Balance Impairments in COPD

Abstract

Chronic Obstructive Pulmonary disease (COPD) not only impacts pulmonary function but has deleterious impacts on musculoskeletal system and balance of patients. In any individual, balance is the result of interplay between musculoskeletal, neurological, and environmental aspects, and disturbance in any one or more can affect overall balance control. In COPD, balance impairments have been increasingly reported over the past few years. There are many multifactorial dimensions behind this rising trajectory. Berg balance scale, time up and go, single leg stance, and mini-balance evaluation system have been established as reasonable, valid, and effective tools for screening balance impairments in COPD. Additionally, amalgamation of balance training, tai chi exercises, and breathing exercises in a pulmonary rehabilitation regime have proven to be effective in improving balance and reducing fall risks in patients living with COPD.

1. Introduction

Chronic Obstructive Pulmonary Disease (COPD) is a chronic respiratory ailment characterized by its progressive nature, which entails a gradual deterioration of lung function, leading to airflow restriction and respiratory distress. Globally, COPD looms as a substantial public health challenge, ranking as the fourth leading cause of mortality in developed nations, and projections suggest it may ascend to the third position by 2030 [1]. This debilitating condition exhibits symptoms of bronchitis, emphysema, and asthma (Figure 1), and it exacts a formidable toll on individuals grappling with it, manifesting through a spectrum of distressing symptoms (Table 1). The most prevalent among these are a persistent and often productive cough, episodes of breathlessness that can be triggered by even minimal exertion, and the production of thick, viscous sputum. Additionally, although less frequent, symptoms like a constricting sensation in the chest, feelings of chest congestion, and audible wheezing can significantly impact one’s quality of life.

Figure 1.

COPD as an amalgamation of three pathologies.

Decreased exercise tolerance

Progressive peripheral muscular weakness

Diminution of functional mobility

Activities of daily living in jeopardy

Balance impairments

Table 1.

Physical manifestations of COPD.

Beyond its systemic manifestations, COPD exerts a profound impact on the holistic well-being of affected individuals. This malady precipitates a notable decline in exercise tolerance, making routine activities increasingly challenging. Peripheral muscles progressively weaken, diminishing overall physical performance and functional mobility. Moreover, recent scientific investigations have unveiled an intriguing facet of COPD - a notable impairment in balance control, which can further exacerbate the difficulties faced by those living with this condition [1, 2, 3, 4, 5, 6].

2. The science of balance control

According to Kisner et al., “Balance is a complex motor control task involving the detection and integration of sensory information to assess the position and motion of the body in space and the execution of appropriate musculoskeletal responses to control body position within the context of the environment and task. Thus, balance control requires the interplay of the nervous and musculoskeletal systems and contextual effects” (Figure 2) [7].

Figure 2.

Integration of three systems for maintaining balance.

3. Balance assessment in COPD

Several tests are available to screen for balance impairments within populations. The most common of these are time up and go (TUG), single leg stance, Berg Balance Scale (BBS), and mini and full balance evaluation systems. To assess the likelihood of a fall, it is recommended to use shorter balance assessment tests, so that fall does not occur during assessment. Whenever a health care provider comes across an older adult, they need to ask some specific questions that have been identified in several clinical practice guidelines (Figure 3). These questions include:

1. Have you experienced fall in last 1 year?

2. Do feel unsteady while getting up, standing or walking?

Figure 3.

Summary of balance screening protocol extracted from different CPGs reported in a research conducted by Beauchamp et al. [8].

If the answer to these questions is yes, then the balance screening and evaluation tests should be used.

3.1 Berg balance scale test

The BBS test is widely used and can be administered by a physical therapist in a time span of almost 15 minutes. It has a cumulative score of 56, and values less than 45 indicate increased risk of fall. It measures a vast variety of performance based tasks ranging from getting up from a chair to standing on one leg. The healthcare provider will guide you through a set of tasks, grading your performance on a scale from 0 to 4 for each. The cumulative scores result from evaluating your ability to complete 14 specific movements:

