Diabetes represents one of the major chronic diseases, with diabetic ulcers being a significant adverse prognosis. Approximately 80% of lower limb amputations are attributed to diabetic foot ulcers, which constitute a primary cause of patient disability and mortality, while also imposing a substantial burden on healthcare systems. Although standardized Western medical protocols for diabetic foot management exist, clinical outcomes remain suboptimal. The amputation rate due to diabetic foot ulcers continues to rise annually, underscoring the urgent need for novel and effective interventions to address this condition.

Quantitative assessment of cutaneous biomechanical parameters may indirectly reflect the cumulative damage inflicted by diabetes on foot tissues. Such evaluation provides critical guidance for predicting susceptibility to recurrent ulceration and determining the necessity of enhanced offloading strategies to prevent ulcer development. By applying specific mechanical loads to the skin and measuring deformation, rebound characteristics, and displacement dynamics under pressure, it becomes possible to quantitatively evaluate parameters such as elastic modulus and viscoelastic properties.

This case-control study aims to investigate the feasibility of utilizing plantar skin quantitative mechanical parameters as objective biomarkers for biomechanical impairment in diabetic foot. Furthermore, it seeks to establish a standardized operating procedure (SOP) for quantitative measurements tailored to diabetic foot scenarios. The study is designed to bridge critical evidence gaps between theoretical consensus and clinically applicable quantitative tools, demonstrating clear innovation and potential clinical value.

Inclusion Criteria:

• For healthy one: Fasting blood glucose < 6.1 mmol/L and glycated hemoglobin < 6.0%, with no history of diabetes; Foot condition: normal appearance of both feet, without wounds, deformities, trauma, infections, or dermatological disorders; voluntary participation in this study with signed informed consent.
• For diabetic one: Confirmation of type 1 or type 2 diabetes mellitus as defined by the World Health Organization (WHO) diagnostic standards; Diagnosis of diabetic foot disease* consistent with the criteria established by the International Working Group on the Diabetic Foot (IWGDF); Voluntary participation in the present study with provision of signed informed consent.

Exclusion Criteria:

• For healthy one: (1) History of foot surgery, trauma, or fractures resulting in skin scars or irreversible cutaneous damage; (2) Active chronic dermatological conditions affecting skin integrity, such as tinea pedis, eczema, or psoriasis; (3) Vascular diseases of the lower extremities (e.g., arteriosclerosis obliterans) causing muscular or cutaneous atrophy in the feet; (4) Systemic diseases impacting the skin or connective tissues, including systemic sclerosis, rheumatoid arthritis, or vasculitis; (5) Prolonged engagement in heavy physical labor or professional sports leading to abnormal thickening or hyperkeratosis of the plantar skin; (6) Presence of extensive, hyperkeratotic lesions (e.g., calluses, corns) or wounds at the measurement site impairing probe contact accuracy; (7) Inability to cooperate or diagnosed psychiatric disorders; (8) Investigator-determined unsuitability for the study or inability to comply with protocol requirements.
• For diabetic one: (1) Uncontrolled severe acute foot infections; (2) Dermatological conditions that interfere with measurement procedures; (3) Irreversible foot skin damage due to non-diabetic etiologies such as trauma or surgical intervention; (4) Coexisting systemic disorders (excluding diabetes) that compromise skin elasticity, including systemic sclerosis, rheumatoid arthritis, or vasculitis; (5) History of above-knee amputation on the measured foot; (6) Inability to cooperate or presence of psychiatric disorders; (7) Investigator-determined ineligibility due to non-compliance concerns or unsuitability for study participation.

both healthy people and diabetic foot patient.