Affiliations: [a] Biomechanics Laboratory, Kaye College of Education,
Beer-Sheva, Israel | [b] Department of Orthopedics, Soroka Medical Center,
Beer-Sheva, Israel | [c] Physical Therapy Department, Ben-Gurion University of
the Negev, Israel
Abstract: The objective of this study was to analyze the performance of knee
muscles in the affected and nonaffected sides of ACL patients as well as with
healthy asymptomatic subjects. Fifty-four males, 27 with asymptomatic knees and
27 patients with tear in ACL were included in the study. Subjects performed
concentric knee extension and flexion efforts at 60\ci/s and 180\ci/s on a
Biodex isokinetic dynamometer. Isokinetic peak torque, angle to peak moment of
quadriceps (Q) and hamstring (H), and hamstrings/quadriceps ratio (HQR) were
measured. There was a significant decline in the mean strength of Q at 60\ci/s
for the involved side compared with either the uninvolved side or with that of
the healthy subjects, but not in H. There was also a significant decrease in
mean Q strength at 180\ci/s of the involved side of ACL patients compared with
the healthy young males. There was a significant difference in mean angle to
peak moment of Q at 180\ci/s in the healthy group compared with the involved
side of the patients and a significant difference for the same parameter in H
at 60\ci/s in the involved compared with the healthy group and uninvolved sides
of the ACL patients. There was no significant difference in
hamstrings/quadriceps ratio between the groups. It was concluded that the
effect of ACL tear on H strength is significantly less than that on the Q one
year post-injury. Angle to peak moment offers original and practical
information for the determination of individual performance in post ACL injury
patients.
Keywords: isokinetics, peak torque, angle to peak moment, quadriceps/hamstrings ratio
