Do Different Visual Conditions Affect Tactile Acuity at Hand in Healthy Young Adults?

Year 2025, Volume: 9 Issue: 1, 33 - 39, 31.01.2025

Bahar Aras , Gulce Kallem Seyyar , Özgen Aras , Utku Türkmen

https://doi.org/10.30621/jbachs.1395644

Abstract

Background and purpose: Subjects should not see the area tested during the two-point discrimination (TPD) test. Various methods are used in the literature to hide the test area. However, there is yet to be a consensus on which method is the best. This study investigated the tactile acuity of different methods to obscure the line of vision in TPD testing in healthy young adults.
Methods: We evaluated the TPD thresholds of the dominant hand's three regions in 30 healthy young adults under four different visual conditions (two eyes open and two eyes closed). Friedman test and Wilcoxon signed rank test were used for statistical analysis.
Results: In all areas tested, the distance required to perceive two stimuli was smaller in the eyes open conditions. 46.70% of the participants reported being more comfortable and distinguishing two points more quickly when their eyes were open.
Conclusion: Although the threshold values of TPD are within clinically appropriate ranges in all four visual conditions, we suggest performing TPD testing while the patients' eyes are open. Clinicians may obtain more accurate results during TPD tests if subjects are tested with their eyes open rather than closed.

Keywords

somatosensory function, tactile acuity, touch perception, two-point discrimination, young adults

Ethical Statement

All participants were informed about the aim and methods of the study, and signed an informed consent. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Medical Ethics Committee of Kutahya Health Sciences University (2018/10-7).

