Objective Measurement Method for Assessing Plank Test Among Female Basketball Players

Abstract

Trunk muscle strength plays a crucial role in the sport-specific movements of basketball players. While the plank test is widely used to assess trunk muscle endurance, its lack of standardization limits its effectiveness in high-performance environments. The study aimed to establish objective criteria for determining when the plank position was no longer maintained and introduced a new variable, postural error (PE). This study involved 23 (age = 15.22 years, weight = 66.3 kg, height = 174 cm) healthy female basketball players from the Hungarian U16 first league. Using optical motion capture, the thoracic kyphosis (TK) and lumbar lordosis (LL) were monitored during the test. The cutting point (CP) was determined based on four mathematical formulas and the estimation of two independent experts. PE was determined based on the area under the curves, which characterizes the magnitude of displacements until the endpoint. According to the difference between the expert-estimated and the calculated CP, the initial angles were calculated as the average of the first 15 seconds, and the CP was set at a ±25° deviation. Additionally, PE was introduced to assess the strategy of maintaining the plank posture, revealing differences in performance even among participants with similar CP times. The present study introduces a new method for determining the test's objective starting angle endpoint and introduces a new variable, PE, to characterize trunk stability, distinguishing between different execution strategies. The findings suggest that this approach provides a more reliable and objective way to assess trunk muscle endurance and core stability.