A cross-sectional analysis of persistent low back pain, using correlations between lumbar stiffness, pressure pain threshold, and heat pain threshold

Abstract

Introduction Little is known about the underlying biomechanical cause of low back pain (LBP). Recently, technological advances have made it possible to quantify biomechanical and neurophysiological measurements, potentially relevant factors in understanding LBP etiology. However, few studies have explored the relation between these factors. This study aims to quantify the correlation between biomechanical and neurophysiological outcomes in non-specific LBP and examine whether these correlations differ when considered regionally vs. segmentally. Methods This is a secondary cross-sectional analysis of 132 participants with persistent non-specific LBP. Biomechanical data included spinal stiffness (global stiffness) measured by a rolling indenter. Neurophysiological data included pain sensitivity (pressure pain threshold and heat pain threshold) measured by a pressure algometer and a thermode. Correlations were tested using Pearson’s product-moment correlation or Spearman’s rank correlation as appropriate. The association between these outcomes and the segmental level was tested using ANOVA with post-hoc Tukey corrected comparisons. Results A moderate positive correlation was found between spinal stiffness and pressure pain threshold, i.e., high degrees of stiffness were associated with high pressure pain thresholds. The correlation between spinal stiffness and heat pain threshold was poor and not statistically significant. Aside from a statistically significant minor association between the lower and the upper lumbar segments and stiffness, no other segmental relation was shown. Conclusions The moderate correlation between spinal stiffness and mechanical pain sensitivity was the opposite of expected, meaning higher degrees of stiffness was associated with higher pressure pain thresholds. No clinically relevant segmental association existed.

Pressure pain thresholds in a real-world chiropractic setting: topography, changes after treatment, and clinical relevance?

“…While our approach was more straightforward than a previous study conducted at our laboratory [ 23 ], the results were similar in that PPT values increased the more caudally on the spine we tested. However, there was a negligible difference between adjacent or nearby vertebrae, similar to what we demonstrated earlier in persistent low back pain patients [ 42 ]. Also, the region of clinical pain had minimal impact on pre-test PPT, and while the participants with multiple pain sites had the lowest PPT values, it did not reach statistical significance.…”

Differential Sensitization of Muscle versus Fascia in Individuals with Low Back Pain

“…It is important to note, however, that the pressure thresholds reported in these studies (in the magnitude of 5–7 lbs/cm 2 ) correspond not only to the skin and subcutaneous tissues but inevitably also stimulate the deep fascia and muscles. Finally, in a study exploring the association of muscle stiffness, PPT and heat pain thresholds in a cohort of 132 individuals with persistent LBP, muscle stiffness was associated with PPT but not with heat pain threshold [ 38 ], strengthening the notion that in LBP, sensitization of deep tissues (muscle and fascia) it is more prominent than that of subcutaneous tissues.…”

Current Concept of Quantitative Sensory Testing and Pressure Pain Threshold in Neck/Shoulder and Low Back Pain

“…Forty-eight studies that measured PPT in the low back area in patients with LBP and/or healthy volunteers are listed in Table 3 . The subjects of the studies were patients with LBP, healthy volunteers, workers, and patients with myofascial pain syndrome [ 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 ]. These articles revealed the normative values of PPT in the lower back area.…”

“…The areas examined were the back, lumbar region, 1–3 cm lateral of the spinous processes, paravertebral muscle, paraspinal muscle, dorsal longissimus, erector spinae muscle, suprainterspinous ligaments, lumbar zygapophyseal joints, and gluteus maximus/medius. The common measurement devices were pressure algometers from Somedic AB and Wagner Instruments, and the measurement units used were mainly kPa, kgf, N/cm 2 , and kg/cm 2 [ 75 , 77 , 78 , 79 , 81 , 83 , 86 , 89 , 92 , 93 , 95 , 96 , 97 , 98 , 100 , 105 , 106 , 107 , 111 , 112 , 113 , 114 , 115 , 117 , 118 , 119 , 120 , 121 , 122 ]. The normative value from the data ranged from 299 to 628 kPa at the back area [ 118 , 119 , 120 , 121 , 122 ].…”