The public health benefits of Tai Ji Quan—Addressing the unmet needs of aging populations in the 21st century

1. Introduction

With the increase in older populations worldwide¹ comes an increased health burden related to chronic diseases.2, 3, 4 One of the most disabling of these is knee osteoarthritis (OA), which occurs in millions of older adults who subsequently live with joint pain and stiffness, leading to chronic disability and a diminished quality of life.5, 6 Epidemiological evidence shows a higher prevalence of OA in older adults living in urban and rural areas of China than in older adults living in the United States.7, 8, 9 Although a wide range of treatment strategies exist,¹⁰ non-pharmacological modalities for long-term management of knee OA, including controlling pain and improving movement function and quality of life, remain largely underexplored.

Tai Ji Quan¹¹ is a component of traditional Chinese medicine that has been popularized throughout the world as a means to improve health and prevent disease.¹² As a potential treatment for knee OA, Tai Ji Quan is attractive from the standpoint of public health and clinical rehabilitation because it involves highly choreographed exercises that engage participants in mindfully controlled, fluid multi-joint and multi-planar motions and regulated breathing. These characteristics make Tai Ji Quan, when practiced with low load-bearing, clinically suitable for people with joint pain and movement limitations since it promotes balance, joint lubrication, and stability. There is emerging research evidence from western countries showing that Tai Ji Quan lessens pain and improves physical function in those with knee OA.13, 14

In the article by Zhu and his colleagues¹⁵ in this special issue of the Journal of Sport and Health Science, additional evidence of the clinical value of Tai Ji Quan in improving gait kinematics and physical function in a sample of older Chinese women with knee OA is detailed. The study makes clear the need for generating convincing evidence of the efficacy of Tai Ji Quan as an alternative treatment modality for reducing pain and maintaining joint movement for older adults who have the disease. The study has some laudable features. It is the first randomized controlled trial (RCT) in China that specifically targets a population of Chinese women with knee OA. Additionally, in terms of design elements, the use of radiography to objectively define knee OA, biomechanical laboratory-based measures of gait, adequate blinding of data collection staff to group assignment of participants, appropriate intervention duration, and a modified Tai Ji Quan routine tailored to the population under scrutiny are all strengths.

Notwithstanding these strengths, the authors acknowledge some significant design and methodological weaknesses and limitations. First and foremost, the age range (between 60 and 70 years old) for the study population is quite narrow in light of the evidence that knee OA occurs primarily in adults aged 65 and over.¹⁶ Additionally, the study would be stronger had the authors considered a study population based on clinical prototypes (bilateral vs. unilateral knee OA, medial vs. lateral tibiofemoral involvement) rather than just the presence of knee OA.

From a clinical perspective, the study lacks a comprehensive assessment of dynamic stability and gait variability resulting from the intervention. Because Tai Ji Quan emphasizes postural alignment and weight centering, an evaluation of gait and weight-bearing symmetry would enhance its clinical relevance to the knee OA population. The tailored Tai Ji Quan routine used is not well delineated and lacks substantive detail in its protocol, especially regarding why the 8 forms were chosen and how they were modified based on the clinical symptoms and movement characteristics of knee OA. Finally, the interpretation of the data may be marred by the failure to control for important confounders such as the severity of the disease at baseline, changes in medication use, and levels of physical activity. Collectively, these issues raise questions regarding both internal and external validity and the generalizability of the intervention.

The weaknesses of Zhu et al.'s¹⁵ study serve as a compelling reminder of the difficulty of finding rigorously designed and well controlled clinical Tai Ji Quan trials conducted in China, a situation that may have created a significant knowledge gap and, subsequently, barriers to meeting public health needs in China. Promoting evidence-based medicine to improve the health of the country's rapidly growing population of older adults¹⁷ is crucial, especially since this population is significantly affected by the increasing prevalence and burden of chronic diseases,4, 17 as well as the financial strains and deficiencies inherent in the healthcare system.18, 19, 20 Therefore, this perplexing situation should serve as an impetus for accelerating scientific research to develop safer and more efficacious chronic disease care interventions for China's aging populace.

2. Future research considerations

Because it originated in China,11, 12 Tai Ji Quan is considered a national treasure deeply rooted in Chinese culture. Over the past century, martial artists, practitioners, and researchers have successfully disseminated this heritage internationally, burnishing its health value,¹² primarily through anecdotal evidence. However, creating an evidence-based case for the clinical value of Tai Ji Quan must now become a priority for the research community. Chinese scholars have the responsibility to continue to spread Tai Ji Quan by transforming it into a contemporary health care/clinical intervention that can be utilized to address significant public health issues facing the country's aging population.

