Modifications in Wheelchair Propulsion Technique with Speed

Abstract

ObjectiveRepetitive loading of the upper limb joints during manual wheelchair (WC) propulsion (WCP) has been identified as a factor that contributes to shoulder pain, leading to loss of independence and decreased quality of life. The purpose of this study was to determine how individual manual WC users with paraplegia modify propulsion mechanics to accommodate expected increases in reaction forces (RFs) generated at the pushrim with self-selected increases in WCP speed.MethodsUpper extremity kinematics and pushrim RFs were measured for 40 experienced manual WC users with paraplegia while propelling on a stationary ergometer at self-selected free and fast propulsion speeds. Upper extremity kinematics and kinetics were compared within subject between propulsion speeds. Between group and within-subject differences were determined (α = 0.05).ResultsIncreased propulsion speed was accompanied by increases in RF magnitude (22 of 40, >10 N) and shoulder net joint moment (NJM, 15 of 40, >10 Nm) and decreases in pushrim contact duration. Within-subject comparison indicated that 27% of participants modified their WCP mechanics with increases in speed by regulating RF orientation relative to the upper extremity segments.ConclusionsReorientation of the RF relative to the upper extremity segments can be used as an effective strategy for mitigating rotational demands (NJM) imposed on the shoulder at increased propulsion speeds. Identification of propulsion strategies that individuals can use to effectively accommodate for increases in RFs is an important step toward preserving musculoskeletal health of the shoulder and improving health-related quality of life.

Fatores relacionados à eficiência da propulsão em cadeira de rodas manual de usuários com paraplegia devido à lesão medular

“…According to the author, during the propulsion of 1.72 m/s, in which the reaction force (60 N) was previously oriented to the MC of the forearm and arm associated with the elbow extensor moment, there was a reduction in the magnitude of the shoulder moment (13 Nm). In contrast, in the propulsion condition of 1.82 m/s, in which the reaction force (54 N) was oriented posteriorly to the forearm and arm MC associated with the elbow flexor moment, there was an increase in the magnitude of the shoulder moment (27 Nm) (Russell et al, 2015). The two examples indicate that the magnitude of the shoulder moment does not necessarily correspond to the propulsion speed, but can be reduced or increased through moments of flexion or elbow extension associated with the reaction forces in the anterior and posterior direction on the forearm and arm MC.…”

“…Gil-Agudo et al (2014 showed results similar to previous studies (Mercer et al, 2006;Collinger et al, 2008) with associations that are more prone to the appearance of pain and injuries with increased strength and shoulder moments after the participants performed rapid propulsion. Russell et al (2015) also demonstrated that the orientation of the reaction forces associated with the elbow moments in the forearm and arm MC is essential to decrease the forces directed at the shoulder. During high-speed propulsion, the reorientation of the reaction forces, generated by the position of the upper limbs concerning the forearm and arm MC has been shown to attenuate the forces directed at the shoulder.…”

“…The positions of the ULs lead to different magnitudes of shoulder moments in the same propulsion condition (Russell et al, 2015). The magnitude of the shoulder moment depends on the forces generated on the mass center (MC) of the forearm and arm (Russell et al, 2015).…”

“…The positions of the ULs lead to different magnitudes of shoulder moments in the same propulsion condition (Russell et al, 2015). The magnitude of the shoulder moment depends on the forces generated on the mass center (MC) of the forearm and arm (Russell et al, 2015). According to the author, during the propulsion of 1.72 m/s, in which the reaction force (60 N) was previously oriented to the MC of the forearm and arm associated with the elbow extensor moment, there was a reduction in the magnitude of the shoulder moment (13 Nm).…”

Forward dynamic optimization of handle path and muscle activity for handle based isokinetic wheelchair propulsion: A simulation study

“…2010; Russell et al. 2015) can impose high mechanical demand on the shoulder muscles which control stabilization and rotation and this may contribute to acute shoulder pain and injury. Boninger et al.…”