Abstract
Introduction:
Balance problems arising from cancer and its treatments can significantly impact daily functionality and quality of life. Improving balance as part of a cancer treatment plan could result in better patient outcomes. Thus, the aim of this study was to determine whether an integrative therapeutic yoga intervention can improve balance in a heterogenous population of cancer survivors (CS).
Methods:
This is a secondary analysis of data from a 16-week feasibility study where therapeutic yoga was supplemented with psychosocial support to maximize health-related quality of life in adult CS of any stage and site. In this study, we investigated balance, as it has been shown to be an important outcome in CS due to its role in physical function and quality of life. The intervention included therapeutic yoga three times per week for 16 weeks and daily psychosocial support provided via text message. Participants’ balance was assessed while standing on a pressure mat with feet together, eyes opened and closed, for 30 seconds in each condition. Data on the “sway path distance” (displacement of the center of gravity) in the two conditions were obtained. Changes in balance after the intervention (from baseline to follow-up) were analyzed using paired-sample t-tests. Changes in balance were also assessed using responder analysis. We described the proportion of participants that improved their balance or not based on 10% difference from baseline scores.
Results:
Of the 29 participants included, 22 (76%) completed post-assessments. Changes in both balance assessment conditions were not statistically significant (eyes opened: 80.06 ± 374.99, p = .702; eyes closed: −1.82 ± 24.01, p = .068). Responder analysis showed that 8 participants improved their balance with eyes opened, while 8 worsened, and 6 did not change. Analysis of balance with eyes closed showed that 5 improved, 8 worsened, and 9 did not change.
Conclusion:
This secondary analysis of data from a heterogenous cohort of adult CS did not support our hypothesis at the group level. However, at the individual level, responder analysis indicated improved balance in some survivors. Future research is needed to determine factors related to the cancer experience which might mediate balance outcomes to inform better integrative interventions.
Background
From the initial psychological shock of diagnosis through the subsequent journey of treatments and survivorship, the cancer experience often takes a heavy detrimental toll on the functionality and quality of life of cancer survivors (CS). 1 Cancer itself and its related treatments can lead to fatigue, pain and a significant decline in physical functioning, with impaired balance being one of the main concerns. 2 Chemotherapeutic agents, commonly used in cancer treatment, can have neurotoxic effects, with possible side effects including peripheral neuropathy. 3 Peripheral neuropathy in the lower extremities can cause a range of debilitating symptoms such as pain, paresthesia, reduced strength, diminished sensation, and altered proprioception. 3 These complications often result in poor balance, which limits mobility and complicates the performance of everyday tasks, thereby adversely affecting quality of life. 3 Eventually, a decline in balance will also increase the risk of falls and fractures, further endangering the well-being of CS.
Traditional rehabilitation programs often focus on a singular aspect of cancer treatment, such as physical well-being (e.g., mobility and physical activity).4,5 However, the cancer experience and its impact on overall health perception is multidimensional, consisting not only of physical but also of mental and spiritual domains. 6 Integrative approaches that address the whole individual offer a more comprehensive strategy for enhancing the overall health of CS. The American College of Sports Medicine convened its second roundtable in 2018, recommending that cancer patients and survivors should “avoid inactivity” even during treatment. The guidelines emphasized that specific doses of combined aerobic, resistance, and balance exercises can improve cancer-related health outcomes, including balance. 7
In a previous study, we investigated the association between various exercise modalities and improvements in physical functioning among breast CS. 8 We found that all exercise modalities (i.e., aerobic, resistance and flexibility exercises, therapeutic yoga, and self-selected exercises) were associated with improved outcomes related to body composition, muscle strength and physical function. 8 However, therapeutic yoga showed to be the best option for improving balance, as assessed using the forward reach test, 8 which is a valid field test for balance. 9 Therefore, moving forward, it is crucial to investigate the effect of therapeutic yoga on balance in a more heterogenous sample of CS. In addition, to address the multidimensional aspects of CS’ well-being, it is also important to explore the role of motivation during exercise program. Thus, incorporating psychosocial support in the program may enhance motivation in CS. The Reversal Theory model provides a framework for understanding motivational states, their variations over time, and differences in motivational profiles among individuals. 10 This model offers a way to assess “what we want at a particular moment” (motivational state) and “how we feel when we get what we want (or don’t).” By using this framework, psychosocial support can be tailored to the specific motivational needs of CS. The model identifies eight motivational states, and the combination of these states experienced at any given time create a rich taxonomy that captures the complex experiences of CS, offering insights into their varying motivations throughout daily experiences.
