title: Effects of treadmill incline and speed on peroneus longus muscle activity in persons with chronic stroke and healthy subjects.
abstract: To examine the effects of walking at different inclines and speeds on Peroneus Longus (PL) muscle activation and medial gastrocnemius (MG) coactivation with PL in healthy controls and subjects with stroke.
  
  
  
  Nineteen persons post-stroke (13M/6F) and fifteen healthy controls (10M/5F) walked on a treadmill at different inclines (0°, 3°, and 6°) and speeds (self-selected, self-selected+20%, self-selected+40%). The electromyographic activity of the PL and MG muscles in the stance phase of gait cycle was measured.
  
  
  
  The paretic PL muscle activity did not change with incline, but increased at +40% speed only (p<0.05). The nonparetic PL increased at 6° incline and at faster speeds (p<0.05). In the healthy group, PL muscle activity increased only on the right side at 6° incline, but increased bilaterally at +40% faster speed (p<0.05). The timing of PL muscle activity did not change with incline (p>0.05), but was significantly delayed at +40% faster speed on the paretic side only (p<0.05). In healthy controls, PL muscle activation timing was unchanged with incline (p>0.05), but was significantly delayed at +40% speed only on the left side (p<0.05). The MG/PL amplitude and timing ratios were not significantly different between various walking conditions (p>0.05).
  
  
  
  An increase in PL activity occurs to provide ankle stability at walking speeds up to 40% faster than the self-selected speed. Important interlimb differences which may be related to leg dominance and motor control were observed in both stroke and healthy control groups in both PL muscle timing and their clinical impact should be investigated in future studies.
authors.affiliation: Neuromuscular Rehabilitation Research Center and Rehabilitation Faculty, Semnan University of Medical Sciences, Semnan, Iran; Physical Therapy Department, Rehabilitation Faculty, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: mohamadipt@gmail.com.
authors.forename: Roghayeh
authors.initials: R
authors.lastname: Mohammadi
authors.affiliation: Spasticity Research Program, West Park Healthcare Centre, Toronto, Canada; Department of Physical Therapy, University of Toronto, Toronto, Canada; Faculty of Health, York University, Toronto, Canada. Electronic address: chetan.phadke@westpark.org.
authors.forename: Chetan P
authors.initials: CP
authors.lastname: Phadke
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D002908:Chronic Disease; D004576:Electromyography; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D012044:Regression Analysis; D020521:Stroke / Q000503:physiopathology*; D016138:Walking / Q000502:physiology*; D000072797:Walking Speed
keywords: Electromyography; Exercise test; Gait; Mobility limitation; Stroke