Musculoskeletal Modeling and Analysis of Trikonasana.

Context: Yoga has origins speculated to date back to pre-Vedic Indian period and is practiced as a common exercise, both in India as well as all around the world. Although the yoga practices are ages old, there is not much research literature available. Moreover, with the advancement in technology, the modern analysis tools are not used up to their full potential.

Aims: This research focuses on developing a framework for analyzing trikonasana, using the optical motion capture system, and validating the noninvasive method for analyzing muscle activity in prominent muscles while performing trikonasana.

Subjects and Methods: We have adopted the noninvasive analysis method using optical motion capture system OptiTrack™ for recording the human motion and musculoskeletal modeling software LifeMod™ to analyze the muscle activity while performing trikonasana. Surface electromyography (sEMG) studies were performed using Trigno™ (Delsys Inc.) wireless sEMG sensors to validate the LifeMod simulation results pertaining muscle activation.

Results: It was observed that the characteristics of the sEMG match to that of the estimated muscle tension from the architecture used in this study. The muscle groups such as external right obliques muscles, rectus abdominis of the front leg, and gluteus maximus and gluteus medius of the rear leg were observed to undergo major activation during an isometric contraction while performing trikonasana. The magnitudes of the muscle tension during the left bend depict a close resemblance to the muscle tension magnitudes during the right bend.

Conclusions: The optical motion capture system and musculoskeletal modeling software can be used to analyze muscle activity in any yoga exercise noninvasively. Since the yoga exercises majorly require the practitioner to maintain a certain posture for a considerable duration, our approach can be used to find the important muscles involved and their corresponding muscle tension when they undergo isometric contraction.