Effect of Weightlifting Shoes on Bilateral Plantar Pressure Distribution During 50 kg Loaded Full Squats in Internationally Competing Weightlifters

The aim of this study is to systematically examine the plantar pressure distribution under constant load in weightlifters wearing weightlifting shoes and to identify possible asymmetries between the right and left feet. The study's research group consisted of 17 male weightlifters who participated in international competitions. Foot pressure measurements were performed using a Sensor Medica (Italy) baropodometric measuring device. A total of 25 pairs of variables (right-left foot) related to peak plantar pressure, mean pressure, contact area, center of pressure, and regional load distribution were analyzed during squat exercises performed by participants with a constant load of 50 kg. The findings showed a statistically significant difference between the right and left foot in 5 out of 25 pairs of variables (p < .05). Most of the significant differences were concentrated in pressure and load parameters (medial and lateral mean pressure of the hindfoot, overall maximum and mean pressure, load on the 2nd and 3rd metatarsal heads), and in these variables, the left foot showed significantly higher values with moderate to large effect sizes (d = 0.72-1.31) compared to the right foot. In contrast, small to moderate differences were found in contact surface variables (total contact surface, toes, 4th-5th metatarsal heads, hindfoot lateral contact percentage) in favor of the right foot (d = -0.55 to -0.97). No significant differences were observed between the two feet in the remaining 32 variables (footprint length, COP indices, Fick angle, forefoot/heel loads, etc.). In conclusion, it was found that the plantar pressure distribution in weightlifters is largely symmetrical, but a significant pressure/load dominance in favor of the left foot, particularly in the rear foot region, and conversely, a tendency for a larger contact surface in the right foot. This pattern is consistent with discussions in the literature regarding the dominant/non-dominant extremity difference and bilateral load symmetry specific to weightlifting. The findings indicate that foot-specific support strategies, rather than identical ones for both feet, should be considered in the design of weightlifting shoes and insoles.