Thus, the purpose of this secondary data analysis was to determine whether a heterogeneous group of CS, who participated in our feasibility parent study, showed improved balance following the therapeutic yoga program supplemented with psychosocial support.
Methods
Recruitment and Design
The research protocol was reviewed and approved by the University of Texas Health Science Center at San Antonio’s (UTHSA) Institutional Review Board (#HSC2019-0637H). In error, we did not prospectively register this trial, but we have now registered it retrospectively at ClinicalTrials.gov: registration number
Of 56 eligible patients, 30 CS were invited between January and March 2020, signed the informed consent, and completed baseline assessments (Figure 1). A sample size of 30 CS was selected based on the pilot nature of the study and resource allocation, which was determined to suffice for the nature of pilot studies.
Study retention flow diagram.
Inclusion/Exclusion Criteria
Individuals were included into the study if they were at least 18 years of age, had a diagnosis of any cancer in their lifetime, had access to mobile phone or computer to complete surveys and respond to text messages, were able to peak and understand English or Spanish, and were oriented to time and place. Individuals were excluded from participation if they were currently enrolled in a competing protocol at the Mays Cancer Center or presented with any absolute contraindication to exercise testing as detailed by the American College of Sports Medicine Guidelines on Exercise Testing and Exercise Prescription. 11
Assessment Procedures
All assessments were performed in our clinic located at the Mays Cancer Center (UTHSA) and took ~3 hours. After signing the informed consent, resting heart rate and blood pressure were measured. Anthropometric measures were then taken, including height and weight to calculate body mass index. 12 Participants were then asked to complete a comprehensive psycho-social questionnaire packet, followed by physical functioning/fitness tests.
Standing balance was assessed using an instrumented platform (Matscan, Tekscan, Inc. Norwood, MA) that utilizes pressure mapping data collection in two 30-second intervals. For the first interval, participants were asked to stand on the mat with feet together while evenly distributing their weight through each foot and to focus their gaze on a target placed on the wall. Immediately after the first trial, the participants were asked to close their eyes for a second 30-second interval. Each interval collected point-by-point (60Hz) data to evaluate sway and postural stability. The data collected during the intervals shows quantitative values for weight bearing within each foot, analyzing anterior/posterior and left/right center of force excursion as well as left/right forefoot/rearfoot weight bearing percentages. In addition to weight-bearing differentials, the platform generates data on sway by assessing the ‘total distance’ in centimeters traveled by the center of gravity side-to-side, front-to-back and diagonally. Balance outcomes were assessed at baseline and follow-up after 16-week of therapeutic yoga.
Intervention Components
Yoga protocol and meditation exercise
Due to the COVID-19 pandemic in early March 2020, the yoga program was delivered via live stream in coordination with the Somatic Engage platform for 75 minutes, three times per week. The program focused on developing breath and body awareness/control (pranayama), focused concentration, meditation, muscular strength, muscular endurance, and mobility (flexibility) training integrating the mind-body-spirit connection.
We have tested a similar yoga sequence successfully with breast CS. 8 The yoga, focused on being a therapeutic sequence, was created by one (ND) of our HEAL (Holistic Exercise Advancement Laboratory) team members. HEAL Therapeutic Yoga is a deliberate integration of yoga, physical therapy and fitness, tailored to both improve and protect joint flexibility and muscle strength. This precision intervention is guided by individual breath-centered movement (“The only thing that you have to do is breathe”), allowing each participant to identify the level at which they can engage in each movement. In addition to the class offering, participants were given access to digital video links that they could use if they were unable to attend in person or live stream.
