Mechanical Deformation of Posterior Thoracolumbar Fascia in
Asymptomatic Participants- A Dynamic Ultrasound Study
Ka-Kit Wong, PT, MS; Huei-Ming Chai, PT, PhD; Yu-Jen Chan PT, Ph.D.; Chung-Li
Wang, MD, Ph.D.; Yio-Wha Shau, Ph.D.; Shwu-Fen Wang PT. Ph.D.
National Taiwan University, College of Medicine, Graduate Institute and School of
Physical Therapy, Taipei, Republic of China Phone: 886-2-33668139
Fax: 866-2-33668161 email: sfwang@ntu.edu.tw
BACKGROUND: Research interest has focused on the biomechanical roles of the
posterior thoracolumbar fascia (PLF) [1]. However, the methodology to quantify
fascia properties in vivo is still lack. PURPOSE: The purpose of this study is to
establish a quantitative and reliable in vivo measurement of the posterior layer of
thoracolumbar fascia, and to compare the deformation of the fascia after contraction
of the attached muscles, Lattismus Dorsi (LD), at different force levels.
METHODS: Individuals who had no history of low back pain and regularly took part
in exercises were recruited. Deformation of the PLF and force output was recorded
simultaneously when participants performed ramped “press up” up to maximal
voluntary contraction (MVC) followed by ramped relaxation. Intra-class correlation
coefficient (ICC) is used to test the reliability of measurement. Repeated measure
ANOVA was used to analyze the deformation of different maximal voluntary
contraction (20, 40, 60, 80, 100 %).
RESULTS: The ICC of the fascia deformation at 100% MVC of LD is 0.98; standard
error of measurement (SEM) is 0.3 mm; minimal detectable difference (MDD) is 0.8
mm. The deformation of the PLF at 20, 40, 60, 80, 100 % of MVC is 3.4±1.2, 5.6±1.7,
7.4±1.7, 8.7±1.7, 9.8±1.8 mm respectively. The paired-wised comparison of the
adjacent level of % MVC is all significant (p<0.005).
DISCUSSION: Deformation of the PLF could be quantified reliably and
demonstrated increment of sliding during contraction in humans using real-time
ultrasound. Further study will investigate the mechanical property of the PLF in vivo
in patient population.
REFERENCES:
[1] Vleeming A, Pool-Goudzwaard AL, Stoeckart R, van Wingerden JP, Sniiders CJ.
The posterior layer of the thoracolumbar fascia: Its function in load transfer from spin
to legs. Spine (Phila Pa 1976) 1995; 20:753-8.