Evaluating Gait Dynamics, Contralateral Limb Compensation, and Load Distribution During Ambulation with a Total Contact Cast (TCC): A Comprehensive Biomechanical Analysis

<i>Background</i> Diabetic foot ulcers represent one of the most persistent and complex complications in clinical management. These ulcers pose significant challenges, often leading to morbidity and impaired mobility. Total contact casts (TCC) are often utilized in treatment for diabetic foot ulcers. A TCC may result in a functional iatrogenic limb length discrepancy (LLD) due to the inherent structure and material composition of the cast. While a TCC is effective in offloading pressure from affected diabetic foot ulcers and promoting healing, it may also alter gait mechanics and pressure distribution, affecting the contralateral limb. Recognizing and addressing these consequences is crucial for developing comprehensive treatment strategies that not only facilitate wound healing but also preserve functional mobility and prevent secondary complications. The central questions guiding this research are: What is the impact of a TCC-induced Leg Length Discrepancy (LLD) on contralateral limb loading? Can a contralateral lift effectively mitigate these effects? <i>Methods</i> We conducted a study involving thirty healthy adults (16 female, 14 male; mean age 26.5 years). Gait analysis was conducted using a CAREN instrumented treadmill under four experimental conditions: (1) Baseline: shoes only (no cast or lift); (2) TCC: TCC on the right foot, no lift on the left; (3) TCC+Heel: TCC on the right foot, heel lift in the left shoe; and (4) TCC+Full: TCC on right foot, full-length shoe lift on the left. The TCC introduced an approximate 1.9 cm limb length discrepancy (LLD). Gait parameters and ground reaction forces (GRFs) were recorded and analyzed using repeated-measures ANOVA to assess the effects of TCC and lift conditions on contralateral limb loading. <i>Results</i> Key outcomes included walking with a TCC (without a lift) increased peak contralateral foot GRFs by approximately 6% (p<0.05), indicating greater stress on the non-casted foot. Introducing a contralateral heel lift significantly reduced contralateral GRFs (p<0.01), suggesting partially restoring of normal loading patterns. However, a full-length shoe lift did not provide a comparable reduction in contralateral limb loading, showing no statistically significant benefit. <i>Significance </i>This study highlights the importance of recognizing a TCC-induced LLD increases contralateral limb loading. This study demonstrates that a simple contralateral heel lift effectively reduces excess loading and improves gait symmetry, whereas a full-length shoe lift offers little benefit. These findings support the routine use of heel lifts as an adjunctive measure during TCC treatment to improve gait symmetry and protect the non-casted limb.