Document Type

Thesis

Degree Name

Master of Science (MSc)

Department

Health Science

Faculty/School

Faculty of Science

First Advisor

Dr. Diane Gregory

Advisor Role

Supervisor

Abstract

Low back pain (LBP) is the leading cause of musculoskeletal pain worldwide and is often caused by mechanical factors. LBP is especially prevalent in dancers, who perform movements involving repeated spine hyperextension. However, little is known about the spinal extension range of motion (ROM) achieved by dancers or how spine extension affects intervertebral disc mechanics. This study aimed to compare thoracic and lumbar spine ROM in dancers and non-dancers, determine extension angles achieved during dance poses, and investigate the effects of spine extension on the annulus fibrosus (AF) using a porcine model. Dancers and recreationally active non-dancers completed standardized ROM assessments using electromagnetic motion capture. Dancers also performed four extension-based dance poses: bridge, cobra, arabesque, and attitude. Porcine functional spinal units were subjected to 50% or 100% of maximum extension ROM under a 1000 N compressive load for 3000 cycles at 1 Hz, after which anterior and posterior AF samples underwent peel and bilayer testing. Dancers demonstrated significantly greater thoracic extension ROM than non-dancers (57.3 ± 23.9° vs. 36.6 ± 14.0°, p = 0.032). Extension angles differed significantly across dance poses, with bridge and cobra demonstrating greater extension than the ROM assessment. Porcine FSUs subjected to 100% extension exhibited greater peel stiffness and strength and greater bilayer tensile stiffness and toe-region strain than 50% extension samples. These findings suggest that dancers demonstrate greater sagittal ROM and that greater spine extension may alter AF mechanical properties. Further research should investigate the mechanical implications of repeated high-extension movements on spinal tissue health.

Convocation Year

2026

Convocation Season

Fall

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Available for download on Wednesday, August 30, 2028

Included in

Biomechanics Commons

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