Abstract
Background
The idea of “life force” or “subtle pranic energy,” sometimes referred to as prana, ki, qi, vital force, and scientifically accepted as biofield, is prevalent across many cultures.
Objectives
This review's objective is to synthesize data from studies that looked at a range of physical, psychological, and biofield sensations while experiencing prana and receiving biofield therapies.
Method
We looked for qualitative, exploratory, and mixed-method studies on subtle pranic energy perceptions, as well as the physical and emotional experiences connected to biofield therapeutic procedures, through searches in 3 electronic databases, including PubMed, Web of Science, and Scopus. Based on inclusion and exclusion criteria, ninteen studies were appropriate for this review. The results were synthesized using the 6 steps of the thematic analysis approach.
Results
The first concept, “energy experiences,” comprises 4 themes that describe participants’ sensations of prana (awareness of temperature variation; presence of energy; physical sensation of energy; and magnetic sensation). The second concept, “positive experiences,” consists of 3 themes that describe the benefits of undergoing biofield therapy on the physical and emotional conditions of the participants (positive affective experiences; positive physical sensations; and positive valued experiences). The third concept, “experience of awareness,” describes how participants become aware of their mental activities (awareness of mental activities).
Conclusion
Our knowledge of perceptions and experiences related to biofield therapy is enhanced by this meta-synthesis. It gave a comprehensive picture of the enormous sensations and advantages that were felt when engaging in biofield practices.
Introduction
The concept that living matter is composed of subtle energy is not new. Many cultures believe in a “life force” or subtle energy – “prana ”. 1 These subtle energy concepts were named in different cultures as qi (Chinese), ki (Japanese), prana (Sanskrit), universal fluid (Ether), animal magnetism, odic force, etc. 2 Prana, the Sanskrit word for ‘vital energy’ mentioned in the Chandogya Upanishad, was probably composed before 1000 BCE.3,4 Just as we have found energy to be the basic fabric of everything in the physical world, yoga texts call Prana as the basic fabric of all biological systems, as mentioned in the Prashnopanishad. 5 Prana is the basic component of the subtle body and the entire chakra system. 4 Similar concepts about subtle energy in the West are reflected in the Holy Spirit and can be traced back to writings in the Old Testament as well as the practice of laying on hands. 6
The subtle pranic energy has been scientifically recognized and defined as a biofield. Various culture-based practices or therapies for physical and psychological well-being have included similar descriptions of energy called life force. 7 The biofield is a field of energy intimately connected with each organism that holds information central to its higher order of being. It provides the scientific foundation for a holistic view of life and techniques for integrative medicine. Even though, biofield energy is not yet fully understood or measured by scientific instruments, proponents suggest that its effects can be observed and quantified through various physiological, psychological, and even cellular responses. Medical physiology, cell biology, and biophysics provide the scientific framework within which evidence for biofields, their proposed receptors, and functions is presented.8,9
Energy medicine may be useful as a complementary therapy and an adjunct to standard allopathic medical approaches.10,11 Energy medicine is of 2 kinds: “veritable” energy fields that can be measured for diagnosis and treatment, on the other hand, “putative” energy fields (also called biofield) are based on the belief that a subtle form of vital energy infuses all living systems that do not have standardized, reproducible measurements. 12 Several therapeutic procedures, based on explanatory models that describe the use of the hands to sense and alter biofields, have been developed for improving physical and psychological health. Among the most commonly practiced of these biofield therapies are Reiki, Therapeutic touch, Healing touch, external Qigong, pranic healing (PH), distant healing, etc. 13 Energy may be transferred without direct physical contact between the healer and the subject. 14 The concept of pranic energy and methods of its use for healing have been described by various cultures for thousands of years. Despite discrepancies in the conceptions of these proposed forces, the emergence of specific techniques that seek to harness biofield energy to promote one's own healing process is a common thread among their ideas. 6
As Capra (2010) 1 wrote, “a time has arrived to go beyond-to understand the deeper and subtler dimensions of our universe.” In an empirical investigation, participants could accurately identify practitioners of non-contact therapeutic touch, demonstrating that hands were a rich source of energy. 15 In this sense, the therapeutic experiences of many healers and subjects support the fact that vital forces can be felt during healing sessions. 16 There is a way to understand and experience prana and our energetic anatomy by sensitizing our hand chakras, which are in the centre of the palm, to feel the energy between them.17,18 Self-awareness of energy flows within the human body that influence the personality, and it is essential for spiritual development. 19 Therefore, it is crucial to have a comprehensive understanding of pranic energy and how it interacts with the universe.
