Introduction: To examine foot and ankle positions, subtalar joint (STJ) measurements are frequently performed in the clinics because of the high prevalence of lower extremity dysfunctions. The STJN position is also used in casting and orthosis fabrication. Unfortunately, current methods of measuring the STJN position are ambiguous or lack the theoretical rigour required for reliable and clinically useful measurements. Objective: The purpose of this study was to determine if there were any differences in subtalar joint range of motion (ROM) when using OKC and CKC measurement methods, as well as to assess the internal consistency of an inclinometer used in a clinical setting. Methods: The study included ten healthy subjects. The measurements were taken with the subjects prone (open kinetic chain) and standing (closed kinetic chain). Cronbach's alpha was used to calculate the internal consistency of an inclinometer in the subtalar joint's close and open kinematic chains. Results: The result indicates that the inclinometer is a good reliable tool for assessing subtalar joint motion in OKC and CKC measurements, as the value for Cronbach’s alpha is 0.889, indicating good reliability. Discussion & Conclusion: As a result, it is concluded that this inclinometer will be useful in measuring the open and closed kinematic chain measurements of the subtalar joint. This technique should be viewed as an adjunct to an overall lower extremity biomechanical evaluation. This study provides an optional technique for determining the position or movement of the STJ for clinicians who perform lower extremity biomechanical evaluation. Key words: Internal consistency, Open kinematic chain, Closed kinematic chain, Inclinometer.