Garment opening is strongly related to the daily life quality of physically disabled people with scoliosis (PDPSs). This research proposes a kinesiological evaluation method to investigate the influence of garment opening positions in dressing activities of PDPSs. For this purpose, dressing activities are firstly deconstructed into several motions. The performance of different garment opening positions is represented by the performance of the wearer carrying out different motions in dressing activities. The proposed evaluation method is based on the Completion Level (CL), which includes both physical and psychological indicators: Motion Standard Time (MST), Motion Difficulty Degree (MDD) and Motion Independence Degree (MID). MST is a physical indicator regarding the standard time to complete a motion in the dressing activities. It reflects the physical autonomy of the wearer in the dressing activity. MDD and MID are psychological indicators, which are developed to evaluate the psychological independence and difficulty of dressing motions respectively. Subjective evaluation is used to obtain data regarding MDD and MID. Due to the fact that there is always vagueness and uncertainly in the subjective evaluation, fuzzy set theory is applied to the data process regarding MDD and MID. A case study is presented to explain the implications of the proposed method. The case study indicated that garment opening positions have an influence on the dressing activity. PDPS will benefit from a well-constructed garment, and a proper positioning of the opening, in terms of both physical and psychological aspects