The rationale for the review
Many systematic reviews have looked into the therapeutic effects of biofield practices.20-24 These reviews, by bringing all depictions into a unified frame, serve as a bridge to draw conclusions about the overall effectiveness of biofield practices. There are pieces of evidence from numerous biofield therapies that are relevant to the outcomes of distinct clinical populations. A review of Qigong and Tai Chi shows these therapies have positive impacts on health and improve the overall quality of life. 20 Another systematic review examined the data from randomized clinical trials that investigated the clinical efficacy of Healing touch as a complementary therapy. 21 Besides, a systematic review shed light on the effectiveness of biofield therapies (ie, therapeutic touch, healing touch, and Reiki) in the treatment of cancer-related symptoms. 22 Biofield medical therapies have been shown to be useful in reducing stress and improving cognitive response. 23 According to a comprehensive review of biofield therapies, these procedures can have a role in reducing anxiety, improving mood, mental health and wellness. 24
From the above findings, we can say that research and systematic reviews on biofield therapies have mainly comprised randomized controlled trials that utilize condition-related outcome measures. Such trials are vital for establishing an evidence base for biofield therapies, but they provide little insight into how biofield enhances therapeutic outcomes. 15 These research studies solely provided results in terms of outcomes and their consequences. There is evidence for various biofield treatments that were relevant to outcomes for different clinical populations, and most therapeutic studies fell short of providing the experiential aspects of pranic energy experiences or rarely attempted to summarize or synthesize the life force or pranic energy experiences.
Undertaking a qualitative meta-synthesis to understand and explore clients’ experiences of receiving any form of biofield practices might shed light on the characteristics and influences of pranic energy in a wider sense. Qualitative analyses can provide a thorough understanding of clients’ real experiences with biofield practices, explain some difficult and usually contradictory aspects of those experiences, and provide insight into clients’ perspectives on what works for them.25,26 In other words, it is an approach where outcomes from different studies in a particular area are drawn together, reinterpreted and conceptualized relative to each other, so multiple facets of similar findings can be explored.27,28 To our knowledge, no meta-synthesis on the experiences and effects of biofield therapy exists today. A meta-synthesis of qualitative studies on biofield therapies could thus provide a comprehensive picture of participants’ perception of biofield therapies, as well as the diverse ways in which these practices may contribute to participants’ physical, emotional, and mental well-being. By synthesizing the available literature, we aim to provide a comprehensive overview of subtle energy ‘prana’ and associated outcomes during biofield practices.
Methods
Search process and selection criteria
As per PRISMA guidelines, 29 the research team looked through 3 databases: Web of Science, PubMed, and Scopus between January 2022 and September 2022. A search was conducted for qualitative, exploratory, and mixed-method research on subtle pranic energy experiences, physical, mental, and emotional changes associated with biofield practices, and subtle pranic energy perception. Studies that have not explored subtle pranic energy experiences were not considered for meta-synthesis. Only full-text articles published in English between January 1990 and September 2022 were considered. Studies that did not investigate subtle pranic energy sensations were excluded from consideration for meta-synthesis. Systematic reviews, critical or narrative reviews, books or book chapters, dissertations or thesis that have not been published, and studies published prior to 1990, as well as research that solely provides quantitative data, are excluded from this review.
Keyword
“Biofield practices,” “distant healing,” “healing Touch,” “invocation healing,” “marma chikitsa,” “pranic healing,” “Prayer healing,” “Qi healing,” “Qigong,” “reiki,” “ritual healing,” “Shamanic Healer,” “subtle energy,” “therapeutic sensations” and “therapeutic touch”.
Data Collection and Analysis
Study Screening and Selection
A description of the study screening and selection procedure is shown in Figure 1. Using the predefined search terms, 2 researchers conducted the searches. A total of 53,384 records from 3 databases (PubMed, Web of Science, and Scopus) were found. Duplicates (26033) were removed, and studies were screened in 2 steps. Out of 27351 studies, those deemed unrelated to the topic based on their title and abstract were excluded (26885). 447 publications were left out of the eligibility process, including 230 randomized controlled trails, 59 qualitative studies that weren’t focused on subtle energies, 151 reviews and book chapters, 3 non-English papers, and 4 studies published before 1990. 19 studies were included in the final synthesis. Flow chart.
