Measurements of the subtalar joint neutral (STJN) position and passive range of motion (PROM) of the ankle joint and the subtalar joint (STJ) are often part of a physical therapy evaluation. These measurements may be used in treatment planning, such as in the prescription of specialized shoes or orthoses. Therefore, reliability of these measurements, as they are obtained clinically, must be determined. The purpose of this study was to examine the reliability of measurements of the STJN position and of ankle and STJ PROM. To determine reliability, repeated measurements of the STJN position and of STJ PROM were taken on the involved feet of 43 patients with neurologic orthopedic disorders (including both feet of 7 patients), and measurements of ankle PROM (dorsiflexion and plantar flexion) were taken on 42 of these patients (including both feet of 7 patients). Intraclass correlation coefficients (ICCs) for intratester reliability ranged from .74 to .90 for ankle and STJ measurements. The ICCs for intertester reliability were .25 for measuring the STJN position, .32 for STJ inversion, and .17 for SJJ eversion. The ICCs for intertester reliability were .50 for ankle dorsiflexion and .72 for ankle plantar flexion. Goniometric measurements of the STJN position and of PROM of the ankle and STJ appear to be moderately reliable if taken by the same therapist over a short period of time. With the exception of ankle plantar flexion, these measurements cannot be considered to be reliable between therapists.

Physical therapists frequently evaluate the lower extremity, and this evaluation often includes measuring the subtalar joint neutral (STJN) position and subtalar joint (STJ) passive range of motion (PROM). This report critically reviews methods used to measure STJN position and STJ PROM. Standardized methods for taking these measurements, which have been clinically tested and appear to be theoretically sound, are presented. Although these methods are based on anatomical considerations, their reliability is less than optimal. However, these are the only methods of measuring STJN position and STJ PROM that have been tested adequately for reliability.