SCI impacts many body systems both immediately and in the long-term as noted in numerous reviews (Bauman et al. 1999; Shields 2002; Nash 2005). In particular, Nash (2005) and Jacobs and Nash (2004) point to physical deconditioning across the musculoskeletal system (i.e., bone, muscle and joint) and alterations in both cardiac and peripheral vascular structure and functioning in persons with SCI. These issues, when combined with continued inactivity, result in seemingly inevitable body system decline and are linked to the increased incidence of various secondary complications and other health conditions associated with SCI such as cardiovascular disease, respiratory complications, osteoporosis, pain, spasticity and diabetes. Evidence for routine physical activity has been noted as an important factor in maintaining health and wellness and preventing many of these conditions in the able-bodied population and in those with chronic disease such as arthritis (US Department of Health and Human Services 1996; Warburton et al. 2006; Kruk 2007). However, the evidence linking health and physical activity in persons with SCI or similar conditions is far from established, despite the importance placed on physical activity by clinicians, consumers and researchers alike in optimizing recovery and maintaining health (Rimmer 1999; Anderson 2004; Fernhall et al. 2008).
In reviewing the literature associated with various physical activity and exercise interventions in SCI, it was apparent that the vast majority of studies examine physiological parameters (e.g., VO2, cardiovascular responses to exercise) that would be characterized as relating to body function and structure within the framework of the International Classification of Functioning, Disability and Health (ICF). We do not report here the numerous studies that address these physiologic outcome measures other than to note the various conclusions made surrounding specific risk factors associated with the development of cardiovascular disease or other health conditions. There is a relative dearth of studies examining the effect of physical activity interventions on functional outcomes, especially those that might be characterized as measures of activity or participation (as per the ICF). This suggests a target for future research in elucidating either the functional consequences or societal participation benefits associated with physical activity interventions for persons with SCI.
It should be noted that while one of the aims of this chapter is to bring the information about physical activity and SCI into one place, most of these topic areas comprise individual chapters with SCIRE. Therefore, when there may be substantial duplication with an existing SCIRE chapter we have selected to simply reference the existing chapters that contain information about physical activity interventions and to also bring forward the conclusions (evidence statements and bottom-line conclusions) from these chapters so the reader will gain a sense of the degree of evidence across these various conditions. The reader is encouraged to examine the referenced chapter for surrounding discussion and more information concerning the various studies and details about the specific interventions comprising the evidence. Of note, many of the therapies associated with upper limb or lower limb management involve therapeutic exercise programming (often associated with physical or occupational therapy) and for these we simply refer the reader to SCIRE Chapters: Upper Limb Rehabilitation Following Spinal Cord Injury (Connolly et al. 2010) and Lower Limb Rehabilitation Following Spinal Cord Injury (Lam et al. 2010) respectively. This means that the conclusions related to specific rehabilitation interventions (e.g., Body weight supported treadmill training, FES upper and lower limb applications) may not be comprehensive within the present chapter, but should be augmented by those from the noted chapters.
The following section describes the evidence for physical activity as an intervention directed towards persons with SCI in enhancing strength, muscle function, rehabilitation recovery (i.e., functional outcomes) and subjective well-being (including depression and quality of life) as well as in preventing or minimizing common secondary conditions typically encountered following SCI. These include the role of physical activity in maintaining or enhancing cardiovascular health and bone health as well as preventing or mitigating disability associated with respiratory complications, pain, spasticity, and periodic leg movements.