1. Transition from sitting to standing.

2. Stand without support.

3. Sit without support.

4. Move from standing to sitting.

5. Transfer between chairs.

6. Stand with closed eyes.

7. Maintain a standing position with feet together.

8. Reach forward with an outstretched arm.

9. Retrieve an object from the floor.

10. Turn and glance behind you.

11. Rotate in a full circle.

12. Place each foot alternately on a stool in front of you.

13. Stand without support with one foot directly in front of the other.

14. Balance on one leg for as long as possible [9].

However, it considers neither cognitive functionality and its influence on balance nor the impact of unanticipated perturbations on balance. Those two factors are included in the mini-balance evaluations systems (mini-BES) test, which is also used in clinical practices to conduct a balance assessment in COPD patients. Balance assessment while maintaining cognitive functionality is checked in mini-BES test through walking with pivot turns, stepping over obstacles and utilizing time up and go with dual-tasking e.g. ask the subject to count from any number and then say go, or ask the subject to count backwards from 100 to 90 or between any two numbers. Note the speed while performing these activities. Conversely, unanticipated perturbations’ impact is checked in the form of compensatory stepping strategy that will be adapted after removal of backward, lateral and forward external support. Patients with moderate balance disorders tend to take several steps instead of one big step and, in severe balance issues take no step at all and fall spontaneously. The maximum score of the mini-BES test is 28 [10]. After comprehensive analysis of psychometric properties, both the BBS and mini-BES test are recommended to assess patients with COPD.

3.2 Time up and go test

The short duration of the TUG test makes it preferable for COPD patients when functional disability is a concern. The subject is asked to stand from a seated position, walk to a marker 3 meters away, return to the seat, and sit back down (Figure 4). The time required for this activity is the TUG value. Albarrati et al. recommend a value of 8.42 seconds to indicate normal functional activity, while they found an average TUG value of 12 seconds in their older adult COPD patients and found a significant difference between COPD patients and non-COPD subjects in the four age groups that they studied (<49, 50–59, 60–69, and > 79 years of age) [11].

Figure 4.

Time up & go test for measuring time taken to walk back and forth over 3 meters distance. A time > 13 seconds taken to complete this test indicates risk of fall.

Values for TUG and frailty index were greater in COPD patients with frequent exacerbations of symptoms. In addition, a retrospective study showed that TUG has excellent reliability and accuracy for determining the risk of fall in patients with COPD [12, 13].

3.3 Single leg stance

The Single Leg Stance (SLS) test has been shown to be most promising clinical assessment tool in patients with COPD. This test provides results as accurate as those given by long balance-related screening tests. But in a clinical setting where time is short and efficiency is given priority, this test is more acceptable than other tests [14]. The single-leg stance involves standing on one leg without assistance, with eyes open and arms placed on the hips. Timing begins when one foot is lifted from the floor and ends when it touches either the ground or the standing leg, or when an arm leaves the hips. Individuals unable to maintain this stance for a minimum of 5 seconds face an elevated risk of experiencing injurious falls [15].

3.4 Modified Romberg test and Romberg test

The Romberg test includes standing on firm surface without shoes and with feet together. This activity is timed, first with eyes open, and then with closed eyes. Minimum limit is 30 seconds to hold the position if balance issues are absent [16]. The modified Romberg test assesses an individual’s capacity to stand without assistance through four distinct test conditions. These conditions are specifically crafted to evaluate the sensory inputs essential for maintaining balance, including the vestibular system, vision, and proprioception. This test examines participants with both open and closed eyes on firm and compliant surfaces. When eyes are open on a firm surface, visual, proprioceptive, and vestibular systems are assessed. Closing the eyes on the firm surface focuses on vestibular and proprioceptive systems. On the foam pad with open eyes, visual and vestibular systems are challenged, while closing the eyes on the foam pad specifically targets the vestibular system. Presently, the definition of test failure involves a subject being required to open their eyes, moving their arms or feet to regain stability, or starting to fall and necessitating operator intervention to sustain balance within a 30-second timeframe. This test is marked as pass if all four conditions have successfully completed by participant, and marked fail if any one condition has been failed [17].

