title: A comparison of shoulder joint forces during ambulation with crutches versus a walker in persons with incomplete spinal cord injury.
abstract: OBJECTIVE
  To compare 3-dimensional (3D) shoulder joint reaction forces and stride characteristics during bilateral forearm crutches and front-wheeled walker ambulation in persons with incomplete spinal cord injury (SCI).
  
  
  METHODS
  Cross-sectional cohort study.
  
  
  METHODS
  Biomechanics laboratory.
  
  
  METHODS
  Fourteen adult volunteers with incomplete SCI recruited from outpatient rehabilitation hospital services.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Peak force, rate of loading, and force-time integral were compared for each component of the net 3D shoulder joint reaction force during ambulation with crutches and a walker. Stride characteristics were also compared between assistive device conditions.
  
  
  RESULTS
  The largest weight-bearing force was superiorly directed, followed by the posterior force. The superior joint force demonstrated a significantly higher peak and rate of loading during crutch walking (48.9N and 311.6N/s, respectively, vs 45.3N and 199.8N/s, respectively). The largest non-weight-bearing force was inferiorly directed with a significantly greater peak occurring during crutch ambulation (43.2N vs 23.6N during walker gait). Walking velocity and cadence were similar; however, stride length was significantly greater during crutch walking (62% vs 58% of normal).
  
  
  CONCLUSIONS
  Shoulder joint forces during assisted ambulation were large. Crutch use increased the superior force but did not increase walking velocity.
authors.affiliation: Pathokinesiology Laboratory, Rancho Los Amigos National Rehabilitation Center, Downey, CA 90242, USA. lhaubert@larei.org
authors.forename: Lisa Lighthall
authors.initials: LL
authors.lastname: Haubert
authors.forename: Dee D
authors.initials: DD
authors.lastname: Gutierrez
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Newsam
authors.forename: JoAnne K
authors.initials: JK
authors.lastname: Gronley
authors.forename: Sara J
authors.initials: SJ
authors.lastname: Mulroy
authors.forename: Jacquelin
authors.initials: J
authors.lastname: Perry
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003446:Crutches; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010264:Paraplegia / Q000175:diagnosis / Q000534:rehabilitation; D026741:Physical Therapy Modalities; D011379:Prognosis; D011782:Quadriplegia / Q000175:diagnosis / Q000534:rehabilitation; D016059:Range of Motion, Articular / Q000502:physiology; D012785:Shoulder Joint / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000175:diagnosis* / Q000534:rehabilitation*; D013314:Stress, Mechanical; D016896:Treatment Outcome; D014853:Walkers; D016138:Walking / Q000502:physiology*