STUDY DESIGN Case control study with blinded examiner OBJECTIVE To investigate if pressure pain sensitivity is related to specific nerve trunks in the upper extremity of patients with either unilateral lateral epicondylalgia (LE) or carpal tunnel syndrome (CTS) BACKGROUND In the clinical setting patients with LE tend to exhibit radial nerve trunk tenderness whereas patients with CTS exhibit median nerve tenderness No studies have investigated if specific nerve pressure pain hypersensitivity exists in patients with either LE or CTS METHODS Sixteen women with unilateral LE (mean +/- SD age 43 +/- 7 years) 17 women with unilateral CTS (43 +/- 6 years) and 17 healthy women (43 +/- 6 years) were included in this study Pressure pain thresholds (PPT) were bilaterally assessed over the median ulnar and radial nerve trunks as well as over the C5 6 zygapophyseal joints by an examiner blinded to the subjects condition A mixed model analysis of variance was used to evaluate differences in PPT among groups (LE CTS or controls) and between sides (affected/nonaffected or dominant/nondominant) RESULTS The individuals in both the LE and CTS groups demonstrated lower PPT bilaterally over the median (group P< 001 side P = 437) radial (group P< 001 side P = 556) and ulnar (group P< 001 side P = 938) nerve trunks as compared to controls Additionally radial (P< 001) and ulnar (P = 005) nerves were more sensitive bilaterally in patients with LE than in patients with CTS The median nerve was more sensitive bilaterally in patients with CTS than patients with LE (P = 002) Lower PPT over the cervical spine (group P< 001 side P = 233) were found bilaterally in both the LE and CTS groups Further patients with CTS exhibited lower cervical PPT than patients with LE (P< 001) PPT was negatively correlated with both pain intensity and duration of symptoms in both the LE and CTS groups (P< 001) CONCLUSIONS Bilateral mechanical nerve pain hypersensitivity is related to specific and particular nerve trunks in women with either unilateral LE or CTS Our results suggest the presence of central and peripheral sensitization mechanisms in individuals with either LE or CTS J Orthop Sports Phys Ther 2010 40(11) 751 760 doi 10.2519/jospt.2010.3331