<p>Pneumatic artificial muscles (PAMs) can generate multimodal movements, e.g., linear contraction/extension, spiral torsion, and bending motions. Among these motions, contraction and extension movements can be achieved using linear PAMs (LPAMs) designed to mimic human skeletal muscle. LPAMs have considerable potential for wearable applications and can be integrated into soft wearable robotic systems. Due to their inherent compliance, excellent human–robot interaction, safety, and low cost, LPAMs are considered potential alternatives as actuator components in the construction of wearable robots. This review presents a comprehensive overview of the bio-inspired design of LPAMs and their wearable applications. The biomechanics of human skeletal muscle, including anatomy, morphology, and biomechanical characterization, is analyzed to provide design inspirations for LPAMs and determine the assistance requirements of LPAM-based wearable robots. Herein, LPAMs are classified into four categories based on their structural shapes, including cylindrical-shaped muscles, flat-shaped muscles, fold-shaped muscles, and muscles with other shapes. In addition, this review provides an overview of the diverse physical interfaces utilized in wearable robots and presents a comparative analysis of the actuation characteristics of LPAMs and the assistance performance of LPAM-based wearable robots. This analysis was conducted in consideration of several key metrics, including the contraction ratio, maximum force, specific force, response frequency, assistive torque/bodyweight, and net metabolic cost. Finally, this review summarizes the ongoing challenges and future research directions.</p>