| Term | Definition |
|---|
| Range of Motion | Displacement from one extreme to the other extreme for the physiologic range of translation or rotation of a joint for each of its six degrees of motion |
| Plastic Range | If a specimen is loaded beyond its elastic range, it enters the plastic range |
| Newton | The unit of force in the Systeme International d"unites. One newton is the amount of force required to give a 1kg mass an acceleration of 1 meter/second |
| Motion Segment | The functional unit of the spine representing inherent biomechanical characteristics of the lgamentous spine at one spinal level |
| Motion | The relative displacement with time of a body in space, with respect to other bodies or some reference system |
| Moment | A pair of equal and opposite parallel forces, separated by a distance, applied to an object |
| Modulus of Elasticity | The ratio of normal stress to normal strain in a material. Measuring the stiffness of a material |
| Load | A general term describing the application of a force and/or moment to a structure |
| Motion Segment | The intervertebral disc and facet joints connecting any two adjacent vertebrae |
| Allowable Stress | A stress value that is higher than that due to normal loads, but is lower than the yield stress of the material |
| Kinematics | A division of mechanics that deals with the geomety of the motion of bodies without taking into account the forces that produce the motion |
| Kinetics | A branch of mechanics that studies the relations b/w the force system acting on a body and the changes it produces in the body motion |
| Ultimate Load | The largest load a structure can stand without failure |
| Torsion | A type of load that is applied by a couple of forces about the long axis of a structure |
| Shear | A force parallel to the surface on which it reacts |
| Tension | A normal force that tends to elongate the fibers of a material |
| Stress | The force per unit area of a structure and a measurement of the intensity of the force |
| Rotation | Motion of a rigid body in which a certain straight line of the body or its rigid extension remains motionless |
| Strain | The change in unit length or angle in a material subjected to a load |
| Relaxation | The decrease in stress in a deformed structure with time when the deformation is held constant |
| Stiffness | A measure of resistance offered to external loads by a specimen or structure as it deforms |
| Translation | Motion of a rigid body in which a straight line in the body always remains parallel to itself |
| Force | Any action that tends to change the state of rest or motion of a body to which it is applied |
| Elastic Range | A range of loading within which a specimen or a structure remains elastic |
| Elasticity | Property of a material or a structure to return to its orgiinal form following the removal of the deforming load |
| Dynamic Load | A load applied to a specimen is called dynamic if it varies with time |
| Deformation | The change in length or shape |
| Creep | The gradual, permanent deformation of a body produced by continued application of a load. |
| Coupling | A phenomenon of consistent association fo one motion about an axis with another motion about a 2nd axis |
| Compression | The force that tends to push together material fibers |
| Clinical Stability | the ability of the spine under physiologic load to limit patterns of displacement so as not to damage or irritate the spinal cord or nerve roots, and, in addition, to prevent incapacitating deformity or pain due to structural changes |
| Center of Gravity | The point in a body at which the mass is centered |
| Buckling | A structure is said to buckle under axial load if ther eis a sudden "give" or lateral deformation of the structure. A structure that buckles will typicall have multiple bends in it. |
| Bending | when a load is applied to a long structure tht is not directly supported at the point of application of the load, the structure deforms, and this deformation is called bending. The material on the convex side of the structure will elongate by tension forces, while the concave side will shorten due to compression. |
| Axial Force | A force that pushes material fibers together |
| Luxation | Dislocation of displacement of the articulating sufraces of a joint resulting in loss of anatomic relationship |
| Lordosis | A spinal curvature of the sagittal plane with posterior concavity |
| Kyphosis | A spinal curvature in the sagittal plane with anterior concavity |
Combine with other sets
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