3.5 Fall efficacy scale-international (FES-I)

The FES-I comprises 16 questions designed to evaluate participants’ apprehension regarding falling while engaging in 16 distinct ADLs (cleaning, bathing, shopping, cooking, dressing, getting up or out of chair, cooking, using stairs, walking in neighborhood, reaching overhead or to the ground, picking up the phone before it stops ringing, walking on wet grounds, paying a visit to friend or relative, walking in crowded regions, walking on uneven surfaces, slopes, and attending a social gathering). Each item on the FES-I is graded on a 4-point scale (1 = not at all concerned to 4 = very concerned). The cumulative score spans from 16 to 64, with 16 representing “no concern” and 64 signifying an “extreme concern about falling” while carrying out the activities outlined in the questionnaire [18].

3.6 Six minute walk test

The 6-minute walk test (6MWT) evaluates the distance walked within a 6-minute duration, serving as a sub-maximal assessment of aerobic capacity/endurance [19]. Additionally, if the covered distance is below 331 meters, it signals an increased risk of falls [20].

3.7 Activity specific balance confidence scale

The Activities-specific Balance Confidence (ABC) scale is a structured survey designed to gauge an individual’s confidence in ambulatory activities, ensuring they can perform these activities without fear of falling or feeling unsteady. Developed in 1995 by Powell and Myers, the scale comprises 16 questions that assess the individual’s confidence levels during various activities. It scores from 0 to 100, 100 indicates maximum confidence for performing ADLs [21].

The characteristics of the commonly used tests are summarized in Table 2. All tests have good construct validity in COPD and show statistical significance between high and low risk of fall.

Test name	Purpose	Time Taken
Berg Balance Scale (BBS)	Core balance	15 minutes
Mini-Balance evaluation system (BES) Test	Core balance	15 minutes
Time up & go	Fall risk	<5 minutes
Single Leg Stance (SLS)	Fall risk	<5 minutes

Table 2.

Characteristics and validity of balance screening tests in COPD patients [8].

4. The shaky ground: a closer look at balance impairments

When integration of all these systems is disrupted by some underlying pathology, balance problems emerge. However, with aging even normal adults begin to face balance-related issues due to changes in the musculoskeletal system, the nervous system, and the ability to track contextual factors [22].

A study performed by Zahra et al. that included 2004 older individuals without COPD above 60 years from Pakistan showed that 89.67% (1797) failed the modified Romberg Balance Test and 10.33% (207) passed it. Failed candidates are those in which some kind of balance impairment is present. Participants those who failed in phase 2 did not get tested for phase 3 and phase 4, similarly those who fail in phase 3 were not considered for phase 4. 654 out of 2004 failed second phase (32%), 464 out of 1350 failed third phase (34%), and 678 out of 884 people failed in phase 4 (77%). Chi-square test showed p value less than 0.05, showing increasing age was significantly correlated with balance disturbances [23]. In contrast to that, a study by Khan et al. in 2021 conducted on younger women between 18 and 30 years of age showed 98 percent of them passed Romberg test, and only 1.3% failed [24]. Hence, age does play a role in disturbing balances.

Deficiencies in the motor aspects of balance control can be attributed to problems in the musculoskeletal system, such as poor posture, limited joint movement, and weakened muscles, and in the neuromuscular system, such as poor motor coordination and pain. One COPD-related musculoskeletal issue that affects balance is the typical thoracic kyphosis, which shifts the body’s center of mass away from the subject’s base of support, increasing the risk of losing balance.

In cases where the legs function as closed chains (i.e., with the foot position fixed), limitations in range of motion or muscle strength at one joint can influence the overall posture and balance of the entire limb. For instance, if ankle motion is restricted due to contractures or ankle dorsiflexor weakness, the use of an ankle-based balance strategy is diminished, and the hip and trunk muscles are relied on more strongly for balance control.

In individuals with neurological conditions like stroke, traumatic brain injury, or Parkinson’s disease, difficulties in generating sufficient muscle force due to abnormal muscle tone or impaired coordination of motor strategies may restrict their ability to engage the necessary muscles for maintaining balance. Moreover, persistent pain can alter movements, reduce a person’s normal stability, and, over time, lead to additional issues with strength and mobility. Addressing these factors is crucial when focusing on rehabilitation for balance and mobility [7]. In COPD, loss of muscular strength and poor posture are believed to be the primary causes for balance impairments.