Data Extraction
MB has extracted the following information from the included studies: the country of study, study characteristics, population characteristics, and methodological aspects. The researcher assessed the findings of each paper independently, and qualitative data related to the sensory experiences and therapeutic effects (physical and psychological) of participants were extracted. Where the authors were unsure or disagreed, discussions were held with the full research team to reach a consensus.
Data Synthesis
The results of the articles that were included based on inclusion criteria were combined using an inductive thematic analysis. The studies’ topics and ideas were evaluated for their applicability to the goals of the current meta-synthesis. The 6 stages of thematic analysis suggested by Braun and Clarke 30 were followed. In phase 1, MB familiarized herself with the data by repeatedly reading the results sections of the existing papers, while searching for meanings and common topics. In phase 2, initial codes were created that summarized the key concepts and subjects of each study. However, for initial coding, summative data from the discussion section was used when the authors did not use the participants exact words, but instead gave data that helped identify a specific theme. In phase 3, these initial codes from diverse research were compared, contrasted, and combined to generate overarching concepts and themes. Phase 4 involves further development and refinement of the emerging ideas and themes. The subtheme and main theme, as well as their associations, have been labeled in phase 5. Writing the meta-synthesis was the last step, and it was a dynamic process that allowed for more in-depth consideration and fine-tuning of the topics. Three other teammates met on a regular basis to discuss and fine-tune the analysis process and the emerging codes, subthemes, and core themes, at each step.
Results
Description of Study Characteristics
Shows the Characteristics of Included Studies.
Aims and objectives for the included studies
All 19 studies addressed how participants experienced biofield sensations; however, several of the studies also looked at other topics or subjects that were not relevant to this review.
Study setting and different modes of biofield therapies
Out of 19 studies, the majority ie, 8 in the USA, 6 were conducted in India, 4 in the UK, and 1 in South Korea. These studies represent the significance of different biofield practices, consisting of 4 studies on therapeutic touch and 3 studies on each modality like healing touch, pranic energy perception, and reiki. Meditation on twin hearts and qigong therapies comprise 2 studies from each modality along with a single investigation into pranic healing. Studies on tai chi, yoga, meditation, and reiki are among the studies that are listed.
Participants
The sample size of the included studies ranged from 1 to 1284 participants, with a total of 2197 participants from both genders. The age of the participants in all the studies ranges from 14 to 84 years. In most studies, female volunteers made up the majority. While some research introduced the therapy to healthy people, some studies identified subjects with specific health conditions.
Data collection and analysis
Data from 9 studies were collected via individual interviews, where they used open-ended questionnaires for collecting the data. Ten other studies used open-ended questionnaires to gather written descriptions. For the meta-synthesis's critical examination, the questions were segmented under a variety of headings based on the topics they covered.
Critical Appraisal of Study Quality
Ten questions make up the Critical Appraisal Skill Program (CASP) 50 which evaluates various methodological issues. The questions were divided up under a variety of headings for the meta-synthesis's critical evaluation in accordance with the broader topics they covered. Special attention was paid to the evaluation of the data analysis approaches, the presentation of the findings and the general applicability of the study. These aspects were the most important in evaluating each study's overall contribution to the knowledge of prana and its experiences during therapeutic procedures. The CASP was not used with the purpose of providing an overall quality score for each study or excluding individual studies. We believed it was important to synthesize all relevant evidence, even if some studies were appraised as methodologically poor. 51 However, it became apparent that methodologically rigorous studies, which provided a deeper description of themes, contributed more substantially to the themes identified in the meta-synthesis than studies with insufficient descriptive analyses.
Appraisal of Studies.
The research aims and design
All studies that met the criteria for inclusion adequately articulated their aims. A few studies justified the use of their study designs. 13 studies explained the use of more focused qualitative methods for their selection.31-34,36-38,40,41,45,47-49
Sampling
A thorough explanation of the sampling procedure and the criteria used to select participants is given in eighteen studies. This has not been considered in the case study. 32
Primary researchers’ reflections on their background and preconceptions
All these studies provided information on the researchers’ backgrounds but did not discuss how these might influence the analysis process.
