Biomechanical Precision Assessment of Trikonasana Through Trigonometric Modelling and Goniometric Measurement for Injury Prevention

Abstract

This study evaluates the accuracy of a Cosine Law–based geometric method for estimating joint angles during Trikonasana (Triangle Pose) and compares it with conventional goniometric measurements. The research involved 30 adolescents aged between 13 and 19 years, each of whom performed the Trikonasana pose while their body positions were analyse Joint angles at the shoulder, hip, and knee. Adolescent participants from Chengalpattu, India. Angles were calculated using triangle geometry derived from body segment positions and statistically compared with goniometer readings using descriptive statistics and independent samples t-tests. The Cosine-based method demonstrated mean values closely aligned with goniometric measurements for the shoulder (60.16° vs. 60.32°), hip (59.20° vs. 59.28°), and knee (60.64° vs. 61.10°). Independent samples t-tests revealed no statistically significant differences between the two methods across all joints (p > 0.05), with mean differences remaining below 1°. These findings indicate strong agreement between the Cosine Law approach and standard clinical measurements, supporting its reliability for ensuring proper alignment and contributing to injury prevention in yoga practice. The proposed method offers a non-invasive and mathematically robust alternative for posture analysis in yoga instruction, rehabilitation, and biomechanical research.