5. COPD’s sneaky move: the unseen tango with balance impairments

People diagnosed with COPD face a notable risk of experiencing falls due to a combination of various factors (Figure 5). Among these factors are issues such as poor postural control, weakness in the lower limb muscles, and compromised functional performance. Additionally, individuals with COPD who are able to walk but require a constant oxygen supply may encounter the risk of stumbling over the oxygen lines and experiencing a fall. Research findings have underscored the significance of this concern, indicating that COPD ranks as the second highest chronic pathology associated with falls, trailing only behind osteoarthritis [25]. The incidence rate of falls among individuals with COPD ranges from 25 to 46% [25, 26].

Figure 5.

COPD and its direct impact on balance.

Apart from factors like age, depression, malnutrition, and cognitive problems, faulty postural balance emerges as a major intrinsic risk factor for falls within the COPD population. Understanding the mechanisms behind these balance disorders reveals a complex interplay between sensory input and motor function. When individuals with COPD face postural challenges that disrupt their balance, their trunk and respiratory muscles, especially the diaphragm, play a crucial role in stabilizing their bodies. However, it is reasonable to suggest that the increased workload on respiratory muscles in COPD may compromise their ability to maintain stable postures.

Moreover, recent research has highlighted specific balance issues in the COPD population, particularly when they engage in more dynamic activities that demand the use of their lower limb muscles. Numerous studies have linked balance difficulties in stable COPD cases to muscular weakness. As the severity of the disease progresses, individuals with COPD experience muscle mass loss, primarily in their thigh muscles. Consequently, these patients endure reduced endurance levels, heightened fatigue, and breathlessness even during minimal exertion. These symptoms limit their daily activities and exercise tolerance, setting in motion a cycle of decreased mobility and functionality.

Lower limb muscular weakness emerges as a non-pulmonary risk factor for falls, yet individuals with COPD face a greater risk of falling compared to the general population. Poor postural control is not exclusive to COPD but is a common concern among the elderly. About 30% of individuals over the age of 60 experiences at least one fall annually, with the incidence rising to 45% among those over 70 [25]. Faulty postural control becomes more pronounced when underlying chronic conditions are present, and COPD is more prevalent in older populations.

Evidence supports the connection between age and faulty postural control in individuals with COPD, which in turn elevates their risk of falls. Other well-established risk factors for falls, including lower limb muscle weakness, labyrinthine disorders, functional dependence, and the inability to regain balance after a stumble, are frequently encountered by COPD patients. While the risk of falls may seem less urgent when compared to the respiratory challenges of COPD, these falls are associated with increased mortality, dependency, reduced physical function, and a diminished quality of life, affecting both COPD patients and the general population. Furthermore, the consequences of falls are economically burdensome for the healthcare system, as they lead to higher mortality and morbidity rates and to functional decline and earlier admission to care facilities. Therefore, reducing the incidence of falls is a crucial goal within the healthcare system [25, 27, 28, 29, 30, 31, 32, 33, 34, 35].

Balance issues are not an isolated aspect of the COPD patient’s health. They are part of a type of positive feedback system that can lead to acceleration of the decline of a patient’s health (Figure 6). If a balance issue leads to a fall, it can lead to a hospital stay or otherwise to reduced activity that leads to decreased muscle performance. Decreased muscle performance can then increase the probability of a consecutive fall and reduce respiratory performance. Reduced respiratory performance can further reduce activity, leading to a further decrease in muscle performance and further exacerbating the balance issues.

Figure 6.

Vicious cycle of muscle impairments, increased hospital stays, falls and decreased respiratory functions in COPD.

6. Stepping carefully: COPD’s impact on balance unveiled in the research literature

Chuatrakoon et al. [36] conducted a systematic review aimed at identifying balance deficits and evaluating the impact of physiotherapy interventions on patients diagnosed with COPD. This comprehensive review incorporated data from fifteen cross-sectional studies and four Randomized Controlled Trials (RCTs), which were sourced from a variety of reputable electronic databases, including the Cochrane Library, Scopus, PubMed, and CINAHIL. To assess the quality of the included studies, the National Institute of Health (NIH) quality assessment tool was utilized. This assessment indicated that ten of the cross-sectional studies exhibited a moderate to high level of quality, as they achieved an NIH score greater than 7. Additionally, the quality of the RCTs was appraised using the Pedro scale, which indicated that these trials ranged from good to excellent in quality, with Pedro scores ranging from 6 to 9. The key findings of this systematic review underscore the significant presence of balance impairment among individuals suffering from COPD, as determined through various balance assessment tests when compared to the general population. Consequently, the review strongly advocates for the incorporation of balance training as an integral component of physiotherapy rehabilitation programs designed for individuals with COPD, aiming to address and ameliorate their balance issues.

