Relationship Between Pressure Pain Threshold and Pain Intensity, Affect and Disability in CLBP

Cross-modality Matching Between Pressure Pain Threshold and Subjective Ratings of Pain Intensity, Affect and Disability in Patients With Chronic Low Back Pain.

The association between pressure pain threshold and different aspects of low back pain has garnered attention over the years. However, since most of such studies in the past employed cross sectional designs, a longitudinal study design with follow-up measurements is required to further investigate this relationship. Studying this relationship will not only offer insights into the phenomenon of pain but may also bring us one step closer to achieving the seemingly insurmountable goal of objectively measuring back pain and its different dimensions.

This study is aimed to examine and evaluate the true extent of the relationship between pressure pain threshold (PPT) and different aspects of somatic pain, by studying the interplay between PPT and different variables, and by further exploring the predictive capability of PPT values to estimate pain intensity, pain affect and disability associated with chronic low back pain (CLBP). In order to estimate these dimensions a calculator based on mathematical equations using different predictive models will be developed. This tool (calculator) will take into account PPT reading from the lower back region and some other variables having confounding effects on PPT and pain, and will be able to predict pain intensity, affect and associated disability with reasonable accuracy. Patients with chronic low back pain shall be the target population and shall be recruited through referrals from the medical Out-Patients Department of Institute of Physical Medicine & Rehabilitation, Dow University of Health Sciences and Department of Rehabilitation Medicine PNS-Shifa Hospital, Karachi, Pakistan after initial screening in accordance with the inclusion and exclusion criteria. Screened patients shall then be briefed about the research project. After explaining the study objectives, procedures, potential benefits and discomforts, written informed consent shall be obtained from the patients. Only upon their agreement shall they become study participants and undergo assessments. The study participants shall receive handouts to document Depression and Anxiety, Pain Intensity, Pain Affect, and Disability. Pressure pain threshold (PPT) shall be measured using a manual Algometer. These measurements shall be followed by a session of physiotherapy treatment, after which Pain Intensity, Pain Affect, and Disability shall be recorded again.

Inclusion Criteria:

• Adult males with low back pain with an age group of 18-50 years.

Exclusion Criteria:

1. Individuals having low back pain for less than 3 months.
2. Individuals with specific underlying pathology as the cause of CLBP. (Active oncological disease, Known disc derangement, cauda equina syndrome, spinal trauma i.e. fracture, neuropathy i.e. sciatica or severe root compression, spinal structural deformity, infection, inflammatory joint disease, spinal stenosis, spondylolysis, spondylolisthesis).
3. Individuals having neurological diseases (including central and peripheral diseases); metabolic diseases (i.e. diabetes and hypothyroidism); coagulopathies (i.e. haemophilia).
4. Individuals with fibromyalgia syndrome (FMS); myofascial pain syndrome (MPS); allodynia (stroking hyperalgesia).
5. Individuals suffering from aphasia or suffering from deafness, blindness or muteness.
6. Individuals with skin disease (i.e. psoriasis, scleroderma, leprosy, etc.) or skin lesions (i.e. abrasion/laceration/ bruise) in the low back region.
7. Individuals having oral temperature of 100 F or above.
8. Individuals who have undergone spinal surgery.
9. Individuals scoring 28+ for depression, 20+ for anxiety, 34+ for stress on DASS-21.
10. Individuals in whom prone lying causes significant discomfort (i.e. dyspnoea etc.).
11. Individuals who do not perceive pressure pain below 10 kg/cm2 during PPT testing.
12. Individuals evincing bruising to PPT testing.