title: Unilateral hip osteoarthritis: Its effects on preoperative lower limb muscle activation and intramuscular coordination patterns.
abstract: The objective of this study was to test if patients with unilateral hip osteoarthritis (OA) show greater muscle activity asymmetry between their affected and non-affected limbs than healthy controls between their left and right limbs. Seventeen patients with unilateral hip OA (7 females, 10 males) and 17 age-matched healthy controls (7 females, 10 males) participated in this study. Both groups performed instrumented gait analysis at comparable speeds. Muscle activity was recorded simultaneously for the tibialis anterior (TA), gastrocnemius medialis (GM), vastus lateralis (VL), semitendinosus (ST), tensor fasciae latae (TFL), and gluteus medius (GLM) muscles. In hip OA patients, EMG data showed greater activity of the TA muscle in the non-affected limb, and greater TFL muscle activity in the affected limb. Compared to healthy controls, greater asymmetries between paired limbs were observed for the TA and GM muscles. Finally, the TFL muscle of the affected limb contributed more to the total limb muscle activity than did the non-affected limb. The observed alterations in TA and GM muscle activity in hip OA patients may be due to the greater peak braking and peak vertical forces measured in the non-affected limb. Contrary to this, greater TLF muscle activity of the affected limb indicates the demands put on stabilizing the hip during stance phase. Further studies are necessary to test whether leg length discrepancy affects muscle activation alterations between the affected and non-affected limb in unilateral hip OA patients.
authors.affiliation: Experimental Orthopedics & Trauma Surgery, Frankfurt Initiative for Regenerative Medicine, Johann Wolfgang Goethe University Frankfurt, Marienburgstraße 2, 60528 Frankfurt/Main, Germany; Orthopedic University Hospital Friedrichsheim gGmbH, Marienburgstraße 2, 60528 Frankfurt/Main, Germany. Electronic address: andre.schmidt-jena@gmx.de.
authors.forename: André
authors.initials: A
authors.lastname: Schmidt
authors.affiliation: Orthopedic University Hospital Friedrichsheim gGmbH, Marienburgstraße 2, 60528 Frankfurt/Main, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Stief
authors.affiliation: Department of Sports Medicine, Johann Wolfgang Goethe University Frankfurt, Ginnheimer Landstraße 39, 60487 Frankfurt/Main, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Lenarz
authors.affiliation: Orthopedic University Hospital Friedrichsheim gGmbH, Marienburgstraße 2, 60528 Frankfurt/Main, Germany.
authors.forename: Dara
authors.initials: D
authors.lastname: Froemel
authors.affiliation: Frankfurt University of Applied Sciences, Nibelungenplatz 1, 60318 Frankfurt/Main, Germany.
authors.forename: Frederick
authors.initials: F
authors.lastname: Lutz
authors.affiliation: Experimental Orthopedics & Trauma Surgery, Frankfurt Initiative for Regenerative Medicine, Johann Wolfgang Goethe University Frankfurt, Marienburgstraße 2, 60528 Frankfurt/Main, Germany.
authors.forename: John
authors.initials: J
authors.lastname: Barker
authors.affiliation: Orthopedic University Hospital Friedrichsheim gGmbH, Marienburgstraße 2, 60528 Frankfurt/Main, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Meurer
mesh_terms: D000328:Adult; D000368:Aged; D004576:Electromyography; D005260:Female; D005684:Gait / Q000502:physiology*; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D015207:Osteoarthritis, Hip / Q000503:physiopathology*; D057234:Preoperative Period
keywords: Asymmetry index; Electromyography; Gait analysis; Ground reaction force