Psychosocial Support
In addition to therapeutic yoga, participants received daily psychosocial support messaging based on their motivational state through the BlueJay Engage telehealth portal. Messages were based on the Reversal Theory model designed to align with participants’ motivational states, encouraging health-enhancing behaviors while promoting psychological and spiritual well-being. Participant state was measured by capturing these states utilizing the Reversal Theory State Measure Bundled Version. 10 The prompt for responding to the state measure was sent to the participants through the Blue Jay Engage telehealth portal at 10:15 a.m. each day. The link stayed active throughout the day. The participant could open the link at a time of their choice. Within the telehealth application, an algorithm retrieved and immediately texted the relevant messages back to the participant.
Treatment of Data
The targeted sample size of 30 for the parent one-armed pilot study was primarily based on testing the feasibility and efficacy of the intervention to improve health-related quality of life and generate hypotheses. Participants acted as their own controls in a paired repeated measures design. Continuously distributed outcomes were summarized by descriptive statistics and categorical outcomes described as counts and percentages. For group analysis of balance change data, paired sample T-tests were conducted with statistical significance set at p < .05. Changes in balance (sway) after the intervention were also assessed using responder analysis. A responder analysis provides insights into the effect of the intervention on the outcome of interest by categorizing participants based on their response to the treatment. 13 Thus, a 10% decrease in sway measures (follow-up scores minus baseline scores, in centimeters) was used as a threshold for improvement. 13 We described the proportion of participants that either improved their balance or not based on the 10% threshold. Those who showed balance changes ≥10% in sway were considered “improvers,” <10% were considered “worsened,” and those who had around 0% change, were considered “did not change.” Data analyses were conducted using SPSS v.27 (IBM corporation).
Results
Participants
Of the 30 participants invited to the HEAL lab for baseline assessments, 29 (86% female, 58.2 years old and obese [BMI = 31.35]) completed baseline and follow-up assessments (Table 1). One participant did not want to commit to study activities due to time constrains and did not sign the consent form.
Participants Demographics.
Balance results are listed in Table 2. Differences in balance were not statistically significant from baseline to follow-up after a 16-week intervention. With eyes open, the change was 80.06 cm ± 374.99 (p = .702), and with eyes closed, the change was −1.82 cm ± 24.01 (p = .068). Responder analyses using a 10% difference as a threshold for improvement indicated that 8 participants improved balance with eyes opened, while 8 worsened, and 6 did not change. Analysis of balance with eyes closed showed that 5 improved, 8 worsened, and 9 did not change.
Balance Results.
Discussion
The purpose of this study was to assess the effect of therapeutic yoga combined with psychosocial support to improve balance in a cohort of survivors of cancer. While we hypothesized that therapeutic yoga would improve balance, the group data did not support this hypothesis. The high variability in the balance (sway) data (see Table 2) precluded the identification of significant changes under both eyes-open and eyes-closed conditions. However, when applying a threshold of 10% change to assess individual changes, the results varied among participants. To help explain why some improved their balance while others did not, we explored the data on yoga sessions attendance, but attendance was similar across participants, suggesting that other factors may have influenced balance outcomes. Given the complexity of bipedal standing balance, factors such as chemotherapy-induced peripheral neuropathy, chronic pain, fatigue, and malaise may have affected individual responses to the intervention. The fact that some individuals showed a 10% or greater improvement in balance suggests that these factors can be positively influenced by the intervention in some CS. Other factors such as stage of disease or ongoing treatment, may have also impacted participants’ responses.
For future studies, it will be important to quantify how much of the intervention is received by comparing online yoga participation time with data from wearable activity tracking devices. Relatedly, understanding how many participants received psychosocial support is crucial, as the supportive messages could have motivated increased general activity. Tracking activity with wearable devices would provide an objective measure of participation and help assess the impact of psychosocial support on motivation and activity levels. Moreover, including a larger sample size of CS and categorizing them by disease stage and cancer type at diagnosis would improve the evaluation of the intervention's efficacy in improving balance outcomes.
