A Mathematical Method for Electromyography Analysis of Muscle Functions during Yogasana.

CONTEXT: For the past few decades, the number of people practicing yoga is increasing in number. Yogasanas need smooth body movements in the process of attaining defined postures that the person must hold on to activate specific muscles of the body related to that asana. Yogasanas should be performed with perfection to derive maximum benefits. OBJECTIVE: The objective of this study was to introduce a mathematical method to understand muscle functionalities while doing Yogasanas. MATERIALS AND METHODS: Used Delsys surface electromyography (sEMG) - Trigno™ (Delsys Inc.) sensors for data recording and analyzing muscle activation patterns. RESULTS: Performance analysis was quantified using normalized sEMG signals. The sEMG data during final posture were fit to a straight line using linear regression analysis. CONCLUSION: The results suggested that the slope of the best fit line is a good metric for monitoring the muscle activity during Yoga performance. The advantages of this method are the slope of the line is a good indicator for monitoring the muscle activity while doing Yogasana and the method suggested in this study can be extended for analyzing other asanas as well.

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.

Holistic assessment of anger in adolescents - Development of a rating scale.

BACKGROUND: Anger related issues in adolescents are an important contributor to adolescent mortality and many negative developmental outcomes. Anger being the most primitive defence mechanism, determining its maladaptive nature is a complex phenomenon. Further, it lacks clarity in terms of its definition, demarcation from aggression and hostility, and also its assessment. Available anger rating scales do not represent anger adequately or comprehensively. The concept of anger is dealt with exhaustively in Indian classical texts. According to these texts, anger is an evil virtue that is born out of Rajasic nature and leads to momentary loss of cognitive functional abilities. Manifestation of anger occurs at behavioural (kayika), verbal (vachika) and mental (manasika) levels. Based on these principles, a psychometric scale is developed for assessment of anger in adolescents. OBJECTIVE: The objective of this study was to develop a psychometric scale for assessment of anger in adolescents based on behavioural (kayika), verbal (vachika) and mental (manasika) levels. MATERIALS & METHODS: Item generation was done referring to the existing scales, texts on spirituality and psychology. It also included discussions with children, teachers and parents. Item reduction was carried out using expert opinion, focused group discussion and factor analysis. Testretest reliability was checked with 127 children (63 girls and 64 boys). The final scale was administered to 757 children (427 girls and 330 boys) to ascertain reliability co-efficient values. RESULTS: Co-efficient of Alpha value for final scale recorded 0.804. Test-retest reliability showed .835 correlation. CONCLUSION: Anger can be assessed holistically using Trikarana (kayika, vachika and manasika) concept as dealt in almost all Indian classical texts. A 23-item adolescent anger scale is a comprehensive tool to assess behavioural, verbal and mental anger in adolescents.

Fiber bragg grating sensor based device for simultaneous measurement of respiratory and cardiac activities.

This paper reports a novel optical ballistocardiography technique, which is non-invasive, for the simultaneous measurement of cardiac and respiratory activities using a Fiber Bragg Grating Heart Beat Device (FBGHBD). The unique design of FBGHBD offers additional capabilities such as monitoring nascent morphology of cardiac and breathing activity, heart rate variability, heart beat rhythm, etc., which can assist in early clinical diagnosis of many conditions associated with heart and lung malfunctioning. The results obtained from the FBGHBD positioned around the pulmonic area on the chest have been evaluated against an electronic stethoscope which detects and records sound pulses originated from the cardiac activity. In order to evaluate the performance of the FBGHBD, quantitative and qualitative studies have been carried out and the results are found to be reliable and accurate, validating its potential as a standalone medical diagnostic device. The developed FBGHBD is simple in design, robust, portable, EMI proof, shock proof and non-electric in its operation which are desired features for any clinical diagnostic tool used in hospital environment.

Understanding Vrikshasana using body mounted sensors: A statistical approach.

AIM: A scheme for understanding how the human body organizes postural movements while performing Vrikshasana is developed in the format of this paper. SETTINGS AND DESIGN: The structural characteristics of the body and the geometry of the muscular actions are incorporated into a graphical representation of the human movement mechanics in the frontal plane. A series of neural organizational hypotheses enables us to understand the mechanics behind the hip and ankle strategy: (1) Body sway in the mediolateral direction; and (2) influence of hip and ankle to correct instabilities caused in body while performing Vrikshasana. MATERIALS AND METHODS: A methodological study on 10 participants was performed by mounting four inertial measurement units on the surface of the trapezius, thoracolumbar fascia, vastus lateralis, and gastrocnemius muscles. The kinematic accelerations of three mutually exclusive trials were recorded for a period of 30 s. RESULTS: The results of every trial were processed using two different approaches namely statistical signal processing (variance and cross-correlation). Conclusions obtained from both these studies were in favor of the initial hypothesis. CONCLUSIONS: This study enabled us to understand the role of hip abductors and adductors, and ankle extensions and flexions in correcting the posture while performing Vrikshasana.

A mathematical model of effects on specific joints during practice of the Sun Salutation--a sequence of yoga postures.

The 'Sun Salutation' consists of a sequence of ten yoga postures, each posture counteracting the preceding one producing a balance between flexion and extension, performed with synchronized breathing and aerobic activity. As this sequence is often performed and recommended by many yoga practitioners, there is a need for the development of a biomechanical model to support its reported clinical benefits. This requires a detailed knowledge of the nature of the forces and moments at the various joints involved. A simple mathematical model based on rigid body mechanics is developed for each of the Sun Salutation postures. Dynamic moments with high magnitudes and rates, applied with unusual distribution patterns, optimal for osteogenesis, are found to occur. Also, the joints are subjected to submaximal loadings thus ensuring that none of the joints are overstressed.

Time-frequency analysis of human motion during rhythmic exercises.

Biomechanical signals due to human movements during exercise are represented in time-frequency domain using Wigner Distribution Function (WDF). Analysis based on WDF reveals instantaneous spectral and power changes during a rhythmic exercise. Investigations were carried out on 11 healthy subjects who performed 5 cycles of sun salutation, with a body-mounted Inertial Measurement Unit (IMU) as a motion sensor. Variance of Instantaneous Frequency (I.F) and Instantaneous Power (I.P) for performance analysis of the subject is estimated using one-way ANOVA model. Results reveal that joint Time-Frequency analysis of biomechanical signals during motion facilitates a better understanding of grace and consistency during rhythmic exercise.

Yoga techniques as a means of core stability training.

Core stability in general involves the muscular control required around the lumbar spine to maintain functional stability. Stability and movement are critically dependent on the coordination of all the muscles surrounding the lumbar spine. This paper aims to show that an age-old yoga practice, called Uddhyana Bhanda and Nouli, is an effective means of core stability.