Effects of white cane handle angle and technique on upper limb biomechanics and comfort in visually impaired users.

The white cane is a fundamental mobility aid for individuals with visual impairments. While previous studies have examined cane characteristics, the ergonomic interaction between handle angle and usage technique remains underexplored. This quasi‑experimental study investigated the effects of white cane handle angle and technique on upper-limb posture, discomfort, and usability. Sixteen visually impaired participants completed eight experimental conditions combining four handle angles (0°, 10°, 20°, and 30°) with two cane techniques (two-point touch and constant contact) while walking an eight-meter path. Wrist flexion/extension, wrist radial/ulnar deviation, and elbow flexion/extension were measured using a twin-axis Biometrics electrogoniometer. Discomfort and usability were assessed using the Persian version of the Borg's Category Ratio-scale-10 (P-Borg CR-10) and the Persian version of the System Usability Scale (P-SUS), respectively. Significant main effects of handle angle and cane technique were observed on upper-limb posture. Handle angle significantly influenced wrist flexion/extension and ulnar deviation, while cane technique affected all posture variables. A significant interaction between handle angle and technique was found for elbow posture. Although angled handles reduced discomfort in some regions, they increased it in others. Notably, the traditional 0° handle achieved the highest usability ratings. These findings demonstrate an ergonomic trade-off between biomechanical improvement and perceived usability, highlighting the importance of considering both handle design and cane technique.