title: The effect of decompressive surgery on lumbar paraspinal and biceps brachii muscle function and movement perception in lumbar spinal stenosis: a 2-year follow-up.
abstract: OBJECTIVE
  Chronic low back pain and lumbar spinal stenosis (LSS) seem to deteriorate lumbar muscle function and proprioception but the effect of surgery on them remains unclear. This study evaluates the effect of decompressive surgery on lumbar movement perception and paraspinal and biceps brachii (BB) muscle responses during sudden upper limb loading in LSS.
  
  
  METHODS
  Low back and radicular pain intensity (VAS) and Oswestry Disability Index (ODI) were measured together with lumbar proprioception and paraspinal and BB muscle responses prior to and 3 and 24 months after surgery in 30 LSS patients. Lumbar proprioception was assessed by a previously validated motorized trunk rotation unit and muscle responses for sudden upper limb loading by surface EMG.
  
  
  RESULTS
  Lumbar perception threshold improved after surgery during 3-month follow-up (from 4.6° to 3.1°, P = 0.015) but tend to deteriorate again during 24 months (4.0°, P = 0.227). Preparatory paraspinal and BB muscle responses prior to sudden load as well as paraspinal muscle activation latencies after the load remained unchanged.
  
  
  CONCLUSIONS
  Impaired lumbar proprioception seems to improve shortly after decompressive surgery but tends to deteriorate again with longer follow-up despite the sustaining favorable clinical outcome. The surgery did not affect either the feed-forward or the feed-back muscle function, which indicates that the abnormal muscle activity in LSS is at least partly irreversible.
authors.affiliation: Department of Orthopaedics, Traumatology and Handsurgery, Kuopio University Hospital, PL 100, 70029, Kuopio, Finland. tommi.kaariainen@kuh.fi.|Department of Physical and Rehabilitation Medicine, Kuopio University Hospital, Kuopio, Finland. tommi.kaariainen@kuh.fi.|Bone and Cartilage Research Unit, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland. tommi.kaariainen@kuh.fi.
authors.forename: Tommi
authors.initials: T
authors.lastname: Kääriäinen
authors.affiliation: Evalua International, Helsinki, Finland.
authors.forename: Simo
authors.initials: S
authors.lastname: Taimela
authors.affiliation: Lääkärikeskus Ikioma, Medical Center Ikioma, St Michel, Finland.
authors.forename: Timo
authors.initials: T
authors.lastname: Aalto
authors.affiliation: Department of Orthopaedics, Traumatology and Handsurgery, Kuopio University Hospital, PL 100, 70029, Kuopio, Finland.|Bone and Cartilage Research Unit, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Kröger
authors.affiliation: Department of Physical and Rehabilitation Medicine, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Arto
authors.initials: A
authors.lastname: Herno
authors.affiliation: Department of Orthopaedics, Traumatology and Handsurgery, Kuopio University Hospital, PL 100, 70029, Kuopio, Finland.
authors.forename: Veli
authors.initials: V
authors.lastname: Turunen
authors.affiliation: Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Sakari
authors.initials: S
authors.lastname: Savolainen
authors.affiliation: Department of Physical and Rehabilitation Medicine, Tampere University Hospital, Tampere, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Kankaanpää
authors.affiliation: Department of Physical and Rehabilitation Medicine, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Olavi
authors.initials: O
authors.lastname: Airaksinen
authors.affiliation: Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Ville
authors.initials: V
authors.lastname: Leinonen
mesh_terms: D000328:Adult; D019299:Decompression, Surgical / Q000379:methods*; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017116:Low Back Pain / Q000209:etiology / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000601:surgery*; D008161:Lumbosacral Region / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods; D064170:Paraspinal Muscles / Q000503:physiopathology; D011434:Proprioception / Q000502:physiology; D020127:Recovery of Function; D013130:Spinal Stenosis / Q000150:complications / Q000601:surgery*; D034941:Upper Extremity / Q000503:physiopathology
keywords: Decompressive surgery; Feed-forward control; Lumbar proprioception; Lumbar spinal stenosis; Paraspinal reflexes