Keywords:pressure pain threshold, tissue hardness, subscapular skinfold thickness
Objective: The aim of this study was to evaluate the pressure pain threshold (PPT) of the shoulder girdle and upper back muscles and associated factors in the normal population.
Study design: A cross-sectional descriptive study.
Setting: Out-patient clinic, Department of Rehabilitation Medicine, Khon Kaen University.
Subjects: Healthy Thai persons 18-70 years old who did not have pain in the shoulder girdle or upper back were studied from March to August 2015.
Method: The pressure pain threshold of the bilateral upper trapezius, infraspinatus, teres minor, levator scapulae and T6 paraspinal muscles were measured using an algometer. Factors associated with pressure pain threshold, including baseline cha-racteristics (age, sex and occupation), tissue hardness, and subscapular skinfold thickness, were recorded and analyzed using univariate analysis and multiple linear regression.
Results: One hundred seventy-one participants with mean age of 39.68 (SD 15.77) years were included in the study. The mean PPT of the shoulder girdle and upper back muscles in all participants was 5.68 (SD 1.76) kg/cm2, 6.35 (SD 1.82) kg/cm2 for females and 4.99 (SD 1.39) kg/cm2 for males. Factors significantly associated with PTT were female sex (a mean difference of 0.91; 95% CI 0.35 to 1.47, p=0.002), income (a mean difference of -1.74; 95% CI -2.79 to -0.71, p=0.001), and computer use (a mean difference of 0.70; 95% CI 0.15 to 1.26, p=0.01).
Conclusion: The mean pressure pain threshold of the shoulder girdle and upper back muscles in the normal Thai population was 5.68 (SD 1.76) kg/cm2. Female sex, low income, and prolonged occupational computer use were the factors associated with high PPT.
2. Fischer AA. Documentation of myofascial trigger points. Arch Phys Med Rehabil. 1988;69:286-91.
3. Fischer AA. Pressure algometry over normal muscles. Standard values, validity and reproducibility of pressure threshold. Pain. 1987;30:115-26.
4. Richard HG. Studies of Pain in Human Subjects. In: Stephen BM, Martin K, Irene T, Dennis CT, editors. Text book of pain. 6th ed. London: Saunders; 2013. p. 283-300.
5. Alabas OA, Tashani OA, TAbasam G. Johnso MI. Gender role affects experimental pain responses: A systematic review with meta-analysis. Eur J Pain. 2012;16:1211-23.
6. Myers, CD, Riley JL, Robinson ME. Psychosocial contributions to sex-correlated differences in pain. Clin J Pain. 2013;19:225–32.
7. Zhang Y, Zhang S, Gao Y, Tan A, Yang X, Zhang H. et al. Factors Associated with the pressure pain threshold in healthy Chinese men. Pain Med. 2013;14:1291-300.
8. Wong-anant S, Prakopphol W, Panchan S, Eungpinichpong W, Wanpen S, Ninprapan A. Pain Pressure threshold in normal subjects aged 18-22 years (Abstract). J Med Technol Phys Ther. 1997;9:170-1.
9. Sangpeth J, Eungpinichpong W, Buranrak O, Chatchawan U. Pain pressure threshold in Thai female subjects aged 13-20 years and 30-45 years (Abstract). J Med Technol Phys Ther. 1999;11:28.
10. Fillingim RB, Maixner W. Gender differences in the responses to noxious stimuli. Pain Forum. 1995;4:209-21.
11. Bernardes SF, Keogh E, Lima ML. Bridging the gap between pain and gender research: a selective literature review. Eur J Pain. 2008;12:427-40.
12. Thaweesit S. Development of women’s well-being in Thailand. In: Punpuing S, Sunpuwan M, editors. People and social Thailand’s population in transition: A turning point for ThaiSociety. Bangkok: Duentula press; 2011. p. 161-79.