title: Quadriceps femoris activation changes in genu varum: a possible biomechanical factor in the pathogenesis of osteoarthrosis.
abstract: This study was designed to determine whether the presence of an alignment deformity of the lower leg, known as genu varum, causes abnormalities in individual- or group-activation of the surrounding knee extensors, a situation which might accelerate knee deterioration. Nine healthy women with normal tibial alignment were compared with nine age-matched healthy women with genu varum. The outcome measure of maximal quadriceps femoris activity was recorded during successive maximal concentric isometric and isokinetic contractions of the knee extensors performed on a dynamometer using surface electromyography. The results showed that, taken as a whole, the percentage utilization of quadriceps motor units was higher for those subjects with genu varum (p < 0.01). These findings demonstrate that the extensors surrounding a varus knee might function less efficiently than those surrounding a normally aligned knee. As such they suggest that pathological force generation across a varus knee might be caused, in part, by associated alterations in quadriceps tension generating capacity.
authors.affiliation: Department of Medicine, University of Alberta, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Marks
authors.forename: J S
authors.initials: JS
authors.lastname: Percy
authors.forename: J
authors.initials: J
authors.lastname: Semple
authors.forename: S
authors.initials: S
authors.lastname: Kumar
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D007866:Leg / Q000002:abnormalities*; D009132:Muscles / Q000503:physiopathology*; D010003:Osteoarthritis / Q000209:etiology* / Q000503:physiopathology