Anterior Cruciate Ligament—Deficient Potential Copers and Noncopers Reveal Different Isokinetic Quadriceps Strength Profiles in the Early Stage after Injury
- 28 January 2010
- journal article
- research article
- Published by SAGE Publications in The American Journal of Sports Medicine
- Vol. 38 (3), 586-593
- https://doi.org/10.1177/0363546509349492
Abstract
Background: Isokinetic muscle strength testing using the peak torque value is the most frequently included quadriceps muscle strength measurement for anterior cruciate ligament (ACL)—injured subjects. Purpose and Hypotheses: The purpose of this study was to investigate quadriceps muscle performance during the whole isokinetic curve in subjects with ACL deficiency classified as potential copers or noncopers and to investigate whether these curve profiles were associated with single-legged hop performance. We hypothesized that quadriceps muscle torque at other knee flexion angles than peak torque would give more information about quadriceps muscle strength deficits. Furthermore, we hypothesized that there would be significant torque differences between potential copers and noncopers and a significant relationship between angle-specific torque values and single-legged hop performance. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Seventy-six individuals with a complete unilateral ACL rupture within the last 3 months were included. The subjects were classified as potential copers and noncopers. Isokinetic quadriceps muscle tests were performed at 60 deg/s. Mean torque values were calculated for peak torque as well as for specific knee flexion angles. The 1-legged hop and the 6-m timed hop tests were included, and symmetry indices were used. Results: The peak torque value did not identify the largest quadriceps muscle strength deficit. Rather, these were established at knee flexion angles of less than 40°. There were significant differences in angle-specific torque values between potential copers and noncopers (P < .05). Moderate to strong associations were disclosed between angle-specific torque values and single-legged hop performance, but only for noncopers (r ≥ .32-.58). Conclusion: Angle-specific quadriceps muscle torque values of less than 40° of knee flexion provide more information on the quadriceps strength deficits after ACL injury than the commonly used peak torque values. Interpretation of the isokinetic curve profiles seems to be of clinical importance for the evaluation of quadriceps muscle performance after ACL injury.Keywords
This publication has 54 references indexed in Scilit:
- Preoperative quadriceps strength is a significant predictor of knee function two years after anterior cruciate ligament reconstructionBritish Journal of Sports Medicine, 2009
- Mechanisms of Noncontact Anterior Cruciate Ligament InjuryJournal of Athletic Training, 2008
- Triple-Hop Distance as a Valid Predictor of Lower Limb Strength and PowerJournal of Athletic Training, 2008
- A 10-Year Prospective Trial of a Patient Management Algorithm and Screening Examination for Highly Active Individuals with Anterior Cruciate Ligament InjuryThe American Journal of Sports Medicine, 2007
- Hop Testing Provides a Reliable and Valid Outcome Measure During Rehabilitation After Anterior Cruciate Ligament ReconstructionPTJ: Physical Therapy & Rehabilitation Journal, 2007
- Relationship between quadriceps femoris muscle volume and muscle torque after anterior cruciate ligament repairScandinavian Journal of Medicine & Science in Sports, 2007
- A Comparison of Lower-Body Flexibility, Strength, and Knee Stability Between Karate Athletes and Active ControlsJournal of Strength & Conditioning Research, 2007
- Isokinetic Muscle Performance After Anterior Cruciate Ligament Surgery: Long-Term Results and Outcome Predicting Factors After Primary Surgery and Late-Phase ReconstructionInternational Journal of Sports Medicine, 1996
- Combined knee loading states that generate high anterior cruciate ligament forcesJournal of Orthopaedic Research, 1995
- Quantitative Assessment of Functional Limitations in Normal and Anterior Cruciate Ligament-Deficient KneesClinical Orthopaedics and Related Research, 1990