Measurement of contractures of the digits in systemic sclerosis. Development of digit-goniometers and definitions of normal joint motility of the digits of elderly persons.

New goniometers were constructed for the measurement of joint motility in the proximal interphalangeal (PIP) and metacarpophalangeal (MP) joints of the digits. 25 patients with systemic sclerosis (mean age 60 years, range 32-83) were studied, and compared with 25 healthy controls, matched for sex and age (mean age 58 years, range 29-87). The flexion, extension and entire joint motility of the PIP and MP joints were significantly decreased. From the measurements in the controls, standards for normal joint motility were defined (mean +/- 1 to 2 SD): PIP joint flexion 110 degrees, extension 5 degrees, entire motility 130 degrees; MP joint flexion 90 degrees, extension 20 degrees, entire motility 110 degrees. Joint motility was not correlated to sex and age in these elderly controls. The entire joint motility was reduced in the PIP joint in 19 (76%) patients, and in the MP joint in 17 (68%) patients with systemic sclerosis according to the standards. This corresponded well with the clinical assessment of contracture.