For persons with SCI who require a wheelchair as their primary means of mobility, an estimated 90% of them will use a manual wheelchair (Kaye et al. 2000). In order to self-propel, manual wheelchair users must exert significant forces through their shoulders and other upper extremity (UE) joints (Boninger et al. 2002; Crane 2007; Langenhoff 1998). Thus, the demand on the upper extremity in children with SCI who rely on wheeled mobility is significant (Hasara Krey & Calhoun 2004; Schnorenberg, Slavens, Graf et al. 2014; Slavens et al. 2015). This puts them at risk of developing pain and upper extremity pathology which may interfere with their independence (Hasara Krey & Calhoun 2004; Schnorenberg, Slavens, Graf et al. 2014; Schnorenberg, Slavens, Wang et al. 2014). Although data pertaining to the impact of manual wheelchair use in children is limited, their risk of developing upper extremity injury, pain, and dysfunction that might impact manual wheelchair use, transfers, independence, and quality of life is substantial, particularly since children with SCI who are manual wheelchair users have long life expectancies and will rely on upper extremity function for mobility, including transfers and wheeled mobility, over the lifespan (Crane 2007). In this section, studies examining manual wheelchair users’ biomechanics are reviewed; these studies are summarized in Table 8. These studies focus mainly on understanding biomechanics which may theoretically affect the risk of upper extremity injury, but provide little insight for clinical implications.
The available data on manual wheelchair use in children with SCI is limited; most data come from three observational trials using the same SmartWheel technology to evaluate biomechanics of manual wheelchair users in real-time. In these studies, joint biomechanics vary between subjects; the implications of specific forces acting at various joints have yet to be determined in children who use manual wheelchairs post-SCI. There is evidence from one pre-post study that wheelchair training programs may improve the effectiveness of wheelchair propulsion, albeit modestly (5.6% improvement in efficiency) (Schottler et al., 2019). There are no studies on the effectiveness or efficiency of various wheelchair propulsion stroke patterns. Observational studies by the same group of authors both describe the stroke patterns of 12 patients with the same findings: one subject used the single-looping over propulsion pattern, 3 subjects used the double-looping over propulsion pattern, 3 subjects used the recommended semicircular (SC) pattern; and, 5 subjects used a mixture of patterns making the primary pattern unidentifiable (Schnorenberg, Slavens, Graf et al. 2014; Slavens et al. 2015).