Ankle�Foot injuries are amongst the most common injuries of the lower limb and almost 25,000 people experience ankle injuries each day due to vigorous activities. Traditionally, ankle injuries are rehabilitated via physiotherapy using simple equipment like elastic bands and rollers, requiring intensive efforts of therapists and patients. Currently, Stewart platform rehabilitation devices are actuated by various methods including double acting pneumatic cylinder, hydraulic, electric motor and shape memory alloy. The limitation of using these actuation methods is that it provides lower range of motions and requires higher maintenances. A less known type is Pneumatic Artificial Muscles (PAMs). PAMs are operated by pneumatic pressure and are contractible naturally upon inflation. The objective of this study is to fabricate Stewart platform using Pneumatic Artificial Muscle, to analyze the range of motion produce by various diameter of the PAMs. The diameters of PAM used were 8, 10 and 12 mm. It was observed that Stewart Platform actuated by PAM of diameter of 12 mm produced maximum platform angle of 31.73°, whereas PAM with the diameter of 10 and 8 mm produced maximum platform angle of 28.62° and 25.31°, respectively. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.