Short-Term Foot and Postural Adaptations During an Industrial Workday: A Workplace-Based Biomechanical Assessment

Background: Prolonged standing is common in industrial environments and may induce functional adaptations in the foot and postural system. This study aimed to evaluate short-term changes in foot posture and plantar pressure distribution after a working day in assembly line workers. Methods: Forty participants (31 males, 9 females; mean age 44 ± 7 years; BMI 26.1 ± 3.6 kg/m2) performed standing tasks during an 8 h shift. Static baropodometric measurements and 3D foot scans were obtained before and after the workday to assess plantar pressure, contact area, and arch height. The Spanish versions of the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) and the Foot Function Index (FFI) were used to evaluate discomfort and functional status. Paired t-tests were applied, and correlations were analyzed (p < 0.05). Results: Left-foot arch height decreased significantly after the workday (mean change = 0.6 mm; p = 0.027). Both mean and peak plantar pressures declined (p < 0.001), along with moderate reductions in contact area (p ≤ 0.05). The center of pressure shifted mediolaterally, and discomfort was most frequent in the lower back, knees, and feet. A positive correlation was found between arch height reduction and FFI score (r = 0.349; p = 0.028). Conclusions: Prolonged standing was associated with measurable adaptations in foot posture and plantar pressure, possibly indicating short-term fatigue or compensatory postural adjustments. These results emphasize the importance of assessing plantar load and foot morphology as indicators of potential functional responses to sustained standing and as possible targets for ergonomic and rehabilitation strategies.