Effects of Osteopathic Manual Therapy on Plantar Pressure Distribution in Adolescents with Functional Lower Limb Postural Deviations: A Pilot Study

(1) Background: Adolescence is a period of rapid musculoskeletal development during which functional postural deviations may occur without structural deformity. This pilot study investigated changes in the plantar pressure distribution following osteopathic manual therapy (OMT) in adolescents with functional postural deviations. (2) Materials and Methods: Twenty adolescents aged 14–16 years (8 females and 12 males) participated in this study. Functional postural status was characterized using clinical screening and Kineod three-dimensional postural assessment, while plantar pressure outcomes were recorded using the BTS P-WALK platform under static and dynamic conditions. Participants completed 10 individualized OMT sessions over three months, consisting primarily of soft-tissue and muscle-energy techniques. (3) Results: Mediolateral plantar load distribution did not change significantly. Forefoot loading increased from 32.65 ± 12.58% to 39.67 ± 9.29%, with a reciprocal reduction in rearfoot loading from 67.35 ± 12.58% to 60.34 ± 9.29% (Holm-adjusted p = 0.006; Cohen’s dz = 0.842). The right dynamic Arch Index also increased significantly from 13.73 ± 8.86% to 17.37 ± 7.44% (Holm-adjusted p = 0.025; dz = 0.701). Other Arch Index changes were not significant after correction for multiple testing. (4) Conclusions: In this pilot cohort, OMT was followed by measurable changes in the forefoot–rearfoot plantar load distribution and the right dynamic Arch Index. These findings should be interpreted as preliminary functional changes in plantar loading rather than evidence of structural correction or definitive therapeutic efficacy. Larger controlled studies are needed to determine whether these changes are specifically attributable to OMT.