Clinician's Commentary on Roig et al.

Abstract

The article by Roig and colleagues1 in this issue of Physiotherapy Canada highlights an important secondary impairment among individuals with chronic obstructive pulmonary disease (COPD). While impairments such as skeletal muscle weakness and decreased exercise capacity are well established in COPD,2 deficits in postural balance have only recently been shown to be common in individuals with this condition.3–5 The study by Roig and colleagues adds to the growing body of evidence6 on this emerging area of interest in COPD and provides compelling support for the inclusion of balance training as part of pulmonary rehabilitation for this population. The primary objective of the authors' study was to evaluate balance deficits in individuals with COPD relative to age-matched controls, using the Sensory Organization Test (SOT). The authors also sought to explore the potential contribution of skeletal muscle weakness to any observed balance deficits in this population. They found that participants with COPD had lower overall SOT scores than controls and that deficits in balance were not associated with quadriceps muscle strength. These findings underscore the importance of including balance-specific exercises and fall-prevention education as part of the rehabilitation of patients with COPD. The American Geriatrics Society recommends exercise with balance training as an essential component of any multifactorial falls intervention strategy for older adults who are at risk of falling.7 Indeed, individuals with COPD have been shown to have a high incidence of falls8 and to possess many known risk factors for falling, including skeletal muscle weakness, impaired functional mobility, use of multiple medications, and, as Roig and colleagues have shown, impaired balance. In addition, the high prevalence of osteoporosis9 places these individuals at an even greater risk of fracture should they experience a fall. Therefore, it would seem reasonable for balance training and fall risk reduction strategies to be key components of rehabilitation for patients with COPD. We know, however, that this is not the case. Balance training and fall-prevention strategies are not currently included in international guidelines for pulmonary rehabilitation, and very few programmes in Canada include any standardized balance assessment.2,10 As conventional pulmonary rehabilitation has only modest effects on balance and fall risk,11 more tailored interventions designed specifically to target balance are needed for this population. As physiotherapists working in the specialized area of pulmonary rehabilitation, we need to recognize the non-respiratory impairments in our patients with COPD. Although our patients are often referred for disease-specific interventions such as dyspnea management and endurance training, we must consider a comprehensive approach to assessment and treatment to optimize the gains made during rehabilitation and prevent the development of secondary disability. Increasingly, we are seeing the benefits of multifaceted approaches to rehabilitation in areas where we have traditionally focused on primary impairments. For example, in patients with stroke, rehabilitation historically focused on restoring normal movement and functional independence; more recently, however, aerobic training has been shown to be a valuable addition to the routine rehabilitation of these patients12 and is likely an important consideration for secondary prevention. Similarly, I would suggest that balance assessment and training be provided for individuals with COPD undergoing respiratory rehabilitation—both to increase functional independence during daily life and to reduce fall risk. There remain some questions, however, that should be addressed in future research in order for fall risk reduction programmes to have optimal efficacy in patients with COPD. As Roig and colleagues note, the mechanism for reduced balance in these patients is unclear. Many theories have been proposed, including low levels of physical activity,3,4 peripheral muscle weakness,3 altered trunk muscle mechanics,5 hypoxemia,13 and somatosensory deficits.14 While Roig and colleagues did not find an association between muscle strength and physical activity and balance in their study, further studies with larger samples are needed to confirm these findings. There is also a need to identify the specific components of balance that are impaired in COPD, to guide the development of balance training interventions for this population. The study by Roig and colleagues contributes important evidence to the growing body of literature on balance impairments in individuals with COPD. Given the devastating consequences of falls for older adults, balance assessment and treatment would be a welcome addition to pulmonary rehabilitation. Fall-prevention strategies should also be taught as part of the patient education self-management programme. Future research is warranted to explore the mechanism underlying the observed balance deficits in COPD and to determine the optimal intervention for improving balance in these individuals.