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Flashcards in Final Deck (249)
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What is a plane?

• A flat surface determined by the position of three points in space: sagittal; frontal (coronal); transverse (axial)


What is plane motion?

• Motion in which all points of a rigid body move parallel to a fixed plane (2-D)


What motion occurs in the sagittal, frontal, and transverse planes?

• Sagittal: flexion, extensions
• Frontal: right lateral flexion, left lateral flexion
• Transverse: rotation


What is out of plane motion?

• All points of a rigid body do not move in a single plane (3-D)


What is an axis?

• A line; rotation or translation occur around /along it


What is the x-axis?

• Line passes horizontally from side to side; frontal or coronal axis; mov’t around it is in sagittal plane


What is the y-axis?

• Longitudinal or vertical axis; perpendicular to ground; axis of the transverse plane


What is the z-axis?

• Sagittal axis; lie from back to front; axis of the frontal plane


What are degrees of freedom?

• Number of ways a body can move; one degree is translation or rotation about one axis; spinal segments have 6 degrees (3 translations and 3 rotations)


What is the instantaneous axis of rotation (IAR)?

• An axis perpendicular to the plane of motion that passes through a point that is instantaneously not moving; used to describe any vertebral motion in a 2-D plane; can shift with different force vectors applied to a vertebra; differs under changing loads, and is different for cervical, thoracic, and lumbar spinal segments


What is a motion segment?

• The functional unit of the spine; smallest spinal segment with biomechanical characteristics similar to those of entire spine; 2 adjacent vertebrae and their interconnecting disc, joints, capsule, and ligaments; 6 degrees of freedom


What is coupled motion?

• Consistent association of one motion (translation or rotation) about one axis with another motion about a second axis; one motion cannot be produced without the other; two motions occurring at the same time along two different axes


What is an example of coupled motion?

• Bending neck to left or right, to the left involves right coupled axial rotation of the upper cervical spine, and left coupled AR of the subaxial cervical spine; and vice versa


What is loose-packed joint position?

• Joint capsule and ligaments are most relaxed; maximum joint play is possible; articulating surfaces are maximally separated; position used for traction or joint mobilization; Ex: when facet joints are half-way between flexion and extension


What is closed-packed joint position?

Capsule and ligaments are maximally tightened; there is no joint play; there is maximal contact b/w the articular surfaces; Ex: when facet joints are in full flexion or extension


• What is the breakdown of the vertebrae, including numbers in regions and curvature?

o 33 vertebrae- 7 cervical, 12 thoracic, 5 lumbar, sacrum (5 fused), coccyx (4 fused)
o Kyphosis in thoracic and sacral; lordosis in cervical and lumbar


• What are the regional spinal coupling patterns seen in left lateral flexion?

LLF outweighs RLF, which is seen to some degree in C2-T1(slight) and T1-L1 (moderate)


• What is the flexion-extension regional range of motion of vertebrae?

o Cervical: great, peaks at C4
o Thoracic: low
o Lumbar: greater, peaking at S1


• What is the lateral bending regional range of motion of vertebrae?

o Cervical: high, peaks at C3-C4
o Thoracic: lower/moderate, no peaks
o Lumbar: moderate, peaks at T12, L4


• What is the axial rotation regional range of motion of vertebrae?

o Cervical: great peak at C1
o Thoracic: higher than most C, and L, peak at T1
o Lumbar: very little


• What is the breakdown of flexion and extension regional range of motion of vertebrae?

o Flexion: lumbar most, then cervical, then thoracic (all roughly similar)
o Extension: cervical most, then lumbar, then thoracic (T and L ~same)
-~ 135d total both flex and ext


• What is the breakdown of lateral flexion regional range of motion of vertebrae?

o Equal to right and left; cervical -> lumbar -> thoracic (roughly equal); <90d total to one side


• What is the breakdown of regional axial rotation range of motion of vertebrae?

o Equal to right and left; cervical -> thoracic -> lumbar; ~170 total to one side


• What is the articular anatomy of the occiput (CO)?

o Has 2 condyles, face laterally and inferiorly, form convex rockers, sit in concave surface of superior articular facet of C1


• What is the articular anatomy of the Atlas (C1)?

o Has 2 superior articular facts, concave surface, face medially and superiorly, complement condyles, allow occipital condyles to rock


• Describe the articulation of CO-C1 flexion and extension:

o Occiput glides posteriorly (flexion) and rolls anteriorly (extension); greatest ROM in CO-C1; excursion is 10 d flexion and 25 d extension


• Describe the articulation of CO-C1 lateral flexion:

o Occiput rolls on side of lateral flexion and glides on opposite side; ROM 5 d each side (minimal)


• Describe the articulation of CO-C1 rotation:

o Occiput glides posteriorly on side of rotation and anteriorly on side opposite rotation; limited by alar lig (taut on side opp rot); ROM 5d each side (minimal)


• What is the articular anatomy of the C1-C2 (atlas-axis) jt?

o Two facet jts plus the atlas-odontoid jt; planes of facet jts of C1-C2 are mostly horizontal; inferior facets of C1 are slightly convex and face inferior and medially, superior facets of C2 are slightly convex (yes, both are convex) and superior and laterally


• Describe the atlas-odontoid jt:

o Synovial jt b/w odontoid and anterior arch of atlas; transverse lig courses around posterior aspect of odontoid