A 2016 study conducted by de Castro et al. [37] examined the differences in functional and static balance between individuals with COPD and a control group without COPD. The study also explored how gender and the severity of COPD might influence balance. The study’s findings indicated that COPD patients exhibited poorer static and dynamic balance compared to their healthy counterparts. Notably, gender appeared to play a role, with men performing better in functional balance assessments, while women demonstrated superior results in static balance tests.

Oliveira et al. [38] investigated the extent of fear of falling (FOF) in individuals afflicted with COPD. Additionally, they sought to unravel the intricate nexus between FOF and various factors: the muscular strength exerted during physical activities, the ability to maintain balance, and the maximum level of physical exertion sustainable by COPD patients during any given task. To gauge the participants’ FOF, the researchers employed the Falls Efficacy Scale International (FES-I). Meanwhile, the assessment of physical functionality in both the COPD and control groups entailed the use of quadriceps hand-held dynamometry, the Six-minute Walk Test, and the BBS. The findings of their investigation shed light on significant disparities. They observed that, as the severity of COPD increased, individuals exhibited poorer control over their balance and a decline in their ability to carry out everyday activities. This result was corroborated by statistical significance, with a p-value of 0.01. Moreover, those with COPD displayed higher scores on the FES-I, signifying an elevated level of fear of falling (p < 0.01) when compared to their healthy counterparts.

Riaz [39] compared balance impairments among COPD and healthy population. They conducted research on 16 patients with diagnosed COPD and 16 healthy adults between ages of 40 to 65 years. An ABC questionnaire was used to gauge the participants’ balance confidence while doing complex and daily living tasks. In addition, BBS and TUG were used to assess static and dynamic balance and risk of falls, respectively. Moreover, the impacts of age, gender, and BMI on balance were studied.

BBS scores (< 45 indicates risk of fall) were 33–51 for COPD and 49–56 for healthy people. ABC scores (total 100%) were 63–74.3% for COPD and 66–90.14% for healthy. TUG scores (≤13 sec is normal) were 12–16 seconds for COPD and 7–13 seconds for healthy [36, 37, 38].

Comparisons for the BBS (p < 0.05), ABC (p < 0.05) and TUG (p < 0.05) scores between the COPD and healthy subjects were statistically significant, as determined from an independent t test. Age and cigarette smoking did not significantly impact the BBS and TUG scores, whereas BMI correlated with all three measures [39].

Additional data provided by Riaz et al. show that BBS was significantly correlated with age (p = 0.02) and smoking (0.03) in the COPD group, and no significant correlation was found between BBS and BMI in COPD patients (p = 0.9). In contrast, BBS in the healthy population was significantly correlated with BMI only, with p < 0.05, and no correlation was found with smoking and age, with p = 0.20 & p = 0.24 respectively.

A BBS score greater than 45 indicates the ability to perform functional activities independently without having the risk of fall. None of the COPD patients’ scores exceeded 51, and the peak number of participants was recorded at scores of 45 and 49 (Figure 7). However, in healthy population BBS score peaks were 55 and 56 (Figure 8). Thus, the ability to perform functional activities without experiencing falls is greater for healthy subjects than for COPD patients.

Figure 7.

Bar chart showing berg balance scale scores in COPD (scores: 38–51) (un-reported and additional data from study conducted by Riaz et al.)

Figure 8.

Bar chart showing berg balance scale scores in healthy population (scores 51–56). (un-reported and additional data from study conducted by Riaz et al.)

