title: Prediction of voluntary activation, strength and endurance of elbow flexors in postpolio patients.
abstract: To examine the long-term effects of polio, maximal voluntary strength and voluntary activation of elbow flexor muscles of 177 patients from a postpolio clinic were investigated using twitch interpolation. Muscle endurance was studied in 142 patients during 45 min of submaximal exercise, and predictors of impaired muscle performance were investigated. Twenty-nine of 177 patients (16.4%) had impaired voluntary drive to their elbow flexor muscles, but only 16 (9.0%) had markedly reduced elbow flexor strength, despite 74 (41.8%) reporting they were initially affected in their tested limb and 172 (97.2%) patients reporting new generalized symptoms. Seven patients had impaired muscle endurance in the tests of strength and voluntary drive. During the submaximal exercise, 16 patients (11.3%) had impaired peripheral muscle endurance with normal voluntary activation. These results confirm a low incidence of impaired upper-limb muscle performance in postpolio patients, despite many patients having subjective symptoms consistent with postpolio syndrome. There was an increased relative risk for impaired muscle function in those patients with a subjective decrease in strength in the tested limb, a recent decline in activities of daily living in their tested limb, and who used orthotic devices in their tested limb. Monitoring of function in prior-polio patients with impaired muscle performance may be useful, particularly when combined with investigation of other potential contributory factors to the functional impairment.
authors.affiliation: Prince of Wales Medical Research Institute, High Street, Randwick, Sydney, NSW 2031, Australia.
authors.forename: Gabrielle M
authors.initials: GM
authors.lastname: Allen
authors.forename: J
authors.initials: J
authors.lastname: Middleton
authors.forename: P H
authors.initials: PH
authors.lastname: Katrak
authors.forename: S R
authors.initials: SR
authors.lastname: Lord
authors.forename: S C
authors.initials: SC
authors.lastname: Gandevia
mesh_terms: D000328:Adult; D000368:Aged; D003402:Creatine Kinase / Q000097:blood; D004550:Elbow / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010807:Physical Endurance; D016262:Postpoliomyelitis Syndrome / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D011379:Prognosis; D012306:Risk
chemical_list: D007334:Insulin-Like Growth Factor I; D003402:Creatine Kinase