Ethics
Six studies reported receiving ethics committee approval.31,34,39,40,41,45 Twelve studies briefly discussed obtaining participants informed-consent. The ethical issues were not mentioned in 1 study. 32
Analysis and presentation of findings
The analysis was a synthesis of the opinions expressed by participants rather than descriptions of the phenomenon, as evidenced by the analysis in the majority of studies. The qualitative results of several investigations were also discovered as a secondary outcome. Eleven studies stood out as having better scientific rigor, providing psychologically significant themes, and summarizing the participant narratives in a more conceptual way.31,33,36-38,40,41,45,47-49
Findings from Meta-Synthesis.
Thematic synthesis on Pranic energy experiences during biofield practices.
Table 3 lists the themes and explanations of participant experiences from the studies that were included and contributed to each of the new themes in the meta-synthesis. Some of those studies' labels and the new theme we created have considerable similarities.
Core concept 1: Energy Experiences
The subtle energy experiences that took place when practicing pranic energy perception and receiving any kind of biofield therapy are categorized into 4 main themes that make up this concept.
Awareness of temperature variation. This theme covers the experiences associated with temperature change while engaging in biofield practices. The description of experiences was mentioned in 14 studies. A few studies briefly mention whether study participants had warm or cool sensations.34,35,38,40,42-44,46,49 Only 5 studies, however, gave a thorough explanation of temperature variance. In a study, a participant expressed about temperature variations as “After the Reiki sessions, I can feel my feet. They used to be like ice, but now they are warm, sometimes hot in the center. That feeling of heat calms me down” (P3).
37
Some subjects had contradictory temperature experiences, feeling both cold and warm at the same time.
39
Awareness of the presence of energy: During the therapeutic process, participants could sense the prana, or energy present within and surrounding their bodies. Sixteen studies referred to the idea of gaining awareness of the presence of energy during therapeutic procedures. However, 9 studies briefly mentioned participants’ awareness of prana or vital energy in a small description like “Noticing sensations of an increase in energy”, “Noticed the presence of energy,” and “Open and sensitive to the flow of the life energy that is moving freely in the body,” “energized,” “increased energy level,” “Wave of energy” and “light enter the bodies.”31,33,35,36,39,40,42-44 In a reiki study, participants expressed, “I could feel my energy, suddenly this light lit up, and I could feel my energy going through my body.” I suddenly felt this real kind of tightness in my chest, and then I just started to cry, it is almost like all this energy was trapped and it was just coming out and it had been suddenly allowed to release, and you could see this light, this sort of almost strong light in my head and in my feet and all over my body” (P2)
49
Physical sensation of energy This theme covers the sensations felt by participants that are tactile in nature. In 18 studies descriptions of the experience of the physical sensation of energy were mentioned. Participants from a few studies briefly mentioned the physical sensations of the energy they experienced, such as tingling sensation in hand or body, heaviness in the hands, pressure in hands, seeing of colors, electric sensations, the sensation of the ball, sensations of vibration and floating, etc.31,33-35,40,42-44,46 In a study, a participant felt, “During the Tai Chi class, I noticed a tingling, light sensation in my palms and a flow-like feeling going down my arms”.
37
A participant expressed, “I experienced a weird sensation when you placed your hands over the back of my head. I felt something happen. I know that your hands were not touching me, but it felt as if there was a connection of some kind between us. I felt a weird pulling sensation”.
32
Magnetic sensation Participants reported experiencing a kind of attraction or magnetic sensation between their hands while meditating and perceiving pranic energy. The description of experiences with magnetic sensation was mentioned in 4 studies. However, 2 studies gave a short description of this sensation.42,43 A study on Meditation on Twin heart gave a detailed account of the participants' experience of magnetic sensation.
“Magnetic attraction between hands, the attraction was more at the tip of the fingers”
48
Core Concepts 2: Positive Experiences
The focus of this meta-synthesis was also on synthesizing the psychological and physical sensations that participants had while engaging in biofield practices. There are 3 themes that fall under the concept of positive experiences.
