Comparison of tactile acuity between patients with chronic patellofemoral pain with central sensitization and healthy persons: A cross-sectional study

ABSTRACT

Background

Patellofemoral pain (PFP) is a common multifactorial condition in young and physically active people.

Objective

The occurrence of central sensitization may play an important role in sensory disturbance. This study was designed to investigate, in patients with chronic PFP, the presence of disturbances in tactile acuity with central sensitization.

Methods

Thirty patients with chronic PFP and 30 matched healthy controls entered this cross-sectional study. Graphesthesia (numerical score), two-point discrimination (mm), and point-to-point sensation (mm) were assessed in all participants.

Results

The results of between-group comparisons showed that there were significant differences between the involved knee in patients with chronic PFP and healthy participants in graphesthesia (median = 13 [case], 19 [control]; p < .001), two-point discrimination (median = 25.8 [case], 20.3 [control]; p < .001), and point-to-point sensation (median = 14.5 [case], 6.2 [control]; p < .001). There was also a significant difference in graphesthesia between the non-involved knee in patients with chronic PFP and healthy participants (median = 17 [case], 19 [control]; p = .003). The results of within-group comparisons revealed a significant difference in graphesthesia, two-point discrimination, and point-to-point sensation between the involved and non-involved knee in patients with chronic PFP (p < .001). Moreover, there was a positive correlation between two-point discrimination and pain in patients with chronic PFP (r = 0.446, p = .014).

Conclusion

The findings of this study reveal that there is a sensory deficit in patients with chronic PFP. Because sensory information is necessary for motor control and pain perception, we can assume that clinical symptoms in these patients are related to sensory deficits.

KEYWORDS:

• Two-point discrimination
• graphesthesia
• point-to-point sensation
• tactile acuity
• central sensitization
• patellofemoral pain

Acknowledgments

The authors thank the Rehabilitation Research Center (Department of Physical Therapy, School of Rehabilitation Sciences, Shiraz University of Medical Sciences) for their support, and Karen Shashok (AuthorAID in the Eastern Mediterranean) and Joost van Wijchen for improving the use of English in the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was funded by Shiraz University of Medical Sciences under Grant number 25371.