Is proprioception altered during loaded knee extension shortly after ACL rupture?
Knee joint angle reproduction was measured without loading of the quadriceps and during concentric quadriceps contractions at 20% of maximal voluntary contraction. The threshold of movement detection was measured. The reproducibility of the methods and the effect of an acute ACL rupture < 10 wks post-injury were examined. A test-retest protocol with a 1 wk hiatus was conducted on 15 healthy subjects. Side-to-side differences were tested in 10 patients with acute ACL rupture. The test-retest protocol did not show any significant differences and yielded correlations of r=0.7-0.9 (p<0.01) and coefficients of variations of 5.7-13.0%. No side-to-side differences were detected in the ACL subjects. Quadriceps loaded; injured 3.96 +/- 2.21 , uninjured 4.7 +/- 1.23, unloaded; injured 2.85 +/- 0.56 degrees, uninjured 2.92+/-1.20 degrees. Threshold of movement detection; injured 1.48+/-0.81 degrees, uninjured 1.44+/-0.65 degrees. Therefore, it may be questioned if the ACL itself plays a major role in proprioception performance as it is commonly measured in the laboratory.
Fischer-Rasmussen
T
T
Sports Medicine Research Unit, Bispebjerg University Hospital, Copenhagen, Denmark. t.fischer-r@dadlnet.dk
Jensen
T O
TO
Kjaer
M
M
Krogsgaard
M
M
Dyhre-Poulsen
P
P
Magnusson
S P
SP
D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D004867:Equipment Design; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D011434:Proprioception / Q000502:physiology*; D015203:Reproducibility of Results; D012421:Rupture