Positive affective states This theme deals with the experiences related to positive emotional states experienced by the participants. The description of participants’ experiences with positive affective states was mentioned in fifteen studies. However, 9 studies had a short description of these states, such as calm, relaxed, happy, a sense of inner peace, joy, etc.33,35,36,39,40,42,45,47 A participant from a reiki study explained, “I feel deep relaxation the day after I’ve had my reiki. I think it has just made me a lot calmer, just accepting of things and grateful for what I have and given me a lot more clarity” (P2)
41
Positive physical sensation This theme represents the physical benefits participants get from biofield practices. In 5 of the ten studies, participants’ expressions of physical benefits were only briefly noted, with descriptions like “freshness in the eyes and other parts of the body,” “feeling lightness in the body,” “feeling relaxed and falling asleep,” “less pain and muscle relaxation.”33,35,43,47,48 A participant narrated, “After the Reiki sessions, I feel refreshed. I’m calmer and have fewer aches and pains. I feel energized and motivated. I now have more energy to give, to staying interested at work.”
37
Positive valued experiences Participants in some therapy experienced meaningful positive experiences that can contribute to their general well-being. The description of positive valued experiences expressed by participants was found in 7 studies. However, 5 studies had a short description of this experience felt by participants as a feeling of enthusiasm, inspiration, clarity, and a sense of wholeness.33,42,47-49 A participant has stated, “There’s always hope, as long as there’s life there, there’s hope, and there’s new things coming out all the time, and reiki just puts you in that position to find the peace to cope with all this and the wellbeing” (P4).
41
One participant stated in a study, “Healing touch has brought me the sense of wholeness and peace that I feel at the end of a treatment” (P39).
40
Core Concept 3: Awareness Experiences
This category explains participants’ awareness of various mental activities occurring in them during the biofield practices.
Awareness of mental activities Eight studies have described the awareness states of the participants during the therapy. Seven studies have provided a description of the awareness state, such as “a sense of quietness in mind,” “improvement in concentration ability,” “increased mental clarity,” and “Problem-solving better and thinking clearly.”33,35-37,43,47,48 In a study, a participant stated, “When we finished, my thoughts had slowed down, and I could concentrate more. I felt very focused and ready to do what was necessary.”
38
Mode of Energy Therapies Influenced Participants to Experience Different Sensations Relative to Three Major Themes.
Discussion
To attempt to better understand the physical, emotional, and mental effects of pranic energy perception and biofield practices as described in 19 qualitative and exploratory studies, the current review aimed to synthesize participants’ experiences of subtle energy. In this review, participants’ descriptions related to the theme of “awareness of the presence of energy” present that clients are aware of the energy’s influence over them. The majority of the research in this review discusses these expressions. It is significant to note from a pranic energy study that everyone may feel the presence of this energy in the body regardless of gender, age, or education. 52
In a study, participants felt pressure, tingling, vibration, temperature changes, electromagnetic field, and other physical sensations during biofield practice. 53 In some studies from this review, healers also noticed sensations present in their clients. The characteristic of these therapeutic sensations observed across studies is that their occurrence is often not confined to the point of place or stimulation, but rather spread throughout the body. The exact pathways they follow have hardly been scientifically researched. The relationship between physical sensations and the healing process is a complex and multifaceted aspect of human well-being. Physical sensations often play a significant role in how we perceive and interpret our bodies responses to therapeutic interventions. Clients relate their energy experiences to the effectiveness of the therapy they are going to receive. 54 2 studies conducted in China report that patients consider the occurrence of the needle sensation to be very important for acupuncture treatment, and most of them believe that the stronger the needle sensation is, the more effective the treatment is.55,56 Besides, Neuroscientific research shows that greater activation of a subset of brain regions, namely the insula and temporoparietal junction, during these practices leads to awareness of one’s body sensations.57,58 With no sensual circumstances, higher mental processes engage bodily representations in central somatosensory areas and generate conscious bodily sensations. 53 It is also possible that information from the environment is absorbed by organisms not only through receptors but also outside the realm of sensory experiences. 59
The occurrence of a tingling sensation is not restricted to some pathological reasons or mechanical stimulations.60,61 Some studies have interpreted the sensation of tingling as the presence or flow of energy.37,62,63 The sensation of tingling or any other during these interventions is often caused by (1) attention-related processes and (2) changes in peripheral physiology, for example, during relaxation, static postures, slow exercises, or deep breathing brought on by autonomic and somatic motor self-regulation and affective processes. 64
The most common experience identified in most studies is a sense of calm and relaxation. Furthermore, individuals gained hope and courage in their lives. In a study on Reiki, participants gained inspiration and clarity, such as realizing what to do next in their lives or gaining new ideas. These experiences could result from achieving an ideal autonomic state. 65 Some previous studies shed light on the neurophysiological mechanisms behind those states. According to Baldwin, 66 there is considerable clinical evidence that Reiki activates the parasympathetic nervous system and results in therapeutic benefits similar to the relaxation response. As consistent with amine and endorphin theories, the reinforcement of parasympathetic tone and the cutback of sympathetic activity resulted in a decrease in blood pressure, levels of stress-related hormones (eg, cortisol) anxiety, and stress levels after the short-term practice of qigong.67-69
In the awareness experience, participants were aware of their mental activities and reported having clarity, better focus, improved concentration, and enhanced problem-solving abilities. The Center for Contemplative Mind in Society places a strong emphasis on how meditation and other biofield techniques aid in problem-solving and bring about insights. After training in meditation, individuals showed improved cognitive flexibility.70,71 There is a lack of in-depth information about the interplay of the mechanisms behind these sensations.
