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Logo for the Journal of Rehab R&D
Volume 40 Number 6, November/December 2003
Pages 527 — 538


Biomechanical analysis of cervical orthoses in flexion
and extension: A comparison of cervical collars and cervical thoracic orthoses
Thomas M. Gavin, CO; Gerard Carandang, MS; Robert Havey, BS; Patrick Flanagan, CO;
Alexander Ghanayem, MD; Avinash G. Patwardhan, PhD
Musculoskeletal Biomechanics Laboratory, Edward Hines Jr., Department of Veterans Affairs (VA) Hospital,
Hines, IL; BioConcepts, Inc., Orthotic-Prosthetic Center, Burr Ridge, IL; Department of Orthopaedic Surgery
and Rehabilitation, Loyola University Chicago, Maywood, IL
Abstract-The analysis of current cervical collars (Aspen and Miami J collars) and cervical thoracic orthoses (CTOs) (Aspen 2-post and Aspen 4-post CTOs) in reducing cervical intervertebral and gross range of motion in flexion and extension was performed using 20 normal volunteer subjects. The gross sagittal motion of the head was measured relative to the horizon with the use of an optoelectronic motion measurement system. Simultaneous measurement of cervical intervertebral motion was performed with the use of a video fluoroscopy (VF) machine. Intervertebral motion was described as (1) the angular motion of each vertebra and (2) the translational motion of the vertebral centroid. We used surface electromyographic (EMG) signal data to compare subject efforts between the two collars and between the two CTOs. Each orthosis significantly reduced gross and intervertebral motion in flexion and extension (p < 0.05). No statistically significant differences were found between the Miami J and Aspen collars in reducing gross or intervertebral sagittal motion, except at C5-6. Both CTOs provided significantly more restriction of gross and intervertebral flexion and extension motion as compared to the two collars (p < 0.05). The Aspen 2-post CTO and 4-post CTO performed similarly in flexion, but the Aspen 4-post CTO provided significantly more restriction of extension motion (p < 0.05).
Key words: biomechanics, brace, cervical, cervical thoracic orthoses (CTO), collars, extension, flexion, orthosis, spine.

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