Relationship between Isokinetic Strengths, Subjective Knee Scores, and Functional Performance after ACL Reconstruction

The purpose of this study is to examine the relationship between isokinetic strengths, subjective knee scores, and functional performance in patients with an ACL-reconstructed knee. Methods: Fifty-five male patients between the ages of 16~53 years were enrolled in this study. At the time of testing, a mean 19.7 months had elapsed since the patients had received ACL reconstruction. Muscle strength of the affected knee was measured using an isokinetic dynamometer at the following velocities; 60, 180, 240°/s. The patients scored their affected knee function using 3 subjective knee scores: Lysholm, IKDC, and the Tegner Scores. Functional performance of the affected knee was measured using the one leg hop test for distance. Results: Isokinetic measurements showed a significant correlation only with the Tegner score. At 60°/s, peak torque (r=.322, p<.05) and peak torque to weight ratio, also written as peak torque % body weight (r=.395, p<.01), were positively correlated with the Tegner score. At 180°/s, peak torque % body weight (r=.336, p<.05), total work (r=.354, p<.05), and total work % body weight (r=.400, p<.01) were positively correlated with the Tegner score. At 240°/s, peak torque % body weight (r=.304, p<.05), total work (r=.318, p<.05), and total work % body weight (r=.331, p<.05) were positively correlated. At 60°/s, all isokinetic measurements for both extensors and flexors were significantly correlated with the functional performance of that knee (p<.01), of which the total work % body weight showed the strongest correlation (r=.600, p<.001). At 180°/s, all isokinetic measurements, except for total work by flexor muscles, were significantly correlated with functional performance (p<.05). At 240°/s, all isokinetic measurements were significantly correlated with functional performance (p<.05). Conclusion: The clinical information derived from measuring total work, as a reflection of knee function, has been undervalued and is as good as that derived from peak torque. *Author for correspondence Indian Journal of Science and Technology, Vol 8(S9), 390–396, May 2015 ISSN (Print) : 0974-6846 ISSN (Online) : 0974-5645 Relationship between Isokinetic Strengths, Subjective Knee Scores, and Functional Performance after ACL Reconstruction Soo-Jin Oh1, Jin-Goo Kim2 and Seung-Kil Lim3* 1Sports Medical Center, Seoul Paik Hospital, Inje University, Korea 2Orthropedic Surgery/Sports Medical Center, Konkuk University Medical Center, Korea 3Department of Exercise Prescription, Dongshin University, Korea; [email protected]