Caenorhabditis elegans is a worm that could be mutated to have different muscle arms, which may generate distinct force patterns when the worm moves. In this paper, an integrated system employing both a novel PDMS device and a visual feedback from the device is reported. The silicone elastomer-based PDMS device consists of arrays of pillars, which form open channels for the worm to move in and bend the pillars in contact. Enabled by a single vision sensor (CCD/CMOS) camera, the computer vision system is able to transform the forces generated by C. elegans, through detecting the deflection of the pillars with sub-pixel accuracy. The experimental results demonstrate that the current vision-based force sensing system is capable of performing robust force measurements at a full 30 Hz with a 1.52 μN resolution. The framework has the potential to significantly facilitate the study on the relationship between muscle arms and force patterns of C. elegans in motion, and thus gives a better understanding of muscle arms development and modelling.