Histology and macrophage expression in the connective tissues of the low back.

<p>A–D: Representative images of Hematoxylin/Eosin staining of soft tissues from the lumbar region in a rodent in vehicle (A), vehicle/stretch (B), carrageenan (C) and carrageenan/stretch (D). Tissue structures from top to bottom (superficial to deep) include the dermis, pannicular muscle, nonspecialized connective tissues and the deep back muscles. E–H: Representative images of macrophage immunolabeling within the nonspecialized connective tissues from vehicle/no treatment (E), vehicle/stretch (F), carrageenan/no treatment (G), and carrageenan/stretch (H) groups. I: Macrophage expression quantified by calculating the percent CD 68 immunostaining area within each image. Bar graph represents means for each group ± S.E. Scalebars: black = 1 mm, white = 25 µm. Results are means = 4 carrageenan/sham, N = 8 all other groups. (**p<.01, ***p<.001).</p

Gait analysis measurements.

<p>Stride length (A) and intrastep distance (B) across experimental groups. Open and closed circles respectively denote the average measurements for vehicle and carrageenan groups. Standard errors (S.E.) are indicated with error bars. N = 4 carrageenan/sham, N = 8 all other groups. (***p<.001).</p

Ultrasound imaging and measurements.

<p>A–D: Examples of ultrasound images from vehicle/no treatment (A), vehicle/stretch (B), carrageenan/no treatment (C) and carrageenan/stretch (D) groups. White arrows indicate the location where ultrasound measurements of tissue thickness were obtained. E: Open and closed bars respectively represent the mean ± S.E tissue thickness (E) for vehicle and carrageenan groups. N = 4 Carrageenan/sham, N = 8 all other groups. (**p<.01, ***p<.001).</p

Methods for injection, stretch technique, sham technique, gait testing and ultrasound measurements.

<p>A: Cartoon illustrating the tissue layers in the low back of the rodent from the dermis to the deep back muscles. The syringe indicates the location 1 cm lateral of L3 where carrageenan or vehicle was injected. B: I<i>n vivo</i> stretch technique showing animals held by the tail and lifted. C: Sham technique (to account for the additional handling associated with stretch) showing animal held by the tail but not lifted. D: Method used for gait analysis. The distance, in centimeters, between ipsilateral walking tracks represents the stride length (black arrows). The diagonal distance between consecutive right and left walking tracks produces the intrastep distance (yellow arrows). E: Ultrasound imaging tissue thickness measurements (indicated by yellow stars).</p

pigpaper_SS

Ultrasound shear strain measurement

Gait analysis.

<p>Gait speed (m/sec) was measured at week 8. There was a significant main effect of movement restriction on gait speed <i>(ANOVA p</i> = .03), but no significant effect of injury (ANOVA <i>p = 2</i>.<i>56)</i>.</p

pigpaper_cortisol

Salivary cortisol measurement

pigpaper_cgrp_data

Spinal cord substance P and CGRP measurement

pigpaper_wt

Pig Weight

pigpaper_gait_data

Gait measurement