Affiliations: [a] Discipline of Physiotherapy, School of Health Sciences, The University of Newcastle, NSW, Australia | [b] Priority Research Centre for Physical Activity and Nutrition, The University of Newcastle, NSW, Australia
Correspondence:
[*]
Corresponding author: Erin Nugent, School of Health Sciences, Hunter Building, The University of Newcastle, Callaghan, NSW 2308, Australia. Tel.: +61 2 4921 2089; Fax: +61 2 4921 7053; E-mail:Erin.Nugent@uon.edu.au
Abstract:
BACKGROUND: The reproducibility of the HUMAC-NORM isokinetic
dynamometer
has not yet been established for the muscles around the knee.
Previous research suggests practice-based improvement (PBI) may
impact upon the reproducibility of isokinetic testing. OBJECTIVE: To investigate test-retest reproducibility of knee
flexion and extension isokinetic findings at different velocities,
including the influence of familiarisation. METHODS: Seventy physically active, healthy participants with no
experience in isokinetic dynamometry performed five repetitions of
continuous concentric knee flexion and extension at 60, 120, 180 and 240°/s on four occasions. Peak moment, angle of peak moment, total work and
average power were recorded. Reproducibility was determined using percentage
change in the mean, typical error and intraclass correlation coefficients
(ICC). RESULTS: For knee flexion and extension, group data met desirable
reproducibility criteria for most outcomes and velocities after Trial 2.
Within-subject reproducibility generally met acceptable reliabilty criteria
after Trial 2 for knee extension, but was predominantly unacceptable for
knee flexion. ICC's were acceptable from Trial 2, except for angle of peak
moment which did not achieve an acceptable level of reliabilty across any
trials, outcomes or velocities. CONCLUSIONS: The HUMAC-NORM demonstrates excellent
reproducibility for peak moment, average power and total work parameters for the major knee muscles after one trial.
One familiarisation session is recommended prior to testing to
minimise the impact of PBI. Additional familiarisation is beneficial when
testing individuals, higher velocities and knee flexion.
Keywords: Reproducibility of results, muscle strength dynamometer, practice-based improvement, knee
