title: The Effects of Hip and Spine Orthoses on Braking Parameters: A Simulated Study With Healthy Subjects.
abstract: BACKGROUND
  Although a person's fitness to drive has gained more attention over the past few years, investigations have focused mainly on postsurgical (eg, hip arthroplasty) driving performance. Few data are available on how orthoses affect the ability to perform an emergency stop.
  
  
  OBJECTIVE
  To determine whether common lumbar and hip orthoses impair driving performance by increasing brake response time and weakening brake force (BF).
  
  
  METHODS
  Crossover repeated measures design.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  A crossover, repeated-measures design was used to test 30 healthy volunteers with and without each of the orthoses in random order.
  
  
  METHODS
  A custom-made simulator was created from a car cabin fitted with measurement equipment to record braking parameters under realistic spatial constraints.
  
  
  METHODS
  Reaction time (RT), foot transfer time (FTT) (these 2 together: brake response time), and maximum BF.
  
  
  RESULTS
  Although spine orthoses lead to statistically significant increases in RT (Vertebradyn-Strong, P = .002; Horizon 637 LSO, P = .32; and SofTec Dorso, P = .013), this effect was not observed in hip orthoses, where instead FTT was prolonged (DynaCox and Hohmann-like orthosis, P < .001). BF was not significantly altered in any of the orthoses.
  
  
  CONCLUSIONS
  This study demonstrates that hip and spine orthoses lead to impaired driving performance. Depending on the type of immobilization, this effect mostly increases RT or FTT, lengthening total stopping distances by up to half a meter at 100 km/h. However, in the absence of an underlying pathological condition in individuals with orthoses, their braking performance should be sufficient to continue driving.
authors.affiliation: Department of Orthopedic Surgery, University Hospital of Tübingen, Hoppe-Seyler-Strasse 3, D-72076 Tübingen, Germany(∗). Electronic address: ulf.hofmann@med.uni-tuebingen.de.
authors.forename: Ulf Krister
authors.initials: UK
authors.lastname: Hofmann
authors.affiliation: Department of Orthopedic Surgery, University Hospital of Tübingen, Tübingen, Germany(†).
authors.forename: Stefan
authors.initials: S
authors.lastname: Thumm
authors.affiliation: Department of Orthopedic Surgery, University Hospital of Tübingen, Tübingen, Germany(‡).
authors.forename: Maurice
authors.initials: M
authors.lastname: Jordan
authors.affiliation: Department of Orthopedic Surgery, University Hospital of Tübingen, Tübingen, Germany(§).
authors.forename: Christian
authors.initials: C
authors.lastname: Walter
authors.affiliation: Institute for Medical Statistics and Epidemiology, University Hospital of the Technical University of Munich, Munich, Germany(¶).
authors.forename: Ina-Christine
authors.initials: IC
authors.lastname: Rondak
authors.affiliation: Department of Orthopedic Surgery, University Hospital of Tübingen, Tübingen, Germany(#).
authors.forename: Ingmar
authors.initials: I
authors.lastname: Ipach
mesh_terms: D000293:Adolescent; D000328:Adult; D001334:Automobile Driving; D018592:Cross-Over Studies; D005260:Female; D064368:Healthy Volunteers; D006615:Hip; D006801:Humans; D008161:Lumbosacral Region; D008297:Male; D009068:Movement / Q000502:physiology*; D009989:Orthotic Devices; D011930:Reaction Time / Q000502:physiology*; D013647:Task Performance and Analysis; D055815:Young Adult