British Journal of Sports Medicine, Vol 30, Issue 2 161-164, Copyright © 1996 by British Association of Sport and Medicine
Isokinetic strength of the quadriceps and hamstrings and functional ability of anterior cruciate deficient knees in recreational athletes
RC Li, N Maffulli, YC Hsu and KM Chan
Hong Kong Centre of Sports Medicine and Sports Science, Hong Kong.
OBJECTIVE: To test the hypothesis that increasing the hamstrings and
quadriceps (H:Q) isokinetic strength ratio will, in the short term, improve
the functional ability of an anterior cruciate ligament (ACL) deficient
knee. METHODS: The isokinetic muscular characteristics at a speed of 60
degrees s-1 and 180 degrees s-1 of 46 recreational athletes with an
arthroscopically confirmed ACL tear were determined using the Cybex II+
isokinetic dynamometer. The variables tested included peak torque,
endurance ratio, total work output, and explosive power. Functional ability
was scored with the Cincinnati rating system, measuring the severity of
pain and swelling, the degree of giving way, and the overall ability to
walk, run, ascent and descent stairs, jump and twist. RESULTS: Among all
muscular characteristics, the H:Q ratio at 180 degrees s-1 at 30 degrees of
knee flexion was shown to have the highest correlation to the functional
score (r = 0.6249, P < 0.001). All variables involving hamstring
strength were shown to be significantly correlated to the functional
ability score (P < 0.01), while none of the variables involving
quadriceps strength showed significant correlation with the functional
ability of the injured knee. CONCLUSIONS: The H:Q ratio is strongly
correlated to the functional ability of ACL deficient knees in Chinese
recreational athletes. It could be used as an additional measure to guide
in the decision making process in the management of ACL deficient knees.
