The Orthopaedic Section of the American Physical Therapy Association presents this sixth set of clinical practice guidelines on Achilles pain, stiffness, and muscle power deficits that are characteristic of Achilles Tendinitis. These clinical practice guidelines are linked to the International Classification of Functioning, Disability, and Health (ICF). The purpose of these practice guidelines is to describe evidence-based orthopaedic physical therapy clinical practice and provide recommendations for (1) examination and diagnostic classification based on body functions and body structures, activity limitations, and participation restrictions, (2) interventions provided by physical therapists, (3) and assessment of outcome for common musculoskeletal disorders.

J Orthop Sports Phys Ther. 2010:40(9):A1-A26. doi:10.2519/jospt.2010.0305

KEY WORDS: APTA, clinical practice guidelines, ICD, ICF, Orthopaedic Section

Study Design: Repeated-measures counterbalanced design. Objectives: To determine the effect of rate of force application on anterior tibial displacement and anterior tibial stiffness when measured with the KT-2000 knee arthrometer. Background: Clinicians and researchers frequently use the KT-2000 to quantify anterior tibial displacement and stiffness. While many factors (ie, tibial rotation, alignment of the arthrometer, etc) have been identified to affect KT-2000 measurements, the effect of the rate of force application has not been studied. Methods and Measures: Seventeen recreationally active males between the ages of 19 and 36 years (mean age ± SD, 27.8 ± 5.3 years) with no previous history of knee injury participated. With the knee in 25° of flexion, the KT-2000 was applied to the participants’ anterior tibia. While the distal femur was stabilized, the first author applied a posterior-to-anterior force at a fast and slow rate. Three trials for the slow and fast rates of force application were averaged and used for statistical analysis. Anterior tibial displacement (mm) was measured at 133 N and the related anterior tibial stiffness (N/mm) values were calculated between 89 and 133 N. Separate paired t tests with Bonferroni adjustment were used to determine if differences in displacement and stiffness between rates of force application were present. Results: Stiffness was significantly greater in the slow (mean ± SD, 58 ± 22 N/mm) as compared to the fast trials (mean ± SD, 47 ± 19 N/mm) (P = .005). Differences in displacement, however, were small and not significant (P = .132) between the slow (mean ± SD, 3.9 ± 1.5 mm) and fast (mean ± SD, 4.0 ± 1.6 mm) trials. Conclusion: The rate of force application affects anterior tibial stiffness but not anterior tibial displacement when measured with the KT-2000. This suggests that to ensure reliable results when using the KT-2000, the rate of force application must be controlled when measuring stiffness between 89 and 133 N, but not when measuring anterior tibial displacement at 133 N.

J Orthop Sports Phys Ther. 2004;34(3):132-139. doi:10.2519/jospt.2004.1146

Key Words: ACL, anterior cruciate ligament, KT-2000, viscoelasticity