title: Reliability of force per unit cross-sectional area measurements of the first dorsal interosseus muscle.
abstract: The purpose of this study was to determine the reliability of maximum voluntary isometric force (MVIF), cross-sectional area (CSA) and force per unit CSA measures, of the first dorsal interosseus (FDI) muscle, using a custom-built dynamometer and ultrasonography. Twenty-seven participants completed MVIF and CSA measurements on two separate occasions under the same conditions. Reliability was determined using paired samples t-tests, systematic bias ratio and ratio limits of agreement (RLoA), intra-class correlation (ICC) and coefficient of variation (CV). MVIF of the FDI muscle (mean ± s; 31.8 ± 7.6 N and 31.6 ± 7.3 N) was not different between trials (P = 0.63); RLoA between trials were 1.00 ×/÷ 1.09, ICC = 0.990 and CV = 3.22%. CSA of the FDI muscle (22.6 ± 6.9 and 22.9 ± 6.9 mm²) was also not different between trials (P = 0.31); RLoA between trials were 0.98 ×/÷ 1.19, ICC = 0.979 and CV = 6.61%. Force per unit CSA was not different between trials (1.49 ± 0.43 and 1.46 ± 0.44 N·mm²; P = 0.18), RLoA were 1.02 ×/÷ 1.17, ICC = 0.985 and CV = 5.76%. The techniques used to determine MVIF and CSA of the FDI muscle were reliable and can be combined to calculate force per unit CSA.
authors.affiliation: a Department of Sport Science , Nottingham Trent University , Clifton , UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Martin
authors.forename: Simon
authors.initials: S
authors.lastname: Cooper
authors.forename: Craig
authors.initials: C
authors.lastname: Sale
authors.forename: Graham
authors.initials: G
authors.lastname: Compton
authors.forename: Kirsty
authors.initials: K
authors.lastname: Elliott-Sale
mesh_terms: D000293:Adolescent; D000328:Adult; D004867:Equipment Design; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000502:physiology; D015203:Reproducibility of Results; D014463:Ultrasonography; D055815:Young Adult
keywords: first dorsal interosseus muscle; isometric force; strength testing; ultrasonography