Supporting Institution

-

Thanks

-

References

• Lundy-Ekman L. Neurosicence: Fundamentals for Rehabilitation. 4th ed. Elsevier: USA; 2013.
• Reed-Geaghan EG, Maricich SM. Peripheral somatosensation: a touch of genetics. Curr Opin Genet 2011;21(3):240-48.
• Gallace, A. Tactile Processing. In: Wright JD, editor. International Encyclopedia of Social & Behavioral Sciences. 2nd ed. Elsevier: London; 2015.
• Harvie DS, Kelly J, Buckman H, et al. Tactile acuity testing at the neck: a comparison of methods. Musculoskelet Sci Pract 2017;32:23-30.
• Citaker S, Gunduz AG, Guclu MB, Nazliel B, Irkec C, Kaya D. Relationship between foot sensation and standing balance in patients with multiple sclerosis. Gait Posture 2011;34(2):275-78.
• Kim JS, Yi SJ. Comparison of two-point discrimination perception in stroke patients with and without diabetes mellitus. J Phys Ther Sci. 2013; 25(8):1007-9.
• Auld ML, Boyd R, Moseley GL, Ware R, Johnston LM. Tactile function in children with unilateral cerebral palsy compared to typically developing children. Disabil Rehabil 2012;34(17):1488-94.
• Adamczyk W, Luedtke K, Saulicz E. Lumbar tactile acuity in patients with low back pain and healthy controls. Clin J Pain 2018;34(1):82-94.
• Catley MJ, O'Connell NE, Berryman C, Ayhan FF, Moseley GL. Is tactile acuity altered in people with chronic pain? A systematic review and meta-analysis. J Pain 2014;15(10):985-1000.
• Harvie DS, Edmond-Hank G, Smith AD. Tactile acuity is reduced in people with chronic neck pain. Musculoskelet Sci Pract 2018;33(2018):61-6.
• Luedtke K, Adamczyk W, Mehrtens K, et al. Upper cervical two-point discrimination thresholds in migraine patients and headache-free controls. J Headache Pain 2018;19(1):47.
• Wolny T, Saulicz E, Linek P, Myśliwiec A. Two-point discrimination and kinesthetic sense disorders in productive age individuals with carpal tunnel syndrome. J Occup Health 2016;58(3):289-296.
• Falling C, Mani R. Regional asymmetry, obesity and gender determines tactile acuity of the knee regions: A cross-sectional study. Man Ther 2016;26:150-157.
• Nolan MF. Two-point discrimination assessment in the upper limb in young adult men and women. Phys Ther 1982;62(7):965-69.
• Nolan MF. Limits of two-point discrimination ability in the lower limb in young adult men and women. Phys Ther 1983;63(9):1424-28.
• Ehrenbrusthoff K, Ryan JG, Grüneberg C, et al. The intra- and inter-observer reliability of a novel protocol for two-point discrimination in individuals with chronic low back pain. Physiol Meas 2016; 37(7):1074-88.
• Dane AB, Teh E, Reckelhoff KE, Ying PK. Differences of cutaneous two-point discrimination thresholds among students in different years of a chiropractic program. J Manipulative Physiol Ther 2017;40(7):511-6.
• Shibin K, Samuel AJ. The discrimination of two-point touch sense for the upper extremity in indian adults. IJHRS 2013;2(1):38-43.
• Nolan MF. Quantitative measure of cutaneous sensation: two-point discrimination values for the face and trunk. Phys Ther 1985;65(2):181-5.
• Alsaeed S, Alhomid T, Zakaria H, Alwhaibi R. Normative values of two-point discrimination test among students of Princess Noura Bint Abdulrahman University in Riyadh. IJAMSCR 2014;1(1):42-52.
• Havaei N, Rezaei M, Rostami HR. Dexterity and two-point discrimination of the hand in school-aged children with dysgraphia. Med J Islam Repub Iran 2016;30:434.
• Etter NM, Miller OM, Ballard KJ. Clinically available assessment measures for lingual and labial somatosensation in healthy adults: normative data and test reliability. Am J Speech Lang Pathol 2017;26(3):982-90.
• Rinkel WD, Aziz MH, Van Deelen MJ, et al. Normative data for cutaneous threshold and spatial discrimination in the feet. Muscle Nerve 2017;56(3):399-407.
• Sheng JY, Blackford AL, Bardia A, et al. Prospective evaluation of finger two-point discrimination and carpal tunnel syndrome among women with breast cancer receiving adjuvant aromatase inhibitor therapy. Breast Cancer Res Treat 2019;176(3):617-24.
• Dua K, Lancaster TP, Abzug JM. Age-dependent reliability of Semmes-Weinstein and 2-point discrimination tests in children. J Pediatr Orthop 2019;39(2):98-103.
• Tong J, Mao O, Goldreich D. Two-point orientation discrimination versus the traditional two-point test for tactile spatial acuity assessment. Front Hum Neurosci 2013;7(579):1-11.
• Wolny T, Linek P, Michalski P. Inter-rater reliability of two-point discrimination in acute stroke patients. NeuroRehabilitation 2017;41(1): 127-34.
• Wolny T, Linek P. Reliability of two-point discrimination test in carpal tunnel syndrome patients. Physiother Theory Pract 2018;35(4): 348-54.
• Bell-Krotoski JA. Sensibility testing: history, instrumentation, and clinical procedures. In: Skirven TM, Osterman AL, Fedorczyk JM, editors. Rehabilitation of the hand and upper extremity. 6th ed. Elsevier Mosby: Philadelphia; 2011. p.145-9.
• Won SY, Kim HK, Kim ME, Kim SK. Two-point discrimination values vary depending on test site, sex and test modality in the orofacial region: a preliminary study. J Appl Oral Sci 2016;25(4): 427-35.
• Johnson KO, Van Boven RW, Hsiao SS. The perception of two points is not the spatial resolution threshold. In: Boivie J, Hansson P, Lindblom U, editors. Touch, Temperature, and Pain in Health And Disease: Mechanisms and Assessments. IASP Press; Seattle; 1994. p.389-404.
• Catley MJ, O'Connell NE, Berryman C, Ayhan FF, Moseley GL. Assessing tactile acuity in rheumatology and musculoskeletal medicine: how reliable are two-point discrimination tests at the neck, hand, back and foot? Rheumatology 2013;52(8):1454-61.
• Lundborg G, Rosèn B. The two-point discrimination test-time for a re-appraisal? J Hand Surg Br 2004;29(5):418-22.
• Cashin AG, McAuley JH. Measuring two-point discrimination threshold with a caliper. J Physiother 2017;63(3):186.
• Chui KK, Schmitz TJ. Examination of sensory function. In: O'Sullivan SB, Schmitz TJ, Fulk G, editors. Physical Rehabilitation F.A. Davis Company: Philadelphia 2014. p.87–123.
• Smith, P. Open eyes to sensory testing. Pract Neurol 2016;17(2):167.
• Menier C, Forget R, Lambert J. Evaluation of two-point discrimination in children: reliability, effects of passive displacement and voluntary movement. Dev Med Child Neurol 1996;38(6): 523-37.
• Finnell JT, Knopp R, Johnson P, Holland PC, Schuber W. A calibrated paper clip is reliable measure of two point discrimination. Acad Emerg Med 2004;11(6):710-14.
• Taylor SC, Atkinson G, Dixon J, Robinson JR, Ryan CG. Test-retest reliability of the two-point discrimination test on the sole of the foot in people with multiple sclerosis. Physiol Meas 2020;41(11):11NT01.
• Auld ML, Ware RS, Boyd RN, Moseley GL, Johnston LM. Reproducibility of tactile assessments for children with unilateral cerebral palsy. Phys Occup Ther Pediatr 2012;32(2): 151-166.