title: Exploration of shoulder load during hand-rim wheelchair start-up with and without power-assisted propulsion in experienced wheelchair users.
abstract: Frequent start movements occurred during the day, yielding high upper-extremity stress. The high incidence and impact of shoulder injury on daily life wheelchair use made it clinically relevant to investigate whether power-assisted propulsion is beneficial during the start.
  
  
  
  Eleven hand-rim wheelchair users performed a start-movement in an instrumented wheelchair on a flat surface. Test order was randomly assigned to propulsion with and without power-assist. For each subject, parameters were averaged over 3 repeated starts. For statistical analysis Wilcoxon Signed Rank test was used.
  
  
  
  Intensity of mechanical shoulder loading decreased during power-assisted propulsion for anterior (147.0 (44.8) versus 121.9 (27.4) N; effect size (r)=-.75), posterior (4.8 (14.1) versus 2.7 (11.6) N; r=-.64) and inferior directed forces (82.6 (27.9) versus 68.9 (22.6) N; r=-.78) and abduction (20.2 (14.6) versus 12.9 (7.8) Nm; r=-.88) and extension moments (20.3 (10.7) versus 13.7 (9.1 Nm; r=-.88). Peak resultant force at the rim significantly decreased from 133.5 (38.4) N to 112.2 (25.4) N (r=-.64) and was accompanied by significant decreased shoulder abduction (35.3 (6.7) versus 33.3 (6.8); r=-.67) and significant increased shoulder extension (13.6 (16.3) versus 20.3 (19.1); r=-.78) during power-assisted start-up.
  
  
  
  Power-assist hand-rim wheelchairs are effective in reducing external shoulder load and partly effective in reducing force generation in extremes of shoulder motion during start-up. The use of power-assist wheels might reduce the risk of developing shoulder overuse injuries.
  
  
  
  NTR2661.
authors.affiliation: Roessingh Research and Development, Enschede, The Netherlands; Faculty of Engineering Technology, Laboratory of Biomechanical Engineering, University of Twente, Postbox 217, 7500 AE Enschede, The Netherlands. Electronic address: mariekekloosterman83@gmail.com.
authors.forename: Marieke G M
authors.initials: MG
authors.lastname: Kloosterman
authors.affiliation: Roessingh Research and Development, Enschede, The Netherlands; Faculty of Electrical Engineering, Mathematics and Computer Science, Department of Biomedical Signals and Systems, University of Twente, Postbox 217, 7500 AE Enschede, The Netherlands. Electronic address: j.buurke@rrd.nl.
authors.forename: Jaap H
authors.initials: JH
authors.lastname: Buurke
authors.affiliation: Roessingh Research and Development, Enschede, The Netherlands. Electronic address: l.schaake@rrd.nl.
authors.forename: Leendert
authors.initials: L
authors.lastname: Schaake
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Postbox 30.001, 9700 RB Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Center for Rehabilitation, Postbox 30.001, 9700 RB Groningen, The Netherlands. Electronic address: l.h.v.van.der.woude@med.umcg.nl.
authors.forename: Lucas H V
authors.initials: LH
authors.lastname: Van der Woude
authors.affiliation: Roessingh Research and Development, Enschede, The Netherlands; Faculty of Engineering Technology, Laboratory of Biomechanical Engineering, University of Twente, Postbox 217, 7500 AE Enschede, The Netherlands. Electronic address: j.s.rietman@rrd.nl.
authors.forename: Johan S
authors.initials: JS
authors.lastname: Rietman
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D012090:Cumulative Trauma Disorders / Q000209:etiology / Q000517:prevention & control; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement; D011897:Random Allocation; D012782:Shoulder / Q000502:physiology* / Q000503:physiopathology; D034941:Upper Extremity / Q000502:physiology / Q000503:physiopathology; D016474:Weight-Bearing; D014910:Wheelchairs
keywords: Assistive technology; Kinematics; Kinetics; Upper extremity; Wheelchairs