In reviewing studies related to balance in CS, one observational study compared balance in CS to healthy controls using the Timed Up and Go (TUG) test and postural stability (sway) on a force plate. 1 CS participants showed significantly slower TUG times than controls, indicating worse mobility, balance, and walking ability. However, they did not find a significant difference in postural stability for the eyes-open condition between CS (sway path distance = 39.4 cm) and controls (sway path distance = 39.2 cm), which was measured using a similar system to ours. Although their CS participants had similar heterogeneity to ours in terms of diagnoses, our participants seemed to have much poorer balance than their sample (i.e., baseline sway path distance = 113.8 cm). Unfortunately, we did not assess balance using a more functional test compared to the computerized one. Therefore, future studies should consider pairing functional tests such as the TUG with computerized balance assessments to comprehensively analyze the impact of interventions on balance in CS. Another study found that foam pad balance exercises prevented balance losses caused by chemotherapy in CS. 14 One difference between the cited study and ours was that they limited inclusion criteria to those with normal weight (BMI = 18.5-24.9), whereas our participants were on average obese (BMI = 31.35). Although increased BMI could theoretically make balance improvements more difficult, it is challenging to discern without a more detailed description of participants’ underlying conditions such as diabetes, peripheral neuropathy, vestibular problems, and muscle function.
Furthermore, CS factors influencing the decision to engage in exercise-health promoting behavior are different than those that do not have a history of cancer. We know that survivors can benefit from engaging in health promoting activities but their motivation to do so, due to their fear of injury and individual medical history, can influence greatly the decision to engage in such activities.15,16 We believe that once they engage in activities, the optimal levels of individual activity to optimize outcome can be determined.
Study Limitations and Strengths
The parent study was a one-armed feasibility study; therefore, our results need to be interpreted with caution. We are aware of the problems with having the participants serving as their own control. However, the pilot feasibility nature of this study allowed us to carry a preliminary longitudinal analysis to examine changes in balance after therapeutic yoga in CS who did not present a change in their health status within the study timeframe. To avoid and address the flaws associated with one-armed study design, future research can employ several strategies such as a two-group randomized trial, blinding the tester to group allocation, and using a statistical approach that accounts for the correlated nature of the data and control for potential confounding variables. Although we utilized a validated computerized platform to assess balance, the device exclusively measured static balance. We recognize the importance of also evaluating the dynamic aspect of balance, which can be achieved through functional tests such as the TUG. Additionally, randomizing the order of conditions (e.g., eyes open vs. closed) when assessing static balance could help mitigate any potential learning effects. Our participants exhibited approximately 16 times greater variability in balance during the eyes-open condition (tested first) compared to the eyes-closed condition, suggesting a possible learning effect.
The COVID-19 pandemic (March 2020) caused a major disruption in delivery of our intervention components. We developed the therapeutic yoga program to be delivered three times a week at a set time in our cancer center. The set time and location were important to promote group ownership on their commitment to the program and generate social support. We were only able to execute this plan for the first week before disruption caused by the COVID-19 pandemic. After a six-week pause, we continued the program with live streaming using the Blue Jay engage application with video access to a recorded session. We consider this to be a strength, that we were able to conduct the study during the pandemic. It is difficult to determine the true effect of the pandemic on our overall results as though we did have attendance and observation of the live-stream sessions, we do not know if participants actually practiced the yoga when the videos were accessed. Also, we acknowledge that the retrospective registration of our trial may have introduced bias in our results.
Conclusion
Our study used a holistic approach targeting to improve balance outcomes in a heterogeneous group of adult CS through means of therapeutic yoga with the addition of meditation. While our hypothesis that the program would improve balance was not supported in the group analysis, results from the responder analysis showed that some individuals improved their balance. Thus, more research is needed to look more specifically at how different cancer types, treatments, stages of disease, peripheral neuropathies, co-morbidities, activity levels, or other factors (such as ethnicity/race) might moderate or mediate balance outcomes. Such investigations may enable researchers to improve and standardize integrative interventions targeting this population.
Footnotes
Acknowledgements
The authors sincerely thank the study participants for generously volunteering their time. Their unwavering commitment made this study possible.
Author Contributions
All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Mark Miller, Daniel Hughes, Nydia Darby, Tim Calderon and Gustavo Almeida. The first draft of the manuscript was written by Mark Miller and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
Data availability statement
The data supporting the findings of this study are available from the corresponding author upon reasonable request.
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: Financial assistance provided by the Mays Cancer Center at the University of Texas Health Science Center at San Antonio through the Cancer Center P30 Cancer Center Support Grant from the National Cancer Institute
Assistance for REDCap provided via
Trial Registration
The trial is registered in ClinicalTrials.gov under number
