title: A reproducible and inexpensive method of measuring hip abductor strength.
abstract: The evaluation of hip abductor strength is useful in assessing of the outcome of hip surgery. Hand-held dynamometers are available, but they are less reliable in assessing hip abductor strength than some other muscle groups. We describe a new device designed to measure hip abductor strength, which is practical in a clinical setting. A system of constraints, pads and reference points was devised to make force measurements as little examiner-dependent as possible. Reproducibility was assessed in a controlled setting. The abductor strength of ten healthy young subjects (average age 28 years) was tested twice on each side by two independent examiners. Tests were performed in a supine position, eliminating the influence of gravity and examiner intervention. The results indicated high reproducibility, the maximal measurement uncertainty being within 1 N. Intra-class correlation coefficients ranged from 0.85-0.98 for intra-rater reproducibility, and 0.81-0.96 for inter-rater reporoducibility. The coefficient of variation was lower than 10%. The device described may be suitable for routine clinical assessment of patients after hip surgery.
authors.affiliation: First department of Orthopaedic Surgery, Rizzoli Orthopaedic Institute, Bologna, Italy. traina@tecno.ior.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Traina
authors.forename: Luca
authors.initials: L
authors.lastname: Cristofolini
authors.forename: Marcello
authors.initials: M
authors.lastname: De Fine
authors.forename: Ludovico
authors.initials: L
authors.lastname: Brunetti
authors.forename: Ideal
authors.initials: I
authors.lastname: Frakulli
authors.forename: Caterina Novella
authors.initials: CN
authors.lastname: Abati
authors.forename: Lorenzo
authors.initials: L
authors.lastname: D'Uva
authors.forename: Aldo
authors.initials: A
authors.lastname: Toni
mesh_terms: D000328:Adult; D004867:Equipment Design; D005260:Female; D006615:Hip / Q000502:physiology*; D006621:Hip Joint / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer / Q000191:economics*; D018482:Muscle, Skeletal / Q000502:physiology*; D015588:Observer Variation; D010827:Physiology / Q000379:methods; D020127:Recovery of Function; D015203:Reproducibility of Results