As related to energy experiences, there was an awareness of temperature variation and physical sensations of energy that were commonly experienced by participants in all kinds of energetic therapies in this review. Reporting of tingling and warm sensations followed by pulling sensations were the most commonly occurring sensations among the participants in this review. Whereas experience of magnetic sensation has been reported in practices during pranic energy perception and meditation on twin hearts. These 2 practices led the participants to experience almost all sensations covered under all 8 subthemes.
With the exception of pranic healing therapy, the other biofield practices caused the individuals to experience positive affective states. Participants in pranic healing therapy become conscious of their mental processes. Healing touch therapy has not reported beneficial bodily experiences or awareness of mental activity. Qigong treatment and a multimodal therapeutic study have not reported positive valued experiences. Different factors can explain how biofield practices affect feelings and perceptions. This might be caused by variations in people's perceptual capacities, a lack of client reporting on their experiences, and the type of therapy they would receive.
The synthesizing of participants’ experiences from this meta synthesis supported the idea that while undergoing any kind of energy healing practices, a person can feel and experience the presence of subtle energy through various kinds of tactile and other kinds of sensations. Subtle Pranic energy enables participants to balance their mental and physical well-being. In light of the above findings, qualitative synthesis provide light on the full range of experiences. This synthesis serves as a platform for integrating various biofield experiences.
Limitations
Although the majority of research identified themes with insufficient descriptions, all these studies were incorporated in order to convey the existing body of information. However, it became clear that research with methodological rigor, which offered a more in-depth description of themes, contributed significantly more than studies with poor descriptions. This review has not provided in-depth information about the mechanism behind experiencing all the sensations.
Implication and Direction for Future Studies
The results of this meta-synthesis have broader implications. The interpretations from this review add to the data in an under-researched area, more rigorous investigations are needed. There is a need for empirical data to back up the personal reports of beneficial experiences with biofield treatments documented in this meta-synthesis. With the help of this meta-synthesis findings, a researcher can further study the mechanisms behind sensations and experiences. The relationship between experiences from various themes and whether there are any relationships between them may also be investigated in future studies.
Conclusion
This meta-synthesis expands our understanding of the perceptions and experiences associated with biofield therapy. Synthesizing of participants’ perceptions and effects from different biofield practices contributed to a broad understanding of the vast sensations and physical, mental, and emotional benefits that were experienced by participants during biofield practices. It was evident from the included studies that there are no differences in experiencing energy sensations in the clinical population. Another finding from this review is that the experience of these subtle energy sensations is not limited by gender, age, education, or location. Regardless of these boundaries, one can experience subtle pranic energy during biofield practices. Recognizing and understanding the relationship between subtle energy perception and healing can lead to more comprehensive and effective approaches to health care and well-being.
Footnotes
Authors Contribution
A search for selections of the articles was took by all the 4 authors. Data extraction, data synthesis and paper writing were done by first author. All 4 authors met on a regular basis to discuss and fine-tune the analysis process and entire article.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was funded by World Pranic Healing Foundation India.
Registration of Review
This systematic review has been registered in PROSPERO (CRD42022355333) on 2/9/2022.
