isolated destruction of the columns of the spine,the instantaneous axis of rotation migrated to the remaining intact structures. Anterior releases enhance derotation by removing the primary rotatory stabilizer. Ultimate control of a rotatory deformity or instability lies in the recognition that the anterior structures have a mechanical advantage in resisting torsion. <1> Unique Identifier 92011804 Stokes IA. Gardner-Morse M. Analysis of the interaction between vertebral lateral deviation and axial rotation in scoliosis. Journal of Biomechanics. [JC:hjf] 24(8):753-9, 1991. <2> Unique Identifier 93016170 Lavaste F. Skalli W. Robin S. Roy-Camille R. Mazel C. Three-dimensional geometrical and mechanical modelling of the lumbar spine. Journal of Biomechanics. [JC:hjf] 25(10):1153-64, 1992 Oct. <3> Unique Identifier 93147086 Drerup B. Hierholzer E. Evaluation of frontal radiographs of scoliotic spines--Part II. Relations between lateral deviation, lateral tilt and axial rotation of vertebrae. Journal of Biomechanics. [JC:hjf] 25(12):1443-50, 1992 Dec. <4> Unique Identifier 89341998 Stokes IA. Axial rotation component of thoracic scoliosis. Journal of Orthopaedic Research. [JC:jiq] 7(5):702-8, 1989. <5> Unique Identifier 92309140 Oxland TR. Lin RM. Panjabi MM. Three-dimensional mechanical properties of the thoracolumbar junction. Journal of Orthopaedic Research. [JC:jiq] 10(4):573-80, 1992 Jul. <6> Unique Identifier 90100764 Mimura M. Moriya H. Watanabe T. Takahashi K. Yamagata M. Tamaki T. Three-dimensional motion analysis of the cervical spine with special reference to the axial rotation. Spine. [JC:uxk] 14(11):1135-9, 1989 Nov. <6> Smith TJ. Fernie GR. Functional biomechanics of the spine. Spine. 16(10):1197-203, 1991 Oct.