In reviewing the current state of research on Tai Ji Quan, researchers should carefully consider the following issues as they develop their research plans.

2.1. Transformation

Tai Ji Quan was originally developed as a martial art (Wu Shu) to be used primarily for self-defense.¹¹ Thus, in research studies its techniques are not always applied appropriately to address the effects of chronic diseases in older adults. A “one size fits all” approach in the application of Tai Ji Quan to clinical research is often misguided, and its direct application is not always acceptable given the unique needs and capabilities of older adult populations. Therefore, instead of using Tai Ji Quan as a generic exercise for health promotion and disease prevention, it is time to consider a paradigm shift that transforms its movements into a therapeutically and functionally useful intervention²¹ that can ultimately help older adults reduce their health risks and maintain their ability to live independently.

2.2. Tailoring

Parallel with the notion of transformation is the need for “tailoring”. Just as with prescription medicine, the forms and movements of Tai Ji Quan must be adjusted to address the signs, symptoms, and causes of a particular chronic disease. Specifically, adaption should be purposefully made for specific pathologies (e.g., Alzheimer's, cancer, arthritis) and/or health risk factors (e.g., comorbidity, polypharmacy, physical inactivity). A tailoring approach in research studies makes the intervention more meaningful in practice, and study outcomes can more readily be used to guide community and/or clinical decisions. As an example, older adults with a balance disorder and a history of falls tend to experience a worsening in their motor-sensory systems over time. Therefore, a Tai Ji Quan exercise routine that specifically integrates balance-recovery strategies and sensory organization techniques may be especially beneficial therapeutically since it is designed to improve a person's physical and mental capacity to proactively and reactively respond to and resist unexpected perturbations and/or falls.²¹

In the same vein, a tailored intervention would ideally consider the functional relevance of Tai Ji Quan through a task-oriented approach.²² At this functional level, Tai Ji Quan movements practiced by older adults should be specifically oriented toward developing their ability to carry out functional weight-transferring tasks, such as walking, turning, sitting-to-standing/standing-to-sitting, and reaching; and these movements should be tailored for use in natural environments (at home or in a neighborhood) and in varying circumstances (differing surfaces or visual conditions).

2.3. Integration and delineation

The classical conception of Tai Ji Quan involves uniting a focused state of mind with synchronized breathing while executing a set of intertwined, choreographed, and engaging and disengaging actions. In theory, the successful execution of Tai Ji Quan integrates the following components:

• (1)mindful intention that leads to the initiation of a purposeful action;
• (2)regulated respiration closely synchronized with the intended action;
• (3)physical maneuvers that complete the action.

Behind these actions is the philosophy of yin–yang interaction, which underlies the development of the continuous and circular motion of Tai Ji Quan as reflected in bipolar but highly complementary actions (offensive and defensive, motion and motionless). In practice, however, it is difficult to scientifically quantify these inherent martial art characteristics in a coherent way, and the current literature does not provide much practical information on how the three elements work synergistically or can be incorporated in a way that produces directed movement or actions.

In many research studies, Tai Ji Quan has been conceived of as a physical/callisthenic-like activity and operationalized as such. This approach is not in accord with the essence of Tai Ji Quan practice as described above. When used as a research protocol, this approach makes it difficult to delineate the true effects of Tai Ji Quan in regard to health outcomes. To accurately evaluate and validate the health benefits and effects of Tai Ji Quan, the current paradigm, which typically uses an active experimental vs. a control design, should be augmented with an additional exercise (comparison) modality involving either straightforward exercise programs (strength training, aerobics) or diaphragmatic breathing exercises. This would control for both the physical and breathing effects of Tai Ji Quan training, thereby maximizing the potential for identifying the unique contributions of Tai Ji Quan per se in improving health outcomes. The mechanisms by which Tai Ji Quan may improve health, ranging from the specific contributions of each component to the ways in which the components are integrated, has not been thoroughly studied, but research in this area is essential if the theoretical basis of Tai Ji Quan is to be transformed into the development and application of effective Tai Ji Quan-based interventions.

2.4. Need for mechanistic research

A major question many researchers continue to grapple with is: what specific actions of Tai Ji Quan are related to clinical outcomes? That is, very little is understood about the mechanisms that underlie Tai Ji Quan therapeutic action. For example, what explains the observed improvement in gait characteristics among Tai Ji Quan participants reported in the study by Zhu et al.?¹⁵ One possible hypothesis is that the tailored intervention may have resulted in a reduction in inflammatory activity and thus reduced pain symptoms. Another is that improvement in muscle strength and joint flexibility may have contributed to pain reduction. While the tenability of mechanistic hypotheses such as these can easily be tested, very few RCTs have actually done so. If they did, they might well yield the kind of mechanistic, biological, and physiological insights that would aid in the design of new interventions to determine how Tai Ji Quan produces or improves therapeutic effects. The failure to address this issue may limit opportunities to carry out new exploratory clinical studies. Thus, the current situation calls for more research aimed at discovering possible explanations for how Tai Ji Quan improves various clinical health outcomes.

