Comparison of Foot Kinematics and Foot Plantar Area and Pressure Among Five Different Closed Kinematic Tasks.

Background: Different closed kinematic tasks may present different magnitudes of knee abduction, foot pronation, and foot plantar pressure and area. Although there are plenty of studies comparing knee abduction between different tasks, the literature lacks information regarding differences in foot pronation and foot plantar pressure and area. We compared foot angular displacement in the frontal plane and foot plantar pressure and area among five closed kinematic tasks.

Methods: Forefoot and rearfoot angular displacement and foot plantar pressure and area were collected in 30 participants while they performed the following tasks: stair descent, single-leg step down, single-leg squat, single-leg landing, and drop vertical jump. Repeated-measures analyses of variance were used to investigate differences between tasks with α = 0.05.

Results: Single-leg squat and stair descent had increased foot total plantar area compared with single-leg landing (P = .005 versus .027; effect size [ES] = 0.66), drop vertical jump (P = .001 versus P = .001; ES = 0.38), and single-leg step down (P = .01 versus P = .007; ES = 0.43). Single-leg landing and single-leg step down had greater foot total plantar area compared with drop vertical jump (P = .026 versus P = .014; ES = 0.54). There were differences also in rearfoot and midfoot plantar area and pressure and forefoot plantar pressure.

Conclusions: Differences in foot-striking pattern, magnitude of ground reaction force, and task speed might explain these findings. Clinicians should consider these findings to improve decisions about tasks used during rehabilitation of patients with foot conditions.