title: Gait ground reaction force characteristics of low back pain patients with pronated foot and able-bodied individuals with and without foot pronation.
abstract: The link between gait parameters and foot abnormalities in association with low back pain is not well understood. The objective of this study was to investigate the effects of excessive foot pronation as well as the association of LBP with excessive foot pronation on the GRF components during shod walking.
  
  
  
  Forty-five subjects were equally divided into a control group, a group of subjects with pronated feet only, and another group with pronated feet and LBP. Ground reaction forces were analyzed during shod walking.
  
  
  
  Foot pronation without low back pain was associated with increased lateral-medial ground reaction force, impulse, and time to peak of all reaction forces in heel contact phase (p<0.03). In low back pain patients with pronated foot, greater vertical reaction forces (p=0.001) and loading rate, and time to peak on propulsion force were observed compared to pronated foot without low back pain group. Impulse in posterior-anterior reaction force was smaller in the able-bodied group with normal foot than in the other groups (p<0.05). Positive peak of free moments of the LBP group was significantly greater than that in other groups (p<0.05). In conclusion, foot pronation alone was not associated with elevated vertical ground reaction forces. While, low back pain patients with foot pronation displayed higher vertical ground reaction force as well as higher loading rate. Present results reveal that gait ground reaction force components in low back pain patients with pronated foot may have clinical values on the prognosis and rehabilitation of mechanical LBP patients.
authors.affiliation: Sport Biomechanics Department, Bu-Ali Sina University, Hamedan, Iran. Electronic address: naderfarahpour1@gmail.com.
authors.forename: Nader
authors.initials: N
authors.lastname: Farahpour
authors.affiliation: Sport Biomechanics Department, Bu-Ali Sina University, Hamedan, Iran. Electronic address: amiralijafarnezhad@gmail.com.
authors.forename: AmirAli
authors.initials: A
authors.lastname: Jafarnezhad
authors.affiliation: Faculty of Physical Education and Sport Sciences, Hakim Sabzevari University, Sabzevar, Iran. Electronic address: mohsen.damavandi1@gmail.com.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Damavandi
authors.affiliation: Medical University of Hamedan, Hamedan, Iran. Electronic address: Bakhtiariabbas75@yahoo.com.
authors.forename: Abbas
authors.initials: A
authors.lastname: Bakhtiari
authors.affiliation: Department of Kinesiology, University of Montreal, Montreal, QC, Canada. Electronic address: paul.allard@umontreal.ca.
authors.forename: Paul
authors.initials: P
authors.lastname: Allard
mesh_terms: D000328:Adult; D005528:Foot / Q000502:physiology*; D005684:Gait / Q000502:physiology*; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology*; D008297:Male; D011403:Pronation / Q000502:physiology*; D012775:Shoes; D055815:Young Adult
keywords: Foot pronation; Gait; Ground reaction forces; Impulse; Low back pain