<p>This paper describes a textile optical fiber macro-bend sensor for human body motion monitoring. Two types of textile wearable optical fiber sensors are proposed and analyzed: a wearable textile optical fiber sensor based on an optical signal intensity modulation, and a wearable textile optical fiber sensor based on Mach–Zehnder interferometry (MZI). The two structures used a section of single-mode fiber (SMF) of 90 cm in length. The former structure consists of a straight SMF, while the other sensor is based on a macro-bend fiber sensor with a droplet-bending structure. The two structures were fixed onto an elastic substrate, separately. These structures employ fiber macro-bending effects to capture human limb motion in an angle span between 0° and 90°. As the limb moved gradually, a modulation in the signal visibility and a fringe spectral shift on the periodic transmission spectrum of the MZI was observed. The displacement sensitivities of the sensing head range from around − 0.011 dB/° to − 0.0714 dB/° were obtained for the case of a straight SMF, and from − 0.341 nm/o to − 0.484 nm/° which is more than 5 times higher than the published work for droplet-like structure. Both sensing interrogations, visibility contrast and spectral shift, can be utilized to evaluate the sensing performance. The planned technique could provide an innovative wearable and portable textile solution for monitoring human movement with the benefit of ease of fabrication and environmental robustness. These textile optical fiber sensors are comfortable to wear owing to the flexible nature of the substrate.</p>