7. Treatment options for balance impairments in COPD

Balance training consists of four main exercises (Figure 9). These exercises need to be added to a pulmonary rehabilitation program for COPD, and breathing exercises need to be incorporated in all sessions. Balance training needs to be followed 5 days a week over at least 6–8 weeks to significantly improve the balance of patients with COPD. Tandem walking is placing one foot directly in front of the other in a straight line, aiming to have the heel of the front foot touch the toes of the back foot. If bringing one foot against the other is challenging, strive to get them as close together as possible. Repeat this process four times, covering the 10-foot distance [40]. Then progress by asking the patient to count backwards from 100 to 90 while doing tandem walking. In addition to that, standing is timed on unsteady surfaces such as on foam pads or on wobble boards. It can progress further by removing forward, backward and lateral supports in order to improve reactive balance controls. As far as transition exercises are concerned, start by doing sit to stands on chair with arm rests, and it can become more challenging by decreasing height of chair or using a chair without arm rests. Furthermore, functional training can include safe squats, where a chair is used for balance support, the knees are bent up to only 90 degrees, and the patient is advised to go down with the help of the hip instead of putting stress on knees. The squats can progress in intensity by adding a weight to the thighs or hands while performing squats. For a greater challenge, a gym ball can be used in place of a stable chair during the squats.

Figure 9.

Balance training program.

Beauchamp et al. conducted a randomized controlled trial to examine how a balance-training program influences balance and physical function measures in COPD patients participating in pulmonary rehabilitation (PR). Participants were allocated randomly to either an intervention or control group. The intervention group engaged in balance training three times a week for a duration of 6 weeks, concurrently with PR. The control group exclusively participated in the 6-week PR program. Clinical assessments of balance included the BBS, the BESTest, and the ABC scale. The balance training group scored significantly better than the control group on the BBS (P < 0.01) and BESTest (P < 0.01). However, no notable variations between groups were observed in the score changes on the ABC scale (P = 0.2).

Tai Chi has been shown to be more effective than other usual plan of care therapies for improving balance in patients with COPD. Tai Chi is a form of physical activity characterized by gentle, slow movements, extended periods of standing on one leg, frequent shifts in body weight from side to side and front to back, and contractions of the leg muscles in both lengthening and shortening directions. In individuals without health issues, these actions boost the strength of leg muscles, enhance the sense of joint positioning in the knees and ankles, decrease swaying when standing, and improve the ability to react swiftly to changes in posture, potentially lowering the likelihood of falling. The importance of Tai-chi has been determined by two systematic reviews done by Leung et al. [41] (on 3 RCTs in 2013) and by Ngai et al. [42] (on 12 RCTs in 2016). Meta-analysis of extracted and requested data from authors of original RCTs were done by Review Managing Software in Ngai et al.’s review, whereas, no quantitative analysis were done in the other mentioned review. Both of these reviews compared and contrasted studies incorporating comparisons between utilization of Tai-chi and usual balance exercises programs in addition to pulmonary rehabilitation especially designed for COPD people [41, 42, 43].

8. Conclusion

Individuals with COPD face an increased susceptibility to balance issues, underscoring the importance of proactive intervention. Beyond merely attributing this vulnerability to age, we must recognize the profound impact of faulty postures and diminished endurance, consequences of altered respiratory muscle recruitment, and reduced oxygen levels. To navigate the challenges of COPD effectively, it is imperative to integrate a meticulous balance assessment into the foundation of any pulmonary rehabilitation plan. In the realm of COPD management, the incorporation of dynamic evaluations such as the TUG test, SLS, BBS, 6-minute walk test, and ABC questionnaires is not just advisable but crucial. These assessments serve as the compass guiding us toward targeted, personalized interventions that can genuinely transform the landscape of balance for individuals with COPD. Let us not merely acknowledge the hurdles but, more importantly, champion the potential for improvement. Embracing a multifaceted approach that includes static balance training, the meditative grace of Tai-Chi, purposeful transitional exercises, a robust strengthening program, and functional training exercises, we embark on a journey toward enhanced balance and restored vitality for those grappling with COPD. In cultivating a proactive mindset and implementing these tailored strategies, we empower individuals with COPD to reclaim not just physical equilibrium but a renewed sense of control and confidence in their daily lives. By prioritizing and addressing balance challenges head-on, we not only enhance their immediate well-being but also pave the way for a future marked by resilience, strength, and an improved quality of life.