title: Effect of intramedullary gradual elongation of the shorter limb on gait patterns.
abstract: BACKGROUND
  Seven young patients were followed 52 weeks after intramedullary lengthening for limb length discrepancy (LLD). The mean LLD before surgery was 3.0 +/- 1.1 cm and 1 year after surgery at the time of the nail-removal it was 0.3 +/- 0.3 cm.
  
  
  METHODS
  The plantar pressures and the ground reaction forces (GRF) were recorded simultaneously with electromyographic (EMG) activities at normal and fast walking speeds.
  
  
  RESULTS
  Bilateral comparison indicated that the uncorrected LLD resulted in asymmetrical gait patterns. The peak pressures were higher in the lateral heel and in the medial forefoot in the longer limb as compared to the shorter limb at normal walking speed. At fast walking speed, the peak pressures of the longer limb were higher in the forefoot area but lower in the central midfoot. One year after surgery, a clear improvement in the gait symmetry was observed compared to preoperative condition. Significantly, foot loading models were quite similar 52 weeks after surgery. However, during the follow-up period of 52 weeks, the maximal isometric knee extensor torque still remained at lower levels on the operated side until week 52 postoperatively, but reached the same level with non-operated side within 2 years.
  
  
  CONCLUSIONS
  The improved walking symmetry obtained after surgical treatment may diminish possible pathologic loading of the lower extremity and may prevent the early appearance of arthritis in the lower extremities.
authors.affiliation: Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland. jarmop@sport.jyu.fi
authors.forename: Jarmo R
authors.initials: JR
authors.lastname: Perttunen
authors.forename: Esa
authors.initials: E
authors.lastname: Anttila
authors.forename: Jerker
authors.initials: J
authors.lastname: Södergård
authors.forename: Juhani
authors.initials: J
authors.lastname: Merikanto
authors.forename: Paavo V
authors.initials: PV
authors.lastname: Komi
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D001852:Bone Lengthening; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D005684:Gait; D006801:Humans; D007866:Leg; D007870:Leg Length Inequality / Q000503:physiopathology / Q000601:surgery*; D008297:Male