2.5. Rigor in design and methodology

Although the quantity of Tai Ji Quan research is increasing, few studies have used the kind of rigorous design and methodology that leads to high-quality evidence. It is not uncommon to discover methodological weaknesses in Tai Ji Quan research across many domains of health outcomes.14, 23, 24, 25 Therefore, the need for improved standards in Tai Ji Quan research design remains. In this regard, RCTs²⁶ are highly recommended as the gold standard for evaluating the efficacy of Tai Ji Quan in an area of high public health significance and clinical relevance.

Once a specific clinical problem has been targeted, properly designed trials should include rigorous selection of subjects, carefully controlled comparison conditions that allow clear delineation of intervention effects, a clinically justified and carefully tailored intervention training protocol, a solid plan for close monitoring of intervention fidelity, a well-planned and prioritized health endpoint, the use of reliable and validated outcome measurements, a well-thought-out analytic plan developed in accordance with the research objectives, an adequately powered sample size, and protection against inferential error. Ensuring that these components are part of every research study will enhance the clinical relevance and generalizability of Tai Ji Quan interventions as they are disseminated into clinical practice and/or community preventative services.

2.6. Integrated assessment

As previously described, the practice of Tai Ji Quan involves mindful intention, regulated breathing, and physical execution of movements. However, little is known about how these interwoven elements interact with each other. Therefore, a more complete understanding of Tai Ji Quan training requires an integrated assessment component that simultaneously characterizes, quantifies, and analyzes participant brain, respiration, and body dynamics and their interactions during motion. Such an assessment would add to our knowledge of how intentional movements originate and how they produce specific clinical and functional outcomes.

2.7. Use of advanced technologies and a patient-centered approach

Future exploration of the effects and benefits of Tai Ji Quan training should take better advantage of state-of-the-art technologies and integrated systems, including electroencephalograms (EEGs) (to capture brain activity associated with self-initiated and externally triggered movements), motion capture technologies (to track both kinematics and kinetics of movements), respiration sensors (to measure breathing rate and volume), electromyography (EMG) (to identify muscle activity), and electrocardiograms (EKGs) (to examine the heart's electrical activity). These objective data acquisition methods should be complemented by a patient-centered approach,²⁷ in which participant movement intentions and perceived health benefits are also collected.²⁸ The use of such a combined measurement approach will help advance Tai Ji Quan research not only by contributing to a better understanding of the dynamics of Tai Ji Quan but also by helping researchers design and optimize tailored interventions for targeted diseases.

2.8. Moving from research (efficacy) to reality (effectiveness)

The currently available research on Tai Ji Quan remains heavily focused on demonstrating the efficacy of individual interventions, with many existing studies having been conducted in tightly controlled research environments (or under ideal conditions), with little consideration for how well the results might be generalized to benefit the intended population and improve community-wide evidence-based practice.23, 29 For example, are any of the interventions detailed in the literature, such as the one described in the study by Zhu et al.,¹⁵ ready for community-wide dissemination and implementation? If so, how scalable are they (can they be scaled up to a regional or national level), how sustainable are they (can their effectiveness be maintained so that they continuously improve health outcomes), and how cost-effective are they (are the interventions both highly effective and cost efficient)?

As Harmer²³ points out, research on Tai Ji Quan remains fragmented and unsystematic, and these questions remain largely unanswered, a situation that hinders the broad application of Tai Ji Quan training across various settings and contexts. This, in turn, may have a negative impact on the development of public health policies or clinical guidelines that will support the wider use of Tai Ji Quan. Although it is crucial to recognize the importance of continuing to draw on research-based knowledge from RCTs, there is also a concomitant need in the scientific, public health, and policy arenas to move beyond the “efficacy mode” and include a “pragmatic mode”, which involves an evaluation of the potential for the adoption and integration of evidence-based Tai Ji Quan interventions in broader community and clinical practice contexts.30, 31

3. Conclusion

In closing, the growing interest in Tai Ji Quan in the research community provides momentum for assessing its health benefits in preventing and treating chronic diseases among older adults in China and worldwide. Chinese scholars are in a unique position to move Tai Ji Quan research to a new level in the 21st century, producing, in the process, scientific results that will ultimately impact global public health by reducing the burden of diseases and promoting the harmonic yin–yang balance in health.

Competing interests

The author of this manuscript declares no conflict of interest.