Effects of curved carbon fiber plate bending stiffness on plantar pressure characteristics and performance during speed step in jump rope athletes

This study aimed to (1) investigate the plantar pressure characteristics of the speed step technique and (2) evaluate the effects of curved carbon fiber plates with varying stiffness on plantar pressure distribution and performance. Twenty-six healthy competitive male jump rope athletes completed plantar pressure measurement protocols. Each participant performed at least three trials of speed step sprints under three shoe conditions: control shoe (control), shoe with moderately stiff curved carbon plates (stiff), and shoe with highly stiff curved carbon plates (stiffest). Plantar pressure data and the number of jumps were recorded for each condition. The highest plantar force was observed in the middle forefoot (MidFF), followed by the medial forefoot (MedFF). Maximum peak pressure was greatest in the hallux (H), MidFF, and MedFF. Plantar pressure parameters significantly differed among shoe conditions. Compared with the control, the stiff condition showed significantly lower peak force and force-time integral in the medial midfoot (MedMF). The stiffest condition reduced peak force and force-time integral in the lesser toes (LT), as well as overall plantar peak force. During the speed step, the forefoot region bore the greatest load, with the hallux and first-third metatarsophalangeal joints subjected to the highest mechanical stress. Curved carbon fiber plates did not enhance jump rope performance. However, the stiffest curved plate improved plantar load distribution by reducing forces in the lesser toes and medial midfoot and decreasing overall plantar force through load redistribution.