ORTHOTIC DEVICES COMPREHENSIVE EXAM 2026/2027
QUESTIONS AND SOLUTIONS RATED A+
✔✔Spinal orthosis mechanism - ✔✔Uses three-point pressure system for trunk/head
support, motion control, realignment, and partial weight transfer of head to trunk in
upright.
✔✔Factors affecting spinal orthosis effectiveness - ✔✔Force points,
direction/magnitude, tightness, injury/instability type, body habitus.
✔✔Negative effects of spinal orthoses - ✔✔Axial muscle atrophy, contractures, skin
breakdown (pressure/moisture), psychological dependency.
✔✔3-column spine concept - ✔✔Spine described as anterior, middle, and posterior
columns.
✔✔C0-C1 motion - ✔✔Significant flex/extension; minor lateral bending; little rotation.
✔✔C1-C2 motion - ✔✔Primarily rotation (~50% of all rotation) with limited
flex/extension.
✔✔C3-C7 motion - ✔✔Flex/extension, lateral bending, and rotation.
✔✔Challenges with cervical orthoses - ✔✔High mobility, limited contact area, skin
breakdown risk (occiput/chin), pressure pain (clavicles/chin), hygiene issues.
✔✔SOMI - ✔✔Sterno-occipital-mandibular immobilizer; indicated for instability at or
above C4.
✔✔Yale CTO - ✔✔Cervicothoracic orthosis used for instability C4 and below; rigid collar
with thoracic extensions.
✔✔Four-poster CTO - ✔✔Mandibular/occipital supports with struts to thoracic plates;
excellent flex/ext limitation (allows ~10-28% of normal motion).
✔✔Halo orthosis - ✔✔Maximal cervical immobilization using skull fixation; heavy/top-
heavy considerations.
✔✔Static orthosis (UE) - ✔✔Immobilizes a joint.
✔✔Dynamic orthosis (UE) - ✔✔Uses elastic components to apply forces and permit
motion in a controlled direction.
, ✔✔Serial static orthosis - ✔✔Series of static orthoses providing low-load, long-duration
stretch.
✔✔Static progressive orthosis - ✔✔Applies stress relaxation: tissue stretched and held
at constant length; relaxation over time allows repositioning.
✔✔Orthotic tools (UE) - ✔✔Cutting devices, pliers, hole punches, hand drills, wire
cutters/benders.
✔✔Thermoplastic handling characteristics - ✔✔Conformability/stretch resistance,
memory, rigidity, bonding, heating/working times.
✔✔Thermoplastic physical characteristics - ✔✔Thickness, perforations, colors, coating.
✔✔Orthotic precautions (UE) - ✔✔Avoid excessive compression over superficial nerves
and bony prominences; educate on numbness, paresthesia, burning, pain, color/temp
changes.
✔✔ Orthosis - ✔✔Externally applied device used to correct deformity, improve function,
or relieve symptoms; supports/assists the musculo-neuro-skeletal system.
✔✔Ortho- - ✔✔Prefix meaning 'straight'.
✔✔Force - ✔✔Mass × acceleration.
✔✔Torque (Moment of force) - ✔✔Force × moment arm length.
✔✔Pressure - ✔✔Force ÷ area.
✔✔Linear static equilibrium - ✔✔ΣFx=0, ΣFy=0, ΣFz=0.
✔✔Rotational static equilibrium - ✔✔ΣTx=0, ΣTy=0, ΣTz=0.
✔✔Mechanical purposes of orthoses - ✔✔Control movement, assist movement, or a
combination of both.
✔✔GRF control system - ✔✔Orthotic control dependent on ground contact during
stance; influenced by shoe/orthosis interface.
✔✔3-point pressure system - ✔✔Continuous control in all conditions (stance + swing)
using three forces to control a joint moment.
✔✔First-class lever system (orthoses) - ✔✔Orthotic force systems act like a first-class
lever: force-fulcrum-force.
QUESTIONS AND SOLUTIONS RATED A+
✔✔Spinal orthosis mechanism - ✔✔Uses three-point pressure system for trunk/head
support, motion control, realignment, and partial weight transfer of head to trunk in
upright.
✔✔Factors affecting spinal orthosis effectiveness - ✔✔Force points,
direction/magnitude, tightness, injury/instability type, body habitus.
✔✔Negative effects of spinal orthoses - ✔✔Axial muscle atrophy, contractures, skin
breakdown (pressure/moisture), psychological dependency.
✔✔3-column spine concept - ✔✔Spine described as anterior, middle, and posterior
columns.
✔✔C0-C1 motion - ✔✔Significant flex/extension; minor lateral bending; little rotation.
✔✔C1-C2 motion - ✔✔Primarily rotation (~50% of all rotation) with limited
flex/extension.
✔✔C3-C7 motion - ✔✔Flex/extension, lateral bending, and rotation.
✔✔Challenges with cervical orthoses - ✔✔High mobility, limited contact area, skin
breakdown risk (occiput/chin), pressure pain (clavicles/chin), hygiene issues.
✔✔SOMI - ✔✔Sterno-occipital-mandibular immobilizer; indicated for instability at or
above C4.
✔✔Yale CTO - ✔✔Cervicothoracic orthosis used for instability C4 and below; rigid collar
with thoracic extensions.
✔✔Four-poster CTO - ✔✔Mandibular/occipital supports with struts to thoracic plates;
excellent flex/ext limitation (allows ~10-28% of normal motion).
✔✔Halo orthosis - ✔✔Maximal cervical immobilization using skull fixation; heavy/top-
heavy considerations.
✔✔Static orthosis (UE) - ✔✔Immobilizes a joint.
✔✔Dynamic orthosis (UE) - ✔✔Uses elastic components to apply forces and permit
motion in a controlled direction.
, ✔✔Serial static orthosis - ✔✔Series of static orthoses providing low-load, long-duration
stretch.
✔✔Static progressive orthosis - ✔✔Applies stress relaxation: tissue stretched and held
at constant length; relaxation over time allows repositioning.
✔✔Orthotic tools (UE) - ✔✔Cutting devices, pliers, hole punches, hand drills, wire
cutters/benders.
✔✔Thermoplastic handling characteristics - ✔✔Conformability/stretch resistance,
memory, rigidity, bonding, heating/working times.
✔✔Thermoplastic physical characteristics - ✔✔Thickness, perforations, colors, coating.
✔✔Orthotic precautions (UE) - ✔✔Avoid excessive compression over superficial nerves
and bony prominences; educate on numbness, paresthesia, burning, pain, color/temp
changes.
✔✔ Orthosis - ✔✔Externally applied device used to correct deformity, improve function,
or relieve symptoms; supports/assists the musculo-neuro-skeletal system.
✔✔Ortho- - ✔✔Prefix meaning 'straight'.
✔✔Force - ✔✔Mass × acceleration.
✔✔Torque (Moment of force) - ✔✔Force × moment arm length.
✔✔Pressure - ✔✔Force ÷ area.
✔✔Linear static equilibrium - ✔✔ΣFx=0, ΣFy=0, ΣFz=0.
✔✔Rotational static equilibrium - ✔✔ΣTx=0, ΣTy=0, ΣTz=0.
✔✔Mechanical purposes of orthoses - ✔✔Control movement, assist movement, or a
combination of both.
✔✔GRF control system - ✔✔Orthotic control dependent on ground contact during
stance; influenced by shoe/orthosis interface.
✔✔3-point pressure system - ✔✔Continuous control in all conditions (stance + swing)
using three forces to control a joint moment.
✔✔First-class lever system (orthoses) - ✔✔Orthotic force systems act like a first-class
lever: force-fulcrum-force.
