[Examination of tender points in soft tissue. Palpation versus pressure-algometer]

Tender points may be identified by two methods, either by palpation or employment of a pressure-algometer. The inter- and intra-observer agreements between the two methods are investigated in the present article. The investigation consists of three sections: 1. Twenty-five female patients with various rheumatic conditions were examined by two investigators for tender points at 15 sites of predilection, immediately after one another both as regards palpation/palpation and pressure-algometer/pressure-algometer. Acceptable inter-observer agreement was found on palpation with an average value employing Cohen's kappa-coefficient of 0.68 and an unacceptable inter-observer agreement with average values employing Cohen's kappa-coefficient of 0.42, 0.39 and 0.44 with pressure thresholds of under 3.0, 4.0 and 5.0 kg/cm2. 2. Twenty-five female volunteers in whom only knees were visible were examined twice immediately after one another by the same examiner by palpation on the medial fat pad of the right knee and by pressure with the pressurealgometer on the medial fat pad of the left knee. Good intra-observer agreement was found by both methods with Cohen's kappa-coefficient ranging between 0.75 and 0.83. 3. Sixty-five consecutive patients admitted to Kong Christian X Hospital for Rheumatic Diseases were examined for tender points at 15 sites of predilection by two examiners immediately after one another employing palpation/pressure-algometer. Poor agreement was found between the two methods. Employment of the pressure-algometer may be useful in research where quantitating of the threshold of pain is desired, but, in the daily clinical routine, palpatory examination for tender points is just as good or better than employment of an algometer.