To evaluate muscle strength and endurance of knee extensor and flexor muscle groups in patients undergoing rehabilitation after reconstruction of the anterior cruciate ligament of the knee using either the patellar (P) or the hamstring (H) tendon. To compare side-to-side differences in muscle strength and endurance, a commonly used criteria for return to sports, in both patient groups
A total of 56 patients active in competitive sports (50% females; age range=12-47 yrs; 54% hamstring tendon graft) were evaluated. An isokinetic device was used to measure peak torque of the knee extensors and flexors at an angular velocity of 60 deg/s, on average, 10.7 months post-surgery. Total work was used as an index of local muscular endurance and measured with a 20-repetition test at 240 deg/s. Side-to-side differences (StSD) were calculated for each muscle group as [100 – (100 x injured/non-injured knee)]. A value >10% was considered as abnormal muscle symmetry.
Muscle dysfunction (weakness and fatigue) is frequent after reconstruction of the anterior cruciate ligament of the knee; even close to one year post-surgery. In general, muscle asymmetry is more significant in the knee extensors compared to the knee flexors independent of the type of graft
William Ramos– MSIV, University of Puerto Rico
Brenda Castillo– Attending Physician, Moss Rehab
Belmarie Rodriguez– Private practice, Private practice
William Micheo– Professor and Chair, UPR School of Medicine
Walter Frontera– Professor, University of Puerto Rico School of Medicine