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

Abstract

Push-rim wheelchair propulsion is biomechanically inefficient and physiologically stressful to the musculoskeletal structure of human body. This study focuses to obtain a new, optimized propulsion shape for wheelchair users, which is within the ergonomic ranges of joint motion, thus reducing the probability of injuries. To identify the propulsion movement, forward dynamic optimization was performed on a 3D human musculoskeletal model linked to a handle based propulsion mechanism, having shape and muscle excitations as optimization variables. The optimization resulted in a handle path shape with a circularity ratio of 0.95, and produced a net propulsion power of 34.7 watts for an isokinetic propulsion cycle at 50 rpm. Compared to push-rim propulsion, the compact design of the new propulsion mechanism along with the ergonomically optimized propulsion shape may help to reduce the risk of injuries and thus improve the quality of life for wheelchair users.

In Vivo Biomechanical Assessment of a Novel Handle-Based Wheelchair Drive

“…In this study, we focus on kinematic and kinetic variables during steady propulsion, using the novel wheelchair drive device which has been computationally optimised for maximum power output [20]. Due to the possibility of applying propulsion forces over the entire cycle in combination with the selected gear ratio, we also expect that mobility will be significantly improved in practical use.…”

“…To overcome the limitations of PRP, we applied a similar optimization approach to the one described by Rasmussen et al [19] for pedalling. We developed a novel handle-based wheelchair propulsion (HP) device with an ergonomically optimized propulsion shape that offers a continuous cyclic motion at ergonomic joint ranges and is suitable for ADL [20]. The mechanism does not affect the physical width of the wheelchair and was proven to decrease joint excursions and maximum joint torques developed at the wrist [21].…”

Biophysical aspects of handcycling performance in rehabilitation, daily life and recreational sports; a narrative review

“…Nevertheless, given its physiological and biomechanical benefits, handcycling is also suitable as a safe training mode to regain and maintain fitness [7,62,[64][65][66][67][68][69][70][71][72]. It is also possible to safely train patients who have a very low physical capacity for instance due to a high cervical spinal cord lesion [73][74][75] or because they are at the early start of rehabilitation [6,67,76,77]. Especially for those who are undertrained or those with a relatively high body mass in relation to their available active arm muscle mass, arm crank ergometers can be useful to be able to start training at a very low power output level [74,75].…”

Biophysical perspective on submaximal handcycle propulsion in able-bodied men

“…The paradigm of submaximal short bouts of practice assumes changes in motor control and coordination, yet little physiological training adaptations (67). Although mere physiological training effects with a minimum of 7 weeks of handcycling exercise have been investigated among wheelchair users as well as novices (68)(69)(70)(71)(72)(73)(74), the role of motor learning in that has received little attention. Especially short term (submaximal) practice effects (< 60 minutes) on efficiency and motor control are yet to be investigated in handcycling.…”

“…Nevertheless, given its physiological and biomechanical benefits, handcycling is also suitable as a safe training mode to regain and maintain fitness (59,(61)(62)(63)(64)(65)(66)(67)(68)(69)(70). It is also possible to safely train patients who have a very low physical capacity for instance due to a high cervical spinal cord lesion (71)(72)(73) or because they are at the early start of rehabilitation (6,64,74,75). Especially for those who are undertrained or those with a relatively high body mass in relation to their available active arm muscle mass, arm crank ergometers can be useful to be able to start training at a very low power output level (72,73).…”